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Biomedical subjects

D H Ingvar

Publications and source records attributed to D H Ingvar.

159 records · Page 9Linked to original sources
PubMedDate not supplied

Quantified EEG and cortical evoked responses in patients with chronic traumatic frontal lesions.

Eighteen frontal trauma patients and 17 age-matched control subjects had quantified EEGs and measurements of sensory (SEP) and auditory evoked potentials (P300) using a Biologic Brain Atlas III system. The findings were compared to the conventional paper EEG, and to the frontal lesion volumes, severity of head injury, and outcome variables. The quantified EEG confirmed the pathological findings detected by visual inspection, but some regional abnormalities were more easily detected by topographic mapping. The regional distribution of pathological slowing corresponded well with the morphological lesions in most patients. The modal frequency of EEG correlated both with lesion volume and injury severity and with the outcome variables. There were no pathological findings in the SEPs, and all but one patient had clearly distinguishable P300 responses. There was a significant reduction in P300 amplitude in the frontal patients at the anterior, but not at the posterior electrodes. The topographical distribution of the P300 changes corresponded well with the morphological lesions. Our findings indicate that the P300 potential is, in part, dependent upon the prefrontal cortical areas. The present study thus supports P300 investigations which have shown amplitude reduction in other disorders (e.g., schizophrenia) with a presumed prefrontal dysfunction.

Adult↗
PubMedDate not supplied

History of brain imaging in psychiatry.

This is a brief history of the use of brain imaging in neuropsychology and psychiatry. There are two main parts. The first concerns brain imaging using regional cerebral blood flow (rCBF) measurements with xenon clearance. The 2-dimensional rCBF techniques have been used since 1961. The second concerns application of PET techniques starting in the early 80s. Brain imaging has yielded new information on consciousness, cortical localization, language, emotions and will. In psychiatry, brain imaging has revealed regional cerebral abnormalities in schizophrenia, affective disorders, DAMP, as well as following alcohol intake.

Brain↗
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PET studies of glucose metabolism in patients with schizophrenia.

The hypothesis of abnormal patterns of metabolism in schizophrenia was examined in a series of six young patients with psychotic symptoms satisfying the research diagnostic criteria. After intravenous injection of 11C-glucose obtained through a photosynthetic process, the regional activity of 11C in brain was measured with a four-ring positron camera. Regions of interest were obtained from computed tomographic images. Each patient underwent a second positron emission tomographic examinations after 4-5 weeks of treatment with a neuroleptic drug. No evidence of a hypofrontal pattern was found, but after treatment there was a reduced frontal uptake on the left side compared with temporal regions. The left-right asymmetry in the lentiform nucleus was reduced after treatment.

Acute Disease↗