Cerebrovascular oxygenation measured by near-infrared spectroscopy (NIRS) and motor cortex excitability measured by transcranial magnetic stimulation(TMS) in a patient with epilepsia partialis continua

Near-infrared spectroscopy and assessment of motor cortex excitability by t ranscranial magnetic stimulation (TMS) were performed in a 52-year old pati ent with right-sided epilepsia partialis continua. The infrared light senso r was placed over the left and right frontal motorcortex, respectively. Bot h ictal and postictal data were acquired. Ictally, we found a significant i ncrease of cerebral oxygen saturation (mean: 64%) in the region of the epil etogenic left frontal motor cortex as compared to contralateral measurement s (mean: 49%). After cessation of the status epilepticus, the mean value of the left ipsilateral cerebral oxygen saturation declined to the same level as in the non-epileptogenic hemisphere (mean: 47%). Intracortical excitabi lity, tested according to a double-shock paradigm, showed a reduced inhibit ion in the ipsilateral left motor cortex during the focal motor status. Aft er successful medical treatment, the inhibition of cortical excitability in creased slightly. The ictal intracortical inhibition in the contralateral r ight motor cortex was also reduced and increased postictally. Our results o f NIRS and TMS in a patient with epilepsia partialis continua are in accord ance with the hypothesis of increased ictal metabolism and reduced ictal in tracortical inhibition and suggest that both diagnostic techniques may be v aluable non-invasive tools in localsation-related epilepsy.