ABSTRACT
Magnetoencephalography (MEG) is a noninvasive diagnostic modality that directly measures neuronal signaling by recording the magnetic field created from dendritic, intracellular, electrical currents of the neuron at the surface of the head. In clinical practice, MEG is used in the epilepsy presurgical evaluation and most commonly is an "interictal" study that can provide source localization of spike-wave discharges. However, seizures may be recorded during MEG ("ictal MEG") and mapping of these discharges may provide more accurate localization of the seizure onset zone. In addition, spike-negative EEG with unique MEG spike-waves may be present in up to 1/3 of MEG studies and unique MEG seizures (EEG-negative seizures) have been reported. This case report describes a patient with unique MEG seizures that exhibited MEG pre-ictal spiking in a tight cluster consistent with the independent interictal epileptiform activity. Stereotactic EEG demonstrated pre-ictal spiking concordant with the MEG pre-ictal spiking.
ABSTRACT
Electrical stimulation of a brain region producing a micturition response has never previously been described in the human. This report identifies the anterior cingulate gyrus as a brain region important in the micturition response. Stereo electroencephalography was performed in a 38-year-old female with medically refractory epilepsy. The response of the left anterior cingulate from low- to high-frequency brain stimulation was tested. Stimulation within the left anterior cingulate resulted in a reproducible micturition response. The response was dependent on the frequency of stimulation (present with stimulation at 50-150 Hz and not present at 5 or 350 Hz). These results provide evidence for the presence of a region within the human left anterior cingulate gyrus involved in producing the micturition response. This may have implications in the understanding of the physiological mechanisms of willful micturition and in the treatment of bladder disorders.