For the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease, cortical hyperintensity signals on diffusion-weighted MRI are useful for the cortical form and thalamic hypoperfusion or hypometabolism on cerebral blood flow SPECT or [18F]2-fluoro-2-deoxy-d-glucose PET for the thalamic form.

This study evaluated efficacy and safety of donepezil hydrochloride (donepezil) at 5 mg/day in patients with mild to moderately severe Alzheimer’s disease for 24 weeks in a double-blind, placebo-controlled comparative trial. In this study, 268 patients were enrolled and 39 of these (15%) were withdrawn. In the evaluable population of efficacy, Protocol-Compatible (PC) analyzed patients (n = 228), better effects than that of placebo were confirmed using two primary efficacy measures: a cognitive performance test, the Japanese version of the Alzheimer’s Disease Assessment Scale – cognitive subscale (ADAS-J cog, p = 0.003) and a clinical global assessment, the Japanese version of the Clinical Global Impression of Change (J-CGIC, p = 0.000). The superiority of donepezil was also shown by secondary measures: the Sum of the Boxes of the Clinical Dementia Rating (CDR-SB), the Mental Function Impairment Scale (MENFIS) and the caregiver-rated modified Crichton scale (CMCS). The same results were obtained in the intention-to-treat (ITT) analysis (n = 263). The incidence of drug-related adverse events was 10% (14/136) in the donepezil and 8% (10/131) in the placebo group; no significant difference was seen between the two groups. The main adverse events were gastrointestinal symptoms, and these were almost all mild, and they all disappeared with continued administration or temporary discontinuation of donepezil. These results indicate that the donepezil appears to be effective and well tolerated in patients with mild to moderately severe Alzheimer’s disease.

Nonpsychotic visual hallucinations in Parkinson disease (PD) may be associated with hypoperfusion in the right fusiform gyrus and hyperperfusion in the right superior and middle temporal gyri. These temporal regions are important for visual object recognition and these regional cerebral blood flow changes are associated with inappropriate visual processing and are responsible for nonpsychotic visual hallucinations in PD.

Spinocerebellar ataxia 6 (SCA6) is an autosomal dominant spinocerebellar degeneration caused by the expansion of the polymorphic CAG repeat in the human alpha1A voltage-dependent calcium channel subunit gene (CACNL1A4 gene). We have analyzed 60 SCA6 individuals from 39 independent SCA6 Japanese families and found that the CAG repeat length is inversely correlated with the age of onset (n = 58, r = -0.51, P < 0.0001). SCA6 chromosomes contained 21-30 repeat units, whereas normal chromosomes displayed 6-17 repeats. There was no overlap between the normal and affected CAG repeat number. The anticipation of the disease was observed clinically in all eight parent-child pairs that we examined; the mean age of onset was significantly lower (P = 0.0042) in children than in parents. However, a parent-child analysis showed the increase in the expansion of CAG repeats only in one pair and no diminution in any affected cases. This result suggests that factors other than CAG repeats may produce the clinical anticipation. A homozygotic case could not demonstrate an unequivocal gene dosage effect on the age of onset.

Our results showed that the posterior cingulate areas play some important roles in the dementing process in PDD. However, as the pathological processes responsible for dementia in PD patients may be multifaceted, further studies are necessary.