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TENS for the Treatment of Propriospinal
Myoclonus
Video
A 50-year-old man presented with a 6-year history of abdomi-nal movements. His past medical history was unremarkableapart from diabetes mellitus and arthrosis. The movements werefirst characterized by repetitive abdominal jerks only presentduring sleep. Symptoms rapidly increased with permanentmarked truncal flexion and slight jerks of the leg muscles asso-ciated with abdominal contractions (Segment 1). They worsenedwhen lying down causing severe disability and insomnia. Thiswas not triggered by any stimuli and was decreased when walk-ing. Neurological examination was otherwise normal.
Surface electromyographic recordings confirmed thediagnosis of propriospinal myoclonus (PSM) revealing stereo-typed symmetrical jerks beginning in the rectus abdominismuscles controlled by the low-thoracic spinal level T9-T10before spreading up to the intercostals (T6) and down to theiliopsoas (L3) muscles. Conventional cerebral and spinalMRI, motor evoked potential, CSF examination, routineblood tests, thyroid hormone, serum folate, and vitamin B12level were all normal.
There was no effect of the following drugs: diazepam, car-bamazepine, primidone, lamotrigine, levetiracetam, gabapen-tin, ropinirole, piracetam, intrathecal baclofen, amitriptyline,and tizanidine.
By chance the patient noted that gentle self-rubbing of ab-dominal skin consistently suppressed the jerk (Segment 2).Then, transcutaneous electrical nerve stimulation (TENS) (80Hz, 150-lsecond pulse width) was proposed as a sympto-matic treatment. Electrodes were placed so that the electricalcurrent was delivered over the area controlled by the low-thoracic spinal level (see Video, Segment 3). The intensity ofthe stimulation was gradually increased during an acute test:the abdominal contraction and its propagation decreased at10 mA, disappeared at 12 mA and resumed immediately afterTENS discontinuation (Segment 3). The intensity of 12 mAwas considered as the efficacy threshold and TENS was thendelivered chronically.
Within the following 3 months, the patient graduallydecreased the intensity until 6 mA while at the same timemaintaining efficacy. Six months later, he could switch offthe device between a few hours to a maximum of 4 dayswithout myoclonus occurrence. After 8 months, TENS was
delivered daily with a 12-hour washout period during thenight and a constant effectiveness. At 11 months improve-ment continued.
Although tactile stimulations could suppress focal myo-clonus of peripheral origin,1 TENS was reported to be effi-cient in controlling belly dancer’s dyskinesia.2 Both authorspostulated that the tactile stimulus might act as inhibitoryafferents onto the abnormal inhibitory interneurons at thespinal level. The pathophysiology of PSM remains to beelucidated. However, it has been suggested that an underly-ing mechanism may be a partial release of a limited spinalmotor generator, the latter being capable of recruitingmuscles via long propriospinal pathways into rhythmic com-plex activity.3,4
In the present case, we noted not only an acute effect butalso a permanent efficacy following chronic TENS applica-tion. Thus, we postulated that TENS mediated by large diam-eter afferent fibers, traveling in the dorsal root nerves mightlead to recruitment of inhibitory interneurons active on thepropriospinal pre-motoneurons. This hypothesis seems inagreement with the short onset and the short lastingeffect that we observed during the acute test. Furthermore,this is consistent with the high-frequency TENS mechanisms,i.e. gating effects, which is believed to operate at spinalsegmental.5
Interestingly, the antimyoclonic effect threshold decreasedfrom 12 to 6 mA over several months with a maintained effi-cacy. In addition, the duration between the discontinuation ofTENS and the jerk recurrence reached 4 days after 6 monthsof chronic stimulation. This suggests that chronic TENSmay: (1) modulate neuronal inhibition by changing levels ofneurotransmitter within spinal chord and supraspinal path-way; (2) provoke plastic reorganization of cortical and chordcircuits. This latest hypothesis is corroborated by the fact thatprolonged TENS have been demonstrated to induce recipro-cal changes in corticospinal motor neurons excitability.6
These changes are likely to occur at the cortical level andmainly depend on muscles afferents activation.
Then, we may consider a psychological factor. Recently,Sugimoto et al. described a patient with a combination of PSMand psychosomatic disorders who improved by psychosomatictherapy.7 A placebo effect seems unlikely in our case sinceTENS provided a complete and sudden inhibition of jerks at aprecise intensity. Nevertheless, it is probable that the self-man-agement of TENS could emphasize the control of jerks myoclo-nus via voluntary cortical descending pathways.
Finally, one may wonder whether the jerks could be ofpsychogenic origin. The characteristic electrophysiologicalfindings have been reported in a group of healthy volunteersmimicking the typical PSM jerks.8 Moreover, a patient withprobable psychogenic PSM has been recently reported.9
However, the absence of sudden onset, contemporaneouslegal proceedings related to an injury and spontaneous remis-sion plaids against this hypothesis in our case.10
Additional Supporting Information may be found in the onlineversion of this article.
Published online 29 September 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10.1002/mds.22315
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Movement DisordersVol. 23, No. 15, 2008, pp. 2256–2266� 2008 Movement Disorder Society
LEGENDS TO THE VIDEO
Segment 1. Movements were characterized by markedtruncal flexion and slight jerks of the leg muscles associatedwith abdominal contractions, which suggested a propriospinalmyoclonus. They worsened when the patient was lying downand were not triggered by any stimuli.
Segment 2. Gentle self-rubbing of abdominal skin consis-tently suppressed the jerks. Another person could not repro-duce this effect.
Segment 3. The abdominal rhythmic contraction and it’sup and down propagation disappeared after abdominal trans-cutaneous electrical nerve stimulation (80 Hz, pulse width:150 lsec, 12 mA).
Acknowledgments: The authors are grateful to RichardMedeiros, Rouen University Hospital Medical Editor, forediting the manuscript.
David Maltete, MD*Department of NeurologyRouen University Hospital
Rouen, France*E-mail: [email protected]
Pierre Verdure, MDINSERM U614
Rouen Faculty of MedicineRouen, France
Emmanuel Roze, MD, PhDMarie Vidailhet, MD
Department of NeurologyPitie-Salpetriere Hospital
AP-HP, Paris, France
Emmanuelle Apartis, MD, PhDDepartment of Neurophysiology
Saint- Antoine HospitalAP-HP, Paris, France
Francis Bellow, MDLuc Verdure MD
Department of NeurosurgeryRouen University Hospital
Rouen, France
REFERENCES
1. Assal F, Magistris MR, Vingerhoets JG. Post-traumatic stimulussuppressible myoclonus of peripheral origin. J Neurol NeurosurgPsychiatry 1998;64:673–675.
2. Linazasoro G, Van Blercom N, Lasa A, Fernandez JM, Aranza-bal I. Etiological and therapeutical observations in a case ofbelly dancer’s dyskinesia. Mov Disord 2005;2:251–253.
3. Brown P, Thompson PD, Rothwell JC, Day BL, Marsden CD.Axial myoclonus of propriospinal origin. Brain 1991;114:197–214.
4. Roze E, Apartis E, Vidailhet M, et al. Propriospinal myoclonus:utility of magnetic resonnance diffusion tensor imaging and fibertracking. Mov Disord 2007;22:1506–1509.
5. Johnson MI, Ashton CH, Thompson JW. An in-depth study oflong-term users of transcutaneous electrical nerve stimulation(TENS). Implication for clinical use of TENS. Pain 1991;44: 221–229.
6. Tinazzi M, Zarattini S, Valeriani M, et al. Effects of transcutane-ous electrical nerve stimulation on motor cortex excitability inwriter’s cramp: neurophysiological and clinical correlations. MovDisord 2006;11:1908–1913.
7. Sugimoto K, Theoharides TC, Kempuraj D, Conti P. Responseof spinal myoclonus to a combination therapy of autogenic train-ing and biofeedback. Biopsychosoc Med 2007;1:18.
8. Kang SY, Sohn YH. Electromyography patterns of propriospinalmyoclonus can be mimicked voluntarily. Mov Disord 2006;21:1241–1244.
9. Williams DR, Cowey M, Tuck K, Day B. Psychogenic proprio-spinal myoclonus. Mov Disord 2008;23:1312–1313.
10. Fahn S, William DT. Psychogenic dystonia. Adv Neurol 1988;50:431–455.
Pseudochoreoathetosis Can Be the First
Clinical Manifestation of Anti-Hu-Neuropathy
Associated with Squamous Cell Carcinoma
Video
Paraneoplastic movement disorders are rare. We report thepeculiar constellation of pseudochoreoathetosis associatedwith squamous cell carcinoma.
A 68-year-old right-handed woman with a long standinghistory of tobacco and alcohol use sensed the sudden onsetof a peculiar feeling of her right arm. It felt heavier and herhand would not ‘‘obey’’ properly but would slowly jerk andtwist on action; her gait became slightly unsteady. Symptomsworsened over the next 6 months making fine motor tasksdifficult. A sensation of strain spread from her right arm tothe left shoulder and her left lower face, and hearing lossoccurred gradually. She lost 10 kg.
On initial examination, there was dystonic posturing of herright wrist with adduction of the thumb and extension of her fin-gers and bilateral pedes equini. Distraction, action, and eye clo-sure revealed choreatic movements. Apart from mild myoclonicjerks her finger-nose test was normal. Gait was small based andshowed dystonic inversion of both ankles and mild choreoathe-tosis of the right arm. There was mildly reduced tactile, posi-tion, and vibratory sensation and left-sided amblyacousia. Pos-tural reflexes, eye movements, power, tone, and plantarresponses were normal. Deep tendon reflexes were mildlydecreased.
Electrophysiology showed a sensory-motor axonal polyneu-ropathy with marked sensory preponderance (see Table 1);inflammatory causes or amyloidosis were ruled out by suralnerve biopsy. Cranial imaging, repeated whole body PET- and
Additional Supporting Information may be found in the onlineversion of this article.
Published online 24 September 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10.1002/mds.22302
2257LETTERS TO THE EDITOR
Movement Disorders, Vol. 23, No. 15, 2008
CT-scans, and bronchoscopy failed to reveal any malignancy.All laboratory tests were normal apart from positive oligoclo-nal bands in CSF and positive anti-Hu (ANNA-1)—stronglypositive—, anti-amphiphysin and anti-Ri (ANNA-2)—bothweakly positive—in serum assays. The diagnosis of pseudo-choreoathetosis with anti-Hu-neuropathy was made. Symp-tomatic therapeutic approaches with levodopa, tiapride,tolperison, trihexyphenidyl, and immunoglobulins wereinefficacious.
The patient’s condition worsened over the next 3 months(see video). Tactile, vibratory, and nociceptive sensationdecreased and spread onto the face. Moreover, distal paresisof her upper limbs occurred. Neither symptoms attributableto limbic encephalitis nor bladder nor bowel dysfunctionemerged. A new bronchoscopy revealed a moderately differ-entiated squamous cell carcinoma of the epiglottis. Stagingdid neither show any metastasis nor any further tumor. Thetumor was resected by an ENT-surgeon. Afterwards unfortu-nately the patient was lost to follow-up.
Our patient presented with a complex movement disorderfulfilling the criteria for choreoathetosis.1 For choreoathetoidmovements associated with loss of proprioception, the term‘‘pseudoathetosis’’ was proposed.2 Clinically they may be dif-ferentiated from ‘‘true athetosis’’ by an augmentation on eyelid closure.1
Paraneoplastic pseudochoreoathetosis has rarely beendescribed before. Albin et al.3 report a case that matches oursexactly with regard to time course, evolution of symptoms,clinical presentation, and laboratory findings. The tumor wasa small cell lung carcinoma (SCLC), though. At autopsythere were no histopathological changes within the basal gan-glia but only in the dorsal root ganglia and the dorsal columnof the spinal cord.
It remains unclear why our patient developed predomi-nantly pseudochoreoathetosis, although in all other respectsshe exhibited the typical findings of anti-Hu-neuropathy.Usually patients present with sensory and/or cerebellarataxia,4 for anti-Hu-antibodies are associated with Purkinjecell loss. Maybe in most cases pseudochoreoathetosis ismasked by an incapacitating cerebellar syndrome.
Over 85% of patients with high titer anti-Hu-antibodiesand sensory neuropathy harbor a lung tumor, usuallySCLC.4 The rest suffer from extrathoracic tumors includ-ing prostate, gastrointestinal, breast, bladder, pancreas, andovary cancer. To our knowledge, a moderately differenti-ated squamous cell carcinoma has not been describedbefore.
In contrast to paraneoplastic pseudochoreoathetosis, para-neoplastic chorea is well recognized in literature5 and prob-ably caused by immune-mediated striatal encephalitis. Itusually exhibits a more widespread neural involvement thanpseudochoreoathetosis: the majority shows CNS involve-ment (most frequently retinopathy, cerebellar degeneration,limbic and/or brainstem encephalitis) as well as neuropathy.The underlying tumor most frequently expresses CRMP-5-(anti-CV2) antibodies5,6; anti-Yo (anti-PCA-1)7 and anti-Hu8–10 antibodies are only rarely associated with choreaticmovements.
In summary, paraneoplastic choreatic movement disordersmay present either as ‘‘true choreoathetosis’’ due to striatalencephalitis being almost invariably associated with otherneurological manifestations or as ‘‘pseudochoreoathetosis’’with exclusive involvement of the dorsal root ganglia (andmaybe the dorsal column). The tumor associated with ‘‘pseu-dochoreoathetosis’’ usually is SCLC, but other tumors mustbe ruled out, too.
LEGENDS TO THE VIDEO
The 68-year-old patient 2 months after the diagnosis ofanti-Hu-neuropathy.
Segment 1. Sitting at rest reveals dystonic inversion ofthe right foot and mild involuntary writhing of both upperextremities (chiefly distally, more pronounced on the rightside). The involuntary movements increase when stretchingout both arms.Segment 2. When stretching out arms dystonic posturing
can be observed with a flexion of the wrist and hyperexten-sion of the fingers. Involuntary choreoathetotic movementsincrease visibly when the patient closes her eyes. Note thedysmetria during finger-nose test without any intentiontremor hinting to impaired kinaesthesia. Note also mild facialchoreic movements.Segment 3. Tapping with the less impaired left hand ren-
ders the left arm dystonic. Tapping on the right is ataxic.Action enhances choreoathetosis and dystonia not only in theextremities involved, but also the feet. Note that the involun-tary movement are distally more pronounced reflecting thedistribution of proprioceptive malfunction.Segment 4. Walking is small based and unsteady with
dystonic cramping of the toes. Chorea and dystonic posturingin upper extremities does not increase while walking.
TABLE 1. Neurographic findings
Motor nerve CMAP (mV) MCV (m/s) Sensory nerve CMAP (mV) SCV (m/s)
Right median 4.2 53 Right median n/a n/aLeft median 5.0 56 Left median n/a n/aRight ulnar 5.4 64 Right ulnar n/a n/aLeft ulnar 9.4 58 Left ulnar n/a n/aRight peroneal 4.2 53Left peroneal 5.4 64Right tibial 1.8 35 Right sural n/a n/aLeft tibial 1.6 39 Left sural n/a n/a
CMAP, compound muscle action potential; MCV, motor conduction velocity; SCV, sensory conduction velocity; n/a, not available.
Movement Disorders, Vol. 23, No. 15, 2008
2258 LETTERS TO THE EDITOR
Christoph Schrader, MD*Guldan Alwan, MD
Karin Weissenborn, MDDepartment of Neurology and Clinical Neurophysiology
Medical School of HannoverHannover, Germany
*E-mail: [email protected]
REFERENCES
1. DeJong R. Abnormal movements. In: Haerer AF, editor. The neuro-logic examination. Philadelphia: Lippincott; 1990. p 402–419.
2. Euphemius H. Uber die sogenannten pseudoathetotischen Spontan-bewegungen. Zeitschr Neurol Psychol 1919;40:194–212.
3. Albin RL, Bromberg MB, Penney JB, Knapp R. Chorea and dysto-nia: a remote effect of carcinoma. Mov Disord 1988;3:162–169.
4. Graus F, Keime-Guibert F, Rene R, et al. Anti-Hu-associatedparaneoplastic encephalomyelitis: analysis of 200 patients. Brain2001;124 (Part 6):1138–1148.
5. Vernino S, Tuite P, Adler CH, et al. Paraneoplastic chorea asso-ciated with CRMP-5 neuronal antibody and lung carcinoma. AnnNeurol 2002;51:625–630.
6. Kinirons P, Fulton A, Keoghan M, Brennan P, Farrell MA,Moroney JT. Paraneoplastic limbic encephalitis (PLE) and cho-rea associated with CRMP-5 neuronal antibody. Neurology2003;61:1623–1624.
7. Krolak-Salmon P, Androdias G, Meyronet D, Aguera M, Hon-norat J, Vighetto A. Slow evolution of cerebellar degenerationand chorea in a man with anti-Yo antibodies. Eur J Neurol2006;13:307–308.
8. Tremont-Lukats IW, Fuller GN, Ribalta T, Giglio P, GrovesMD. Paraneoplastic chorea: case study with autopsy confirma-tion. Neuro Oncol 2002;4:192–195.
9. Heckmann JG, Lang CJ, Druschky A, Claus D, Bartels O, Neu-ndorfer B. Chorea resulting from paraneoplastic encephalitis.Mov Disord 1997;12:464–466.
10. Dorban S, Gille M, Kessler R, Pieret F, Declercq I, Sindic CJ.[Chorea-athetosis in the anti-Hu syndrome]. Rev Neurol (Paris)2004;160:126–129 (in French).
Transcranial Direct Current Stimulation in
Two Patients with Tourette Syndrome
Tourette syndrome (TS) is a chronic neuropsychiatric disor-der, characterized by the presence of multiple motor andphonic tics, with onset in early childhood.1 Because weakelectrical currents applied to the brain induce persistent excit-ability changes in humans,2,3 and because neurophysiologicalstudies document abnormal motor cortex excitability inpatients with TS,4–6 we investigated whether transcranialdirect current stimulation (tDCS) might reduce the frequencyof these patients’ tics. Here we report the results of the appli-cation of tDCS for five consecutive days in two patients withTS.
The first patient was a 26-year-old man in whom TS firstmanifested as a compulsive disorder at the age of 13 andprogressively involved eyes, right arm, hands, and face andwere associated with vocalization. Despite the drug treat-ment (pimozide: 16 mg/day, fluvoxamine: 200 mg/day), the
patient experienced frequent phonic tics while speaking.The second patient was a 31-year-old man who had neverreceived medication for TS. Complex phonic tics and sim-ple/complex motor tics suddenly appeared at the age of 11. Inboth patients, tics onset and predominant expression were onthe right side of the body. Before tDCS treatment, we adminis-tered the Minnesota Multiphasic Personality Inventory-2 (S.R.Hathaway and J.C. McKinley) to assess the presence of psy-chiatric disorders, the Yale-Brown Obsessive CompulsiveScale to test the presence of obsessions and compulsions, anda Yale Global Tic Severity Scale (YGTSS) with a 1-weekinterval to evaluate tics. Table 1 summarizes the patients’ clin-ical features. Both patients were studied after their informedconsent. The study was approved by the local Ethic Commit-tee, and it was in agreement with the principles stated in theDeclaration of Helsinki.
tDCS was delivered in two 5-day sessions, one for shamand one for cathodal tDCS (Fig. 1a). Two washout weekselapsed between sessions. Each day of the session, tDCSwas applied monolaterally (2 mA for 15 minutes, currentdensity 0.0714 mA/cm2; total charge 0.043 C/cm2, EldithDC Stimulator, Germany) through a pair of thick (0.3 mm)rounded saline-soaked sponge electrodes, one placed overthe left motor areas of the cerebral cortex (area 21 cm2,controlateral to the most affected side) and the other overthe right deltoid muscle (area 64 cm2).7,8 To guaranteepatients’ blindness to the type of tDCS delivered, becausetDCS induce an initial itching sensation that disappears afterabout 10 seconds, for sham tDCS, electrodes were placed asfor real stimulation but the stimulator was turned off after 10seconds. Each day, before and after tDCS, the patients wereassessed through a 10-minute videotape according to the proto-col proposed by Goetz et al.9 for tic count and through a Vis-ual Analog Scale (VAS) for general wellness (happy/unhappy;health/unease; quiet/lather) to test the subjective perception oftDCS effects. In addition, to evaluate the global effect of thetDCS session, on the first and on the last day of each 5-daysession, the global YGTSS was assessed. Then, the patientsrepeated the VAS for the 2 weeks following the treatment.The intensity and frequency of motor and phonic tics wererated by a blind examiner and used for the analysis. To evalu-ate the effect of tDCS, data obtained the last day of treatment(day 5) were referred to baseline (first day, before tDCS) aspercentage changes.
TABLE 1. Patients’ baseline screening
Clinicalexamination
Baseline evaluation
Patient no. 1 Patient no. 2
MMPI-2 Ma 72(cutoff 65)
Ma 65(cutoff 65)
Si 65(cutoff 65)
Y-BOCS Moderate 20/40 Absent 4/40YGTSS Moderate 59/100 Moderate 66/100
MMPI-2, Minnesota Multiphasic Personality Inventory Scales(S.R. Hathaway and J.C. McKinley); Ma, hypomania disorder; Si,introversion sociality; Y-BOCS, Yale-Brown Obsessive CompulsiveScale; YGTSS, Yale Global Tic Severity Scale.
Published online 11 September 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10.1002/mds.22292
2259LETTERS TO THE EDITOR
Movement Disorders, Vol. 23, No. 15, 2008
Although sham tDCS was not effective, cathodal tDCSsignificantly decreased the number of motor and phonic ticsin both patients at the end of the 5-day treatment. The ticreduction achieved after 5 days was greater than the average
reduction during the first 4 days of treatment (Fig. 1b,c).The YGTSS decreased in both patients at the end of thecathodal tDCS 5-day session (patient 1: 220.3%; patient 2:210.6%) but not after sham (patient 1: 25.08%; patient 2:
FIG. 1. (a) tDCS protocol: tDCS was applied over the scalp on the motor–premotor cortex for 5 consecutive days. The first and the last daybaseline and final evaluation were performed. Each day a videotape and a VAS evaluation were done. (b) Percentage changes of the number ofmotor and phonic tics during the 5-day session of cathodal tDCS (the black solid line is the average of the first 4 days to compare to the reductionobtained after 5 days of treatment). (c) Percentage changes of the number of phonic and motor tics after sham and cathodal tDCS. (d) VASassessment for quiet/lather from baseline to 2 weeks after the end of the cathodal tDCS session.
Movement Disorders, Vol. 23, No. 15, 2008
2260 LETTERS TO THE EDITOR
0%). Both patients reported an improvement of their sensa-tion of general wellness after 5 days of cathodal tDCS(patient 1: 1132%; patient 2: 1450%). Figure 1d showsthat, after 2 weeks, the subjective perception of improvedquietness that followed cathodal tDCS returns to baseline inboth patients.
Cathodal tDCS over the motor areas of the cerebral cortexdecreased tics in two patients with TS. Neither patientexperienced adverse reactions or complained of discomfortrelated to tDCS. Because cathodal tDCS decreases corticalexcitability, it could contribute to an adaptive mechanism ofwidespread reduced motor cortical excitability that is thoughtto control unwanted movement release.4,5 In addition, it ispossible that, as well as in extradural motor cortical stimula-tion, the bilateral effects of unilateral modulation are due tobilateral afferent and efferent connections between corticaland subcortical structures.10
This is a preliminary observation that cathodal tDCS couldcontribute to the treatment of TS. Because tDCS is simple,safe, and cheap, this technique could be more extensivelytested as a noninvasive therapeutic approach complementaryto pharmacotherapy in patients with TS.
Acknowledgments: The study was supported by a grantfrom the Tourette Syndrome Association, by FondazioneIRCCS Ospedale Maggiore Policlinico, Mangiagalli, ReginaElena (Milan, Italy), Universita degli Studi di Milano (Italy),Ministero della Sanita (Italy), Ministero dell’Universita edella Ricerca Scientifica e Tecnologica (Italy). S. Marcegliais a Ph.D. student at the Dipartimento di Bioingegneria, Poli-tecnico di Milano, Milan (Italy).
Simona Mrakic-Sposta, MSSara Marceglia, PhD
Francesca Mameli, BSRobertino Dilena, MD
Laura TadiniAlberto Priori, MD, PhD*
Clinical Center for Neuronanotechnologyand Neurostimulation
Fondazione IRCCS Ospedale Maggiore Policlinico,Mangiagalli e Regina Elena
Department of Neurological SciencesUniversity of Milan, Italy
*E-mail: [email protected]
REFERENCES
1. Cohen DJ, Leckman JF. Developmental psychopathology and neu-robiology of Tourette’s syndrome. J Am Acad Child Adolesc Psy-chiatry 1994;33:2–15.
2. Nitsche MA, Paulus W. Excitability changes induced in thehuman motor cortex by weak transcranial direct current stimula-tion. J Physiol 2000;527(Pt 3):633–639.
3. Priori A. Brain polarization in humans: a reappraisal of an oldtool for prolonged non-invasive modulation of brain excitability.Clin Neurophysiol 2003;114:589–595.
4. Orth M, Munchau A, Rothwell JC. Corticospinal system excitabil-ity at rest is associated with tic severity in tourette syndrome.Biol Psychiatry 2008;64:248–251.
5. Ziemann U, Paulus W, Rothenberger A. Decreased motor inhibi-tion in Tourette’s disorder: evidence from transcranial magneticstimulation. Am J Psychiatry 1997;154:1277–1284.
6. Bohlhalter S, Goldfine A, Matteson S, et al. Neural correlates oftic generation in Tourette syndrome: an event-related functionalMRI study. Brain 2006;129(Pt 8):2029–2037.
7. Nitsche MA, Liebetanz D, Lang N, Antal A, Tergau F, Paulus W.Safety criteria for transcranial direct current stimulation (tDCS) inhumans. Clin Neurophysiol 2003;114:2220–2222; author reply2222–2223.
8. Ferrucci R, Marceglia S, Vergari M, et al. Cerebellar transcranialdirect current stimulation impairs the practice-dependent proficiencyincrease in working memory. J Cogn Neurosci 2008;20:1687–1697.
9. Goetz CG, Pappert EJ, Louis ED, Raman R, Leurgans S. Advan-tages of a modified scoring method for the Rush Video-Based TicRating Scale. Mov Disord 1999;14:502–506.
10. Priori A, Lefaucheur JP. Chronic epidural motor cortical stimula-tion for movement disorders. Lancet Neurol 2007;6:279–286.
Early Stimulation of DYT1 Primary
Generalized Dystonia Prevents from Its
Secondary Irreversible Complications
Video
The efficacy of globus pallidus pars interna chronic stimu-lation (GPCS) in reducing severe dystonia in primary gener-alized dystonia (PGD) is known,1–8 though with heterogene-ous results and no predictive factors of effectiveness. Wereport two unrelated patients suffering DYT1-linked PGD9
who, having similar ages at onset and comparable dystoniaseverity scores, expressed a quite different outcome followingGPCS.
At age 10 Patient 1 expressed dystonia in the left foot,and within 3 years this had developed in the upper limbs,trunk, and neck. Severe and irreducible inversion of the leftfoot, inducing difficulties for independent locomotion, hadoccurred along with laterocollis, retrocollis with phasicmovements associated with trunk dystonia and major thor-aco-lumbar cyphoscoliosis (Video 1, segment 1). The dysto-nia worsened progressively leading to cervical myelopathy,right coxarthrosis (see Fig. 1) and fixed, left foot deformity(Video 1, segment 1). Treatment associating trihexyphenidylwith diazepam had little effect, and the patient was subse-quently operated on for bilateral GPCS, aged 48. Leads wereimplanted in both globus pallidus par interna (GPi) undergeneral anesthesia.6 The posterolateral ventral section of GPiwas identified by magnetic resonance imaging, ventriculogra-phy, and intraoperative electrophysiological recording. Priorto surgery, the validated Burke–Fahn–Marsden Dystoniascale (BFMDS)10 movement score was 82.5 while the dis-ability score was 12. One year following surgery, thesescores had decreased to 37 (255%) for movement and 9(225%) for disability. Repetitive limb and neck movementsimproved within a few weeks though foot dystonia withvarus deformity and scoliosis remained (Video 1, segment 2).Electrical stimulation settings (ESS) 12 months followingsurgery were as follows: right GPi: implanted pulse generator(IPG)1, contact 1-, 3.5 V/60 microseconds/130 Hz; left GPi:
Additional Supporting Information may be found in the onlineversion of this article.
Published online 12 September 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10.1002/mds.22152
2261LETTERS TO THE EDITOR
Movement Disorders, Vol. 23, No. 15, 2008
contact 4-, 3.5 V/90 microseconds/130 Hz. Within 1 year,fixed left foot varus and right coxarthrosis again worseneduntil the patient was unable to walk. These results are nowconsidered stable 3 years later.
Patient 2 initially suffered left foot dystonia when 8 yearsold. The dystonia became generalized over just a few monthsand led to an inability to walk and complete dependence forthe activities of daily life. He was equally unable to remainseated because of marked opisthotonos and ballistic move-ments of the lower limbs (Video 2, segment 1). The left footwas inverted (Video 2, segment 1), even during general anes-thesia. Trihexyphenidyl with diazepam at the maximum dosetolerable proved inefficient and he therefore underwentGPCS, aged 15 with the same procedure. Prior to surgery,the BFMDS movement score was 74.5 with a disability scoreof 15. The left foot inversion remained irreducible even dur-ing general anesthesia, though it improved progressively dur-
ing the 12 months following surgery and subsequently (Video2, segments 2, 3 and 5). Phasic repetitive involuntary move-ments decreased within 7 days (Video 2, segment 2). Overthe 12 months postsurgery, the movement score decreased to10 (287%), disability score to 2 (287%), and the patientwas able to walk, swim and ride a bicycle (Video 2, seg-ments 3–6). Left foot dystonia decreased strongly (Video 2,segment 5). ESS were as follows: right GPi: IPG1, contact0- and contact 1-, 3.2 V/60 microseconds/130 Hz; left GPi:contact 4-, contact 5-, 2.5 V/60 microseconds/130 Hz. Fiveyears on, these results are considered permanent.
Although phasic, repetitive movements improved in bothpatients, their disability outcome was clearly dissimilar. Themain difference between the patients was disease durationprior to surgery, 38 and 7 years for Patients 1 and 2, respec-tively. In DYT1-PGD, global improvement after GPCS was90% in a series of dystonic children,4 and 50% when the se-ries included only adults.6 There is an appreciable intervalbetween the large improvement in movement score and thepoor improvement in disability score of Patient 1. He wassuffering severe complications of dystonia such as coxartho-sis, cyphoscoliosis, cervical myelopathy, or fixed inverted leftfoot that were irreversible despite GPCS and that worsenedagain following surgery. Cervical dystonia may lead progres-sively to irreversible cervical myelopathy with tetraparesis.11
Owing to major coxarthrosis, Patient 1 remained unable towalk 1 year following GPCS. Thus, GPCS improves move-ment and disability scores because of dystonia but is ineffi-cient at reducing secondary complications such as cervicalmyelopathy and osteoarticular lesions. Patient 2 was operatedon when he was 15 years old, 7 years after disease onset,before such complications occurred and before the left footvarus became irreversible.
Despite the two patients having the same disease (DYT1 1mutation), the clinical features are different. In addition, they donot have exactly the same electrode position and electricalparameters; therefore, the clinical interpretation of the report islimited.
Patients with severe PGD, responsible for functional dis-ability despite medical treatment, should be proposed forGPCS before the occurrence of irreversible neurological ororthopedic complications. Short disease duration and the lackof irreversible complications at surgery could be consideredas predictive factors of good postoperative results. This con-sideration should be confirmed by further controlled studiesincluding more patients. Moreover, the pattern of dystoniaand the underlying pathophysiology may contribute to thevariability in the therapeutic outcome.3,12
LEGENDS TO THE VIDEO 1
Segment 1. Preoperative: Severe generalized dystonia.Segment 2. Postoperative (1 year following surgery):
Repetitive movements improved but left foot varus dystoniaseverity was only mildly decreased. The patient is able towrite with right hand while sitting, but cannot walk aloneanymore because of worsening right side coxarthrosis.
LEGENDS TO VIDEO 2
Segment 1. Preoperative: Severe generalized dystonia.
FIG. 1. Cervico-thoraco-lumbar radiography of Patient 1, 1 year fol-lowing surgery. Severe thoraco-lumbar cyphoscoliosis and markedright coxarthrosis.
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Movement Disorders, Vol. 23, No. 15, 2008
Segment 2. Postoperative (7 days following surgery):Hyperkinetic involuntary movements decreased while sitting.Left foot deformity already mildly decreased.
Segment 3. Postoperative (2 months following surgery):Marked reduction of involuntary movements. The patient wasable to walk slowly and with little help. Left foot varusdecreased again.
Segment 4. Postoperative (6 months following surgery):The patient is able to swim.
Segment 5. Postoperative (6 months following surgery):Movements and disability improved again. He is able to walkalone having only a moderate left foot dystonic posture,though he is obliged to limp.
Segment 6. Postoperative (12 months following surgery):Marked disability improvement and functional benefit. Thepatient is able to ride a bicycle.
Mathieu Anheim, MD*Department of Neurology
University Hospital A. MichallonGrenoble, France
Department of NeurologyUniversity Hospital, Strasbourg, France
*E-mail: [email protected]
Laurent Vercueil, MDValerie Fraix, PhD
Department of NeurologyUniversity Hospital A. Michallon
Grenoble, FranceDepartment of Clinical and Biologic Neurosciences
Joseph Fourier University and INSERM U318Grenoble, France
Stephan Chabardes, MDEric Seigneuret, MD
Department of NeurosurgeryUniversity Hospital A. Michallon
Grenoble, FranceDepartment of Clinical and Biologic Neurosciences
Joseph Fourier University and INSERM U318Grenoble, France
Paul Krack, MDDepartment of Neurology
University Hospital A. MichallonGrenoble, France
Department of Clinical and Biologic NeurosciencesJoseph Fourier University and INSERM U318
Grenoble, France
Alim-Louis Benabid, MD, PhDDepartment of Neurosurgery
University Hospital A. MichallonGrenoble, France
Department of Clinical and Biologic NeurosciencesJoseph Fourier University and INSERM U318
Grenoble, France
Marie Vidailhet, MDDepartment of Neurology
University Hospital La Pitie SalpetriereParis, France
Pierre Pollak, MDDepartment of Neurology
University Hospital A. MichallonGrenoble, France
Department of Clinical and Biologic NeurosciencesJoseph Fourier University and INSERM U318
Grenoble, France
REFERENCES
1. Tronnier VM, Fogel W. Pallidal stimulation for generalizeddystonia. Report of three cases. J Neurosurg 2000;92:453–456.
2. Vercueil L, Pollak P, Fraix V, et al. Deep brain stimulationin the treatment of severe dystonia. J Neurol 2001;248:695–700.
3. Volkmann J, Benecke R. Deep brain stimulation for dystonia:patient selection and evaluation. Mov Disord 2002;17 (Suppl3):S112–S115.
4. Coubes P, Roubertie A, Vayssiere N, Hemm S, Echenne B.Treatment of DYT1-generalised dystonia by stimulation of theinternal globus pallidus. Lancet 2000;355:2220–2221.
5. Coubes P, Cif L, El Fertit H, et al. Electrical stimulation of theglobus pallidus internus in patients with primary generalized dys-tonia: long-term results. J Neursurg 2004;101:189–194.
6. Vidailhet M, Vercueil L, Houeto JL, et al. Bilateral deep-brainstimulation of the globus pallidus in primary generalized dysto-nia. N Engl J Med 2005;352:459–467.
7. Kupsch A, Benecke R, Muller J, et al. Pallidal deep-brain stimu-lation in primary generalized or segmental dystonia. New Engl JMed 2006;355:1978–1990.
8. Vidailhet M, Vercueil L, Houeto JL, et al. Bilateral, pallidal,deep-brain stimulation in primary generalised dystonia: a pro-spective 3-year follow-up study. Lancet Neurol 2007;6:223–229.
9. Bressman SB, Sabatti C, Raymond D, et al. The DYT1 pheno-type and guidelines for diagnostic testing. Neurology 2000;54: 1746–1752.
10. Burke RE, Fahn S, Marsden CD, Bressman SB, Moskowitz C,Friedman J. Validity and reliability of a rating scale for the pri-mary torsion dystonias. Neurology 1985;35:73–77.
11. Konrad C, Vollmer-Haase J, Anneken K, Knecht S. Orthopedicand neurological complications of cervical dystonia—Review ofthe literature. Acta Neurol Scand 2004;109:369–373.
12. Vercueil L, Krack P, Pollak P. Results of deep brain stimulationfor dystonia: a critical reappraisal. Mov Disord 2002;17 (Suppl3):S89–S93.
Cortical Myoclonus Masquerading as
Spinal Myoclonus
Video
Myoclonus is defined as a sudden and brief, shock-like invol-untary movement caused by either muscle contraction or in-hibition generated in any region of the nervous system.1
Myoclonus may be classified as focal, segmental, multifocal,
Additional Supporting Information may be found in theonline version of this article.
Published online 21 October 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10/1002/mds.22165
Movement Disorders, Vol. 23, No. 15, 2008
2263LETTERS TO THE EDITOR
or generalized according to its distribution; cortical, reticu-lar, spinal, or peripheral according to its origin; and physi-ological, essential, epileptic or symptomatic according tothe etiology.2 This case report illustrates the diagnostic dif-ficulty of cortical myoclonus in a patient with abdominaland truncal muscle jerks triggered by physical activity andat sleep onset.
A previously healthy 21-year-old man presented withparoxysmal myoclonic jerks involving the pelvic girdle,typically after exercise or preceding sleep. Jerks appearedon a daily basis, mostly in ventral decubitus, lasting fromminutes to more than 1 hour and disappearing gradually.The neurological examination was normal. Relaxation inventral decubitus immediately after repeated voluntaryabdominal flexions induced myoclonic jerks involving theabdominal, paravertebral, and gluteal muscles on the leftside, twisting the trunk ipsilaterally. Three siblings suf-fered from epilepsy. An electromyography study (EMG)suggested rhythmic myoclonic jerks. An electroencephalo-gram (EEG) performed during myoclonic activity showedperiodic bursts of 5–7 Hz sharp waves on the left sidemainly to the temporal lobe. A brain computerized tomog-raphy (CT) and a spinal magnetic resonance imaging(MRI) were normal. A brain single photon emission com-puted tomography (SPECT) performed outside attacksdepicted hypoperfusion in the left temporal region. Carba-mazepine was ineffective and phenitoin produced only amild effect. Two milligrams clonazepam completely abol-ished the jerks. The patient was reevaluated 14 years later.Because of irregular clonazepam intake, paroxysmsreturned following a 72-hour medication-free period, andwere unremitting for 22 hours, suggesting epilepsia partia-lis continua. Giant somatosensory potentials (SEPs) evokedby stimulation of the median nerve were recorded. Cere-bral MRI scan was normal. Jerks were abolished followingthe coadministration of 1,500 mg/day valproate and 6 mg/day clonazepam. After a few weeks, he remained asymp-tomatic with only 2 mg/day clonazepam.
The diagnosis of myoclonic disorders may be challeng-ing. Topographycally, this patient seemed to suffer from asegmental myoclonus. Pathophysiologically, restriction toaxial muscles suggested a spinal origin.3 The EMG find-ings and the normal spinal cord MRI together with theclinical features led to the diagnosis of propriospinalmyoclonus. This hypothesis was reinforced by the fact thatjerks were always triggered during relaxation beforesleep.4 The clonazepam effect also supported this diagno-sis. On the other hand, although the EEG and SPECT wereabnormal, cortical myoclonus was not considered at thetime because jerks were not focal, limb muscles werenot involved, and the EEG and SPECT findings were ipsi-lateral to the jerks.
Fourteen years later, two facts led to a change of diagno-sis. First, after medication withdrawal for 72 hours, thepatient presented continuous jerks of the axial muscles com-patible with epilepsia partialis continua, which was verysimilar to the patient reported by Rosenbaum and Hoehn.5
Second, a giant SEP was recorded. These findings were con-sistent with cortical myoclonus. Interestingly, the study of
Moraes et al.6 in 2007 showed a significant increase in betawaves at frontal and central areas after an 8-minute rest fol-lowing exercise, which might be related to increased corticalactivation. This could explain why jerks always appearedduring relaxation in our patient.
As Fish and Marsden7 pointed out in 1994, epilepsy canmimic a movement disorder, thereby leading to diagnosticuncertainties. In our patient, an axial myoclonus of corticalorigin mimicked propriospinal myoclonus with a positiveclonazepam effect.
The present case illustrates the importance of the electro-physiologic studies in all myoclonus patients, including EEG,EMG, SEP, and neuroimaging.
LEGENDS TO THE VIDEO
Segment 1. Pre-exercise: Sitting and lying down withoutmyoclonic jerks.
Segment 2. Exercise.Segment 3. Post-exercise: Lying down without jerks; lying
on stomach with jerks at the hips, mainly on the left side.The myoclonus persists while standing up.
Acknowledgments: The authors are indebted to Dr LindaWhite and Prof. Maurice Vincent for kindly reviewing themanuscript and to Dr. Romeu Cortes Domingues for the MRIscans.
Ana Lucia Rosso, MD, PhD*James Pitagoras de Mattos, MD, PhD
Denise Hack Nicaretta, MD, BScMarcia Waddington Cruz, MD, PhD
Ismar Fernandes Filho, MD, BScSergio Novis, MD, PhD
HUCFF/UFRJ-NeurologyRua Marques de Abrantes 177/604
RJ Rio de Janeiro, Brazil*E-mail: [email protected]
REFERENCES
1. Cassin F, Houdayer E. Neurophysiology of myoclonus. Neuro-physiol Clin 2006;36:281–291.
2. Hallett M. Myoclonus: phenomenology, etiology, physiology andtreatment. In: Fahn S, Jankovic J, Hallet M, Jenner PG, editors.A comprehensive review of movement disorders for the clinicalpractitioner. Philadelphia: Churchill Livingstone Elsevier; 2005.p 157–229.
3. Brown P, Thompson PD, Rothwell JC, Day BC, Marsden CD.Axial myoclonus of propriospinal origin. Brain 1991;114:197–214.
4. Montagna P, Provini F, Plazzi G, Liguori R, Lugaresi E. Proprio-spinal myoclonus upon relaxation and drowsiness: a cause ofsevere insomnia. Mov Disord 1997;12:66–72.
5. Rosenbaum DH, Hoehn AJ. Unilateral truncal seizure: frontal or-igin. Epilepsia 1990;31:37–41.
6. Moraes H, Ferreira C, Deslandes A, et al. Beta and Alpha elec-troencephalographic activity changes after acute exercises. ArqNeuropsiquiatr 2007;65:637–641.
7. Fish DR, Marsden CD. Epilepsy masquerading as a movementdisorder. In: Marsden CD, Fahn S, editors. Movement disorders3. Oxford, UK: Butterworth-Heinemann; 1994. p 347–358.
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Movement Disorders, Vol. 23, No. 15, 2008
Hemimasticatory Spasm with
Lateral Jaw Deviations
Video
Hemimasticatory spasm (HMS) is a very rare disorder of thetrigeminal nerve characterized by paroxysmal involuntarycontraction of the jaw-closing muscles on one side.1,2 Typi-cally, HMS involves the masseter, temporalis, and occasion-ally medial pterygoids. Movements consist of brief twitchesor prolonged spasms. Chewing and jaw closure are potentialprecipitants. Hypertrophy of the involved muscle may occur.The spasms are generally painless. Severe spasms can resultin temporomandibular joint disclocation or tissue injury.3,4
Prior published videographic documentations of HMS notewaves of involuntary muscle contractions involving only themasseter muscle.5,6 Botulinum toxin injection is the mosteffective available treatment.
The characteristic EMG findings of HMS include irregularbursts of motor unit potentials that correlate with the involun-tary masseter spasms.1,7,8 The spasm is accompanied by lossof the silent period. Absent or delayed masseter reflex sug-gests deafferentation of muscle spindles due to involvementof the Ia fibers.2,4 Impaired inhibition of masseter contractionmay relate to ectopic excitation secondary to focal demyelin-ation of the trigeminal motor fibers.
Although jaw-opening muscles (lateral pterygoids) are notbelieved to be affected in HMS,8 we report a patient withHMS in whom jaw opening in addition to jaw closure wasfrequently seen.
A 54-year-old woman was evaluated for a 5-year historyof painless, episodic left-sided jaw closures, forceful enoughto injure the tongue and cheek. She noted side-to-side move-ments of the jaw. Her jaw pushed to the left side andreturned after a few seconds to the midline. The only identi-fied precipitant was biting or chewing. A trial of carbamaze-pine was not successful. Periodic botulinum toxin injectionsinto the temporalis and masseters resulted in significantrelief. Her past history included restless leg syndrome, hypo-thyroidism, and symptoms suggestive of Lhermitte phenom-enon. Seven years prior to evaluation, an area of atrophicdepigmentation on her left chin developed, diagnosed aslichen atrophicus. She received topical steroids and had beenaware of nonprogressive atrophy of the left chin. Her medica-tions included levothyroxine and pramipexole. The only ab-normality on her exam was intermittent left jaw clenchingand side-to-side jaw movements. The former were noted withher mouth closed, and the latter with the mouth partiallyopen. Also present was atrophy of the lower part of the leftface. Her antinuclear antibody and anti SS-A and SS-B anti-bodies were elevated. Paraneoplastic antibodies were nega-tive. The cervical spine MRI showed a 2 mm focus of hyper-intense signal located in the posterior aspect of the cord atthe C5-6 level at which there was a disc-osteophyte complexthat resulted in effacement of the subarachnoid space. A
brain MRI with contrast was unremarkable. CT of the facedemonstrated atrophy of the soft tissues in the lower part ofthe face (Fig. 1). Based on the involvement of the subcutane-ous tissue, morphea (linear scleroderma) was considered.Neurophysiology studies showed an absent jaw jerk on theleft. The blink reflex was normal except for a lower ampli-tude of R1 on the left. Silent period studies were not done.Trigeminal conduction velocity, as assessed by R1 and R2latencies on the blink reflex, was normal. The left massetershowed high frequency, irregular, motor unit potential burstsin association with jerking, involuntary jaw movements.These bursts were not recorded from the left pterygoid. Shewas given botulinum toxin injections in the left temporalis,left masseter, and left lateral pterygoid. The lateral pterygoidswere injected because of the noted side-to-side movements.The benefit from each set of injections lasted for over a year.
This case suggests that the lateral pterygoids may beinvolved in HMS. In a reported patient with HMS, MRIshowed hypertrophy of the lateral pterygoid though involun-tary lateral deviations of the jaw were not observed.5 Themuscles involved in facial atrophy associated-HMS likelydepends on the site of atrophy. In hemifacial atrophy the tri-geminal nerve may be compromised in the confined space ofthe infratemporal fossa between the lateral pterygoid andskull surface. In linear scleroderma, as in our patient, the ter-minal branches involved and muscles affected may dependon the site of focal atrophy. The pterygoids may need to beinjected with botulinum toxin when a history of lateral jawmovements is obtained. The blink reflex is typically normalin HMS, and addditional studies are needed to determine thesignificance of reduction in the R1 amplitude on the involvedside in our patient.
FIG. 1. CT skull with a cut across the mandible showing the atro-phy of subcutaneous tissue and muscle in relation to the left chin.
Additional Supporting Information may be found in the onlineversion of this article.
Published online 29 September 2008 in Wiley InterScience (www.
interscience.wiley.com). DOI: 10.1002/mds.22304
2265LETTERS TO THE EDITOR
Movement Disorders, Vol. 23, No. 15, 2008
LEGEND TO VIDEO
In the first part of the video, the patient describes herinvoluntary movements. In the latter half, the side-to-sidemovement she describes is captured. Also evident is atrophyof the left chin.
Neeraj Kumar, MD*Bruce R. Krueger, MD
J. Eric Ahlskog, MD, PhDDepartment of Neurology
Mayo ClinicRochester, Minnesota, USA
*E-mail: [email protected]
REFERENCES
1. Auger RG, Litchy WJ, Cascino TL, Ahlskog JE. Hemimastica-tory spasm: clinical and electrophysiologic observations. Neurol-ogy 1992;42:2263–2266.
2. Cruccu G, Inghilleri M, Berardelli A, et al. Pathophysiology ofhemimasticatory spasm. J Neurol Neurosurg Psychiatry 1994;57:43–50.
3. Kaufman MD. Masticatory spasm in facial hemiatrophy. AnnNeurol 1980;7:585–587.
4. Thompson PD, Obeso JA, Delgado G, Gallego J, Marsden CD.Focal dystonia of the jaw and the differential diagnosis of unilat-eral jaw and masticatory spasm. J Neurol Neurosurg Psychiatry1986;49:651–656.
5. Ebersbach G, Kabus C, Schelosky L, Terstegge L, Poewe W.Hemimasticatory spasm in hemifacial atrophy: diagnostic andtherapeutic aspects in two patients. Mov Disord 1995;10:504–507.
6. Mir P, Gilio F, Edwards M, et al. Alteration of central motorexcitability in a patient with hemimasticatory spasm after treatmentwith botulinum toxin injections. Mov Disord 2006;21:73–78.
7. Lagueny A, Deliac MM, Julien J, Demotes-Mainard J, FerrerX. Jaw closing spasm–a form of focal dystonia? An electro-physiological study. J Neurol Neurosurg Psychiatry 1989;52:652–655.
8. Kim HJ, Jeon BS, Lee KW. Hemimasticatory spasm associatedwith localized scleroderma and facial hemiatrophy. Arch Neurol2000;57:576–580.
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