The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee.
The review focuses on the clinical diagnostic utility of transcranial magnetic stimulation (TMS). The central motor conduction time (CMCT) is a sensitive method to detect myelopathy and abnormalities may be detected in the absence of radiological changes. CMCT may also detect upper motor neuron involvement in amyotrophic lateral sclerosis. The diagnostic sensitivity may be increased by using the triple stimulation technique (TST), by combining several parameters such as CMCT, motor threshold and silent period, or by studying multiple muscles. In peripheral facial nerve palsies, TMS may be used to localize the site of nerve dysfunction and clarify the etiology. TMS measures also have high sensitivity in detecting lesions in multiple sclerosis and abnormalities in CMCT or TST may correlate with motor impairment and disability. Cerebellar stimulation may detect lesions in the cerebellum or the cerebellar output pathway. TMS may detect upper motor neuron involvement in patients with atypical parkinsonism and equivocal signs. The ipsilateral silent period that measures transcallosal inhibition is a potential method to distinguish between different parkinsonian syndromes. Short latency afferent inhibition (SAI), which is related to central cholinergic transmission, is reduced in Alzheimer's disease. Changes in SAI following administration of cholinesterase inhibitor may be related to the long-term efficacy of this treatment. The results of MEP measurement in the first week after stroke correlate with functional outcome. We conclude that TMS measures have demonstrated diagnostic utility in myelopathy, amyotrophic lateral sclerosis and multiple sclerosis. TMS measures have potential clinical utility in cerebellar disease, dementia, facial nerve disorders, movement disorders, stroke, epilepsy, migraine and chronic pain.
Division of Neurology, Toronto Western Research Institute, University of Toronto, 7MC411, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ont., Canada M5T 2S8. Electronic address: robert.chen@uhn.on.ca.
Robert
R
Chen
Department of Neurology, Massachusetts General Hospital, Boston, USA.
Didier
D
Cros
Department of Neurological Sciences, Ospedale A. Fiorini Terracina, LT, University of Rome La Sapienza Polo Pontino, Italy.
Antonio
A
Curra
Istituto di Neurologia, Università Cattolica, Rome, Italy.
Vincenzo
V
Di Lazzaro
Service de Physiologie - Explorations Fonctionnelles, Hopital Henri Mondor, Creteil, France.
Jean-Pascal
JP
Lefaucheur
Department of Clinical Neuroscience, University Hospital of Geneva, Geneva, Switzerland.
Michel R
MR
Magistris
Department of Clinical Neurophysiology, Kings College Hospital, London, United Kingdom.
Kerry
K
Mills
Department of Neurology, University Hospital of Berne, Berne, Switzerland.
Kai M
KM
Rösler
Department of Neurology, University of Florida, Gainesville, FL, USA.
William J
WJ
Triggs
Department of Neurology, The University of Tokyo, Tokyo, Japan.
Yoshikazu
Y
Ugawa
Department of Neurology, Johann Wolfgang Goethe University of Frankfurt, Frankfurt, Germany.
Ulf
U
Ziemann
D004558:Electric Stimulation / Q000379:methods*; D004576:Electromyography / Q000379:methods / Q000706:statistics & numerical data; D019054:Evoked Potentials, Motor / Q000502:physiology; D006801:Humans; D009422:Nervous System Diseases / Q000175:diagnosis* / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods* / Q000706:statistics & numerical data*