Recovery of spontaneous neuromagnetic activity after extracranial-intracranial bypass in a patient with middle cerebral artery occlusion.

PATIENT AND METHODS

Cerebral blood flow and neuromagnetic activity were measured using (123)I-iodoamphetamine-single photon emission computed tomography (IMP-SPECT) and magnetoencephalography (MEG), before and after extracranial-intracranial (EC-IC) bypass surgery in a 55-year-old woman with unilateral middle cerebral artery occlusion that occurred with intraventricular haemorrhage. Frequency analysis of slow waves measured on MEG was performed using an adaptive beam-former method.

RESULTS AND DISCUSSION

Distribution of delta waves was observed pre-operatively corresponding to areas of cerebral hypo-perfusion as confirmed by IMP-SPECT but disappeared post-operatively with improvements in cerebral blood flow. Imaging of slow-wave distributions with MEG may represent a new technique for identifying cerebral ischaemia.