Motor cortical excitability in patients with poststroke epilepsy.
OBJECTIVE
To gain insight into the mechanisms underlying poststroke epilepsy (PSE), we evaluated motor cortical function in chronic stroke patients with (N = 18) and without (N = 18) PSE.


METHODS
We measured resting motor threshold (RMT), motor evoked potential (MEP) amplitudes, cortical silent period (CSP), intracortical inhibition (ICI), influenced by GABAergic neurotransmission, and intracortical facilitation (ICF), influenced by glutamatergic activity, to transcranial magnetic stimulation.


RESULTS
We found (1) larger MEP amplitudes and ICF, in the affected than unaffected hemispheres of patients in the PSE group but not in patients without epilepsy, and (2) comparably higher RMT and longer CSP in the absence of differences in ICI, H-reflexes or F-waves in the affected and unaffected hemispheres of both PSE and non-PSE patients.


CONCLUSIONS
Enhanced cortical excitability in the affected hemisphere, possibly related to increased glutamatergic activity, could be one of the mechanisms contributing to the development of poststroke epilepsy.
Department of Neurology, Ewha Womans University, Seoul, Korea.
Jee Hyun
JH
Kim
Hyang Woon
HW
Lee
Leonardo G
LG
Cohen
Kee-Duk
KD
Park
Kyoung-Gyu
KG
Choi
D000368:Aged; D000927:Anticonvulsants / Q000494:pharmacology / Q000627:therapeutic use; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D002908:Chronic Disease; D004569:Electroencephalography / Q000187:drug effects / Q000706:statistics & numerical data; D004576:Electromyography / Q000706:statistics & numerical data; D004827:Epilepsy / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D005971:Glutamates / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000187:drug effects / Q000503:physiopathology*; D009433:Neural Inhibition / Q000502:physiology; D012146:Rest / Q000502:physiology; D020521:Stroke / Q000150:complications* / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation
D000927:Anticonvulsants; D005971:Glutamates