Eye movement and random number in NP lupus evaluation.

We evaluated the vulnerability of central nervous system (CNS) in patients with systemic lupus erythematosus (SLE) using exploratory eye movement analysis and random number generation (RNG), and compared the tests in evaluating CNS vulnerability. Nineteen patients received the tests more than a month after SLE onset in nonpsychotic status. Exploratory eye movements were analyzed using an eye-mark recorder that detects corneal reflection of infrared light, and numbers of eye fixations were counted to calculate responsive search score (RSS). Using digits 0 through 9, 100 numbers were vocally generated at a random fashion. "Seriality score" was calculated from the recorded 100 numbers. RSS of SLE patients was similar to that of normal individuals, irrespective of neuropsychiatric lupus history. Seriality score of patients having a history of neuropsychiatric lupus was higher than that of never having it (p < 0.05). No relations were confirmed between RSS and seriality score. The current study suggested heterogeneous nature of SLE in CNS vulnerability when evaluating with seriality score, but not with RSS. There seemed to be a difference between exploratory eye movement analysis and RNG in evaluating CNS vulnerability. Each test seemed to evaluate different aspects of brain function.

Effects of low-dose ketamine on neuropathic pain: An electroencephalogram-electrooculogram/behavioral study.

The aim of the present study was to clarify the neurophysiological changes associated with analgesic and behavioral effects of low-dose ketamine HCl in patients suffering from chronic neuropathic pain. Ten in-patients with neuropathic pain participated in this single-blind, placebo-controlled study after giving written informed consent. Following intravenous injections of a saline solution (placebo), three bolus injections of 5 mg ketamine HCl were administered at 5 min intervals. Changes in pain perception were assessed using a numerical rating scale for pain. Behavioral changes, including psychotomimetic effects, were assessed using the Brief Psychiatric Rating Scale (BPRS). Electroencephalograms (EEG) and electrooculograms (EOG) were recorded continuously throughout the testing period. One minute EEG and closed-eye eye movements were quantified. The effects of ketamine were evaluated by comparing the neurophysiological and behavioral parameters obtained from the placebo and ketamine trials. Pain reduction was significantly correlated with ketamine-induced changes in hallucinatory behavior and excitement as measured by the BPRS. Ketamine injections caused a significant decrease in the EEGalpha amplitude without an accompanying reduction in EEG frequency. The EEGalpha amplitude reduction at the right central electrode was significantly related to subjective pain relief. Subanesthetic doses of ketamine significantly decreased rapid eye movements, but did not initiate slow eye movements. In conclusion, the present EEG-EOG/behavioral results indicate that ketamine-induced failure of neural integration between cortical-subcortical regions induces psychotic symptoms and alters pain perception on neuropathic pain.