Photosensitive occipital lobe epilepsy (POLE) is a rare idiopathic reflex focal epilepsy that can occur in all age groups. It is characterized by occipital lobe seizures induced by flashing stimuli (flashing sunlight, video games, TV commercials and programs, etc.). Photoparoxysmal response on EEG is induced by intermittent photic stimulation; Ictal EEG shows rapid spike rhythms are originated from the occipital region. There are no obvious abnormalities in brain image. POLE responds well to anti-seizure medications and has a good prognosis. This article reviews the research progress on POLE in order to improve the clinician’s understanding and reduce the rates of missed diagnosis and misdiagnosis.
Steady-state visual evoked potential (SSVEP) is one of the commonly used control signals in brain-computer interface (BCI) systems. The SSVEP-based BCI has the advantages of high information transmission rate and short training time, which has become an important branch of BCI research field. In this review paper, the main progress on frequency recognition algorithm for SSVEP in past five years are summarized from three aspects, i.e., unsupervised learning algorithms, supervised learning algorithms and deep learning algorithms. Finally, some frontier topics and potential directions are explored.
Objective To investigate the relationship between graded spinal cord ischemia/reperfusion injury and somatosensory evoked potentials(SEP),neurologic function score（NFS）and the histopathological changes of spinal cord. Methods Forty rabbits were randomized and equally divided into 4 groups: shamoperation group, ischemia for 30min, 45min and 60min groups. The spinal cord ischemiareperfusion injury model was created by occlusion of the abdominal aorta in rabbits. SEP was monitored before ischemia,5,10minutes after ischemia, 15, 30 minutes, 1,2, 24 and 48 hours after reperfusion. NFS was evaluated at 6,12,24 and 48 hours after reperfusion.The pathological changes of spinal cord were observed after reperfusion 48 hours. Results The pathological characters with mild,moderate and severe spinal cord ischemia/reperfusion injury could be simulated by declamping after 30， 45 and 60 minutes infrarenal aorta crossclamping. SEP amplitude returned to normal after reperfusion 15 minutes（Pgt;0.05）and SEP latency returned to normal after reperfusion 30 minutes（Pgt;0.05）during mild spinal cord ischemia/reperfusion injury.SEP amplitude returned to normal after reperfusion 30 minutes（Pgt;0.05）and SEP latency returned to normal after reperfusion 60 minutes（Pgt;0.05）during moderate spinal cord ischemia/reperfusion injury. SEP latency increased and SEP amplitude decreased during severe spinal cord ischemia/reperfusion injury,compared with other groups, there were significant differences in SEP latency and SEP amplitude by clamping the infrarenal aorta for 60min（Plt;0.01）. With graded spinal cord ischemia/reperfusion injury, compared with shamoperation group, spinal cord ischemiareperfusion groups had significant differences in NFS（Plt;0.01）. Conclusion SEP is much quicker in the recovery of amplitude than latency during spinal cord ischemia/reperfusion. SEP is a sensitive and accurate index for spinal cord function during ischemia/reperfusion injury. SEP monitoring spinal cord ischemia/reperfusion injury during operation provides experimental basis for clinical application.
ObjectiveTo investigate the influence and management of blood pressure on intraoperative cortex somatosensory evoked potential (CSEP) in the surgery of severe scoliosis. MethodsFrom June 2009 to March 2012, CSEP monitoring during surgery of severe scoliosis were performed on 43 patients, in whom 4 had abnormal CSEP while blood pressure decline. There were 2 males and 21 females. The average age was 16.1 years. The average preoperative Cobb angle was 96.1° (88.7-107.5°). Latency and amplitude of cortical potentials were observed with the value of the latency extension more than 10% and peak amplitude reduction more than 50% defined as abnormality. The arterial blood pressure (ABP) was used to evaluate the intraoperative blood pressure. ResultThe incidence rate of bilateral CSEP wave abnormalities after blood pressure decline was 9.3% in the surgery of severe scoliosis. One case of CSEP abnormality occurred during the installing of pedicle screws; two cases during the Smith-Petersen osteotomy, and one case during the bone graft after correction. With the ABP dropping to about 92/57 mm Hg (1 mm Hg=0.133 kPa), the amplitude decreased 80% in 24-33 minutes. After the ABP increased to 113/75 mm Hg by treatment, the index was backed up normally in 5-10 minutes. There was no neurological complication after surgery. ConclusionA high incidence rate and significantly decreased amplitude of CSEP abnormality after blood pressure decline in the surgery of severe scoliosis are found. Intraoperative stable blood pressure should be maintained for patients with severe scoliosis. When the amplitude of CSEP decreases followed with blood pressure decline, blood pressure should be actively corrected by treatment, so that the CSEP may get back to normal as soon as possible.