PT  - JOURNAL ARTICLE
AU  - F Sala
AU  - M J Krzan
AU  - G Jallo
AU  - F J Epstein
AU  - V Deletis
TI  - Prognostic value of motor evoked potentials elicited by multipulse magnetic stimulation in a surgically induced transitory lesion of the supplementary motor area: a case report
AID  - 10.1136/jnnp.69.6.828
DP  - 2000 Dec 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 828--831
VI  - 69
IP  - 6
4099  - http://jnnp.bmj.com/content/69/6/828.short
4100  - http://jnnp.bmj.com/content/69/6/828.full
SO  - J Neurol Neurosurg Psychiatry2000 Dec 01; 69
AB  - Surgery involving the supplementary motor area (SMA) places the patient at risk of transient motor deficit. To predict outcome in patients with early postoperative hypokinesis would be relevant to both the patient and the surgical team. A 15 year old girl with a large left thalamic tumour removed through a left transcallosal approach is described. Despite intraoperatively preserved muscle motor evoked potentials (mMEPs) from all limbs, elicited by multipulse electrical stimulation, she awoke with a right hemiplegia and mutism. On the first postoperative day, neurophysiological evaluation using a multipulse magnetic stimulation technique, with a train of four magnetic stimuli, confirmed the presence of mMEPs from the hemiplegic right limbs. Slight spontaneous motor activity of the right limbs and initial speech were seen later on the same day with dramatic improvement over subsequent days.  It is concluded that multiple rather than single magnetic stimulation techniques may be needed to elicit mMEPs for an early postoperative differential diagnosis of SMA damage versus injury to the primary motor cortex or the corticospinal tract.