KISEP CASE REPORT J of The Kor Soc of Ster and Func Neurosur 2006;2:185-188

Deep Brain Stimulation for Residual after Selective Peripheral Denervation - Case Report -

Ji Young Moon, MD*, In Bo Han, MD*, Young Sun Chung, MD, Sang Sup Chung, MD, Ryoong Huh, MD Department of Neurosurgery, Bundang CHA Hospital, Pochon CHA Medical University, Seongnam, Korea

Deep brain stimulation (DBS) is well established for Parkinson’s disease and essential , and has widened the spectrum of therapeutic options for patients with intractable . We present one patient with spasmodic torticollis, which was successfully treated by bilateral pallidal DBS. A 30-year-old male had suffered from jerky head movement and periodic unnatural postioning of the head for 2 years. Neurological examination disclosed rotatory torticollis to the right side. The patient initially had received clo- nazepam and anticholinergic drug, and later had undergone botulinum toxin injection. Because there was no response, selective peripheral denervation was initially performed. After surgery, there was only a limited effect and the level of social-occupational adaptation was low. Therefore, the patient underwent DBS of the globus pallidus internus (Gpi) at 17 months after selective peri- pheral denervation. A marked improvement of the symptoms was observed six days after the initiation of Gpi-DBS, and additio- nal progressive improvement was noted during follow-up period. Bilateral stimulation of Gpi can be a very useful treatment option in spasmodic torticollis, even in patients who do not respond to selective denervation.

KEY WORDS: Deep brain stimulation·Spasmodic torticollis.

INTRODUCTION peripheral denervation.9) Among these surgical options, selective peripheral denervation has been reported to pro- Spasmodic torticollis is the most common form of focal vide the best results with the fewest side effects.3)5)7) For dystonia, characterized by repetitive or sustained contrac- patients who do not respond satisfactorily to selective tions of neck muscles that result in abnormal posture of denervation or who are ineligible for selective denervation, the head and neck. The treatment of dystonia usually however, deep brain stimulation (DBS) of the globus pal- includes oral medications, botulinum toxin injections, phy- lidus internus (Gpi) has been recently introduced.9-11)13) siotherapy, and surgery. These therapies may be used in In this report, we present a patient with spasmodic torti- alone or in combination.4)12) Oral medications include an- collis, which was initially treated by selective peripheral ticholinergic agents, dopamine receptor antagonists, and denervation, and subsequently by bilateral pallidal stimu- GABA-mimetic agents. The efficacy of these medications lation. is limited, although roughly 40% of patients derive some symptomatic relief from anticholinergic agents.1)4) Botuli- CASE REPORT num toxin injection has a high rate of efficacy combined with a low incidence of side effects and are considered the A 30-year-old male had suffered from jerky head mo- first choice in therapy for spasmodic torticollis.4)6) vement and periodic unnatural positioning of the head for 2 In patients who fail to respond to pharmacotherapy, a years. The symptoms of dystonia including neck pain and surgical approach has been performed. Surgical options involuntary movement gradually worsened. The patient include thalamotomy, bilateral , microvascular had no family history of neurological disease or movement decompression of the spinal accessory nerve, or selective disorders and had no significant past history. The patient’s level of and cognitive function were com- Address for correspondence: Ryoong Huh, MD, Department of pletely normal. The patient had been treated with clona- Neurosurgery, Bundang CHA Hospital, Pochon CHA Medical Uni- versity 351, Yatap-dong, Bundang-gu, Seongnam 463-712, Korea zepam and anticholinergic drug, but these drugs were Tel: +82-31-780-5260, Fax: +82-31-780-5269 ineffective. The patient did not also benefit from physio- E-mail: [email protected] therapy and botulinum toxin injection. On admission, the *These authors (Moon JY and Han IB) made an equal contribution to this paper. patient complained of neck pain and neurological exami-

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Fig. 1. A：Photograph showing a preo- perative feature of the patient with rotational torticollis. B：Photograph sho- A B wing normalized neck posture 2 months after bilateral pallidal stimulation. nation disclosed right rotatory torticollis with painful midline at the level of the coronal suture to create a more neck stiffness on attempted passive neck movement. Left perpendicular trajectory through the pallidum. Beginning sternocleidomastoid (SCM) muscle hypertrophy was 10mm above the pallidal target, microelectrode recordings present. The symptoms of dystonia worsened while stan- were obtained while monitoring impedance. After deter- ding and walking. The patient was severely handicapped mining the border of the Gpi by reduced cell activity and (Toronto Western Spasmodic Torticollis Rating Scale reduced background noise, this monitoring electrode was (TWSTRS)：69 points, torticollis severity：23 points, removed and replaced with a Medtronic 3387 quadripolar disability：28 points, pain：18 points). A neuroimaging DBS electrode, which was fixed in the burr hole with the examination including magnetic resonance imaging (MRI) burr hole cap provided (Medtronic, Minneapolis, MN, showed normal findings. USA). A postoperative MRI confirmed the correct elec- Selective peripheral denervation was initially performed. trode position and showed no hemorrhage. Test stimulation Because the patient presented with right rotatory torticol- was begun on the first day after implantation of DBS lis, surgery was initiated with the denervation of the electrodes with a test stimulator (model 3628, Medtronic, contralateral SCM muscle (left spinal accessory nerve Minneapolis, MN, USA). Initial stimulation parameters denervation and myotomy of left SCM muscle). In the se- were set in the following ranges：voltage 1.0-3.0V, pulse cond step the involved posterior neck muscles denervation rate 160-185Hz, and pulse width 90-160μsec. During was accomplished by the resection of the posterior bran- the test stimulation, the patient experienced an immediate ches of C1-5 on the right side. However, only a limited improvement in pain and neck movements. Ten days after improvement was seen after selective denervation and the implantation of DBS electrodes, an implantable pulse level of social-occupational adaptation was low. The score generator (IPG) (Soletra 7426, Medtronic, Minneapolis, on the TWSTRS was 50 (torticollis severity：16 points, MN, USA) was placed in a subclavicular subcutaneous disability：22 points, pain：12 points) after selective pouch and connected to the DBS electrode. During this denervation. The total TWSTRS scores improved by only procedure, the patient was given general anesthesia and the 28% and did not further improve. Therefore, the patient procedure was performed on both sides. The stimulation underwent GPi-DBS at 17 months after selective periphe- parameters were adjusted at each follow-up visit to our ral denervation. clinic, based on the results of neurological examinations The MRI-compatible Leksell stereotactic frame was as well as the patient’s report concerning the activity of applied to the head to be as parallel as possible with the daily living. Six days after initiation of Gpi-DBS, the torti- intercommissural (IC) line. The target was localized using collis severity, disability, and pain scores had dropped from neurosurgery simulator. The following coordinates were 16, 22, and 12 to 6, 4, and 1, respectively. At that time, used for pallidal targeting：3mm anterior to the midcom- the setting parameters were 2.3V, 185Hz, and 160μsec. missural point, 20mm lateral to the midline, and 6mm be- The maximum improvement was reached at 2 months low the midcommissural plane. Bilateral insertion of DBS after surgery. The score on the TWSTRS was 9 (torticol- electrodes in the GPi was performed under local anesthesia. lis severity：5 points, disability：4 points, pain：0 points) Two precoronal burr holes were made 2.5cm lateral to the and a significant reduction (82%) in the TWSTRS score

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Ji Young Moon, et al：Deep Brain Stimulation for Spasmodic Torticollis

was established. Neurological examination revealed mild with spasmodic torticollis.2) Furthermore, the modified dystonic spasm and jerky head movement. No stimulation- Bertrand procedure has been reported to be safe and offer related side effects were induced. The last stimulation persistent relief in the majority of patients regardless of parameters were set as follows：voltage 3.3V, pulse rate their response to botulinum toxin therapy. To date, there- 185Hz, and pulse width 210μsec. fore, if a surgical procedure has to be considered, selective peripheral denervation has been used extensively among DISCUSSION all surgical options.3)5)7) However, it has been reported that the torticollis often The injection of botulinum toxin has been proven effec- recurs due to inadequate denervation or nerve regeneration tive in 75% of patients with torticollis and side effects have after selective peripheral denervation and thus the benefits been rare and if present have been usually mild and trans- of surgery wear off over time. Furthermore, peripheral ient. Therefore, repeated injections of botulinum toxin have surgery is not indicated in a subset of spasmodic torticollis been considered to be the treatment of first choice in symp- patients including those with head tremor and , tomatic patients with spasmodic torticollis.1)6) However, marked phasic dystonic movements, sagittal and lateral despite its widespread use, it has been reported that 6 to translation, anterocollis, and combined complex forms of 14% of patients do not benefit primarily and 3 to 10% of cervical dystonia.9) Therefore, based on the high efficacy patients lose benefit during repeated use of botulinum of DBS for Parkinson’s disease and , there toxin mostly due to antibody formation.4) has been a reemergence of interest in the central treatment When pharmacotherapy fails, surgery has been under- of spasmodic torticollis by using pallidal DBS, and good taken to interrupt, at various levels of the , results have been reported. This treatment may be more the pathways responsible for the abnormal neck move- applicable in a subset of patients with a more complex ments. Some operations intentionally damage small regions and generalized form of dystonia.9-11)13) of the thalamus or globus pallidus in an attempt to “reba- It has been usually reported that generalized dystonia lance” movement and posture control. These surgeries gradually benefits from pallidal DBS in a delayed and have had widespread use in Parkinson’s disease, and the progressive manner over time and severity of neck move- results in dystonia have been promising. Cooper reported ments is not effectively treated as pain.9) However, in the an overall improvement in 70% of patients with dystonia present case, six days after initiation of GPi-DBS, the total after thalamotomy. However, thalamotomy, particularly TWSTRS scores substantially improved by 78%. Two when they were performed bilaterally, had the high in- months later, all scores further improved by 82%. The cidence of complications including speech disturbances, severity score improved by 69%, the disability score by motor weakness, and pseudobulbar palsy. Because palli- 82%, and the pain score by 100%, as compared to preope- dotomy could improve dystonia in patients with Parkin- rative scores. In contrast to previous reports, the present son’s diease, globus pallidus has recently been considered case showed rapid clinical response and similar improve- the preferred target for surgical treatment of dystonia.13) ments in all subscores of the TWSTRS, although one study In recent reports, bilateral pallidotomy yielded a 50-80% reported similar results.8) improvement in dystonia scores. However, bilateral palli- Along with the type of torticollis a patient has, other dotomy has been associated with uncontrollable side ef- factors influence the success of an operation. Every patient fects such as speech deficit, vision problems, and cognitive is unique and the muscles involved may vary from one dysfunction and the failure to achieve long-term relief has patient to another. Therefore, the preoperative evaluation been noted over time.9) is very important and the patient’s head and neck move- Other surgical approaches include serving one or more ments and the muscular contractions should be identified of the contracting neck muscles (muscle resection), cut- and characterized. ting nerves going to the nerve roots deep in the neck close to the (rhizotomy), and removing the nerves CONCLUSION at the point they enter the contracting muscles (selective peripheral denervation：Bertrand procedure). Bertrand et To date, selective peripheral denervation has been con- al. reported excellent or good results in 88% of the patients sidered to provide the best results combined with a low

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