Telomere length shortening in patients with dementia with Lewy bodies.

BACKGROUND AND PURPOSE: Shortened telomere length has been considered to be associated with various age-related diseases, especially in dementia such as Alzheimer's disease and vascular dementia. However, changes in telomere length in dementia with Lewy bodies (DLB) remain unclear. To elucidate these changes, we set out to determine telomere length in peripheral leukocytes as well as the level of urinary 8-hydroxy-deoxyguanosine (8-OHdG) as a marker of oxidative stress in DLB. METHODS: Blood samples were obtained from 33 patients with a clinical diagnosis of probable DLB and 35 age-matched, non-demented elderly controls (NEC). Telomere length was assessed by quantitative real-time polymerase chain reaction of genomic DNA extracted from leukocytes, whereas oxidative stress was assessed on the basis of urine 8-OHdG level, which was measured using high-performance liquid chromatography. RESULTS: Telomere length was significantly shorter in the DLB group than in the NEC group. Urinary 8-OHdG levels were significantly higher in the DLB group than in the NEC group. There was a negative correlation between telomere length and age in the DLB group; however, there were no significant relationships between telomere length and clinical findings including disease duration, severity of cognitive decline, presence or absence of fluctuation in cognitive function, visual hallucinations, and Parkinsonism. In both groups, the correlation between telomere length and urinary 8-OHdG levels was not significant. CONCLUSIONS: These findings indicate that the etiopathology of DLB is considered to be an accelerated aging process.

Regional cerebral blood flow changes in patients with idiopathic REM sleep behavior disorder.

BACKGROUND: Recent studies have shown an association between rapid eye movement sleep behavior disorder (RBD) and neurodegenerative disorders, especially alpha-synucleinopathies. OBJECTIVE: We investigated regional cerebral blood flow (rCBF) changes using single photon emission computed tomography (SPECT) in patients with idiopathic RBD (iRBD), to determine functional brain alterations associated with the disorder. METHODS: The SPECT data of 24 patients with iRBD were compared with those of 18 age-matched normal controls using statistical parametric mapping 2. RESULTS: We found decreased rCBF in the parietooccipital lobe (precuneus), limbic lobe, and cerebellar hemispheres in patients with iRBD, which is commonly seen in patients with Lewy body disease (Parkinson's disease and dementia with Lewy bodies) or multiple system atrophy. CONCLUSION: Our SPECT study suggests that iRBD can be a presymptomatic stage of alpha-synucleinopathies.

Differences in clinical course between dementia with Lewy bodies and Alzheimer's disease.

BACKGROUND AND PURPOSE: To investigate whether there may be differences in the clinical course and changes in cognitive progression between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). METHODS: We compared the time from the first visit to endpoints (discontinuation of visits because of admission, death, or institutionalization) between 56 patients with DLB and 111 patients with AD. Mini-Mental State Examination (MMSE) scores of patients were every 12 months examined up to 60 months. RESULTS: Dementia with Lewy bodies had a significantly shorter time to reaching endpoints than those with AD (median time; 40 months vs. 52 months, P < 0.0001). The proportion of admission (or death) was significantly higher in DLB than in AD (30% vs. 14%, P < 0.05), while the difference in institutionalization in nursing homes did not reach statistical significance (25% vs. 17%). Rates of longitudinal MMSE score decline for DLB and AD groups were equivalent. CONCLUSION: Dementia with Lewy bodies had a greater risk of admission (or death) because of most commonly fall-related injuries and bronchopneumonia than AD, but the two groups did not differ in rate of cognitive decline.

Deep gray matter hyperperfusion with occipital hypoperfusion in dementia with Lewy bodies.

Although decreased occipital perfusion is a characteristic feature of dementia with Lewy bodies (DLB), not all patients with DLB show a significant decreased perfusion in the occipital lobe. We explored characteristics of perfusion changes to improve the identification of DLB, in addition to occipital hypoperfusion. Statistical image analysis of single photon emission computed tomography data was performed on 22 patients with DLB and 25 patients with Alzheimer's disease (AD). A significant decreased perfusion in the occipital lobe was found in 16 patients with DLB (72%) and three patients with AD (12%), while a significant increased perfusion in the deep gray matter (striatum and/or thalamus) was found in 18 patients with DLB (81%) and eight patients with AD (31%), respectively. Either occipital hypoperfusion or deep gray matter hyperperfusion was found in 21 patients with DLB (95%), while in nine patients with AD (35%), indicating a sensitivity of 95% and a specificity of 65% in discriminating DLB from AD. Our results suggest that the addition of deep gray matter hyperperfusion to occipital hypoperfusion may be useful in the clinical differentiation of DLB and AD.