Electrophysiological correlates of active and passive attentional states after severe traumatic brain injury.

We aimed to investigate attentional resources distribution in traumatic brain injury (TBI) patients. Auditory event-related potentials (ERPs) were recorded from 35 severe TBI patients in post-acute care, and 35 age- and gender-matched controls using an auditory oddball paradigm under passive (ignore stimuli) and active (count deviants) conditions. Six components (P1, N1, P2, N2, P3, N3) in four waveforms were studied, i.e., the waveforms elicited by standard and by deviant tones in the passive and active task, respectively. In addition to alterations of latency and/or amplitude of single components, particularly of the late components N2 and P3, we observed in patients a different response pattern to task condition. We found evidence of deficits in the early stages of information processing and allocation of attentional resources. The analysis of the response to standards was crucial for detecting new aspects of attentional impairments.

Valproic acid induced encephalopathy--19 new cases in Germany from 1994 to 2003--a side effect associated to VPA-therapy not only in young children.

Valproic acid (VPA) is a broad-spectrum antiepileptic drug and is usually well-tolerated. Rare serious complications may occur in some patients, including haemorrhagic pancreatitis, bone marrow suppression, VPA-induced hepatotoxicity and VPA-induced encephalopathy. The typical signs of VPA-induced encephalopathy are impaired consciousness, sometimes marked EEG background slowing, increased seizure frequency, with or without hyperammonemia. There is still no proof of causative effect of VPA in patients with encephalopathy, but only of an association with an assumed causal relation. We report 19 patients with VPA-associated encephalopathy in Germany from the years 1994 to 2003, none of whom had been published previously.