470 Case Reports / Journal of Clinical Neuroscience 19 (2012) 470–471 Successful treatment of cervical dystonia induced by basal ganglion venous angioma with Gamma Knife thalamotomy Chun-Ming Yen a, Jason Sheehan b, Hung-Chuan Pan a,⇑ a b Department of Neurosurgery, Taichung Veterans General Hospital, 160 Taichung-Kang Road Sec. 3, Taichung 407, Taiwan Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, USA a r t i c l e i n f o Article history: Received 15 April 2011 Accepted 22 April 2011 Keywords: Cervical dystonia Gamma knife Thalamotomy Venous angioma a b s t r a c t Stereotatic radiosurgery is typically not the first line of treatment for cervical dystonia. We present a patient with a rare cervical dystonia induced by a venous angioma in the right basal ganglion. The patient was successfully treated with a gamma knife thalamotomy after failed treatments of botulinum toxin injections and peripheral denervation. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Repeated injections of botulinum toxin into the dystonic muscles are considered the treatment of choice for cervical dystonia. About 6% to 14% of patients do not benefit from this procedure, and 3% to 10% of patients will only experience short-term relief.1,2 Selective deactivation of the dystonic muscles and preservation of normal function is the common goal of contemporary surgery.3 With widespread use of botulinum toxin and peripheral denervation, the option of functional stereotactic surgery is only used in those patients who are either not ideal candidates for a peripheral approach or who have failed the primary treatment modalities. Among the stereotactic approaches, thalamotomy or palliodotomy have afforded improvement in 17% to 80% of patients.4,5 Recently, either subthalamic or globus pallidus deep brain stimulation has also been investigated and the results seemed promising.6,7 There have been few published reports detailing the ablative procedure by Gamma Knife (GK) radiosurgery for the treatment of cervical dystonia. We report a patient with cervical dystonia induced by a basal ganglia venous angioma, who has been successfully treated with GK thalamotomy. 2. Case report A 32-year-old male initially suffered from muscle twitching over his neck. Later, the symptoms spread to include horizontal rotation of his head accompanied by occasional involuntary movement in the right upper limb since February 2003. Initially, he underwent a dorsal rhizotomy from C2 to C4 and muscle denervation at a regional hospital, and he experienced symptomatic improvement for approximately 3 months. After recurrence of his symptoms, he was referred to our hospital. He underwent an MRI. The T1-weighted, contrast-enhanced magnetic resonance (MR) sequence revealed a tubular signal void in the right lentiform nucleus, posterior limb of the internal capsule, and thalamus region (Fig. 1A and B). In August 2003, a GK thalamotomy was performed using a 4-mm collimator and a maximum dosage of 120 Gy targeted on his right ventral intermediate (Vim) nucleus using a previously established protocol (Fig. 1C and ⇑ Corresponding author. Tel.: +886 4 23592525x5081; fax: +886 4 23741218. E-mail address: ll0432@yahoo.com.tw (H.-C. Pan). D).8 Within 2 months post-radiosurgery, the patient’s symptoms markedly improved. The MRI obtained 3 months post-radiosurgery demonstrated a small ring of enhancement on the T1-weighted MRI and a hyperintense lesion on the T2-weighted MRI over the right thalamus (Fig. 1E and F). The patient continued to improve clinically, and, at 18 months, he has had total relief of symptoms and has remained symptom free for 72 months. The MRI findings were unchanged (Fig. 1G and H). 3. Discussion Cervical dystonia, like all other dyskinesias, is probably a manifestation of basal ganglion dysfunction. The bulk of evidence points to striatal dysfunction as the cause of cervical dystonia.9 Of three patients with symptomatic cervical dystonia described in the literature with definite pathology, two presented with an arteriovenous malformation involving the contralateral caudate nucleus and the third had a post-traumatic hemorrhage in the area of the striatum.10,11 Venous angiomas may present subtly. Some are discovered incidentally while others may present with a seizure or intracerebral hemorrhage. However, to our knowledge, a patient with a venous angioma has not presented with cervical dystonia.12 We postulate that the cause of dystonia in our patient may be an aberrant connection in the basal ganglion. The treatment of cervical dystonia includes medication, botulinum injection, and surgical intervention.1–7 Among the various types of surgical interventions, peripheral denervation is the treatment of choice. In the modern era, stereotactic neurosurgery, including thalamotomy, pallidotomy, or deep brain stimulation, have only been used in those patients in whom medical treatment and denervation has failed. Various target points for stereotactic lesioning have included the ventralis oralis anterior, the ventrooralis internus, the ventraloralis posterior, the Vim, the ventral lateral, and the globus pallidus interna. The surgical efficacy ranges from 17% to 80%.4,5 In anecdotal reports, ablative thalamotomy achieved better results in a patient with cervical dystonia associated with myoclonus or tremor.13 Our patient, who presented not only the rotational head movement but also occasional myoclonic movement involving his right hand, experienced a complete resolution of his symptoms following GK thalamotomy. Hence, the Vim should be considered a useful target in such patients. Case Reports / Journal of Clinical Neuroscience 19 (2012) 470–471 471 Fig. 1. MRI of a 32-year-old male who presented with persistent cervical dystonia despite treatment with botulinum toxin injection and muscle denervation: (A, axial; B, coronal) T1-weighted MRI with gadolinium enhancement showing a vascular structure over the right lentiform nucleus, posterior limb of the internal capsule, and thalamus region – these imaging characteristics favored a venous angioma; (C, axial; D, coronal T1-weighted procedural MRI) gamma knife (GK) thalamotomy was conducted over the right ventral intermediate (Vim) nucleus with a 4-mm collimator and maximum dose of 120 Gy in T1-weighted MRI imaging; (E) axial gadolinium enhanced T1-weighted MRI 3 months after GK showing a ring-enhancing lesion in the right thalamus; (F) axial T2-weighted MRI of the area corresponding to (E) showing a hyperintense lesion; (F) axial T1-weighted MRI with gadolinium 72 months after GK showing the enhancing lesion in the right thalamus; (G) T2-weighted MRI of the area corresponding to (F) showing a hyperintense lesion; the patient remained symptom free. (This figure is available in colour at www.sciencedirect.com.) GK ablation in the treatment of movement disorder has been reported in limited cases, but data about this technique for the treatment of cervical dystonia is scare.11 Our lesioning of the Vim nucleus afforded excellent results with amelioration of the symptom 2 months after treatment and persistent relief for 72 months. GK should be considered a treatment alternative for cervical dystonia, especially in patients who harbor deep vascular lesions and would be considered high risk for microsurgical resection. References 1. Brin MF, Comella CL, Jankovic J, et al. Treatment of cervical dystonia using botulinum toxin. In: Kurla R, editor. Treatment of movement disorders. Philadelphia: Lippincott Williams & Wilkins; 1995. p. 183–246. 2. Jankovic J, Schwartz K. Response and immunoresistance to botulinum toxin injections. Neurology 1995;45:1743–6. 3. Krauss JK, Toups EG, Jankovic J, et al. 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