Error-monitoring abnormalities may underlie positive symptoms of schizophrenia. Response-synchronized event-related potentials during picture-word matching yielded error- and correct-response-related negativity (ERN, CRN) and positivity (Pe, Pc) and preresponse lateralized readiness potentials (LRP) from 18 schizophrenic patients and 18 controls. Both groups responded faster to matches than nonmatches, although patients were generally slower and made more errors to nonmatches. Compared with controls, patients, particularly with paranoid subtype, had smaller ERNs and larger CRNs, which were indistinguishable. LRPs showed evidence of more response conflict before errors than before correct responses in controls but not patients. Despite ERN/CRN abnormalities, post-error slowing and Pe were normal in patients, suggesting a dissociation of ERN and error awareness. Anterior cingulate and dorsolateral prefrontal cortical dysfunction in schizophrenia are implicated.

Chronic memory deficits are a major cause of morbidity following traumatic brain injury (TBI). In the rat, the hippocampal theta rhythm is a well-studied correlate of memory function. This study sought to investigate disturbances in hippocampal theta rhythm following lateral fluid percussion injury in the rat. A total of 13 control rats and 12 TBI rats were used. Electrodes were implanted in bilateral hippocampi and an electroencephalogram (EEG) was recorded while the rats explored a new environment, and also while navigating a modified version of the Barnes maze. Theta power and peak theta frequency were significantly attenuated in the injured animals. Further, injured rats were less likely to develop a spatial strategy for Barnes maze navigation compared to control rats. In conclusion, rats sustaining lateral fluid percussion injury demonstrated deficits in hippocampal theta activity. These deficits may contribute to the underlying memory problems seen in chronic TBI.

ObjectivesThe spontaneous spinal epidural hematoma (SSEH) is a rare clinical entity. Patients typically present with sudden onset back pain followed by neurological deficits.MethodsDiagnosis of SSEH is usually made with MRI and standard treatment is surgical evacuation. In 1996, Groen published the most comprehensive review on the SSEH in which he analyzed 333 cases. We review 104 cases of SSEH presented in the English literature since the last major review and add three of our own cases, for a total of 107 cases.ResultsOur patients presented with back pain and neurologic deficits. Two made excellent functional recovery with prompt surgical decompression while one continued to have significant deficits despite evacuation. Better postoperative outcome was associated with less initial neurological dysfunction, shorter time to operation from symptom onset and male patients.ConclusionWe discuss the etiology of SSEH and report current trends in diagnosis, treatment, and outcome.