Progressive Focal Degenerative Disease of the Posterior Associative Cortex

Abstract

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...

The syndrome of progressive posterior cortical dysfunction: A multiple case study and review

“…However, there have been a few case reports and series of patients studied clinically and/or pathologically that presented visual object agnosia. 31 , 35 , 36 , 38 , 41 , 43 - 45 The detailed pathological analysis of autopsies found a more extensive disconnection of a specific component of corticocortical visual associative systems. The distribution of lesions correlated well with neurological symptomatology presented and supports the hypotheses that long corticocortical projections are disrupted in AD.…”

“…Previous articles on functional imaging include several single case reports and a few series of small samples. 32 , 42 , 43 , 45 , 47 - 50 The most common finding of functional imaging in SPPCD is hypoperfusion or hypometabolism (with SPECT or positron emission tomography, respectively) in occipital and posterior parietal areas, usually more marked on the right side. Occasionally the temporal associative cortex is involved and frontal extension found.…”

Focal Cortical Atrophy Syndromes

“…As with PPA, the onset of PCA, based on reports over the past 10 years, is presenile with an average age of 59.8 (range 45-68). Imaging may show parieto-occipital atrophy on CT or MR and parieto-occipital hypoperfusion is usually evident on functional imaging Attig, Jacquay, Uytdenhoef, & Roland, 1993) (see Fig. 6.)…”

Visual perception without awareness in a patient with posterior cortical atrophy: Impaired explicit but not implicit processing of global information

“…In some cases, patients can experience a single visual cognitive deficit for a number of years prior to the development of any other visual cognitive disturbances. Further, the profile of visual impairment in PCA patients can change as the disease progresses (Attig et al, 1993;Della Sala et al, 1996;Mendez & Cherrier, 1998;Ross et al, 1996).…”