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Meige's syndrome: A cranial dystonia treated with bilateral pallidal deep brain stimulation
Clinical Neurology and Neurosurgery 112 (2010) 344–346
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Case report
Meige’s syndrome: A cranial dystonia treated with bilateral pallidal deep brain stimulation Elli Markaki, Zinovia Kefalopoulou, Miltiadis Georgiopoulos, Anna Paschali, Constantine Constantoyannis ∗ Functional Neurosurgery Unit, Department of Neurosurgery, Medical School of Patras, Patras 26500, Greece
a r t i c l e
i n f o
Article history: Received 9 June 2009 Received in revised form 16 November 2009 Accepted 7 December 2009 Available online 12 January 2010 Keywords: Blepharospasm Deep brain stimulation Meige’s syndrome Oromandibular dystonia Globus pallidus internus
a b s t r a c t Background: Meige’s syndrome is a rare form of segmental dystonia characterized by blepharospasm and oromandibular dystonia. Medical treatment including botulinum toxin injections usually present disappointing results. The experience on Deep Brain Stimulation (DBS) in the treatment of Meige’s syndrome and other segmental dystonias is still limited. At the moment, only a few cases of pallidal DBS have been reported to improve this rare form of dystonia. Case description: We report on a case of a woman with a 7-year history of Meige’s syndrome, which rendered her functionally blind. The treatment with botulinum toxin injections failed to improve her symptoms, whereas stereotactic bilateral DBS of the pallidum led to a dramatic clinical improvement. Clinical assessment using the Burke–Fahn–Mardsen Dystonia Rating Scale (BFMDRS) in a double-blind manner, showed an improvement of 70% in the Movement score and 93.33% in the Disability score (84% reduction of the total score) on the 3 and 6 month follow-up. Conclusions: Stereotactic pallidal DBS might be considered as a potential treatment in the management of Meige’s syndrome. © 2009 Elsevier B.V. All rights reserved.
1. Introduction Meige’s syndrome is a form of adult-onset dystonia, characterized by the combination of oromandibular dystonia (OMD) and blepharospasm. Nonetheless, dystonia may also involve the upper limbs, the neck and the trunk [1,2]. Patients present with increased blinking and uncontrollable bilateral closure of the eyelids, which in some cases can lead to functional blindness [3]. Several palliative treatments are available for the treatment of Meige’s syndrome. Botulinum toxin injections with electromyographic guidance in selected muscles constitute the treatment of first choice, but effectiveness often decreases over time [3,4]. In addition, medical therapy (anticholinergics, tetrabenazine, and benzodiazepines) has usually poor results [3,5]. Globus pallidus internus (GPi) DBS is an established treatment for medically refractory primary forms of dystonia [6] and several groups have reported satisfactory results in cases of cervical [7] and secondary dystonia as well [8]. The reports on Meige’s syndrome and its responsiveness to pallidal DBS treatment are still very few [2,4,9–14] but their results encourage the use of DBS in this population of patients.
∗ Corresponding author. Tel.: +30 2610 999 495; fax: +30 2610 992 997. E-mail address: [email protected] (C. Constantoyannis). 0303-8467/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2009.12.005
We report here the case of a patient suffering from Meige’s syndrome, who underwent bilateral GPi DBS. 2. Case report A 49-year-old woman had been suffering from progressively evolving bilateral blepharospasm and oromandibular dystonia (Meige’s syndrome) for 7 years. The first symptom presented was increased involuntary blinking, which frequency and duration augmented over time, becoming more and more incapacitating. In addition, she suffered from photophobia, which forced her to wear sunglasses during daylight. After 4 years, the uncontrollable tonic spasms of the orbicularis oculi muscles led to prolonged forceful closure of the eyelids, which rendered the patient functionally blind for the last 3 years. She also presented slight dystonic contractions of the oromandibular muscles that caused a sideways deviation of the jaw, lip tightening and retraction of the corners of the mouth (Fig. 1). Speech was also mildly affected due to the presence of dysphonia. The functional blindness due to the blepharospasm, rendered her unable to attend to her job and compelled her to quit. Gradually she became socially isolated and lost interest in any activity. There was no family history of dystonic conditions and her past medical history revealed no other possible causes of Meige’s syndrome. Her neurological examination did not reveal any other
E. Markaki et al. / Clinical Neurology and Neurosurgery 112 (2010) 344–346
345
Table 1 The BFMDRS Movement and Disability Scale scores before and after DBS. Pre-operative
6 months follow-up
BFMDRS Movement scale score BFMDRS Disability scale score
10 15
3 1
Total score
25
4
Fig. 1. The patient pre-operatively, with spasms of the orbicularis oculi muscles and dystonic contractions of the oromandibular muscles.
abnormalities, except for blepharospasm and OMD, while her brain MRI, the electroencephalogram and the laboratory tests were normal. The Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS) Movement score was 10 and the Disability score was 15 (Total score: 25). The patient had been treated with several medications (dopaminergic/anticholinergics drugs, benzodiazepine, dopamine depletors, Baclofen) and with botulinum toxin injections, to which the blepharospasm did not respond and so she decided to undergo DBS. The patient underwent a stereotactic bilateral implantation of electrodes in the GPi. A Cosman-Roberts-Wells (CRW) head ring was applied under local anesthesia. A high resolution T1-weighted MRI was consequently performed (slice thickness 2 mm without gap), with a 1 Tesla MRI scanner (Philips, Gyroscan, Intera). With the use of the Frame-Link v. 4.0 software, the Stealthstation workstation (Medtronic, MN) and the Stealthenbraned and Wahren atlas the mid-sagittal plane, the anterior commissure (AC) and the posterior commissure (PC) were identified. The GPi was selected 4 mm below AC–PC, 19 mm laterally and 2 mm anteriorly to the mid-commissural point. Intraoperatively, microelectrode recordings (MER) of the neuronal activity of the target, and the patient’s responses to stimulation were recorded. Finally, two electrodes (model 3389, Medtronic, Inc., Minneapolis, MN) were implanted in the GPi bilaterally. There were no peri- or post-operative complications. The activation of the electrodes took place a few hours after surgery. The stimulation parameters were 2 V, 185 Hz, 210 s, with monopolar stimulation on contacts 0 and 4 and led to an immediate significant attenuation of blepharospasm and oromandibular dystonia. The coordinates of the final location of the active contacts were 2.5 mm anterior to mid-AC–PC, 20.2 mm lateral and 3.3 inferior to the AC–PC line for the right side and 2.3 mm anterior mid AC–PC, 21 mm lateral and 3.7 inferior to the AC–PC for the left side electrode. After 1 week, an almost complete resolution of the symptoms was observed, and during the subsequent programming sessions, minor adjustments were applied to the stimulation parameters (final stimulation parameters were 2.6 V, 185 Hz, 210 s). There were no side effects related to the stimulation. The clinical outcome was assessed at 3 and 6-month intervals after surgery in a double-blind manner. Neither the patient, nor the rating examiner was aware of which condition was applied, “on-” or “off-DBS”, during the evaluation. To blind the examiner to the stimulator’s condition, the stimulator was switched -on and -off by a different investigator. Some
Fig. 2. The patient post-operatively with an almost complete resolution of the symptoms.
patients are aware immediately when the stimulator is switched on and this could potentially unblind them. In order to minimize the risk of unblinding during the assessment, the patient was blinded by placing the programmer (N’vision programmer, Medronic) on the patient’s chest, turning the DBS -on briefly then randomly pressing the -on or -off button. The stimulator was turned -off for 2 h before the assessments for the double blind evaluation. At the 3-month follow-up visit, the BFMDRS Movement scale score was 3 and the Disability scale score was 1 (84% reduction of the total score) and remained unaltered at the 6-month follow-up assessment (Table 1) (Fig. 2). 3. Discussion Several palliative treatments are available for the treatment of Meige’s syndrome [3,15]. Botulinum toxin injections with electromyographic guidance in selected muscles constitute the treatment of first choice, but effectiveness often decreases over time [3,4]. Several side effects, including facial weakness, dysphagia, dry mouth, flu-like syndrome [16] are additional problems of local injections. Surgery (eyelid myectomy, blepharoplasty and lid lifts) has little if any role in therapy and drug treatment (dopaminergic/anticholinergics drugs, benzodiazepine, dopamine depletors, Baclofen), although sometimes helpful, is usually of no benefit [3,5]. Given the dramatic clinical improvement experienced after DBS in patients with primary generalized dystonia [17,18,6], trials of pallidal DBS have been performed for the treatment of segmental dystonia. Still, the experience on Meige’s syndrome is limited. Nonetheless, the few reports existing present encouraging results for the use of DBS in these patients [2,4,9–14]. We presented, in this report, a patient suffering from Meige’s syndrome, who was rendered functionally blind by the blepharospasm. This patient underwent DBS and experienced a spectacular improvement: her eyes opened almost immediately after the stimulator was turned on and a week later, there was a complete resolution of all the dystonic
346
E. Markaki et al. / Clinical Neurology and Neurosurgery 112 (2010) 344–346
symptoms. After 6 months, our patient presents the same clinical improvement without side effects and enjoys a better quality of life. The pathophysiology of Meige’s syndrome is not well understood and various hypothesis have been formulated [19]. A recent study using fMRI, revealed that there is a reduced activation of the primary motor and ventral premotor cortex in these patients during oromandibular motor execution, which is probably secondary to a reduced cortical inhibition in motor and premotor areas. Additionally, the same study revealed an increased activation of the somatosensory areas and of the caudal supplementary motor area, which indicates an altered somatosensory representation [20]. 4. Conclusion The experience on DBS in the treatment of Meige’s syndrome and other segmental dystonias is still limited. Nevertheless, the dramatic, prompt and sustained clinical improvement of our patient is in line with previous studies and suggests that GPi DBS can offer an excellent therapeutic effect in patients with Meige’s syndrome. References [1] Blomstedt P, Tisch S, Hariz MI. Pallidal deep brain stimulation in the treatment of Meige syndrome. Acta Neurol Scand 2008;118:198–202. [2] Houser M, Waltz T. Meige syndrome and pallidal deep brain stimulation. Mov Disord 2005;20:1203–5. [3] Horn S, Comella C. In: Jankovic J, Tolosa E, editors. Parkinson’s disease and movement disorders. Philadelphia: Lippincott Willson & Wilkins; 2002. p. 348–51. [4] Ostrem JL, Marks Jr WJ, Volz MM, Heath SL, Starr PA. Pallidal deep brain stimulation in patients with cranial-cervical dystonia (Meige syndrome). Mov Disord 2007;22:1885–91. [5] Greene P, Shale H, Fahn S. Analysis of open-label trials in torsion dystonia using high dosages of anticholinergics and other drugs. Mov Disord 1988;3(1):46–60.
[6] Vidailhet M, Vercueil L, Houeto JL, Krystkowiak P, Benabid AL, Cornu P, et al. Bilateral deep brain stimulation of the globus pallidus in primary generalized dystonia. N Engl J Med 2005;352:459–67. [7] Hung SW, Hamani C, Lozano AM, Poon YY, Piboolnurak P, Miyasaki JM, et al. Long-term outcome of bilateral pallidal deep brain stimulation for primary cervical dystonia. Neurology 2007;68:457–9. [8] Zhang JG, Zhang K, Wang ZC, Ge M, Ma Y. Deep brain stimulation in the treatment of secondary dystonia. Chin Med J 2006;119:2069–74. [9] Bereznai B, Steude U, Seelos K, Bötzel K. Chronic high-frequency globus pallidus internus stimulation in different types of dystonia: a clinical, video, and MRI report of six patients presenting with segmental, cervical, and generalized dystonia. Mov Disord 2002;17:138–44. [10] Capelle HH, Weigel R, Krauss JK. Bilateral pallidal stimulation for blepharospasm-oromandibular dystonia (Meige syndrome). Neurology 2003;60:2017–8. [11] Foote KD, Sanchez JC, Okun MS. Staged deep brain stimulation for refractory craniofacial dystonia with blepharospasm: case report and physiology. Neurosurgery 2005;56:415. [12] Muta D, Goto S, Nishikawa S, Hamasaki T, Ushio Y, Inoue N, et al. Bilateral pallidal stimulation for idiopathic segmental axial dystonia advanced from Meige syndrome refractory to bilateral thalamotomy. Mov Disord 2001;16:774–8. [13] Opherk C, Gruber C, Steude U, Dichgans M, Bötzel K. Successful bilateral pallidal stimulation for Meige syndrome and spasmodic torticollis. Neurology 2006;66:E14. [14] Vercueil L, Pollak P, Fraix V, Caputo E, Moro E, Benazzouz A, et al. Deep brain stimulation in the treatment of severe dystonia. J Neurol 2001;248:695–700. [15] Horstink MW, Van de Warrenburg BP, Speelman JD. In: Wolters ECh, Van Laar T, Berendse H.W., editors. Parkinsonism and related disorders. Amsterdam: VU University Press; 2007. p. 327–53. [16] Dressler D, Benecke R. Autonomic side effects of botulinum toxin type B treatment of cervical dystonia and hyperhidrosis. Eur Neurol 2003;49:34–8. [17] Coubes P, Cif L, El Fertit H, Hemm S, Vayssiere N, Serrat S, et al. Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results. J Neurosurg 2004;101:189–94. [18] Kupsch A, Benecke R, Müller J, Trottenberg T, Schneider GH, Poewe W, et al. Pallidal deep-brain stimulation in primary generalized or segmental dystonia. N Engl J Med 2006;355:1978–90. [19] Berardelli A, Rothwell JC, Day BL, Marsden CD. Pathophysiology of blepharospasm and oromandibular dystonia. Brain 1984;108:593–608. [20] Dresel C, Haslinger B, Castrop F, Wohlschlaeger AM, Ceballos-Baumann AO. Silent event-related fMRI reveals deficient motor and enhanced somatosensory activation in orofacial dystonia. Brain 2006;129:36–46.
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Case report
Meige’s syndrome: A cranial dystonia treated with bilateral pallidal deep brain stimulation Elli Markaki, Zinovia Kefalopoulou, Miltiadis Georgiopoulos, Anna Paschali, Constantine Constantoyannis ∗ Functional Neurosurgery Unit, Department of Neurosurgery, Medical School of Patras, Patras 26500, Greece
a r t i c l e
i n f o
Article history: Received 9 June 2009 Received in revised form 16 November 2009 Accepted 7 December 2009 Available online 12 January 2010 Keywords: Blepharospasm Deep brain stimulation Meige’s syndrome Oromandibular dystonia Globus pallidus internus
a b s t r a c t Background: Meige’s syndrome is a rare form of segmental dystonia characterized by blepharospasm and oromandibular dystonia. Medical treatment including botulinum toxin injections usually present disappointing results. The experience on Deep Brain Stimulation (DBS) in the treatment of Meige’s syndrome and other segmental dystonias is still limited. At the moment, only a few cases of pallidal DBS have been reported to improve this rare form of dystonia. Case description: We report on a case of a woman with a 7-year history of Meige’s syndrome, which rendered her functionally blind. The treatment with botulinum toxin injections failed to improve her symptoms, whereas stereotactic bilateral DBS of the pallidum led to a dramatic clinical improvement. Clinical assessment using the Burke–Fahn–Mardsen Dystonia Rating Scale (BFMDRS) in a double-blind manner, showed an improvement of 70% in the Movement score and 93.33% in the Disability score (84% reduction of the total score) on the 3 and 6 month follow-up. Conclusions: Stereotactic pallidal DBS might be considered as a potential treatment in the management of Meige’s syndrome. © 2009 Elsevier B.V. All rights reserved.
1. Introduction Meige’s syndrome is a form of adult-onset dystonia, characterized by the combination of oromandibular dystonia (OMD) and blepharospasm. Nonetheless, dystonia may also involve the upper limbs, the neck and the trunk [1,2]. Patients present with increased blinking and uncontrollable bilateral closure of the eyelids, which in some cases can lead to functional blindness [3]. Several palliative treatments are available for the treatment of Meige’s syndrome. Botulinum toxin injections with electromyographic guidance in selected muscles constitute the treatment of first choice, but effectiveness often decreases over time [3,4]. In addition, medical therapy (anticholinergics, tetrabenazine, and benzodiazepines) has usually poor results [3,5]. Globus pallidus internus (GPi) DBS is an established treatment for medically refractory primary forms of dystonia [6] and several groups have reported satisfactory results in cases of cervical [7] and secondary dystonia as well [8]. The reports on Meige’s syndrome and its responsiveness to pallidal DBS treatment are still very few [2,4,9–14] but their results encourage the use of DBS in this population of patients.
∗ Corresponding author. Tel.: +30 2610 999 495; fax: +30 2610 992 997. E-mail address: [email protected] (C. Constantoyannis). 0303-8467/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2009.12.005
We report here the case of a patient suffering from Meige’s syndrome, who underwent bilateral GPi DBS. 2. Case report A 49-year-old woman had been suffering from progressively evolving bilateral blepharospasm and oromandibular dystonia (Meige’s syndrome) for 7 years. The first symptom presented was increased involuntary blinking, which frequency and duration augmented over time, becoming more and more incapacitating. In addition, she suffered from photophobia, which forced her to wear sunglasses during daylight. After 4 years, the uncontrollable tonic spasms of the orbicularis oculi muscles led to prolonged forceful closure of the eyelids, which rendered the patient functionally blind for the last 3 years. She also presented slight dystonic contractions of the oromandibular muscles that caused a sideways deviation of the jaw, lip tightening and retraction of the corners of the mouth (Fig. 1). Speech was also mildly affected due to the presence of dysphonia. The functional blindness due to the blepharospasm, rendered her unable to attend to her job and compelled her to quit. Gradually she became socially isolated and lost interest in any activity. There was no family history of dystonic conditions and her past medical history revealed no other possible causes of Meige’s syndrome. Her neurological examination did not reveal any other
E. Markaki et al. / Clinical Neurology and Neurosurgery 112 (2010) 344–346
345
Table 1 The BFMDRS Movement and Disability Scale scores before and after DBS. Pre-operative
6 months follow-up
BFMDRS Movement scale score BFMDRS Disability scale score
10 15
3 1
Total score
25
4
Fig. 1. The patient pre-operatively, with spasms of the orbicularis oculi muscles and dystonic contractions of the oromandibular muscles.
abnormalities, except for blepharospasm and OMD, while her brain MRI, the electroencephalogram and the laboratory tests were normal. The Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS) Movement score was 10 and the Disability score was 15 (Total score: 25). The patient had been treated with several medications (dopaminergic/anticholinergics drugs, benzodiazepine, dopamine depletors, Baclofen) and with botulinum toxin injections, to which the blepharospasm did not respond and so she decided to undergo DBS. The patient underwent a stereotactic bilateral implantation of electrodes in the GPi. A Cosman-Roberts-Wells (CRW) head ring was applied under local anesthesia. A high resolution T1-weighted MRI was consequently performed (slice thickness 2 mm without gap), with a 1 Tesla MRI scanner (Philips, Gyroscan, Intera). With the use of the Frame-Link v. 4.0 software, the Stealthstation workstation (Medtronic, MN) and the Stealthenbraned and Wahren atlas the mid-sagittal plane, the anterior commissure (AC) and the posterior commissure (PC) were identified. The GPi was selected 4 mm below AC–PC, 19 mm laterally and 2 mm anteriorly to the mid-commissural point. Intraoperatively, microelectrode recordings (MER) of the neuronal activity of the target, and the patient’s responses to stimulation were recorded. Finally, two electrodes (model 3389, Medtronic, Inc., Minneapolis, MN) were implanted in the GPi bilaterally. There were no peri- or post-operative complications. The activation of the electrodes took place a few hours after surgery. The stimulation parameters were 2 V, 185 Hz, 210 s, with monopolar stimulation on contacts 0 and 4 and led to an immediate significant attenuation of blepharospasm and oromandibular dystonia. The coordinates of the final location of the active contacts were 2.5 mm anterior to mid-AC–PC, 20.2 mm lateral and 3.3 inferior to the AC–PC line for the right side and 2.3 mm anterior mid AC–PC, 21 mm lateral and 3.7 inferior to the AC–PC for the left side electrode. After 1 week, an almost complete resolution of the symptoms was observed, and during the subsequent programming sessions, minor adjustments were applied to the stimulation parameters (final stimulation parameters were 2.6 V, 185 Hz, 210 s). There were no side effects related to the stimulation. The clinical outcome was assessed at 3 and 6-month intervals after surgery in a double-blind manner. Neither the patient, nor the rating examiner was aware of which condition was applied, “on-” or “off-DBS”, during the evaluation. To blind the examiner to the stimulator’s condition, the stimulator was switched -on and -off by a different investigator. Some
Fig. 2. The patient post-operatively with an almost complete resolution of the symptoms.
patients are aware immediately when the stimulator is switched on and this could potentially unblind them. In order to minimize the risk of unblinding during the assessment, the patient was blinded by placing the programmer (N’vision programmer, Medronic) on the patient’s chest, turning the DBS -on briefly then randomly pressing the -on or -off button. The stimulator was turned -off for 2 h before the assessments for the double blind evaluation. At the 3-month follow-up visit, the BFMDRS Movement scale score was 3 and the Disability scale score was 1 (84% reduction of the total score) and remained unaltered at the 6-month follow-up assessment (Table 1) (Fig. 2). 3. Discussion Several palliative treatments are available for the treatment of Meige’s syndrome [3,15]. Botulinum toxin injections with electromyographic guidance in selected muscles constitute the treatment of first choice, but effectiveness often decreases over time [3,4]. Several side effects, including facial weakness, dysphagia, dry mouth, flu-like syndrome [16] are additional problems of local injections. Surgery (eyelid myectomy, blepharoplasty and lid lifts) has little if any role in therapy and drug treatment (dopaminergic/anticholinergics drugs, benzodiazepine, dopamine depletors, Baclofen), although sometimes helpful, is usually of no benefit [3,5]. Given the dramatic clinical improvement experienced after DBS in patients with primary generalized dystonia [17,18,6], trials of pallidal DBS have been performed for the treatment of segmental dystonia. Still, the experience on Meige’s syndrome is limited. Nonetheless, the few reports existing present encouraging results for the use of DBS in these patients [2,4,9–14]. We presented, in this report, a patient suffering from Meige’s syndrome, who was rendered functionally blind by the blepharospasm. This patient underwent DBS and experienced a spectacular improvement: her eyes opened almost immediately after the stimulator was turned on and a week later, there was a complete resolution of all the dystonic
346
E. Markaki et al. / Clinical Neurology and Neurosurgery 112 (2010) 344–346
symptoms. After 6 months, our patient presents the same clinical improvement without side effects and enjoys a better quality of life. The pathophysiology of Meige’s syndrome is not well understood and various hypothesis have been formulated [19]. A recent study using fMRI, revealed that there is a reduced activation of the primary motor and ventral premotor cortex in these patients during oromandibular motor execution, which is probably secondary to a reduced cortical inhibition in motor and premotor areas. Additionally, the same study revealed an increased activation of the somatosensory areas and of the caudal supplementary motor area, which indicates an altered somatosensory representation [20]. 4. Conclusion The experience on DBS in the treatment of Meige’s syndrome and other segmental dystonias is still limited. Nevertheless, the dramatic, prompt and sustained clinical improvement of our patient is in line with previous studies and suggests that GPi DBS can offer an excellent therapeutic effect in patients with Meige’s syndrome. References [1] Blomstedt P, Tisch S, Hariz MI. Pallidal deep brain stimulation in the treatment of Meige syndrome. Acta Neurol Scand 2008;118:198–202. [2] Houser M, Waltz T. Meige syndrome and pallidal deep brain stimulation. Mov Disord 2005;20:1203–5. [3] Horn S, Comella C. In: Jankovic J, Tolosa E, editors. Parkinson’s disease and movement disorders. Philadelphia: Lippincott Willson & Wilkins; 2002. p. 348–51. [4] Ostrem JL, Marks Jr WJ, Volz MM, Heath SL, Starr PA. Pallidal deep brain stimulation in patients with cranial-cervical dystonia (Meige syndrome). Mov Disord 2007;22:1885–91. [5] Greene P, Shale H, Fahn S. Analysis of open-label trials in torsion dystonia using high dosages of anticholinergics and other drugs. Mov Disord 1988;3(1):46–60.
[6] Vidailhet M, Vercueil L, Houeto JL, Krystkowiak P, Benabid AL, Cornu P, et al. Bilateral deep brain stimulation of the globus pallidus in primary generalized dystonia. N Engl J Med 2005;352:459–67. [7] Hung SW, Hamani C, Lozano AM, Poon YY, Piboolnurak P, Miyasaki JM, et al. Long-term outcome of bilateral pallidal deep brain stimulation for primary cervical dystonia. Neurology 2007;68:457–9. [8] Zhang JG, Zhang K, Wang ZC, Ge M, Ma Y. Deep brain stimulation in the treatment of secondary dystonia. Chin Med J 2006;119:2069–74. [9] Bereznai B, Steude U, Seelos K, Bötzel K. Chronic high-frequency globus pallidus internus stimulation in different types of dystonia: a clinical, video, and MRI report of six patients presenting with segmental, cervical, and generalized dystonia. Mov Disord 2002;17:138–44. [10] Capelle HH, Weigel R, Krauss JK. Bilateral pallidal stimulation for blepharospasm-oromandibular dystonia (Meige syndrome). Neurology 2003;60:2017–8. [11] Foote KD, Sanchez JC, Okun MS. Staged deep brain stimulation for refractory craniofacial dystonia with blepharospasm: case report and physiology. Neurosurgery 2005;56:415. [12] Muta D, Goto S, Nishikawa S, Hamasaki T, Ushio Y, Inoue N, et al. Bilateral pallidal stimulation for idiopathic segmental axial dystonia advanced from Meige syndrome refractory to bilateral thalamotomy. Mov Disord 2001;16:774–8. [13] Opherk C, Gruber C, Steude U, Dichgans M, Bötzel K. Successful bilateral pallidal stimulation for Meige syndrome and spasmodic torticollis. Neurology 2006;66:E14. [14] Vercueil L, Pollak P, Fraix V, Caputo E, Moro E, Benazzouz A, et al. Deep brain stimulation in the treatment of severe dystonia. J Neurol 2001;248:695–700. [15] Horstink MW, Van de Warrenburg BP, Speelman JD. In: Wolters ECh, Van Laar T, Berendse H.W., editors. Parkinsonism and related disorders. Amsterdam: VU University Press; 2007. p. 327–53. [16] Dressler D, Benecke R. Autonomic side effects of botulinum toxin type B treatment of cervical dystonia and hyperhidrosis. Eur Neurol 2003;49:34–8. [17] Coubes P, Cif L, El Fertit H, Hemm S, Vayssiere N, Serrat S, et al. Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results. J Neurosurg 2004;101:189–94. [18] Kupsch A, Benecke R, Müller J, Trottenberg T, Schneider GH, Poewe W, et al. Pallidal deep-brain stimulation in primary generalized or segmental dystonia. N Engl J Med 2006;355:1978–90. [19] Berardelli A, Rothwell JC, Day BL, Marsden CD. Pathophysiology of blepharospasm and oromandibular dystonia. Brain 1984;108:593–608. [20] Dresel C, Haslinger B, Castrop F, Wohlschlaeger AM, Ceballos-Baumann AO. Silent event-related fMRI reveals deficient motor and enhanced somatosensory activation in orofacial dystonia. Brain 2006;129:36–46.