Selective Dorsal Rhizotomy for Spasticity Treatment: a New Surgical Method in Slovenia 73 Slovenia Klinični Center Ljubljana, Ljubljana, Slovenija HUMAN REPRODUCTION

SHORT SCIENTIFIC ARTICLE

eng slo element article-lang en Selective dorsal rhizotomy for spasticity 10.6016/ZdravVestn.2898 doi

12.11.2018 date-received treatment: a new surgical method in 2.4.2019 date-accepted Slovenian Slovenia Human reproduction Reprodukcija človeka discipline Medical Short scientific article Klinični primer article-type Journal Zdravljenje spastičnosti s selektivno dorzalno rizotomijo: Selective dorsal rhizotomy for spasticity treat- Zdravljenje spastičnosti s selektivno dorzalno article-title Prikaz nove kirurške metode v Sloveniji ment: a new surgical method in Slovenia rizotomijo: Prikaz nove kirurške metode v Slo- veniji Peter Spazzapan,1 Tomaž Velnar,1 Zoran Rodi,2 Nataša Kos,3 Andreas Kupsch,4 Roman 1 Selective dorsal rhizotomy for spasticity Zdravljenje spastičnosti s selektivno dorzalno alt-title Bošnjak treatment rizotomijo cerebral palsy, muscle tone, case report, surgi- cerebralna paraliza, mišični tonus, prikaz primera, kwd-group cal treatment, rehabilitation kirurško zdravljenje, rehabilitacija The authors declare that there are no conflicts Avtorji so izjavili, da ne obstajajo nobeni conflict of interest present. konkurenčni interesi. Abstract year volume first month last month first page last page 1 Department of Spasticity is characterised by an abnormal increase in muscle tone, which may affect normal Neurosurgery, Division of 2020 89 1 2 73 84 movements and the patients’ quality of life. Only a few paediatric neurosurgeons are concerned Surgery, University Medical with this pathology, mainly because decades ago the neurosurgeons were able to offer these Centre Ljubljana, Ljubljana, children only a modest relief. Since then, the pharmacological therapy of spasticity has improved name surname aff email Slovenia along with the neurosurgical and orthopaedic interventions. The medications may limit the ef- 2 Institute of Clinical Tomaž Velnar 1 [email protected] fects of the disease and surgical treatment is gaining in importance, thus improving the quality of Neurophysiology, Division of Neurology, University patients’ life. We present a case study of a child affected by spastic paraparesis treated with the name surname aff Medical Centre Ljubljana, neurosurgical technique SDR, which was performed in Slovenia for the first time. Ljubljana, Slovenia Peter Spazzapan 1 3 Medical Rehabilitation Izvleček Zoran Rodi 2 Unit, University Medical Spastičnost je motorična motnja, ki jo zaznamuje porast mišičnega tonusa do take mere, da ote- Centre Ljubljana, Ljubljana, žuje gibanje in vzdrževanje položaja telesa, kar vpliva tudi na kakovost življenja. S to patologijo Nataša Kos 3 Slovenia se kljub pogostosti in pomembnosti ukvarja malo pediatričnih nevrokirurgov, najverjetneje za- 4 Department of Andreas Kupsch 4 to, ker so bile možnosti za nevrokirurško zdravljenje dolgo omejene in nezanesljive. O prvi se- Anaesthetics and Surgical riji dorzalnih rizotomij je leta 1979 poročal Fasano, do takrat pa so nevrokirurgi takim otrokom Roman Bošnjak 1 Intensive Care, Division of Surgery, University Medical lahko nudili le skromno pomoč. Farmakološko zdravljenje spastičnosti se je do danes močno Centre Ljubljana, Ljubljana, razvilo in obsega zdravila za peroralno, intramuskularno in intratekalno dajanje. Kirurške tehnike eng slo aff-id Slovenia zdravljenja, kamor uvrščamo nevrokirurške in ortopedske posege, pa poleg delne sekcije peri- Department of Neurosurgery, Klinični oddelek za 1 fernih živcev in globoke možganske stimulacije vključujejo tudi selektivno dorzalno rizotomijo Division of Surgery, University nevrokirurgijo, Kirurška klinika, Correspondence/ (SDR). Izbira najbolj ustreznega zdravljenja je individualna in odločanje poteka interdisciplinar- Medical Centre Ljubljana, Univerzitetni klinični center Korespondenca: no. Predstavljamo primer otroka s spastičnostjo in zdravljenje z nevrokirurško tehniko SDR, ki Ljubljana, Slovenia Ljubljana, Ljubljana, Slovenija Tomaž Velnar, e: tvelnar@ smo jo v Sloveniji izvedli prvič. hotmail.com Institute of Clinical Klinični inštitut za klinično 2 Neurophysiology, Division of nevrofiziologijo, Nevrološka Key words: Cite as/Citirajte kot: Spazzapan P, Velnar T, Rodi Z, Kos N, Kupsch A, Bošnjak R. Selective dorsal rhizotomy Neurology, University Medical klinika, Univerzitetni klinični cerebral palsy; muscle for spasticity treatment: a new surgical method in Slovenia. Zdrav Vestn. 2020;89(1–2):73–84. Centre Ljubljana, Ljubljana, center Ljubljana, Ljubljana, tone; case report; surgical Slovenia Slovenija treatment; rehabilitation DOI: https://doi.org/10.6016/ZdravVestn.2898

Medical Rehabilitation Unit, Inštitut za medicinsko 3 Ključne besede: University Medical Centre rehabilitacijo, Univerzitetni cerebralna paraliza; mišični Copyright (c) 2020 Slovenian Medical Journal. This work is licensed under a Ljubljana, Ljubljana, Slovenia klinični center Ljubljana, tonus; prikaz primera; Creative Commons Attribution-NonCommercial 4.0 International License. Ljubljana, Slovenija kirurško zdravljenje; Department of Anaesthetics and Klinični oddelek za 4 rehabilitacija Surgical Intensive Care, Division anesteziologijo in intenzivno of Surgery, University Medical terapijo operativnih strok, Centre Ljubljana, Ljubljana, Kirurška klinika, Univerzitetni Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 73 Slovenia klinični center Ljubljana, Ljubljana, Slovenija HUMAN REPRODUCTION

Received: 12. 11. 2018 1 Introduction ter. For the most frequent spastic type, a Accepted: 2. 4. 2019 highly increased muscle tone is character- Spasticity is a motor disorder that af- which in the most extreme form manifests istic. Spasms can sometimes be brought fects many people and is most often con- as spasticity. This is related to the speed of on by unexpected aural or visual stimu- nected to cerebral palsy, where brain disor- movement and causes an increased resis- lus. Other types of coordination include ders cause interference in the operation of tance to the passive movement of a mus- the dyskinetic type, which includes jerky the corticospinal tract, resulting in weak- cle. Muscle tone is not always increased movements of limbs and the head and ness, increased muscle tone and simulta- under spasticity; however, this growth is problems with movement control; hypo- neous activation of agonist and antagonist related to the speed of movement and oth- tonic type with severely loose and flaccid muscles (1). It can also be the result of er external stimuli (fear, cold, etc.) (1,5). muscle tone; the ataxic type, which is the other motion disorders, such as dystonia Spasticity can be classified by number of rarest and is marked by issues with coor- or athetosis. Therapy for spasticity has two affected limbs. This classification is espe- dination and balance; and the mixed type, goals: lower the inflow of afferent stimu- cially important for surgeons when de- which includes the characteristics of all li (through SDR or other ablative tech- ciding on surgical therapy, and includes the types described above (9-11). niques) that contribute to increased tone, spastic tetraparesis, paraparesis, spastic The clinical image of a child with ce- or raise the inhibition activity (with medi- hemiparesis or monoparesis. Spasticity rebral palsy is marked by the spasticity of cation, such as for example baclofen) (2,3). can also impact the muscles of the body, muscles, tiredness and pain from muscle Locally, spasticity and muscle spasms can e.g. paravertebral muscles; however, this spasms. This most often occurs at night be treated by injecting a botulin toxin di- type of affliction is not included in this (9). Spasticity characteristically affects rectly into the muscles that exhibit symp- classification (5-7). The currently accepted some muscle groups more than others. toms. This can avoid systemic effects of a classification of cerebral palsy from 2000 Adductors and flexors are affected the medication such as baclofen (3). is different and includes several subtypes, most, and with spastic paraparesis, this Muscle tone is normally regulated with divided by increased muscle tone in one results in bent knees and hips, a stiffness activity of the alpha-motoric neurone, or several limbs, and consideration as to in the fingers and an inverted rotation of and is affected by afferent and descendent whether the muscle tone is changing (8). the lower limbs. Gait is unstable, usually stimuli (4,5). Spasticity develops because This classification also includes spastic di- scissor gait, or there is toe walking. De- of an imbalance between the stimuli rais- plegia or spastic monoplegia cerebral pal- formations of bones and joints may also ing the tone and those lowering it. With sy, dyskinetic cerebral palsy (includes dys- occur (10). When examining a child with an overflow of the stimuli that increases tonic and choreoathetoid cerebral palsy) spastic paraparesis, there is an increased the tone, and thereby the activity of the and ataxic cerebral palsy. resistance in passive movements, especial- alpha-motoric neuron, myotatic reflex- ly the lower limbs, related to the speed of es strengthen, and muscle tone increases, 2 Clinical image and the the movement. Pathological clonus of the assessment of the level of foot is always present, while the plantar re- Table 1: The Modified Ashworth scale for classification of the degree of sponse is present when stretching out. In spasticity. spasticity time, spasticity leads to changes in muscles and tendons, which become shorter Grade Description We consider cerebral palsy when a (12,13). 0. No increase in muscle tone. child at a certain age cannot achieve nor- Assessing muscular strength with ac- mal motor development (raising the head, tive mobility is important when assess- 1. Slight increase in tone giving a catch and release or minimal resistance at the end of the motion range when the limb is flexed sitting, standing, walking) (4). These chil- ing spasticity and setting indications for or extended. dren often have irregular posture with potential treatment (14). The most useful increased muscle tone, or their muscles scale for assessing spasticity is the Ash- 1+. Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder of the motion are first loose, and spasticity occurs later. worth scale, and the very similar Modi- range. Characteristic symptoms, regardless of the fied Ashworth scale used for determining type of cerebral palsy, include an abnor- spasticity. Motor functions, which may 2. More marked increase in muscle tone through most of the movement range. The limb can be flexed easily. mal muscle tone, balance disorders and also be very impaired, are assessed using increased (reflexes) (5,6). Cerebral palsy the Gross Motor Function Classification 3. Considerable increase in muscle tone – passive movement can be accompanied by epileptic seizures, System scale (GMFSC) (Table 1 and Table difficult. disorders in swallowing, speech, feeling 2) (4,10,15,16). 4. Limb rigid in flexion or extension. and incontinence for excrement and wa- Spasticity cannot be confirmed using

74 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898 SHORT SCIENTIFIC ARTICLE

ter. For the most frequent spastic type, a imaging examinations, as we can get no highly increased muscle tone is character- characteristic signs which would specifi- istic. Spasms can sometimes be brought cally point to this diagnosis (17). Images on by unexpected aural or visual stimu- of brains of children with cerebral palsy, lus. Other types of coordination include made using computer tomography (CT) the dyskinetic type, which includes jerky and magnetic resonance imaging (MRI), movements of limbs and the head and describe the changes, characteristic for problems with movement control; hypo- periventricular leukomalacia, which re- tonic type with severely loose and flaccid flects the condition after a postpartum muscle tone; the ataxic type, which is the ischemic impairment. Neurophysiologic rarest and is marked by issues with coor- tests, such as electromyography (EMG), dination and balance; and the mixed type, cannot be used to quantitatively asses which includes the characteristics of all spasticity (17,18). When setting a diagno- the types described above (9-11). sis and classification, the main resource The clinical image of a child with ce- must be the clinical image, including a gait rebral palsy is marked by the spasticity of sample and the results of measurements of muscles, tiredness and pain from muscle the scope of joint movements (10,15). spasms. This most often occurs at night (9). Spasticity characteristically affects 3 Therapies for spasticity some muscle groups more than others. Adductors and flexors are affected the Therapies for spasticity must begin as most, and with spastic paraparesis, this soon as possible, as this is the only way results in bent knees and hips, a stiffness to prevent the onset of muscle shortening in the fingers and an inverted rotation of (1,5). The objective of therapy is improv- the lower limbs. Gait is unstable, usually ing the child’s functional condition, mak- scissor gait, or there is toe walking. De- ing care easier, preventing contractions formations of bones and joints may also and easing pain. Not all children require occur (10). When examining a child with therapy. Those with a mild form of spas- spastic paraparesis, there is an increased ticity, which does not hinder everyday ac- resistance in passive movements, especial- tivities and does not cause painful spasms, ly the lower limbs, related to the speed of do not need therapy. There are two meth- the movement. Pathological clonus of the ods, one involving medication, the other foot is always present, while the plantar re- surgery, and therefore a multidisciplinary Table 1: The Modified Ashworth scale for classification of the degree of sponse is present when stretching out. In team of physicians with experience in each spasticity. time, spasticity leads to changes in mus- of the types of therapy recommends the cles and tendons, which become shorter appropriate therapy (12,19,20). Grade Description (12,13). Therapy with medication includes 0. No increase in muscle tone. Assessing muscular strength with ac- oral, intramuscular, and intrathecal med- tive mobility is important when assess- ication. The first group includes agonist 1. Slight increase in tone giving a catch and release or minimal resistance at the end of the motion range when the limb is flexed ing spasticity and setting indications for gamma-Aminobutyric acids (GABA) ba- or extended. potential treatment (14). The most useful clofen, benzodiazepines (diazepam), al- scale for assessing spasticity is the Ash- pha-2 agonist tizanidine, and the inhibitor 1+. Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder of the motion worth scale, and the very similar Modi- of the dopamine transporter modafinil range. fied Ashworth scale used for determining (18,21). Injections into muscles are based spasticity. Motor functions, which may on the intake of botulin toxin, alcohol or 2. More marked increase in muscle tone through most of the movement range. The limb can be flexed easily. also be very impaired, are assessed using phenol with the most noticeable effect the Gross Motor Function Classification on decreased contractions of the joints 3. Considerable increase in muscle tone – passive movement System scale (GMFSC) (Table 1 and Table (21,22). This method of therapy is suitable difficult. 2) (4,10,15,16). for those forms of spasticity, where only 4. Limb rigid in flexion or extension. Spasticity cannot be confirmed using specific muscle groups are affected, and is

Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 75 HUMAN REPRODUCTION

not suitable for generalized forms. As the not affect the decrease of the muscle tone effect is not permanent, and the medica- (spasticity) in the target muscles, but de- tion only has a transitory affect, the injec- creases the muscle spasms. Consequently, tion therapy must be repeated. It is used this method is suitable for treating spasms especially in early childhood, between in individual muscle groups, and not for ages two and six, when it becomes clear treating generalized spasticity (21,24). if the child is a candidate for continuing treatment with SDR or for treatment with 4 Selective dorsal rhizotomy an inserted intrathecal baclofen pump (5). Baclofen is especially used as intrathecal SDR is a surgical technique that plays medication, as it is an effective drug for a big role in treating spasticity and has treating spasticity of the upper and low- seen great success in the last few decades er limbs. Intrathecal administration of (20). The first surgeons to perform dor- baclofen is made through a customizable sal rhizotomy on a human were Abbe pump, which is surgically inserted into and Bennett in 1889, while a decade later, the subcutaneous pocket, and connected Sherrington described the effects dorsal with the subdermal space, where the drug root section had on spasticity in animals is released. The concentration of baclofen (25). In the beginning of the 20th century, in the cerebrospinal fluid is much higher Cushing also conducted a few procedures. after it is administered this way than after Foerster was the first to conduct a section taking medication. This makes it more ef- of dorsal roots L2 to S1 and reported fa- fective (3,5,21). vourable results. Because of loss of feel- Alongside newer methods, such as ing and ataxia following a full section of deep brain stimulation and SDR, surgical sensory roots, these procedures were not procedures for treating spasticity include performed for many years. Then in 1967, the described peripheral neurectomies, Gros completed a partial non-selective where we cut into 50–80% of nerve tissues rhizotomy which contributed to lower of peripheral nerves (23). The most fre- muscle tone and retained tactility for sur- quent targets are the posterior tibial nerve, face and deep sensibility. The first to de- the obturator nerve, and the musculocuta- scribe the SDR procedure – as performed neous nerve, which decreases the spasms today – was Fasano in 1979. He cut only in plantar flexors, hip adductors and those fasciculi that caused pathologi- flexors of the elbow. This procedure does cal muscle spasms at neurophysiological stimulus. In his reports, the success rate Table 2: The Gross Motor Function Classification System (GMFCS). of this method stood at 71 percent (7,25). Steinbok demonstrated in his series that Level Description non-selective rhizotomy, i.e. without any Level I: walks well in all settings. Balance and speed may be limited neurophysiological monitoring, where we compared with children developing normally. non-selectively cut 70% of fasciculi, is also effective (26). Such a procedure was per- Level II: walks in most settings but may have difficulty walking long distances or with balance. May utilise personal or environmental formed through a longer laminotomy (L1 mobility aids to climb stairs. to S1), so that every root was anatomically exactly identified at the entry into the Level III: walks with the use of hand-held mobility aids such as K-walkers in most indoor settings. Uses wheeled mobility for longer appropriate foramen. The procedure can distance travel. also be performed using the less invasive L1 laminectomy, as this method makes it Level IV: walks with the use of hand-held mobility aids such as K-walkers in most indoor settings. Uses wheeled mobility for longer possible to identify all the lumbar roots distance travel. right at their exit from the conus. Such a procedure cannot be performed without Level IV: clinical indications and contraindications for SDR. neurophysiological monitoring. Today,

76 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898 SHORT SCIENTIFIC ARTICLE

SDR success rate differs by centres. Some 5%. Indications for SDR above age of 16 report of up to 100% improvement after are rare, as it is difficult to strengthen mus- surgery (27). cles and alter the gait pattern after the pro- Children who are treated with SDR re- cedure at this age (29,30). cover through the transitory phase with decreased muscle strength. Spasticity is 6 Case study decreased, while muscle weakness becomes even more apparent (6). This period We describe the case of a child with usually last three weeks. During this time spastic paraparesis resulting from cere- there may be an onset of paraesthesia and bral palsy and the SDR technique we per- burning pain in the lower limbs, which formed for the first time in Slovenia, and fades over time. Muscle tone clearly de- which was introduced into neurosurgical creases, and the gait pattern is improved. clinical treatment. Because of the inhibition effect (i.e. lower We admitted a 15-year boy to the Neu- excitation effect) on ascending interneu- rosurgery Clinical Department for SDR. rons, the spasticity of the upper limbs also He was born at the gestation age of 35 decreases, and the control of the bladder weeks and suffered postnatal grade 2 in- improves (2,7). In the period after the pro- traventricular brain haemorrhaging. Af- cedure, rehabilitation is essential, and the ter that, he recovered. He was regularly condition for this is appropriate and good monitored at the neurological paediatric motivation of the child and their parents. clinic and physiatrics. His cognitive de- The effects of SDR are permanent, and the velopment was model and he exhibited probability of complications is low. After no clinical signs of hydrocephalus. After the operation, the deformations and the one year, he was entered into a rehabilita- shortened tendons that had already oc- tion programme because of higher muscle curred need to be repaired with orthopae- tone in the lower limbs, as spastic diple- dic procedures (9). gia gradually progressed. Physiatric and orthopaedic therapy and medication were 5 Selecting the right therapy sufficient for easing spasticity for several years; however, because his biceps femo- Selecting the most appropriate therapy ris, semitendinosus, semimembranosus depends on the individual and is done at and calf muscles were shortening, he re- an interdisciplinary level (28). The child’s quired an orthopaedic procedure. Due to age, the objective of the therapy (decreas- advancing spasticity and problems with ing spasms, improving motor functions, walking and sitting, as well as numerous easing care), the changing level of impair- muscle spasms in the lower limbs, he was ment and the level of spasticity all have to sent to the neurosurgery department. be taken into account. With some mild We did not detect any interference in forms of spasticity, surgical procedures the operation of his brain nerves and up- are not required, as activities are not sig- per limbs during the examination. The nificantly hindered. More severe forms lower limbs were spastic. According to the of spasticity require therapy (7). Ideal pa- Modified Ashworth scale, his muscle tone tients for SDR therapy are children aged was given a grade of 4, while according to 3 to 8 with a spastic paraparesis which the GMFCS scale is was level III. The pat- impacts their gait pattern. These are most- tern of spastic, scissor gait was clear. There ly children with cerebral palsy. The ob- were no issues related to bladder or bowel jective is to retain strength in their lower control. After the initial neurosurgical and limbs, while lowering the onset of muscle multidisciplinary assessment, SDR thera- spasms. Only a few children with cerebral py was recommended for lowering muscle palsy meet these requirements, fewer than tone.

Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 77 HUMAN REPRODUCTION

guished the thecal sac, and using ultra- sound imaging determined the location of the conus and the roots of the cauda equina. Using a surgical microscope, we cut in- to the dura matter and the arachnoid ma- ter. We identified the conus with the roots of the cauda equina and separated the left and the right roots. We first started on the left side and anatomically identified the root of L1. This consists of three fasciculi, of which the ventral has the most motor functions, while the remaining two have sensory. Both fasciculi were then separated from the motor part. One of these two roots was electro-coagulated and severed (Figure 1) This switched off 50% of sensory fibres. Next, we separated ventral, i.e. motor, roots from the dorsal, i.e. sensory roots. Figure 1: The exposure and isolation of the L1 root. The root is Figure 3: The intraoperative separation of the L2 root, which had been composed of three fasciculi, which had been separated. The motor After anatomic identification of the lat- eral sulcus, which separates motor from separated into five small fasciculi. They will be monitored with an fascicle is held with two electrophysiological probes. electrophysiological probe and 70% of them will be cut. sensory roots, we separated them using elastic cloth (4 cm × 1.5 cm). Using nee- After preparation for general anaes- dle electrodes, we monitored the electro- thesia, we inserted electrodes for elec- myographic (EMG) signal from the myo- tro-physiological monitoring during the tome muscles L2 to S3, i.e. muscles of the procedure. The spinous process of the L1 thigh, tibia and calves and the sphincter. vertebra was determined using radiog- Unlike with sensory roots, touching the raphy for the purpose of orientation and motor roots with an instrument triggers determining the location of conus medul- the EMG potential. The L2 root, which laris. After laminotomy of L1, we distin- is located the most laterally, was separated from others using a soft cotton cloth, and verified with electro-physiologic measurements; we stimulated the root with electric stimulations while monitoring EMG reflex responses in the muscles of the lower limb (Figure 2). With a healthy person, stimulating the dorsal (sensory) root would not trigger a response in the muscles, while with a spastic person, this condition causes such an effect on the dis- inhibited lower part of the motor neuron. By monitoring the pattern of muscle activation, we were also able to confirm the segment level. Using a small blunt micro- dissector, we then split the dorsal root to four fasciculi (Figure 3). We stimulated Figure 2: Electromyographic responses in each of them, similarly to how we stim- the left lower limb muscles after electrical ulated the whole root earlier, except that stimulation of the left L3 dorsal root. we used the tetanic stimulation and ob-

78 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898 SHORT SCIENTIFIC ARTICLE

guished the thecal sac, and using ultra- blocked. The L2 root was then removed sound imaging determined the location of from the bundle of dorsal roots. We per- the conus and the roots of the cauda equi- formed the same procedure on roots L2 to na. Using a surgical microscope, we cut in- S1. The number of fasciculi to which the to the dura matter and the arachnoid ma- roots were divided was between four and ter. We identified the conus with the roots seven, and we blocked two thirds of these of the cauda equina and separated the left fasciculi, i.e. the ones with an abnormal and the right roots. We first started on the physiological response. The S2 root re- left side and anatomically identified the quired special attention, as it also includes root of L1. This consists of three fasciculi, the fibres from the perineum, pelvic floor, of which the ventral has the most motor urinary tract, sex organs, etc. We divided functions, while the remaining two have it into two fasciculi, and recorded the ac- sensory. Both fasciculi were then separat- tion potential of the dorsal root after the ed from the motor part. One of these two stimulation of the dorsal nerve of the pe- roots was electro-coagulated and severed nis (Figure 4A). Because we did not detect (Figure 1) This switched off 50% of senso- any action potential, we blocked one of the ry fibres. two fasciculi. We repeated the procedure Next, we separated ventral, i.e. motor, on the right side. There, we also did not roots from the dorsal, i.e. sensory roots. detect a pudendal action potential of the Figure 1: The exposure and isolation of the L1 root. The root is Figure 3: The intraoperative separation of the L2 root, which had been composed of three fasciculi, which had been separated. The motor After anatomic identification of the lat- S2 dorsal root, so we blocked half of the eral sulcus, which separates motor from separated into five small fasciculi. They will be monitored with an fibres of the S2 root. At the same time, we fascicle is held with two electrophysiological probes. electrophysiological probe and 70% of them will be cut. sensory roots, we separated them using also monitored the reflexive response of elastic cloth (4 cm × 1.5 cm). Using nee- the external anal sphincter after stimula- dle electrodes, we monitored the electro- served the pattern of muscle activation to tion of the dorsal nerve of the penis (pu- myographic (EMG) signal from the myo- identify those fasciculi whose stimulation dendoanal reflex), which did not change tome muscles L2 to S3, i.e. muscles of the caused the most abnormal electro-physio- significantly after lower lumbar fasciculi thigh, tibia and calves and the sphincter. logical activity; e.g. activation of muscles were blocked (Figure 4B). Unlike with sensory roots, touching the from other myotomes that under normal This was followed by a detailed intra- motor roots with an instrument triggers circumstances are not connected to the dural haemostasis and suturing of the the EMG potential. The L2 root, which nerves of the stimulated root, or contralat- dura. Lamina was attached to its position is located the most laterally, was separat- eral muscular groups. Fasciculi with a lot with a suture, and the lesion was closed by ed from others using a soft cotton cloth, of abnormal activity were coagulated and layers. After the surgery, the boy was in and verified with electro-physiologic mea- neurosurgical intensive care, and on the surements; we stimulated the root with following day he was transferred to the electric stimulations while monitoring ward. Muscle tone decreased the day after EMG reflex responses in the muscles of operation, with lower muscle strength in the lower limb (Figure 2). With a healthy lower limbs; however, it did not weaken so person, stimulating the dorsal (sensory) much that it would hinder his gait. We did root would not trigger a response in the not detect any motor impairment and the muscles, while with a spastic person, this sphincters operated flawlessly. Pain and condition causes such an effect on the dis- muscle spasms in the lower limbs gradu- inhibited lower part of the motor neuron. ally diminished. We gradually started with By monitoring the pattern of muscle ac- physical therapy, which was first based on tivation, we were also able to confirm the passive, then on active exercises, posture segment level. Using a small blunt micro- and movement control, after establishing dissector, we then split the dorsal root to protocol on the first day after the operation four fasciculi (Figure 3). We stimulated Figure 4: The S2-S3 dorsal root action potential (DRAP) after electrical and continued until he was discharged. Figure 2: Electromyographic responses in each of them, similarly to how we stim- stimulation of the dorsal nerve of the penis (A). After section of the Special focus was put on correct move- the left lower limb muscles after electrical ulated the whole root earlier, except that fascicle with lesser DRAP, there was no significant change in the ments and verticalization with sitting. The stimulation of the left L3 dorsal root. we used the tetanic stimulation and ob- pudendoanal reflex (B). boy did not suffer from any issues in this

Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 79 HUMAN REPRODUCTION

part of therapy either. In this procedure, only those fasciculi that Ten days after surgery, he was admitted caused pathological muscle activation to the University Rehabilitation Institute during electro-physiological stimulation – Soča for further therapy. At discharge, were surgically blocked. Currently, SDR the assessments according to the Modi- is among frequently used ablative proce- fied Ashford scale and GMFCS were both dures for treating spasticity in cerebral graded 2. A neurosurgical examination palsy in children. In exceptional cases, was made after one month and his gener- we can also perform SDR on adults with al condition had significantly improved. spasticity, and sometimes even with dys- The boy was able to walk independently, tonia, even though there is only little data and his muscle tone was lower (grades ac- in literature to support such a procedure cording to the Modified Ashford scale and in adults of up to 45 years (32,33). Indi- GMFCS were 2). The boy did not report cations include spastic paraparesis result- on any sensory and sphincter-related is- ing from cerebral palsy, haemorrhagic or sues. We planned the next neurosurgical ischemic stroke and damage to the brain assessment in three to six months, and and the spinal cord, resulting from injury continued rehabilitation therapy. and toxic, hypoxic and metabolic causes and infections (Table 3) (32,34). Effects of 7 Discussion SDR on spasticity and improved gait were beneficial. Salame et al. report on a 100% Selective dorsal rhizotomy is not a new improvement of spasticity after the proce- technique for treating spasticity, as it has dure, as well as permanent improvement been practised since the beginning of the of the gait, joint mobility reach, spasticity 20th century. The early surgical proce- of the upper limbs, bladder operation and dures were effective; however, they were speech (27). Technical advancements in also related with sensory impairments and the past two decades have contributed to ataxia, which cropped up along the whole lower invasiveness of the procedure (7,9). part of dorsal sensory roots (generally the With regard to the effect on the limbs roots from L2 to S1 were blocked) (20,31). and spasticity, we can divide cerebral palsy This resulted in a temporary suspension to the hemiplegic, paraplegic and tetraple- of using this technique for several de- gic types (31,35). Paraplegic type is most cades, and in 1979, Fasano described se- commonly the result of decreased blood lective dorsal rhizotomy, known as SDR. supply to the child’s brain in the third tri- mester of pregnancy. We rarely diagnose Table 3: Clinical indications and contraindications for SDR. it at birth and usually only detect it at six months. Diagnosis is set when a child fails Indications for SDR Contraindications for SDR to achieve normal motor development at a • Age 2 to 45 years • Cerebral paralysis (CP)/intrauterine certain age. In the early phase, muscles are • Spastic paraparesis or encephalitis loose and in early childhood typical signs tetraparesis • Mixed CP and dystonia, rigidity, athetosis, of cerebral palsy are perhaps not evident, • Emerging locomotive or ataxia functions • Spastic hemiplegia and spasticity may occur later. Symptoms • Premature birth and • Familial spastic paraplegia vary, from a nearly imperceptible clumsi- neonatal asphyxia • Basal ganglia injury in children younger ness to a major impairment (9,29). With • Potential for significant than 5 years the spastic form of cerebral palsy, which postoperative functional • Head injury, hypoxic encephalopathy is the most frequent, muscle tone is ex- gains • Severe thoracolumbar scoliosis or lumbar lordosis ceptionally increased, and the reflexes are • Motor impairment with no head control very energetic. This type of cerebral palsy, • Psychiatric disorder in adults which the described patient also suffered • Lack of commitment for postoperative from, is the most suitable for SDR therapy therapy (7,9,36).

80 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898 SHORT SCIENTIFIC ARTICLE

Spasticity with cerebral palsy is the we are mindful of the nerves of the pelvic most frequent indication for SDR; howev- floor and that we do not block the sacra er, not all patients with cerebral palsy and fasciculi (for the bladder and sphincter spasticity require therapy (7,9). With low muscles) (20,36,43). levels of spasticity, day-to-day activities Cerebral palsy therapy is demanding are not impaired enough that an opera- and requires a multidisciplinary approach, tion would result in improvement, and the which must be customized to the individ- same applies to high levels of spasticity. ual. The motivation of the child and the The goal is improving the child’s function- parents must always be taken into account al condition, especially gait pattern, pre- before the surgery (44,45). Because SDR is venting contractions, deformation, pain an ablative surgical technique, it is an irre- and easing everyday care. Success rate is versible procedure, and consequently the the highest with those patients who have assessment before the operation and de- grade 1, 2 or 3 according to the Modi- tailed planning are exceptionally import- fied Ashford scale, even though recent ant (9,28,38). When deciding on a thera- research has shown beneficial long-term py, the age of the child and the long-term effects of SDR also with more severe forms plan for improving their functional and of spasticity (Ashford grade 4) (28,36,37). neurological condition are of importance. In Slovenia, SDR was performed for the The ideal age for SDR is between four and first time in October 2017. Since then, we eight, as brain growth and myelination have been regularly performing it as part are nearly completed at this age. Rarely is of our neurosurgical practice. Until that indication for SDR justified after the age time, children with spasticity resulting of 15, as it is very difficult to strengthen from cerebral palsy were treated abroad, the muscles and change the already es- for example in St. Louis Children’s Hospi- tablished gait pattern after the operation tal in Missouri, where T.S. Park operates, (44). Because of the evident and advanc- who was among the pioneers of SDR. The ing spasticity and gait issues we decided to first assessment and the therapy, followed treat spastic paraparesis in our patient de- by post-operative and continued rehabil- spite his age. However, SDR does not mean itation, were performed at the University that the therapy is concluded. Spasticity is Rehabilitation Institute of the Republic of decreased after the operation. However, Slovenia – Soča. The neurosurgical tech- because spasticity partially supplemented nique that we used on our patient was the muscle strength in the gait pattern, mus- same as described by Park et al. (38-42). cle strength itself is not sufficient after the We introduced it with the assistance and procedure, thereby temporarily worsen- cooperation of the neurophysiology team ing standing and gait. This period usually of the Charité hospital in Berlin, where lasts between three and eight weeks (29). we studied, and we performed the first During this time, temporary paraesthe- operation together. Electrophysiological sia and burning or pain may occur. These monitoring during the procedure is of key gradually disappear, as the muscle tone importance and helps surgeons verify the decreases significantly, while the strength right selection of roots and in determining and gait pattern improve (29,45). With the abnormally active fasciculi that need to our patient, spasticity decreased imme- be blocked. Generally, every sensory root diately after the procedure, while we did is split into four to eight fasciculi. Each of not note any sensory decrease. In gener- them is electrophysiologically assessed, al, we did not note any side effects of the then the ones that elicit the most abnor- operation. SDR is a safe operation, and mal muscular response are blocked. This literature includes reports on different way we block approximately two thirds of exacerbations and complications which the roots. It is especially important that vary by frequency between centres (44).

Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 81 HUMAN REPRODUCTION

The most frequent are infections and is- the lower limbs or incontinence, and im- sues with healing lesions, bleeding during pairments in the operation of the bow- surgery and after, onset of haematoma in els and the bladder (7,47‑52). With our the spinal canal or subdermia, resulting patient, the operation was a success, and from a poor dural suture, headache after the recovery was smooth. In the future, the operation due to lower cerebrospi- we will include more patients with spastic nal fluid pressure and meningitis. Pain in paraparesis in our multidisciplinary pro- legs and lower lumbar part can also occur gramme for treating spasticity, which will (in 30%). With operations that take place also include the SDR technique, thereby across a big scope of laminotomy or even contributing to improving the quality of laminectomy L2-S2 there is a chance for life for children with cerebral palsy. various spinal deformations, such as ky- phosis, scoliosis (in 28%, of which 40% 8 Conclusion required therapy), stenosis of the spinal canal, onset of hyperlordosis or spondy- SDR is an effective surgical technique lolisthesis on the operated area, smaller for decreasing spasticity, especially with desensitisations and hypersensitizations small children with a spastic paraparesis in the lower limbs (in 8%), and therefore resulting from cerebral palsy. The opera- the need for collective orthopaedic sur- tion demands detailed electrophysiologi- geries (in 59%) (30,46,47). Other possible cal monitoring during the procedure, fol- complications of the procedure include lowed by an uninterrupted rehabilitation incomplete decrease of spasticity, tempo- with long-term monitoring. The effects rary urine retention and muscle weakness, of treating spasticity with SDR are per- general complications, such as pneumo- manent, while side effects are minimum nia, bronchospasm, ileus and dangers re- when carefully adhering to the technique. lated to general anaesthesia. Rarely, there The patient’s parents permitted the are permanent impairments of feeling in publication of the report on the SDR case.

References

1. Herzog W. Skeletal muscle mechanics: questions, problems and possible solutions. J Neuroeng Rehabil. 2017;14(1):98. DOI: 10.1186/s12984-017-0310-6 PMID: 28915834 2. Nahm NJ, Graham HK, Gormley ME, Georgiadis AG. Management of hypertonia in cerebral palsy. Curr Opin Pediatr. 2018;30(1):57-64. DOI: 10.1097/MOP.0000000000000567 PMID: 29135566 3. Ingale H, Ughratdar I, Muquit S, Moussa AA, Vloeberghs MH. Selective dorsal rhizotomy as an alternative to intrathecal baclofen pump replacement in GMFCS grades 4 and 5 children. Childs Nerv Syst. 2016;32(2):321-5. DOI: 10.1007/s00381-015-2950-9 PMID: 26552383 4. Roberts A. Surgical management of spasticity. J Child Orthop. 2013;7(5):389-94. DOI: 10.1007/s11832-013- 0512-9 PMID: 24432100 5. Matthews DJ, Balaban B. Management of spasticity in children with cerebral palsy. Acta Orthop Traumatol Turc. 2009;43(2):81-6. DOI: 10.3944/AOTT.2009.081 PMID: 19448346 6. Garriz-Luis M, Sanchez-Carpintero R, Alegre M, Tejada S. Selective dorsal rhizotomy: a review of the literature on this technique for the treatment of spasticity in infantile cerebral palsy. Rev Neurol. 2018;66(11):387-94. PMID: 29790572 7. Steinbok P. Selective dorsal rhizotomy for spastic cerebral palsy: a review. Childs Nerv Syst. 2007;23(9):981- 90. DOI: 10.1007/s00381-007-0379-5 PMID: 17551739 8. Surveillance of Cerebral Palsy in EuropeSurveillance of cerebral palsy in Europe: a collaboration of cerebral palsy surveys and registers. Dev Med Child Neurol. 2000;42(12):816-24. PMID: 11132255 9. Farmer JP, Sabbagh AJ. Selective dorsal rhizotomies in the treatment of spasticity related to cerebral palsy. Childs Nerv Syst. 2007;23(9):991-1002. DOI: 10.1007/s00381-007-0398-2 PMID: 17643249

82 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898 SHORT SCIENTIFIC ARTICLE

10. Roberts A, Stewart C, Freeman R. Gait analysis to guide a selective dorsal rhizotomy program. Gait Posture. 2015;42(1):16-22. DOI: 10.1016/j.gaitpost.2015.04.004 PMID: 25979183 11. Groleger K. Klinične smernice za diagnostiko in spremljanje otrok s cerebralno paralizo v rehabilitaciji. Rehabilitacija (Ljubljana). 2014;13(1):84-96. 12. Silva S, Nowicki P, Caird MS, Hurvitz EA, Ayyangar RN, Farley FA, et al. A comparison of hip dislocation rates and hip containment procedures after selective dorsal rhizotomy versus intrathecal baclofen pump insertion in nonambulatory cerebral palsy patients. J Pediatr Orthop. 2012;32(8):853-6. DOI: 10.1097/ BPO.0b013e31826ba7b2 PMID: 23147631 13. Ohata K, Tsuboyama T, Haruta T, Ichihashi N, Kato T, Nakamura T. Relation between muscle thickness, spasticity, and activity limitations in children and adolescents with cerebral palsy. Dev Med Child Neurol. 2008;50(2):152-6. DOI: 10.1111/j.1469-8749.2007.02018.x PMID: 18201305 14. Ryan JM, Cassidy EE, Noorduyn SG, O’Connell NE. Exercise interventions for cerebral palsy. Cochrane Database Syst Rev. 2017;6:CD011660. PMID: 28602046 15. Katusic A, Alimovic S. The relationship between spasticity and gross motor capability in nonambulatory children with spastic cerebral palsy. Int J Rehabil Res. 2013;36(3):205-10. DOI: 10.1097/ MRR.0b013e32835d0b11 PMID: 23282668 16. Bohannon RW, Smith MB. Interrater reliability of a modified Ashworth scale of muscle spasticity. Phys Ther. 1987;67(2):206-7. DOI: 10.1093/ptj/67.2.206 PMID: 3809245 17. Qin Y, Li Y, Sun B, He H, Peng R, Zhang T, et al. Functional Connectivity Alterations in Children with Spastic and Dyskinetic Cerebral Palsy. Neural Plast. 2018;2018:7058953. DOI: 10.1155/2018/7058953 PMID: 30186320 18. Ara R, Islam MS, Rahman M, Begum M, Jahan F, Hosneara M, et al. Magnetic Resonance Imaging of Cerebral Palsy in the Assessment of Time of Brain Insult. Mymensingh Med J. 2018;27(3):453-60. PMID: 30141431 19. Graham D, Aquilina K, Mankad K, Wimalasundera N. Selective dorsal rhizotomy: current state of practice and the role of imaging. Quant Imaging Med Surg. 2018;8(2):209-18. DOI: 10.21037/qims.2018.01.08 PMID: 29675362 20. Aquilina K, Graham D, Wimalasundera N. Selective dorsal rhizotomy: an old treatment re-emerging. Arch Dis Child. 2015;100(8):798-802. DOI: 10.1136/archdischild-2014-306874 PMID: 25670404 21. Fehlings D, Brown L, Harvey A, Himmelmann K, Lin JP, Macintosh A, et al. Pharmacological and neurosurgical interventions for managing dystonia in cerebral palsy: a systematic review. Dev Med Child Neurol. 2018;60(4):356-66. DOI: 10.1111/dmcn.13652 PMID: 29405267 22. Lukban MB, Rosales RL, Dressler D. Effectiveness of botulinum toxin A for upper and lower limb spasticity in children with cerebral palsy: a summary of evidence. J Neural Transm (Vienna). 2009;116(3):319-31. DOI: 10.1007/s00702-008-0175-8 PMID: 19142573 23. Elia AE, Bagella CF, Ferré F, Zorzi G, Calandrella D, Romito LM. Deep brain stimulation for dystonia due to cerebral palsy: A review. Eur J Paediatr Neurol. 2018;22(2):308-15. DOI: 10.1016/j.ejpn.2017.12.002 PMID: 29396170 24. Vadivelu S, Stratton A, Pierce W. Pediatric tone management. Phys Med Rehabil Clin N Am. 2015;26(1):69- 78. DOI: 10.1016/j.pmr.2014.09.008 PMID: 25479780 25. Sindou M. [History of neurosurgical treatment of spasticity]. Neurochirurgie. 2003;49(2-3 Pt 2):137-43. PMID: 12746688 26. Steinbok P. Outcomes after selective dorsal rhizotomy for spastic cerebral palsy. Childs Nerv Syst. 2001;17(1-2):1-18. DOI: 10.1007/PL00013722 PMID: 11219613 27. Salame K, Ouaknine GE, Rochkind S, Constantini S, Razon N. Surgical treatment of spasticity by selective posterior rhizotomy: 30 years experience. Isr Med Assoc J. 2003;5(8):543-6. PMID: 12929289 28. Grunt S, Fieggen AG, Vermeulen RJ, Becher JG, Langerak NG. Selection criteria for selective dorsal rhizotomy in children with spastic cerebral palsy: a systematic review of the literature. Dev Med Child Neurol. 2014;56(4):302-12. DOI: 10.1111/dmcn.12277 PMID: 24106928 29. Langerak NG, Lamberts RP, Fieggen AG, Peter JC, Peacock WJ, Vaughan CL. Functional status of patients with cerebral palsy according to the International Classification of Functioning, Disability and Health model: a 20-year follow-up study after selective dorsal rhizotomy. Arch Phys Med Rehabil. 2009;90(6):994- 1003. DOI: 10.1016/j.apmr.2008.11.019 PMID: 19480876 30. Park TS, Liu JL, Edwards C, Walter DM, Dobbs MB. Functional Outcomes of Childhood Selective Dorsal Rhizotomy 20 to 28 Years Later. Cureus. 2017;9(5):e1256. DOI: 10.7759/cureus.1256 PMID: 28649479 31. D’Aquino D, Moussa AA, Ammar A, Ingale H, Vloeberghs M. Selective dorsal rhizotomy for the treatment of severe spastic cerebral palsy: efficacy and therapeutic durability in GMFCS grade IV and V children. Acta Neurochir (Wien). 2018;160(4):811-21. DOI: 10.1007/s00701-017-3349-z PMID: 29116382 32. Reynolds MR, Ray WZ, Strom RG, Blackburn SL, Lee A, Park TS. Clinical outcomes after selective dorsal rhizotomy in an adult population. World Neurosurg. 2011;75(1):138-44. DOI: 10.1016/j.wneu.2010.09.010 PMID: 21492678

Selective dorsal rhizotomy for spasticity treatment: a new surgical method in Slovenia 83 HUMAN REPRODUCTION

33. Gump WC, Mutchnick IS, Moriarty TM. Selective dorsal rhizotomy for spasticity not associated with cerebral palsy: reconsideration of surgical inclusion criteria. Neurosurg Focus. 2013;35(5):E6. DOI: 10.3171/2013.8.FOCUS13294 PMID: 24175866 34. Eppinger MA, Berman CM, Mazzola CA. Selective dorsal rhizotomy for spastic diplegia secondary to stroke in an adult patient. Surg Neurol Int. 2015;6(1):111. DOI: 10.4103/2152-7806.159382 PMID: 26167363 35. O’Shea TM. Diagnosis, treatment, and prevention of cerebral palsy. Clin Obstet Gynecol. 2008;51(4):816-28. DOI: 10.1097/GRF.0b013e3181870ba7 PMID: 18981805 36. Wang KK, Munger ME, Chen BP, Novacheck TF. Selective dorsal rhizotomy in ambulant children with cerebral palsy. J Child Orthop. 2018;12(5):413-27. DOI: 10.1302/1863-2548.12.180123 PMID: 30294365 37. Nemer McCoy R, Blasco PA, Russman BS, O’Malley JP. Validation of a care and comfort hypertonicity questionnaire. Dev Med Child Neurol. 2006;48(3):181-7. DOI: 10.1017/S0012162206000405 PMID: 16483393 38. Park TS, Johnston JM. Surgical techniques of selective dorsal rhizotomy for spastic cerebral palsy. Technical note. Neurosurg Focus. 2006;21(2):e7. DOI: 10.3171/foc.2006.21.2.8 PMID: 16918228 39. Engsberg JR, Olree KS, Ross SA, Park TS. Spasticity and strength changes as a function of selective dorsal rhizotomy. Neurosurg Focus. 1998;4(1):e4. DOI: 10.3171/foc.1998.4.1.10 PMID: 17206774 40. Engsberg JR, Ross SA, Collins DR, Park TS. Predicting functional change from preintervention measures in selective dorsal rhizotomy. J Neurosurg. 2007;106(4):282-7. PMID: 17465361 41. Engsberg JR, Ross SA, Collins DR, Park TS. Effect of selective dorsal rhizotomy in the treatment of children with cerebral palsy. J Neurosurg. 2006;105(1):8-15. PMID: 16871864 42. Park TS. Selective dorsal rhizotomy: an excellent therapeutic option for spastic cerebral palsy. Clin Neurosurg. 2000;47:422-39. PMID: 11197715 43. Tilton A. Management of spasticity in children with cerebral palsy. Semin Pediatr Neurol. 2009;16(2):82-9. DOI: 10.1016/j.spen.2009.03.006 PMID: 19501336 44. Abou Al-Shaar H, Imtiaz MT, Alhalabi H, Alsubaie SM, Sabbagh AJ. Selective dorsal rhizotomy: A multidisciplinary approach to treating spastic diplegia. Asian J Neurosurg. 2017;12(3):454-65. DOI: 10.4103/1793-5482.175625 PMID: 28761524 45. Mittal S, Farmer JP, Al-Atassi B, Gibis J, Kennedy E, Galli C, et al. Long-term functional outcome after selective posterior rhizotomy. J Neurosurg. 2002;97(2):315-25. DOI: 10.3171/jns.2002.97.2.0315 PMID: 12186459 46. Park TS, Edwards C, Liu JL, Walter DM, Dobbs MB. Beneficial Effects of Childhood Selective Dorsal Rhizotomy in Adulthood. Cureus. 2017;9(3):e1077. DOI: 10.7759/cureus.1077 PMID: 28401027 47. Engsberg JR, Park TS. Selective dorsal rhizotomy. J Neurosurg Pediatr. 2008;1(3):177-9. DOI: 10.3171/ PED/2008/1/3/177 PMID: 18352759 48. Peacock WJ, Arens LJ. Selective posterior rhizotomy for the relief of spasticity in cerebral palsy. S Afr Med J. 1982;62(4):119-24. PMID: 7089801 49. Abbott R, Johann-Murphy M, Shiminski-Maher T, Quartermain D, Forem SL, Gold JT, et al. Selective dorsal rhizotomy: outcome and complications in treating spastic cerebral palsy. Neurosurgery. 1993;33(5):851-7. DOI: 10.1227/00006123-199311000-00010 PMID: 8264882 50. Steinbok P, Schrag C. Complications after selective posterior rhizotomy for spasticity in children with cerebral palsy. Pediatr Neurosurg. 1998;28(6):300-13. DOI: 10.1159/000028668 PMID: 9782207 51. Golan JD, Hall JA, O’Gorman G, Poulin C, Benaroch TE, Cantin MA, et al. Spinal deformities following selective dorsal rhizotomy. J Neurosurg. 2007;106(6):441-9. PMID: 17566400 52. Abbott R. Complications with selective posterior rhizotomy. Pediatr Neurosurg. 1992;18(1):43-7. DOI: 10.1159/000120640 PMID: 1419841

84 Zdrav Vestn | January – February 2020 | Volume 89 | https://doi.org/10.6016/ZdravVestn.2898