Objective: To reverse the profile of abnormal intracortical excitability in patients with ALS by administering drugs that promote GABAergic transmission. Background: Transcranial magnetic stimulation (TMS) has revealed abnormalities of cortical inhibition in ALS, a reduction of the silent period, and the absence of intracortical inhibition normally occurring in response to paired TMS. Impaired inhibitory transmission could play a role in the physiopathology of this illness. Methods: Using paired TMS with conditioning stimuli from 1-to-6-msec-interstimulus intervals, we investigated 16 patients with ALS. The protocol included: (1) the 'drug-free' profile of paired TMS; (2) paired TMS 30 minutes after the intake of diazepam (3.5 mg); (3) paired TMS after 3 weeks' treatment with gabapentin (GBP) (600 mg/day) or riluzole (50 mg/twice a day). Results: Intracortical inhibition is lost in patients with ALS, and this abnormal profile is reversed by diazepam or sustained treatment with GBP. We also noted that motor-evoked potential amplitudes to single stimuli increased (p <0.01) after diazepam and GBP. Conclusions: The demonstration of pharmacologic reversal of hyperexcitability in patients with ALS makes a potentially significant contribution toward understanding the pathophysiology of a disease that has so far eluded an effective cure.
|Number of pages||7|
|Publication status||Published - Jan 11 2000|
- GABAergic drugs
- Intracortical inhibition
- Motor evoked potential
- Paired transcranial magnetic stimulation
ASJC Scopus subject areas