DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY ORIGINAL ARTICLE Pallidotomy for medically refractory status dystonicus in childhood CARLO EFISIO MARRAS1 | MICHELE RIZZI2 | LAURA CANTONETTI3 | ERIKA REBESSI1 | ALESSANDRO DE BENEDICTIS1 | FRANCESCO PORTALURI1 | FRANCO RANDI4 | ALESSANDRA SAVIOLI5 | ENRICO CASTELLI3 | FEDERICO VIGEVANO4 1 Neurosurgery Unit, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesu Children’s Hospital (BGCH), Rome; 2 Department of Neurosurgery, IRCCS Fondazione Istituto Neurologico ‘Carlo Besta’, Milan; 3 Neurorehabilitation Unit, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesu Children’s Hospital (BGCH), Rome; 4 Neurology Unit, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesu Children’s Hospital (BGCH), Rome; 5 Intensive Care Unit, Department of Emergency, IRCCS Bambino Gesu Children’s Hospital (BGCH), Rome, Italy. Correspondence to Erika Rebessi, Department of Neuroscience and Neurorehabilitation, Neurosurgery Unit, Bambino Gesu Children’s Hospital, IRCCS 4, Piazza Sant’Onofrio, 00165 Rome, Italy. E-mail: [email protected] This article is commented on by Lumsden on pages 607–608 of this issue. PUBLICATION DATA AIM Status dystonicus is a rare and potentially fatal condition of continuous and generalized Accepted for publication 29th December muscle contraction that can complicate dystonia. As status dystonicus is usually refractory to 2013. traditional pharmacological therapy, alternative and invasive strategies have been developed, Published online 4th April 2014. but so far there are no guidelines on status dystonicus management. Pallidotomy has shown good results in status dystonicus treatment. ABBREVIATIONS METHOD We report indications, surgical strategy, and outcome of bilateral pallidotomy in BFMDRS Burke-Fahn-Marsden Dystonia four pediatric patients (four males; mean age at surgery 11y 5mo) with secondary dystonia, Rating Scale who developed refractory status dystonicus. Pallidotomy was performed in the area GPi Globus pallidus internus corresponding to the mid portion of the globus pallidus internus. ITB Intrathecal baclofen RESULTS This procedure allowed patients to recover the pre-status dystonicus condition, PEG Percutaneous enteral gastrostomy controlling dystonic postures and movements of trunk and limbs. Moreover oromandibular dystonia, which is resistant to conservative approaches and deep brain stimulation, was significantly reduced. No postoperative complications were registered. INTERPRETATION Our study suggests pallidotomy as a feasible treatment in patients with secondary dystonia complicated by status dystonicus. Dystonia is a clinical syndrome characterized by on status dystonicus showed that surgery appears to be an sustained muscle contraction, frequently causing torsional effective treatment.3 and repetitive movements, or abnormal postures, which The aim of this study was to report indications, surgical can be focal or generalized.1 Dystonia may sporadically strategy, and outcome of bilateral pallidotomy in a series evolve toward a life-threatening condition of severe of four children affected by secondary dystonia who generalized dystonia, called status dystonicus or dystonic developed status dystonicus. storm. Status dystonicus is often triggered by events such as fever, infections, exposure to medications, or their abrupt METHOD cessation. This condition could rapidly lead to rhabdomyol- From March 2011 to January 2012, four pediatric patients ysis, metabolic failure, and bulbar complications, requiring (four males), presenting with severe forms of secondary admission to the intensive care unit (ICU) for sedation and dystonia, were referred to the Department of Neuroscience ventilation.2 Status dystonicus can be refractory to tradi- and Neurorehabilitation of the Bambino Gesu Children’s tional pharmacological therapy. Alternative and invasive Hospital in Rome, which receives tertiary patients for strategies have been developed but no guidelines for status specialist consultations. All patients had an exacerbation of dystonicus management have been unequivocally defined. the disease with status dystonicus, refractory to medical Literature reports reveal that a gradual multistage treatment (Table I), and were prospectively studied. They approach, from enteral pharmacological therapy to ICU fulfilled the diagnostic criteria for status dystonicus procedures and surgery (continuous infusion of intrathecal according to the definition by Manji.2 This includes the baclofen, thalamotomy, pallidotomy, or deep brain stimula- development of increasingly frequent and severe episodes tion) may be required. A recent exhaustive literature report of generalized dystonia necessitating urgent hospital © 2014 Mac Keith Press DOI: 10.1111/dmcn.12420 649 admission and accompanied by one or more of the follow- What this paper adds ing life-threatening complications: bulbar weakness com- • It reports efficacy of pallidotomy in the management of status dystonicus. promising upper airway patency with the risk of • The mid portion of the globus pallidus internus (GPi) is an effective target in the treatment of status dystonicus. progressive impairment of respiratory function leading to • the development of respiratory failure; exhaustion and Selection of the mid GPi also allows for subsequent pallidal deep brain stimulation of its posteroventral portion. pain; and metabolic imbalances. Selection criteria for bilateral pallidotomy included the Informed consent was given by parents of all four presence of status dystonicus, which was not responsive to patients. Data collection, recording and analysis was per- pharmacological treatment, and associated with a rapid and formed according to our institutional review board and severe decline of clinical conditions (Table I). waiver of consent was obtained for data collection, de- The method used to target the area for pallidotomy was identification and analysis. based on the 3D built volume routinely used in neuronavi- gation. The technique needs the AC-PC definition to build Surgical treatment the stereotactic volume with the X, Y, and Z coordinates; Pallidotomy was performed, under intravenous general the definition of the globus pallidus internus (GPi) is not anesthesia, by a frameless stereotactic neuronavigation – based on the use of the stereotactic coordinates [18 21mm robotic system (ROSA: RObotized Stereotactic Assistant; laterally, 6mm vertically, and 2mm anteriorly to the inter- Medtech, Newark, NY, USA). The targeted area corre- commissural point to target the posteroventral (VPL) sponding to the mid portion of the GPi, was preoperatively GPi], but on visual direct targeting on magnetic resonance defined by a direct targeting on brain MRI (fast spin echo imaging (MRI) inversion recovery sequences. Afterwards, inversion recovery sequence), and merged with brain CT. the relationship to the mid-commissural point was Microrecording and macrostimulation were performed obtained by the direct targeting that was usually lateral (X) under electromyography (EMG) monitoring to detect the 14 to 18mm, anteroposterior (Y) 3 to 5mm, and vertical nucleus and to exclude the involvement of the pyramidal (Z) 2mm. This target fits with the coordinates used for fibers of the internal capsule by the lesioning. The radio- pallidotomy and with those proposed by other authors for frequency lesion (Cosman RFG-1; Cosman Medical Inc., 4 DBS. Burlington, MA USA) at 40V for 60 second was performed Before the onset of status dystonicus, and before surgery, at the target, 3mm above, and 2mm below it. A second all patients underwent a dystonia assessment including neu- trajectory (2mm posterior, 2mm laterally to the first target) rological evaluation, videotape recording, and the adminis- was used to perform lesioning. tration of the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), brain MRI and cranial-computed tomography Case 1 (CT). These clinical and imaging evaluations were The first patient was 15 years old and had started to repeated 1, 3, and 6 months after surgery, and every experience from hypertonia and severe psychomotor delay 6 months thereafter. Table I: Aetiology and clinical features of the status dystonicus series Age at Age at status Sex, dystonia dystonicus Precipitating Status dystonicus Case age (y) Diagnosis onset onset (y) factors symptoms Complications 1 M, 15 Chromosomopathy 3y 1st status 1st status dystonicus: Continuous Partial amputation dystonicus: 12 pneumonitis oromandibular, of the tongue 2nd status 2nd status dystonicus: trunk, limbs Pneumonia dystonicus: 13 mononucleosis movements Pain 2 M, 19 Epileptic 1mo 17 Fever Generalized dystonic Renal failure, encephalopathy movements, rhabdomyolysis, opisthotonus, respiratory psychomotor agitation distress Pain 3 M, 6.5 Idiopathic 4mo 5 Enteritis/Ileo-ileal Eyelids clonus, Respiratory bilateral striatal Invagination opisthotonus, distress necrosis upper limbs movements, fixed dystonic posture of the left upper limb 4 M, 12 Severe neonatal 8mo 1st status 1st status dystonicus: Generalized dystonic Severe dysphagia, cerebral hypoxia dystonicus: 8 H1N1 infection movement of eyes, sepsis, deep vein 2nd status 2nd status dystonicus: mouth, head and thrombosis dystonicus: 10 unknown limbs, opisthotonus Pain 650 Developmental Medicine & Child Neurology 2014, 56: 649–656 in the first year of life. Genetic testing displayed a chromo- upper limb tremor, eyelid clonus, opisthotonus, and a fixed somopathy (deletion of the long arm of chromosome 22). dystonic