A posterior variant of corticobasal syndrome : evidence from a longitudinal study of cognitive and functional status in a single case

We describe a patient (CG) suffering from early onset dementia who presented with corticobasal syndrome (CBS). The aims of the study were as follows: (i) a detailed description of the cognitive phenotype; (ii) a comprehensive, longitudinal evaluation of apraxia; (iii) an appraisal of the impact of apraxia and other cognitive impairments on patient functional status; and (iv) an indirect mapping of degeneration spreading. A three-year longitudinal, observational follow-up study of cognitive and functional status was performed. Four main results emerged. First, an unusual CBS phenotype appeared that was characterized by symmetrical presentation, asymmetrical course, and prominent posterior (bi-parietal) cognitive and motor cortical manifestations. Second, some findings of limb apraxia in CBS were replicated and substantiated; moreover, some novel findings of other cognitive impairments emerged. Third, an early, significant functional decline, probably related to apraxia and to visuospatial attention impairments, became apparent. Fourth, CG's clinical picture was compatible with an underlying dysfunction of the large-scale, dorsal sensory-motor association network, as already suggested in previous CBS cases. This case report confirms the heterogeneity of CBS and suggests the emergence of a possible less common variant, i.e. the posterior CBS (P-CBS)

Preclinical Polymodal Hallucinations for 13 Years before Dementia with Lewy Bodies

Objective. We describe a case of dementia with Lewy bodies (DLB) that presented long-lasting preclinical complex polymodal hallucinations. Background. Few studies have deeply investigated the characteristics of hallucinations in DLB, especially in the preclinical phase. Moreover, the clinical phenotype of mild cognitive impairment-(MCI-) DLB is poorly understood. Methods. The patient was followed for 4 years and a selective phenomenological and cognitive study was performed at the predementia stage. Results. The phenomenological study showed the presence of hypnagogic and hypnopompic hallucinations that allowed us to make a differential diagnosis between DLB and Charles Bonnet syndrome (CBS). The neuropsychological evaluation showed a multiple domain without amnesia MCI subtype with prefrontal dysexecutive, visuoperceptual, and visuospatial impairments and simultanagnosia, which has not previously been reported in MCI-DLB. Conclusions. This study extends the prognostic value of hallucinations for DLB to the preclinical phases. It supports and refines the MCI-DLB concept and identifies simultanagnosia as a possible early cognitive marker. Finally, it confirms an association between hallucinations and visuoperceptual impairments at an intermediate stage of the disease course and strongly supports the hypothesis that hallucinations in the earliest stages of DLB may reflect a narcolepsy-like REM-sleep disorder