Contemporary clinical neurophysiology applications in dystonia.
Brain plasticity
Dystonia
Network disorder
Neurophysiology
Journal
Journal of neural transmission (Vienna, Austria : 1996)
ISSN: 1435-1463
Titre abrégé: J Neural Transm (Vienna)
Pays: Austria
ID NLM: 9702341
Informations de publication
Date de publication:
04 2021
04 2021
Historique:
received:
23
11
2020
accepted:
18
01
2021
pubmed:
17
2
2021
medline:
16
10
2021
entrez:
16
2
2021
Statut:
ppublish
Résumé
The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.
Identifiants
pubmed: 33591454
doi: 10.1007/s00702-021-02310-6
pii: 10.1007/s00702-021-02310-6
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Review
Langues
eng
Sous-ensembles de citation
IM
Pagination
509-519Références
Abbruzzese G, Pelosin E, Avanzino L (2015) Physiology of dystonia. In: Bhatia K, Rosales RL (eds) Kaňovský, P. Dystonia and dystonic syndromes. Springer-Verlag, Wien, pp 13–25
Alexander GE (1994) Basal ganglia-thalamocortical circuits: their role in control of movements. J Clin Neurophysiol 11:420–431
pubmed: 7962489
Amadio S, Panizza M, Pisano F et al (2000) Transcranial magnetic stimulation and silent period in spasmodic torticollis. Am J Phys Med Rehabil 79:361–368
pubmed: 10892622
Antelmi E, Erro R, Rocchi L et al (2017) Neurophysiological correlates of abnormal somatosensory temporal discrimination in dystonia. Mov Disord 32:141–148
pubmed: 27671708
Bareš M, Rektor I (2001) Basal ganglia involvement in sensory and cognitive processing. A depth electrode CNV study in human subjects. Clin Neurophysiol 112:2022–2030
pubmed: 11682340
Bareš M, Filip P (2018) Cerebellum and dystonia: The story continues. Will the patients benefit from new discoveries? Clin Neurophysiol 129:282–283
pubmed: 29122444
Beck S, Shamim EA, Richardson SP et al (2009) Inter-hemispheric inhibition is impaired in mirror dystonia. Eur J Neurosci 29:1634–1640
pubmed: 19419426
pmcid: 2770695
Berardelli A, Rothwell JC, Hallett M et al (1998) The pathophysiology of primary dystonia. Brain 121:1195–1212
pubmed: 9679773
Berardelli A, Abbruzzese G, Chen R et al (2008) Consensus paper on short-interval intracortical inhibition and other transcranial magnetic stimulation intracortical paradigms in movement disorders. Brain Stimul 1:183–191
pubmed: 20633384
Berman BD, Jinnah HA (2015) Dystonia: Five new things. Neurol Clin Pract 5:232–240
pubmed: 26124980
pmcid: 4469349
Bove M, Brichetto G, Abbruzzese G et al (2004) Neck proprioception and spatial orientation in cervical dystonia. Brain 127:2764–2778
pubmed: 15355873
Bradnam L, Barry C (2013) The role of the trigeminal sensory nuclear complex in the pathophysiology of craniocervical dystonia. J Neurosci 33:18358–18367
pubmed: 24259561
pmcid: 6618800
Bradnam LV, Meiring RM, Boyce M, McCambridge A (2020) Neurorehabilitation in dystonia: a holistic perspective. J Neural Transm. https://doi.org/10.1007/s00702-020-02265-0 ((Epub ahead of print. PMID: 33099684))
doi: 10.1007/s00702-020-02265-0
pubmed: 33099684
pmcid: 33099684
Brugger F, Peters A, Georgiev D et al (2019) Sensory trick efficacy in cervical dystonia is linked to processing of neck proprioception. Parkinsonism Relat Disord 61:50–56
pubmed: 30553617
Chen R (2000) Studies of human motor physiology with transcranial magnetic stimulation. Muscle Nerve 9(Suppl. 1):S26-32
pubmed: 11135281
Chen KS, Chen R (2020) Principles of electrophysiological assessments for movement disorders. J Mov Disord 13:27–38
pubmed: 31986867
pmcid: 6987526
Chen R, Corwell B, Hallett M (1999) Modulation of motor cortex excitability by median nerve and digit stimulation. Exp Brain Res 129:77–86
pubmed: 10550505
Chen JC, Macerollo A, Sadnicka A et al (2018) Cervical dystonia: Normal auditory mismatch negativity and abnormal somatosensory mismatch negativity. Clin Neurophysiol 129:1947–1954
pubmed: 30015084
Conte A, Berardelli I, Ferrazzano G et al (2016) Non-motor symptoms in patients with adult-onset focal dystonia: Sensory and psychiatric disturbances. Parkinsonism Relat Disord 22(Suppl 1):S111–S114
pubmed: 26360238
Cooper I (1965) Effect of thalamic lesions upon torticollis. N Engl J Med 270:567–572
Corp DT, Joutsa J, Darby RR et al (2019) Network localization of cervical dystonia based on causal brain lesions. Brain 142:1660–1674
pubmed: 31099831
pmcid: 6536848
Delmaire C, Vidailhet M, Elbaz A et al (2007) Structural abnormalities in the cerebellum and sensorimotor circuit in writer´s cramp. Neurology 69:378–380
Delnooz C, Pasman JW, Beckmann CF, a, (2013) Task-free functional MRI in cervical dystonia reveals multi-network changes that partially normalize with botulinum toxin. PLoS ONE 8:e62877
pubmed: 23650536
pmcid: 3641096
Delnooz C, Pasman JW, Beckmann CF et al (2015) Altered striatal and pallidal connectivity in cervical dystonia. Brain Struct Funct 220:513–523
pubmed: 24259114
Deuschl G, Toro C, Matsumoto J et al (1995) Movement-related cortical potentials in writer’s cramp. Ann Neurol 38:862–868
pubmed: 8526458
Devanne H, Lavoie BA, Capaday C (1997) Input-output properties and gain changes in the human corticospinal pathway. Exp Brain Res 114:329–338
pubmed: 9166922
Di Lazzaro V, Oliviero A, Profice P et al (2000) Muscarinic receptor blockade has differential effects on the excitability of intracortical circuits in the human motor cortex. Exp Brain Res 135:455–461
pubmed: 11156309
Di Lazzaro V, Pilato F, Dileone M et al (2007) Segregating two inhibitory circuits in human motor cortex at the level of GABAA receptor subtypes: A TMS study. Clin Neurophysiol 118:2207–2214
pubmed: 17709293
Domingo A, Yadav R, Ozelius LJ (2020) Isolated dystonia: clinical and genetic updates. J Neural Transm. https://doi.org/10.1007/s00702-020-02268-x
doi: 10.1007/s00702-020-02268-x
pubmed: 33247415
Draganski B, Thun-Hohenstein C, Bogdahn U et al (2003) “Motor circuit” gray matter changes in idiopathic cervical dystonia. Neurology 61:1228–1231
pubmed: 14610125
Dressler D, Saberi FA, Rosales RL (2020) Botulinum toxin therapy of dystonia. J Neural Transm. https://doi.org/10.1007/s00702-020-02266-z
doi: 10.1007/s00702-020-02266-z
pubmed: 33125571
Fève A, Bathien N, Rondot P (1994) Abnormal movement related potentials in patients with lesions of basal ganglia and anterior thalamus. J Neurol Neurosurg Psychiatry 57:100–104
pubmed: 8301287
pmcid: 485047
Filip P, Gallea C, Lehéricy S et al (2017) Disruption in cerebellar and basal ganglia networks during a visuospatial task in cervical dystonia. Mov Disord 32:757–768
pubmed: 28186664
Frima N, Rome SM, Grünewald RA (2003) The effect of fatigue on abnormal vibration induced illusion of movement in idiopathic focal dystonia. J Neurol Neurosurg Psychiatry 74:1154–1156
pubmed: 12876261
pmcid: 1738585
Gracien R-M, Petrov F, Hok P et al (2019) Multimodal quantitative MRI reveals no evidence for tissue pathology in idiopathic cervical dystonia. Front Neurol 10:914
pubmed: 31507518
pmcid: 6719627
Grünewald RA, Yoneda Y, Shipman JM et al (1997) Idiopathic focal dystonia: a disorder of muscle spindle afferent processing? Brain 120:2179–2185
pubmed: 9448573
Hamano T, Kaji R, Katayama M et al (1999) Abnormal contingent negative variation in writer’s cramp. Clin Neurophysiol 110:508–515
pubmed: 10363774
Han-Joon K, Jeon B (2020) Arching deep brain stimulation in dystonia types. J Neural Transm. https://doi.org/10.1007/s00702-020-02272-1
doi: 10.1007/s00702-020-02272-1
Heimburger RF (1969) The role of the cerebellar nuclei in dyskinetic disorders. Confin Neurol 31:57–69
pubmed: 4242638
Hendrix CM, Vitek JL (2012) Toward a network model of dystonia. Ann NY Acad Sci 1265:46–55
pubmed: 22823747
Hvizdošová L, Nevrlý M, Otruba P et al (2020) The prevalence of dystonic tremor and tremor associated with dystonia in patients with cervical dystonia. Sci Rep 10:1436
pubmed: 31996749
pmcid: 6989505
Ikeda A, Shibasaki H, Kaji R et al (1996) Abnormal sensorimotor integration in writer’s cramp: study of contingent negative variation. Mov Disord 6:683–690
Jinnah HA, Albanese A (2014) The new classification system for the dystonias: why was it needed and how was it developed? Mov Disord Clin Pract 1:280–284
pubmed: 25485288
pmcid: 4254809
Jinnah HA, Hess EJ (2006) A new twist on the anatomy of dystonia: the basal ganglia and the cerebellum? Neurology 67:1740–1741
pubmed: 17130402
Jinnah HA, Neychev V, Hess EJ (2017) The anatomical basis for dystonia: the motor network model. Tremor Other Hyperkinet Mov (N Y) 7:506
Kaji R, Ikeda A, Ikeda T et al (1995a) Physiological study of cervical dystonia. Task- specific abnormality in contingent negative variation. Brain 118:511–522
pubmed: 7735891
Kaji R, Rothwell JC, Katayama M et al (1995b) Tonic vibration reflex and muscle afferent block in writer’s cramp. Ann Neurol 38:155–162
pubmed: 7654062
Kamble NL, Pal PK (2016) Electrophysiological evaluation of psychogenic movement disorders. Parkinsonism Relat Disord 22(Suppl 1):S153–S158
pubmed: 26403429
Kaňovský P (2002) Dystonia: a disorder of motor programming or motor execution? Mov Disord 17:1143–1147
pubmed: 12465050
Kaňovský P, Rosales RL (2011) Debunking the pathophysiological puzzle of dystonia– with special reference to botulinum toxin therapy. Parkinsonism Relat Disord 17(Suppl1):S11–S14
pubmed: 21999889
Kaňovský P, Streitová H, Dufek J et al (1997) Lateralization of the P22/N30 component of somatosensory evoked potentials of the median nerve in patients with cervical dystonia. Mov Disord 12:553–560
pubmed: 9251074
Kaňovský P, Streitová H, Dufek J et al (1998) Change in lateralization of the P22/N30 cortical component of median nerve somatosensory evoked potentials in patients with cervical dystonia after successful treatment with botulinum toxin A. Mov Disord 13:108–117
pubmed: 9452335
Kaňovský P, Streitová H, Dufek J et al (1999a) Lateralization of the P22/N30 precentral cortical component of the median nerve somatosensory evoked potentials is different in patients with a tonic or tremulous form of cervical dystonia. Mov Disord 14:642–651
pubmed: 10435502
Kaňovský P, Bareš M, Rektor I (1999b) The selective gating of the N30 cortical component of the somatosensory evoked potentials of median nerve is different in the mesial and dorsolateral frontal cortex: evidence from intracerebral recordings. Clin Neurophysiol 114:981–991
Kaňovský P, Bareš M, Streitová H et al (2003) Abnormalities of cortical excitability and cortical inhibition in cervical dystonia Evidence from somatosensory evoked potentials and paired transcranial magnetic stimulation recordings. J Neurol 250:42–50
pubmed: 12527991
Kaňovský P, Bhatia K, Rosales RL (eds) (2015) Dystonia and dystonic syndromes. Springer, Wein. ISBN 978-3-7091-1516-9
Katschnig-Winter P, Schwingenschuh P, Davare M et al (2014) Motor sequence learning and motor adaptation in primary cervical dystonia. J Clin Neurosci 21:934–938
pubmed: 24411324
Kujirai T, Caramia MD, Rothwell JC, Day BL, Thompson PD, Ferbert A, Wroe S, Asselman P, Marsden CD (1993) Corticocortical inhibition in human motor cortex. J Physiol 471:501–519
pubmed: 8120818
pmcid: 1143973
LeDoux MS, Brady KA (2003) Secondary cervical dystonia associated with structural lesions of the central nervous system. Mov Disord 18:60–69
pubmed: 12518301
Léhericy S, Tijssen MA, Vidailhet M et al (2013) The anatomical basis of dystonia: current view using neuroimaging. Mov Disord 28:944–957
pubmed: 23893451
Lim VK, Bradshaw JL, Nicholls ME et al (2004) Abnormal sensorimotor processing in pianists with focal dystonia. Adv Neurol 94:267–273
pubmed: 14509684
Macerollo A, Chen JC, Parees I et al (2016) Abnormal movement-related suppression of sensory evoked potentials in upper limb dystonia. Eur J Neurol 23:562–568
pubmed: 26757449
Macerollo A, Brown MJN, Kilner JM et al (2018) Neurophysiological changes measured using somatosensory evoked potentials. Trends Neurosci 41:294–310
pubmed: 29549962
Mazzini L, Zaccala M, Balzarini C (1994) Abnormalities of somatosensory evoked potentials in spasmodic torticollis. Mov Disord 9:426–430
pubmed: 7969209
McCambridge AB, Bradnam LV (2020) Cortical neurophysiology of primary isolated dystonia and non-dystonic adults: A meta-analysis. Eur J Neurosci 29:10. https://doi.org/10.1111/ejn.14987 ((Epub ahead of print. PMID: 32991762.))
doi: 10.1111/ejn.14987
Menšíková K, Kaiserová M, Vaštík M et al (2020) The long-term effect of continuous subcutaneous apomorphine infusions on camptocormia in Parkinson’s disease. Parkinsonism Relat Disord 75:14–16
pubmed: 32442812
Murase N, Kaji R, Shimazu H et al (2000) Abnormal premovement gating of somatosensory input in writer’s cramp. Brain 123:1813–1829
pubmed: 10960045
Nevrlý M, Hluštík P, Hok P et al (2018) Changes in sensorimotor network activation after botulinum toxin type A injections in patients with cervical dystonia: a functional MRI study. Exp Brain Res 236:2627–2637
pubmed: 29971454
pmcid: 6153868
Neychev VK, Gross R, Lehericy S et al (2011) The functional neuroanatomy of dystonia. Neurobiol Dis 42:185–201
pubmed: 21303695
pmcid: 3478782
Obermann M, Yaldizli O, De Greiff A et al (2007) Morphometric changes in sensorimotor structures in focal dystonia. Mov Disord 22:1117–1123
pubmed: 17443700
Oku T, Furuya S (2019) Neuromuscular incoordination in musician’s dystonia. Parkinsonism Relat Disord 65:97–104
pubmed: 31130362
Opavský R, Hluštík P, Otruba P et al (2011) Sensorimotor network in cervical dystonia and the effect of botulinum toxin treatment: a functional MRI study. J Neurol Sci 306:71–75
pubmed: 21492880
Opavský R, Hluštík P, Otruba P et al (2012) Somatosensory cortical activation in cervical dystonia and its modulation with botulinum toxin: an fMRI study. Int J Neurosci 122:45–52
pubmed: 21919815
Oyama G, Hattori N (2020). New Modalities and Directions for Dystonia Care. J Neural Transm (accepted)
Pohl C, Happe J, Klockgether T (2002) Cooling improves the writing performance of patients with writer’s cramp. Mov Disord 17:1341–1344
pubmed: 12465079
Popa T, Hubsch C, James P et al (2018) Abnormal cerebellar processing of the neck proprioceptive information drives dysfunctions in cervical dystonia. Sci Rep 8:2263
pubmed: 29396401
pmcid: 5797249
Prudente CN, Hess EJ, Jinnah HA (2014) Dystonia as a network disorder: what is the role of the cerebellum? Neuroscience 260:23–35
pubmed: 24333801
Ramdhani RA, Simonyan K (2013). Primary dystonia: conceptualizing the disorder through a structural brain imaging lens. Tremor Other Hyperkinet Mov (N Y) 3:tre-03–152–3638–4
Rektor I, Kaňovský P, Bareš M et al (2001a) Event-related potentials, CNV, readiness potential, and movement accompanying potential recorded from posterior thalamus in human subjects. A SEEG study. Neurophysiol Clin 31:253–261
pubmed: 11596532
Rektor I, Bareš M, Kaňovský P et al (2001b) Intracerebral recording of readiness potential induced by a complex motor task. Mov Disord 16:698–704
pubmed: 11481694
Rektor I, Bareš M, Kubová D (2001c) Movement-related potentials in the basal ganglia: a SEEG readiness potential study. Clin Neurophysiol 112:2146–2153
pubmed: 11682354
Rektor I, Bareš M, Brázdil M et al (2005) Cognitive- and movement-related potentials recorded in the human basal ganglia. Mov Disord 20:562–568
pubmed: 15666424
Ridding MC, Sheean G, Rothwell JC et al (1995) Changes in the balance between motor cortical excitation and inhibition in focal, task specific dystonia. J Neurol Neurosurg Psychiatry 59:493–583
pubmed: 8530933
pmcid: 1073711
Ridding MC, Brouwer B, Nordstrom MA (2000) Reduced interhemispheric inhibition in musicians. Exp Brain Res 133:249–253
pubmed: 10968226
Rosales RL, Dressler D (2010) On muscle spindles, dystonia and botulinum toxin. Eur J Neurol 17(Suppl 1):71–80
pubmed: 20590812
Rosales RL, Dressler D (2016) Botulinum toxin type A therapy in dystonia and spasticity - what are current practical applications? In: Rosales RL, Dressler D (eds) Botulinum toxin therapy manual for dystonia and spasticity. Intech Open Access Publishers, Rijeka. ISBN 978-953-51-2851-9
Rothwell JC (1995) The physiology of dystonia. Marcel Dekker, New York
Sadnicka A, Hoffland BS, Bhatia KP et al (2012) The cerebellum in dystonia—help or hindrance? Clin Neurophysiol 123:65–70
pubmed: 22078259
Sadnicka A, Hamada M, Bhatia KP et al (2014a) Cerebellar stimulation fails to modulate motor cortex plasticity in writing dystonia. Mov Disord 29:1304–1307
pubmed: 24797030
Sadnicka A, Patani B, Saifee TA et al (2014b) Normal motor adaptation in cervical dystonia: a fundamental cerebellar computation is intact. Cerebellum 13:558–567
pubmed: 24872202
pmcid: 4155166
Sadnicka A, Teo JT, Kojovic M et al (2015) All in the blink of an eye: new insight into cerebellar and brainstem function in DYT1 and DYT6 dystonia. Eur J Neurol 22:762–767
pubmed: 25039324
Samargia S, Schmidt R, Kimberley TJ (2014) Shortened cortical silent period in adductor spasmodic dysphonia: evidence for widespread cortical excitability. Neurosci Lett 560:12–15
pubmed: 24333913
Sarasso E, Agosta F, Piramide N, Bianchi F, Butera C, Gatti R, Amadio S, Del Carro U, Filippi M (2020) Sensory trick phenomenon in cervical dystonia: a functional MRI study. J Neurol 267:1103–1115
pubmed: 31897600
Shakkottai VG (2014) Physiologic changes associated with cerebellar dystonia. Cerebellum 13:637–644
pubmed: 24879387
pmcid: 4156890
Shakkottai VG, Batla A, Bhatia K et al (2017) Current opinions and areas of consensus on the role of the cerebellum in dystonia. Cerebellum 16:577–594
pubmed: 27734238
pmcid: 5336511
Supnet ML, Rosales RL (2018) Indirect central nervous effects of botulinum toxin. In: Dressler D, Altenmüller E, Krauss JK (eds) Treatment of Dystonia. Cambridge University Press, Cambridge. ISBN 978-1-107-13286-3
Swash M, Fox KP (1976) Normal muscle spindles in idiopathic torsion dystonia. J Neurol Sci 27:525–527
pubmed: 131183
Teo JT, van de Warrenburg BP, Schneider SA et al (2009) Neurophysiological evidence for cerebellar dysfunction in primary focal dystonia. J Neurol Neurosurg Psychiatry 80:80–83
pubmed: 19091711
Tinazzi M, Frasson E, Polo A et al (1999a) Evidence for an abnormal cortical sensory processing in dystonia: selective enhancement of lower limb P37–N50 somatosensory evoked potential. Mov Disord 14:473–480
pubmed: 10348472
Tinazzi M, Frasson E, Bertolasi L et al (1999b) Temporal discrimination of somesthetic stimuli is impaired in dystonic patients. NeuroReport 10:1547–1550
pubmed: 10380978
Tinazzi M, Fiaschi A, Frasson E et al (2002) Deficits of temporal discrimination in dystonia are independent from the spatial distance between the loci of tactile stimulation. Mov Disord 17:333–338
pubmed: 11921120
Tokimura H, Di Lazzaro V, Tokimura Y et al (2000) Short latency inhibition of human hand motor cortex by somatosensory input from the hand. J Physiol 523:503–513
pubmed: 10699092
pmcid: 2269813
Toro C, Deuschl G, Hallett M (2000) Movement-related electroencephalographic desynchronization in patients with hand cramps: evidence for motor cortical involvement in focal dystonia. Ann Neurol 2000(47):456–461
Tseng YJ, Chen RS, Hsu WY et al (2014) Reduced motor cortex deactivation in individuals who suffer from writer’s cramp. PLoS ONE 9:e97561
pubmed: 24831291
pmcid: 4022529
Turco CV, El-Sayes J, Locke MB, Chen R, Baker S, Nelson AJ (2018a) Effects of lorazepam and baclofen on short- and long-latency afferent inhibition. J Physiol 596:5267–5280
pubmed: 30192388
pmcid: 6209752
Turco CV, El-Sayes J, Savoie MJ, Fassett HJ, Locke MB, Nelson AJ (2018b) Short- and long-latency afferent inhibition; uses, mechanisms and influencing factors. Brain Stim 11:59–74
Udupa K, Chen R (2019) Motor cortical circuits in Parkinson disease and dystonia. Handb Clin Neurol 161:167–186
pubmed: 31307598
Van der Kamp W, Rothwell JC, Thompson PD et al (1995) The movement- related cortical potential is abnormal in patients with idiopathic torsion dystonia. Mov Disord 10:630–633
pubmed: 8552116
Wasserman E, Epstein CM, Ziemann U, Wassermann EM (2008) The Oxford handbook of transcranial stimulation. Oxford University Press, Oxford. ISBN 978-0-19-856892-6
Weissbach A, Saranza G, Domingo, (2020) Combined dystonias: clinical and genetic updates. J Neural Transm. https://doi.org/10.1007/s00702-020-02269-w
doi: 10.1007/s00702-020-02269-w
pubmed: 33185802
Zeuner KE, Peller M, Knutzen A et al (2009) Slow pre-movement cortical potentials do not reflect individual response to therapy in writer’s cramp. Clin Neurophysiol 120:1213–1219
pubmed: 19447675
Zheng Z, Pan P, Wang W, Shang H (2012) Neural network of primary focal dystonia by an anatomic likelihood estimation meta-analysis of gray matter abnormalities. J Neurol Sci 316:51–55
pubmed: 22349356
Ziemann U, Lonnecker S, Steinhoff BJ, Paulus W (1996a) Effects of antiepileptic drugs on motor cortex excitability in humans: a transcranial magnetic stimulation study. Ann Neurol 40:367–378
pubmed: 8797526
Ziemann U, Lonnecker S, Steinhoff BJ, Paulus W (1996b) The effect of lorazepam on the motor cortical excitability in man. Exp Brain Res 109:127–135
pubmed: 8740215
Ziemann U, Chen R, Cohen LG, Hallett M (1998) Dextromethorphan decreases the excitability of the human motor cortex. Neurology 51:1320–1324
pubmed: 9818853