National Institute of Psychiatry and Neurology, Department of Neurology, Budapest, Hungary

The case of an 53 years old man in presented. In the background of his severe insomnia and psychosis-like psychopathology left side medio- basal frontal tumor, probably semimalignant astrocytoma was revealed by MRI. His somatic status, neuropsychologic testing was negative, Roschach showed deep regression, panic-like anxiety and mild organic signs. On routine EEG there were only minimal dysfunction signs (some theta waves) bifrontally.

Whole night polysomnography showed only a few minutes of deep slow wave sleep and no. REM sleep at all. Most of the time was spent awake, in stage on sleep and less in stage two. Sleep was extemely fragmented by several hundred awakenings and stage shifts, mostly indiced by the microstructural element K-alpha complex.

At the moment further investigations, potential neurosurgical intervention and pharmacologic treatment is being planned, but the patient became incomplient on account of his pychosis-like, paranoid attitude.

Basal forebrain – medial preoptic and anterior hypothalamic area – is known to be a main sleep regulating complex. It includes the cholinergic arousal system and GABA- ergic and galaninergic sleep promoting centers 1,2, including orbitofrontal cortex and olfactory tubercle, too3,4. Neurobiological role of the basal forebrain structures allows the hypothesis of organic insomnia in this case – dysfunction in the fronto-basal, basal forebrain sleep regulating system induced by the tumor near this region. The tumor may damage sleep inducing structures or – by it`s merge region – stimulate cholinergic arousal system. Irritation of the septal cholinergic nuclei and lesion of frontobasal region might be responsible for the psychosis- like psychosyndrome too.

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