Effects of aging on motor cortex excitability.
To determine whether aging is associated with changes in excitability of the cerebral cortex, we evaluated the excitability of the motor cortex with transcranial magnetic stimulation (TMS). We compared TMS related measures obtained in a group of young people with those of a group of old people. Motor evoked potential (MEP) amplitude was significantly smaller in older than in younger controls (1.3+/-0.8 mV versus 2.7+/-1.1 mV; p<0.0071). Mean cortical silent period (CSP) duration was shorter in older than in younger controls (87+/-29 ms versus 147+/-39 ms; p<0.0071). SP duration/MEP amplitude ratios were similar in both groups. Our results are consistent with an impaired efficiency of some intracortical circuits in old age.
FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca "la Peraleda" s/n, 45071 Toledo, Spain. aoliviero@tiscali.es
A
A
Oliviero
P
P
Profice
P A
PA
Tonali
F
F
Pilato
E
E
Saturno
M
M
Dileone
F
F
Ranieri
V
V
Di Lazzaro
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D016022:Case-Control Studies; D004056:Differential Threshold / Q000528:radiation effects; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology* / Q000528:radiation effects; D018482:Muscle, Skeletal / Q000502:physiology / Q000528:radiation effects; D050781:Transcranial Magnetic Stimulation / Q000379:methods