Cerebral blood flow is known as an indicator of cerebral metabolism. Using the 133Xenon inhalation method, we studied the regional cerebral blood flow (r-CBF) in patients with different subtypes of depression and in remission. A left frontal hypervascularization and a right posterior hypovascularization were found in major depressives, compared to normal subjects, minor depressives, and normothymic bipolar patients. These results tend to confirm the existence of cerebral dysfunction in both hemispheres in major depression, as reported by other authors using different techniques.

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ABSTRACT:A 72-year-old man developed a very progressive neuropsychologic deficit 6 years ago, beginning with isolated visual topographic memory disturbances and visuo-constructive apraxia without additional manifestations of dementia. The syndrome worsened thereafter with the emergence of visual agnosia, simultagnosia, psychic paralysis of gaze, auditivo-verbal agnosia, and recently an amnestic syndrome with confabulation and confusion (at the end of 1989). CT scans, which remained unchanged over the years, showed mild, focal atrophic changes revealed by dilatation of the right occipital horn. His angiograms were normal. Two SPECT studies (with HMPAO measurements), performed 6 years from the onset, detected marked hypoperfusion in both parieto-occipital regions, mainly on the right side. Progressive focal degenerative disease without dementia is a relatively new syndrome, especially in cases with progressive aphasia. 1 As noted in our patient, progressive disturbances initially localized in the right parieto-occipital region followed by posterior bilobar degeneration (pronounced on the right side) without dementia until late in the course may represent another exceptionally reported characteristic of this new syndrome. It is suggested that this variant of the Mesulam syndrome is more likely explained by progressive atrophy of the Alzheimer type. RESUME: Atteinte neurodegenerative focale des aires associatives du cortex posterieur. Un patient de 72 ans a developpe' 6 ans plus tot un deficit neuropsychologique progressif debutant par une perturbation isolee de la memoire topographique visuelle associee a une apraxie visuo-constructive mais sans autre manifestation cognitive suggerant une d6mence. Ce syndrome s'est aggrave tres progressivement par l'apparition d'une agnosie visuelle, de simultagnosie, de paralysie psychique du regard, et d'agnosie auditivo-verbale. En 1989, soit apres 6 ans devolution, il a developpe un syndrome amnesique avec confabulation puis, quelques mois plus tard, un etat confusionnel. Les CT scans cerebraux, demeures inchanges au fil de 1'evolution, montraient une atrophie moderee au niveau de la region parieto-occipitale droite revelee par une dilatation ventriculaire de la corne occipitale. L'angiographic cerebrale etait normale. Deux etudes d6bitmetriques (SPECT, HMPAO) realisees en 1989 detectaient des hypoperfusions posterieures bilaterales parietooccipitales, nettement plus marquees a droite. Ce type de syndrome, qui rentre dans le cadre d'une atteinte neurodegenerative focale sans signe de demence classique, sauf en phase tardive, est connu seulement depuis 1982' dans des cas d'aphasie progressive. Dans notre cas, les symptomes initiaux du patient etaient attribues a un dysfonctionnement localise au niveau de la region parioto-occipitale droite et il n'y eut evidence de demence que beaucoup plus tard. Ceci represente, par sa localisation, une autre caracteristique exceptionnellement decrite dans ce nouveau syndrome. Nous suggerons que cette variante posterieure du syndrome de Mesulam...