The effect of motor activity on the left fronto-central region of the human brain was analyzed spatially and temporally by using noninvasive near-infrared light (NIR) topography. The changes in oxygenation states caused by motor activity were measured using intensity-modulated NIR spectroscopy at ten measurement positions on the head surface. The subject randomly performed unilateral finger opposition for 30 s as motor stimulation. When the subject performed contralateral (right) finger movement, significant increases in both oxygenated hemoglobin (oxy-Hb) and total hemoglobin (total-Hb) and decreases in deoxygenated hemoglobin (deoxy-Hb) were observed in a particular area. By mapping the static topograms of the changes of each Hb and comparing them with an anatomical image of MRI, it was found that the particular area was located on the motor cortex along the central sulcus. By mapping the dynamic topograms of the changes of total-Hb, which reflect the cerebral blood volume, and analyzing the spatiotemporal hemodynamic changes associated with the brain activity, it was found that the regional change in cerebral blood volume in the primary motor area overlaps the global change around the motor cortex. These results demonstrate that NIR topography can be used to effectively observe the human brain activity.

Autonomic and somatomotor responses to electrical stimulation of the posterior hypothalamus are reported in 51 patients with pathologically aggressive behavior. The stimulated area causing rise in blood pressure, tachycardia, and maximal pupillary dilatation lies in the posteromedial hypothalamus, more than 1 mm and less than 5 mm lateral to the lateral wall of the third ventricle, occupying a triangle formed by the midpoint of the intercommissural line, the rostral end of the aqueduct, and the anterior border of the mammillary body. Electrical stimulation of this (ergotropic) triangle resulted in desyncbronization of the electroencephalogram (EEG) with hippocampal theta waves, or diffuse irregular delta waves of high voltage.Cases with violent behavior showed higher plasma levels of non-esterified fatty acids (NEFA) in the fasting stage; these were markedly elevated by electrical stimulation of the ergotropic triangle.Points in the ergotropic triangle where signs of sympathetic discharge were most marked were electrocauterized bilaterally. This procedure produced marked calming effects (95% of the cases) during the follow-up period of more than 2 years. Postoperatively there was a tendency to a decrease in sympathicotonia or an increase in parasympathicotonia. The follow-up plasma level of NEFA was found to have decreased to approximately the normal value.Y. Neurosurg. / Volume 33 / December, 1970 69]

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Summary: Purpose:We sought to establish a noninvasive method for focus diagnosis of epilepsy.Methods: We examined the use of multichannel nearinfrared spectroscopy (NIRS). It is known as a noninvasive method of functional brain mapping. We monitored cerebral blood volume change with NIRS during long-term EEG monitoring of epilepsy in 32 cases with intractable epilepsies to diagnose the epileptogenic focus.Results: In 96% of cases, NIRS showed significant hyperperfusion in the side of seizure foci, whereas ictal SPECT showed hyperperfusion in 69% of cases.Conclusions: Ictal NIRS is a reliable method to evaluate the focus side in epilepsy, especially when it is coupled with ictal SPECT.

The risk of epileptic seizures after craniotomy is extremely important but the incidence of postoperative epilepsy varies greatly, depending on the patient's conditions such as primary diseases, severity of surgical insult, and pre-existing epilepsy. Animal studies suggest that neurosurgical insults lead to seizures by two different mechanisms: One mechanism is mediated by free radical generation and the other by impaired ion balance across the cell membrane caused by ischemia or hypoxia. Conventional antiepileptic agents such as phenytoin, phenobarbital, carbamazepine, and valproic acid are promising for the prevention of early seizures, but the effect in preventing postoperative epilepsy is still controversial. Studies on the prophylactic effect of newer antiepileptic agents in craniotomized patients were very limited. Zonisamide, an antiepileptic agent with antiepileptogenic, free radical scavenging and neuroprotective actions in experimental animals, showed promising effects against postoperative epilepsy in a randomized double blind controlled trial. Prophylactic treatment for craniotomized patients significantly prevented the development of partial seizures during the follow-up period. Most recent studies have not supported the prophylactic use of antiepileptic agents in craniotomized patients, but further studies are required.

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Near infrared spectroscopic topography (NIRS) is widely recognized as a noninvasive method to measure the regional cerebral blood volume (rCBV) dynamics coupled with neuronal activities. We analyzed the rCBV change in the early phase of epileptic seizures in 12 consecutive patients with medically intractable epilepsy. Seizure was induced by bemegride injection. We used eight-channel NIRS in nine cases and 24 channel in three cases. In all of the cases, rCBV increased rapidly after the seizure onset on the focus side. The increased rCBV was observed for about 30-60 s. The NIRS method can be applied to monitor the rCBV change continuously during seizures. Therefore, this method may be combined with ictal SPECT as one of the most reliable noninvasive methods of focus diagnosis.