In the present study carried out in our laboratory, we recorded local field potential (LFP) signals in primary visual cortex (V1 area) of rats during the anesthesia process in the electrophysiological experiments of invasive microelectrode array implant, and obtained time evolutions of complexity measure Lempel-ziv complexity (LZC) by nonlinear dynamic analysis method. Combined with judgment criterion of tail flick latency to thermal stimulus and heart rate, the visual stimulation experiments are carried out to verify the reliability of anesthetized states by complexity analysis. The experimental results demonstrated that the time varying complexity measures LZC of LFP signals of different channels were similar to each other in the anesthesia process. In the same anesthesia state, the difference of complexity measure LZC between neuronal responses before and after visual stimulation was not significant. However, the complexity LZC in different anesthesia depths had statistical significances. Furthermore, complexity threshold value represented the depth of anesthesia was determined using optimization method. The reliability and accuracy of monitoring the depth of anesthesia using complexity measure LZC of LFP were all high. It provided an effective method of realtime monitoring depth of anesthesia for craniotomy patients in clinical operation.
Anesthesia ; methods ; Animals ; Evoked Potentials, Visual ; Microelectrodes ; Monitoring, Physiologic ; Nonlinear Dynamics ; Photic Stimulation ; Rats ; Reproducibility of Results ; Visual Cortex ; drug effects

Aconite is a common remedy of herb doctors and is widely used in the Far East. Clinical aspects of the visual disturbance produced by this drug have been described, but little is known about its pathology. Tinctura aconiti (0.6 mg of total alkaloid/kg 2x) was administered intraperitoneally in rabbits to evaluate its toxic effects on the visual system. The alteration in the visual evoked potential following aconite injection consisted of a delay in the onset and peak latency. Histopathologically, there were damages to the myelin sheath of the visual pathway, spinal cord and peripheral nerves. These findings suggest that aconite may cause primarily myelo-optic neuropathy.
Aconitum/administration & dosage/*toxicity ; Animals ; Evoked Potentials, Visual/*drug effects ; Injections, Intraperitoneal ; Myelin Sheath/*drug effects/ultrastructure ; Optic Nerve/*drug effects/ultrastructure ; Optic Nerve Diseases/*chemically induced/pathology ; Rabbits ; Spinal Cord/*drug effects/ultrastructure

Objective: To analyze the clinical features of children with uridine responsive developmental epileptic encephalopathy 50 (DEE50) caused by CAD gene variants. Methods: A retrospective study was conducted on 6 patients diagnosed with uridine-responsive DEE50 caused by CAD gene variants at Beijing Children's Hospital and Peking University First Hospital from 2018 to 2022. The epileptic seizures, anemia, peripheral blood smear, cranial magnetic resonance imaging (MRI), visual evoked potential (VEP), genotype features and the therapeutic effect of uridine were descriptively analyzed. Results: A total of 6 patients, including 3 boys and 3 girls, aged 3.5(3.2,5.8) years, were enrolled in this study. All patients presented with refractory epilepsy, anemia with anisopoikilocytosis and global developmental delay with regression. The age of epilepsy onset was 8.5 (7.5, 11.0) months, and focal seizures were the most common seizure type (6 cases). Anemia ranged from mild to severe. Four patients had peripheral blood smears prior to uridine administration, showing erythrocytes of variable size and abnormal morphology, and normalized at 6 (2, 8) months after uridine supplementation. Two patients suffered from strabismus, 3 patients had VEP examinations, indicating of suspicious optic nerve involvement, and normal fundus examinations. VEP was re-examined at 1 and 3 months after uridine supplementation, suggesting significant improvement or normalization. Cranial MRI were performed at 5 patients, demonstrating cerebral and cerebellar atrophy. They had cranial MRI re-examined after uridine treatment with a duration of 1.1 (1.0, 1.8) years, indicating significant improvement in brain atrophy. All patients received uridine orally at a dose of 100 mg/(kg·d), the age at initiation of uridine treatment was 1.0 (0.8, 2.5) years, and the duration of treatment was 2.4 (2.2, 3.0) years. Immediate cession of seizures was observed within days to a week after uridine supplementation. Four patients received uridine monotherapy and were seizure free for 7 months, 2.4 years, 2.4 years and 3.0 years respectively. One patient achieved seizure free for 3.0 years after uridine supplementation and had discontinued uridine for 1.5 years. Two patients were supplemented with uridine combined with 1 to 2 anti-seizure medications and had a reduced seizure frequency of 1 to 3 times per year, and they had achieved seizure free for 8 months and 1.4 years respectively. Conclusions: The clinical manifestations of DEE50 caused by CAD gene variants present a triad of refractory epilepsy, anemia with anisopoikilocytosis, and psychomotor retardation with regression, accompanied by suspected optic nerve involvement, all of which respond to uridine treatment. Prompt diagnosis and immediate uridine supplementation could lead to significant clinical improvement.
Male ; Female ; Humans ; Child ; Infant ; Epilepsy/genetics* ; Retrospective Studies ; Drug Resistant Epilepsy ; Uridine ; Evoked Potentials, Visual ; Anemia ; Electroencephalography/adverse effects* ; Neurodegenerative Diseases

BACKGROUNDOptic nerve injury, caused by retinal and optic nerve diseases, can eventually result in vision loss. To date, few effective treatments have been discovered to restore visual function. Previous studies showed that recombinant human erythropoietin (rhEPO) has a neuroprotective effect on the central nervous system, particularly in nerve injury. In this study, we investigated the effects of rhEPO on axonal regeneration and functional restoration following optic nerve injury. This was done by measuring the expression of growth associated protein 43 (GAP-43), a marker for neuronal regeneration, on the retina and flash-visual evoked potential (F-VEP).

METHODSAdult Wistar rats were randomly assigned to rhEPO and control (saline) groups. Optic nerve crush injury models were established and rhEPO or saline were immediately injected into the vitreous cavity. The expression of GAP-43 was detected by immunohistochemistry and the F-VEP was measured pre-injury, immediately after injury, 1 week and 2 weeks post-injury.

RESULTSNo detectable staining for GAP-43 was observed in normal retina. In the control group, the level of GAP-43 expression was higher at 1 week post-injury, but decreased at 2 weeks. In the rhEPO group, the level of GAP-43 expression was notably higher at both 1 week and 2 weeks. At each time point post-injury, the expression of GAP-43 in rhEPO group was significantly higher than the control group (P < 0.05). Obvious changes in F-VEP examination were detected immediately after optic nerve injury, including significantly prolonged latency and decreased amplitude of the P1 wave. In the control group, the changes were still obvious at 1 week. The latency was decreased and the amplitude had slightly recovered to 28.23% of the normal value at 2 weeks. In rhEPO group, there was significantly more recovery than the control group at 1 week and 2 weeks post-injury (P < 0.05). The latency most close to the normal level and the amplitude had recovered to 65.51% of the normal value at 2 weeks.

CONCLUSIONSrhEPO can prolong the expression of GAP-43 and increase its intensity after optic nerve injury, thereby promoting neural repair and axonal regeneration. Under the protection of rhEPO, the conduction velocity of the optic nerve recovered significantly. Therefore, rhEPO has neuroprotective effects on the optic nerve and promotes functional restoration of the optic nerve.

Animals ; Erythropoietin ; pharmacology ; therapeutic use ; Evoked Potentials, Visual ; drug effects ; GAP-43 Protein ; metabolism ; Humans ; Immunohistochemistry ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Optic Nerve ; drug effects ; Optic Nerve Injuries ; drug therapy ; Random Allocation ; Rats ; Rats, Wistar ; Recombinant Proteins ; Retina ; drug effects ; metabolism

We report a rare case of optic nerve atrophy with severe disc cupping resulting from methanol poisoning. A 30-year-old man presented to the hospital complaining of decreased visual acuity in both eyes a day after drinking alcohol containing methanol. His initial visual acuity allowed for only visualizing hand motion and not corrected in either eye. Initial intraocular pressure was within normal limits in both eyes. Initial fundus examination showed optic disc swelling in both eyes. Four years later, he visited our hospital for an eye evaluation. Visual acuity in both eyes still only allowed for visualizing hand motion. No nystagmus was observed in either eye during the optokinetic nystagmus test, and no waves were found in a visual evoked potential test. No specific change was noted on brain magnetic resonance imaging. On fundus examination, there was disc pallor in both eyes and disc cupping with a high cup/disc (C/D) ratio above 0.9 in the left eye. C/D ratio of the right eye was 0.5. Methanol poisoning may induce glaucomatous disc cupping in the late stage as well as optic atrophy. One possible mechanism of disc cupping is ganglion cell loss due to acute demyelination of the retrobulbar optic nerve. This report is the first photographic evidence of methanol induced optic disc cupping in Korea.
Adult ; Diagnosis, Differential ; Evoked Potentials, Visual ; Fluorescein Angiography ; Fundus Oculi ; Humans ; Magnetic Resonance Imaging ; Male ; Methanol/*poisoning ; Optic Atrophy/*chemically induced/pathology/physiopathology ; Optic Disk/drug effects/*pathology ; Papilledema/*chemically induced/pathology/physiopathology ; Severity of Illness Index ; Solvents/poisoning ; Tomography, Optical Coherence ; Visual Acuity

A 63-year-old man with a history of liver transplantation presented to our clinic complaining of visual disturbance. He had been receiving tacrolimus (FK 506) for 30 months (6 mg/day for 2 years and 3 mg/day for 6 months); he reported that the visual disturbance began while taking tacrolimus. A full ophthalmologic examination and electrophysiologic and imaging studies were performed. The best corrected visual acuity was 0.1 in both eyes. There were no abnormal finding in the anterior segment, pupillary reflexes were normal and, there was no swelling in either optic disc. Although the foveal reflex was slightly decreased, fluorescein angiography revealed non-specific signs, with the exception of a window defect. A multifocal electro-retinogram revealed decreased amplitude of the central ring. A Swedish interactive threshold algorithm-standard 10-2 visual field test revealed a central scotoma. These findings suggest that tacrolimus may result in maculopathy. Therefore, careful ophthalmologic examination is necessary in the patients taking tacrolimus.
Electroretinography ; Evoked Potentials, Visual ; Fundus Oculi ; Humans ; Immunosuppressive Agents/*adverse effects/therapeutic use ; Liver Transplantation ; Macula Lutea/*drug effects ; Male ; Middle Aged ; Postoperative Care ; Reaction Time ; Retinal Diseases/*chemically induced/diagnosis ; Scotoma/chemically induced/diagnosis ; Tacrolimus/*adverse effects/therapeutic use ; Tomography, Optical Coherence