Search

Background: The prevalence of frontotemporal lobar degeneration (FTLD) in Japan is unknown. An epidemiological survey study of FTLD was undertaken in Tottori Prefecture, a district in the western region of Japan. Methods: Hospitals in Tottori Prefecture were surveyed by a two-step questionnaire in 2010, and the prevalence of FTLD per 100,000 inhabitants was calculated using the actual number of patients and inhabitants in Tottori Prefecture on the prevalence day of October 1, 2010. Results: In this survey, 66 patients were diagnosed with FTLD. The subtypes of FTLD were as follows: 62 cases of frontotemporal dementia (FTD), 3 cases of progressive nonfluent aphasia, and 1 case of semantic dementia. Among the FTD cases, 5 cases were FTD with motor neuron disease and 1 case was FTD with parkinsonism linked to chromosome 17. The prevalence of FTD in the total population of Tottori Prefecture was 11.2 per 100,000 inhabitants. Based on these results, the prevalence of FTLD in Japan in 2008 was estimated to be 9.5 per 100,000 individuals. Conclusions: Our epidemiological survey results suggest that there are at least 12,000 FTLD patients in Japan, indicating that FTLD is not a rare disease.

Aims: In order to determine the prevalence of dementia and mild cognitive impairment (MCI), we conducted a population-based study in Japan. Methods: Participants included 924 subjects aged 65 years or older who resided in the town of Ama-cho. In phase 1 of the study, the Mini-Mental State Examination and Clinical Dementia Rating were administered for screening purposes. In phase 2 of the study, the subjects who screened positive were further examined by neurologists. Dementia and MCI were diagnosed by means of DSM-IV and International Working Group on MCI criteria, respectively. Results: By the prevalence date of June 1, 2010, 24 subjects had deceased or lived outside the town. In total, 723 of the remaining 900 subjects received a phase 1 test. In phase 2, 98 subjects were diagnosed with amnestic MCI, 113 subjects with non-amnestic MCI, and 82 subjects with dementia. Of the subjects who did not receive the phase 1 test, 66 subjects were diagnosed as having dementia according to data from their town medical card or the Long-term Care Insurance System. The crude prevalence of amnestic MCI, non-amnestic MCI, and dementia were 10.9, 12.6, and 16.4%, respectively. Conclusion: Consistent with the striking increase in the number of elderly individuals, we report higher prevalence of MCI and dementia in Japan than previously described.

Aim: We assessed the long-term prognosis of patients with large subcortical infarctions (LSCI). Methods: We defined LSCI as lesions ≥15 mm confined to deep penetrating arteries without a cardioembolic or atherothrombotic source. Patients with acute ischemic strokes were consecutively registered and followed for 751 ± 441 days. The clinical characteristics and long-term prognoses of patients with LSCI were compared to those of patients with lacunar (LACI), atherothrombotic (ATI) and cardioembolic infarctions (CEI). Results: At discharge from the hospital, the proportion of good outcomes (modified Rankin Scale ≤2) for patients with LSCI (52.1%) was similar to that for ATIs (47.2%), but worse than that for LACIs (73.2%). After a 3-year follow-up period, the mortality rates from LSCI, LACIs, ATIs and CEIs were 8.4, 8.2, 22.3 and 41.1%, respectively; the recurrence rates were 9.3, 14.1, 16.6 and 23.8%, respectively. Conclusions: The short-term prognosis of functional outcomes for LSCI was worse than that for LACIs, but similar to acute-phase ATI outcomes. The long-term prognosis after a LSCI is good, and recurrence tends to be lower than for LACIs.

Background/Aim: To determine the prevalence and incidence of Parkinson’s disease (PD) and compare them with results from our previous studies. Methods: We examined epidemiological characteristics of PD patients using a service-based study in Yonago City, and a door-to-door study in Daisen Town. The prevalence days were April 1, 2004 in Yonago, and April 1, 2003 in Daisen. Results: In Yonago, we identified 254 PD patients. The crude prevalence was 180.3 (95% CI, 158.1–202.4) per 100,000 population. The adjusted prevalence was 145.8 (95% CI, 145.2–146.5) in 1980, 147.0 (95% CI, 146.3–147.6) in 1992, and 166.8 (95% CI, 166.1–167.5) in 2004, when calculated using the Japanese population in 2004. The crude incidence was 18.4 (95% CI, 11.3–25.5) per 100,000 population per year. The crude incidence in 1980 was 10.2 (95% CI, 4.6–15.8), and the adjusted incidence was 9.8 (95% CI, 4.3–15.3) in 1992, and 10.3 (95% CI, 4.7–15.9) in 2004, when calculated using the population in Yonago in 1980. In Daisen, there were 21 PD patients. The crude prevalence was 306.6 (95% CI, 175.7–437.6) and the adjusted prevalence was 192.6 (95% CI, 191.9–193.8). Conclusions: The prevalence of PD had increased, primarily because the population had aged. Differences in prevalence between these adjacent areas may have resulted from differences in the methods of investigation.

Recent epidemiological studies have emphasized the impact of elevated blood homocysteine levels on the pathogenesis of Alzheimer’s disease (AD). In spite of a significant impact of a MTHFR C677T polymorphism on the blood homocysteine levels, the association between the C677T polymorphism and AD remains controversial. Therefore, other unidentified genetic factor(s) that regulate blood homocysteine levels may exist. Here, we have analyzed the 5′-upstream region of the MTHFR gene and examined AD patients (n = 223) and nondemented individuals (n = 323) for polymorphisms in the 5′-upstream region of the MTHFR gene. We identified two polymorphisms (–713G/A and –393C/A, upstream of the start codon). We found no significant relationship between AD and the 5′-upstream region polymorphisms of the MTHFR gene. Thus, our study does not reinforce the hypothesis of an independent involvement of the MTHFR gene upstream region polymorphisms in AD risk.

Migraine is considered to be a polygenic multifactorial disease with various environmental and genetic etiologies. We investigated glutathione S-transferase (GST) P1 Ile105Val, T1 and M1 polymorphisms in 174 Japanese headache sufferers and 372 Japanese controls. The headache group consisted of 38 cases of migraine with aura, 95 migraine without aura (MWOA) and 41 tension-type headache sufferers. The M1 homozygous deletion genotype was significantly higher in MWOA (64%) compared with controls (46%; p < 0.01; odds ratio = 2.18, 95% confidence interval: 1.32–3.61, adjusted for age and gender). In a comparison of the current smokers, the M1 null frequencies in MWOA were further increased. GSTM1 may be one of the genetic risk factors for MWOA in the Japanese population.

In order to study progressive dementia in Alzheimer’s disease (AD) patients, we analyzed the gene expression of apolipoprotein E (apoE). ApoE mRNA level in the brains of patients with AD was determined by the reverse transcriptase-polymerase chain reaction (RT-PCR) method. ApoE genotype and the promoter polymorphisms (–491A/T, Th1/E47cs) were determined by the PCR restriction fragment length polymorphism method. The apoE mRNA level was significantly higher in the AD group than the control group (p < 0.05). ApoE mRNA in the AD group with apoE Ε4 was also significantly higher than that in the control group with apoE Ε4 (p < 0.05). Our result did not indicate the possibility that the promoter polymorphisms modulate the apoE mRNA level. The higher level of apoE mRNA in AD with apoE Ε4 may play an important role in the development of AD.

We examined the expression of presenilin 1 (PS-1) mRNA in cultured skin fibroblasts taken from living patients with Alzheimer’s disease (AD) and human brains taken postmortem from AD patients by RT-PCR analysis. The donors of fibroblasts consisted of 28 cases with AD and 19 neurological patient without dementia (CTL). The brains came from 17 cases with AD and 23 cases with CTL. We found that PS-1 mRNA levels in skin fibroblasts of AD patients were significantly higher than those of CTL patients (p < 0.0001). Moreover, we found that PS-1 mRNA levels in human brains with AD were significantly higher than in those with CTL (p < 0.0001). These findings suggest that high levels of PS-1 mRNA in AD may play an important role in developing AD and that the examination of PS-1 mRNA in skin fibroblasts may be helpful for the diagnosis of AD.

We carried out two separate epidemiological studies on long-term changes, 10 years apart, on the prevalence rate of dementia in the elderly by the same method for the same area in Japan. We also performed a genetic study of patients with dementia of the Alzheimer type (DAT) based on the epidemiological studies. The number of patients with dementia was much larger in 1990 than in 1980. Especially, the number of mildly demented patients was significantly larger in 1990 than in 1980. The 35 patients with DAT did not show any mutations of amyloid-β protein precursor, presenilin 1 and presenilin 2 genes. The frequency of apolipoprotein E (apo E) σ4 allele in DAT was significantly higher than that in control subjects (p < 0.005). This study suggests that the frequency of DAT may increase by aging of the population in the future and we confirm the close association between apoE σ4 allele and DAT in a community-based study in Japan.

Therapy for Parkinson's disease (PD) has been progressing. However, the prognosis for patients with PD is still unclear. We studied the course of PD in patients in the San-in Area of Japan over a long time period. The main purpose of this study was to see whether there was a difference in survival between PD patients and the general population. Information on 114 deceased PD patients, who died between 1989 and 1996, was collected from hospitals belonging to the Tottori University Parkinson's Disease Epidemiology Study Group. Although the duration of illness was prolonged, the survival of PD patients was still poorer than that of the general population. The most common cause of death was pneumonia. The main cause of death in young PD patients was also pneumonia. In order to improve the survival of PD patients, PD-related conditions should be treated more extensively, especially pneumonia.

After the DNA diagnosis, we evaluated the prevalence of Huntington''s disease (HD) in the San-in area of Japan, and confirmed the founder effect. There were 10 patients with HD in the San-in area, who were diagnosed clinically. The expansion of the CAG repeat was observed in 9 patients with HD members in their families, although those family members of the patients had already died. In the patient who had no positive family history, expansion of the CAG repeat was not seen. The prevalence of HD was 0.65/100,000 in this area. The common haplotype studied by the polymorphism marker of D4S136 was shown in all 9 HD patients, although they were observed in only 2.7% of the normal population. These results suggested a common ancestor of these HD patients.

The prevalence of all neurological disorders in a Japanese town was calculated, with a result of 91.1 per 1,000 population. The prevalence of cerebrovascular disease was 28.8; myelopathy and/or radiculopathy caused by deformity of the spine or disc herniation, 23.9; neuralgia, 11.5; dementia, 10.4; peripheral nerve disturbance, 5.5; epilepsy, 4.4; Parkinson's disease, 2.0; mental retardation, 2.9; brain/spinal tumor, 1.4; headache, 10.8, and vertigo/dizziness, 4.4. The prevalence of headache and vertigo/dizziness was also calculated from the results of the questionnaires sent to inhabitants: headache, 79.6, and vertigo/dizziness, 60.8. Neurological disorders are common in Japan and likely to continue to increase.

Apolipoprotein E sigma4 allele (ApoE sigma4) is associated with Alzheimer's disease (AD) in familial and sporadic cases, but the associations of ApoE sigma4 allele and vascular dementia (VD) and/or ischemic cerebrovascular disease (ICVD) are still controversial. To clarify the associations of ApoE polymorphism with AD, VD and ICVD in Japanese, we examined ApoE polymorphism in samples of 255 patients with AD, 87 patients with VD, and 123 patients with ICVD, as compared with 117 age-matched healthy control subjects (CTL). The frequency of the ApoE sigma4 allele was significantly higher in the VD group (0.21), the ICVD group (0.15) as well as in the AD group (0. 26) than in the CTL subjects (0.08). These findings suggest that the genotype of ApoE sigma4 is associated with not only AD but also VD and ICVD, and that ApoE sigma4 plays an important role in the development of dementia and ICVD.