Epidemiological study of acute encephalitis in Tottori Prefecture, Japan.

BACKGROUND AND PURPOSE: To conduct an epidemiological survey of acute encephalitis focusing on non-herpetic acute limbic encephalitis (NHALE) in Tottori Prefecture, western area of Japan. METHODS: A questionnaire survey on the annual number of patients aged 16 years or more with acute encephalitis from 2001 to 2005 was undertaken in 2006. RESULTS: During the study period, 49 patients were diagnosed with acute encephalitis. The subtype of acute encephalitis was as follows: 10 patients with herpes simplex encephalitis (HSE), 12 patients with NHALE, 4 patients with paraneoplastic encephalitis, 2 patients with encephalitis associated with collagen disease, one patient with viral encephalitis other than HSE, 20 patients with encephalitis with unknown causes. The service-based incidence rate of acute encephalitis was 19.0 per million person-years. The incidence rate of NHALE subtype was 4.7 per million person-years. CONCLUSIONS: Our epidemiological survey indicated an estimated 550 patients would develop NHALE per year in Japan, suggesting that NHALE may not be a rare disorder.

Serum proteomic profiling of dementia with Lewy bodies: diagnostic potential of SELDI-TOF MS analysis.

Dementia with Lewy bodies (DLB) is the second most common senile degenerative dementia after Alzheimer's disease (AD). The presentation of overlapping symptoms between these two disorders leads to difficulties in the determination of clinical entities. Serum samples were subjected to surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) analysis in order to identify a diagnostic marker for DLB. Four putative protein peaks (m/z 3,883, 4,964, 7,761 and 10,534) were differentially expressed in DLB patients compared to AD patients and control subjects. Receiver operating characteristics (ROC) analysis of a multivariate logistic model of the combination of three peaks (m/z 3,883, 7,761 and 10,534) exhibited the highest discriminatory ability of DLB subjects from non-DLB subjects with a sensitivity of 83.3%, a specificity of 95.8%, a positive predictive value of 90.9% and a negative predictive value of 92.0%. SELDI-TOF MS profiling, therefore, has revealed a serum signature with high diagnostic potential for DLB.

Rerupture of cerebral aneurysms during angiography--a retrospective study of 13 patients with subarachnoid hemorrhage.

UNLABELLED: OBJECTIVE, BACKGROUND: Cerebral angiography, performed within 24 hr of aneurysmal rupture, carries an increased risk of rebleeding. We have investigated the rerupture rate during angiography procedures under deep general anesthesia and the factors that contribute to rebleeding. METHODS: We divided 69 patients who had experienced aneurysmal rerupture into 2 groups. Group I (n = 13) suffered rebleeding during cerebral angiography and group II (n = 56) who rebled at a different time. We assessed the effects on rebleeding of the (1) time between the first insult and angiography, (2) WFNS clinical grade on admission, (3) blood pressure during angiography, (4) age and sex, (5) Fisher classification on admission, (6) aneurysmal site, and (7) Glasgow outcome score (GOS). RESULTS: Factors that had a statistically relevant effect on rebleeding during cerebral angiography (Group I) were the performance of angiography within 3 hr of the initial insult, the admission grade, and the aneurysmal site. Especially, the rerupture events during cerebral angiography were concentrated within 3 hr of the initial insult; the rate was 23.9% when angiograms were obtained within 3 hr of onset. Group I patients manifested a worse clinical grade and middle cerebral artery (MCA) aneurysms were prevalent in this group. However, there was no significant difference between the 2 groups with respect to blood pressure, age, sex, Fisher classification, and GOS. CONCLUSIONS: Cerebral angiography at ultra-early timing (within 3 hr of the insult) carries a high risk of aneurysmal rerupture, even if the procedure is performed under deep anesthesia and normotensive blood pressure. Cerebral angiography during that period should be avoided.

Serotonin 2C receptor gene Cys23Ser polymorphism: a candidate genetic risk factor of migraine with aura in Japanese population.

OBJECTIVES: The goal of this study is to clarify the association between migraine and Serotonin 2C receptor Cys23Ser polymorphism in Japanese population. MATERIALS AND METHOD: This study included 37 individuals with migraine with aura (MWA), 80 with migraine without aura, 43 with tension type headache (TH) and 360 with controls. The genotypes of Cys23Ser polymorphism were confirmed by polymerase chain reaction-restriction fragment length polymorphism techniques. RESULTS: The Ser allele frequency in control subjects is much less than that in Caucasian population. The Ser allele frequency in patients with MWA was higher than that in control subjects. CONCLUSION: The present study provides that 5HTR2c Cys23Ser polymorphism may be associated with MWA in Japanese population.

Physiological investigation of automobile driver's activation index using simulated monotonous driving.

Monotonous automobile operation in our daily life may cause the lowering of what might be termed an activation state of the human body, resulting in an increased risk of an accident. We therefore propose to create a more suitable environment in-car so as to allow active operation of the vehicle, hopefully thus avoiding potentially dangerous situations during driving. In order to develop such an activation method as a final goal, we have firstly focused on the acquisition of physiological variables, including cardiovascular parameters, during presentation to the driver of a monotonous screen image, simulating autonomous travel of constant-speed on a motorway. Subsequently, we investigated the derivation of a driver's activation index. During the screen image presentation, a momentary electrical stimulation of about 1 second duration was involuntarily applied to a subject's shoulder to obtain a physiological response. We have successfully monitored various physiological variables during the image presentation, and results suggest that a peculiar pattern in the beat-by-beat change of blood pressure in response to the involuntary stimulus may be an appropriate, and feasible, index relevant to activation state.

Glutathione S-transferase polymorphisms: susceptibility to migraine without aura.

Migraine is considered to be a polygenic multifactorial disease with various environmental and genetic etiologies. We investigated glutathione S-transferase (GST) P1 Ile(105)Val, 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.

Muscle weakness in a Japanese family of Arg1239His mutation hypokalemic periodic paralysis.

Familial hypokalemic periodic paralysis is an autosomal dominant disorder. Recently, three predominant mutations were found in the muscle dihydropyridine-sensitive calcium channel alpha 1-subunit gene. We present a Japanese family that displays one of these, the Arg1239His mutation. All the affected individuals of this family displayed this mutation. Two cases had a history of recurrent episodes of muscle weakness and difficulty in running before their first paralytic attack. It is suggested that there are no racial differences with this mutation, and that mild muscle weakness occurs not only after but also preceding the first attack.

A genetic epidemiological study of spinocerebellar ataxias in Tottori prefecture, Japan.

We investigated the genotype frequencies of patients with spinocerebellar ataxias (SCA), using a community-based prevalence study among 613,349 inhabitants in Tottori prefecture, Japan. Prevalence date was April 1, 1998. On this date, 109 SCA patients were identified in this community. The prevalence of SCA was 17.8 per 100,000 individuals. The most common cause of inherited SCA was a mutation at the SCA6 locus (25%), followed by mutation at the SCA1 locus (15%), SCA3 locus (5%) and dentatorubral-pallidoluysian atrophy locus (5%). None of the expanded alleles was found in SCA2, SCA7 or Friedreich's ataxia. Mutation at SCA6 was also the most common form of sporadic SCA at 11%. Prevalences per 100,000 individuals were as follows: SCA6, 2.40; SCA1, 0.48; DRPLA, 0.32, and SCA3, 0.16.

Spinocerebellar ataxia type 6: founder effect in Western Japan.

An accumulation of SCA6 cases has been observed in the Chugoku area of Western Japan. In the Tottori prefecture, located in the northeastern part of the Chugoku district, we observed a cluster of SCA6 families within the eastern area, suggesting that there may be a founder in the Japanese SCA6 population. Genotyping with DNA microsatellite markers linked to the CACNL1A4 gene on chromosome 19p13 demonstrated shared allelic characteristics and revealed a common haplotype in the majority of Japanese families. The common haplotype of the shared (CAG)(22) repeat found in this study may indicate the meiotic stability of CAG repeats in SCA6 patients.

Leukocyte mitochondrial DNA A to G polymorphism at 11084 is not a risk factor for Japanese migraineurs.

Mitochondrial dysfunction has been reported in patients with migraine. We investigated leukocyte mitochondrial DNA 11084 A to G polymorphism in 166 Japanese migraineurs and 483 Japanese controls. The migraine group consisted of 43 patients suffering from migraine with aura (MWA) and 123 from migraine without aura (MOA). The frequency of the transition was 7.2% (12/166) in the migraine group and 7.3% (35/483) in the controls. The frequency of the transition was 4.7% in MWA and 8.1% in MOA. There was no significant difference among the groups (chi-square test). The mitochondrial DNA 11084 A to G transition was more common in Japanese subjects than reported in Caucasians; however, this polymorphism is not a genetic risk factor for migraine in Japanese patients.

[Quality of life in Parkinson's disease].

Parkinson's disease(PD) is a slowly progressive neurodegenerative disease. QOL improvement could be the main endpoint in some clinical trials, such as in those carried out in palliative care or incurable disease. Several instruments that assess to QOL of PD(PDQOL) have been established such as SF36, PDQ39 and PDQL. This article is reviewed about the importance for the improvement of PDQOL and the influence to PDQOL from the point of view from the epidemiological studies in Japanese population. The various approaches to the patients are necessary for the improvement of PDQOL.

Roles of hydrophobicity, protein binding and the probenecid-sensitive transport system in the cerebrospinal fluid delivery of nucleoside analogues with anti-viral activity.

Ten nucleoside analogues with anti-herpes or anti-HIV activity were investigated for their transport into the cerebrospinal fluid (CSF) following intravenous administration in rats. The novel anti-herpes agent 1-beta-D-arabinofuranosyl-2-thio-5-fluorocytosine (5F-araSC) showed the highest CSF/plasma concentration ratio (>20%), while that of acyclovir (ACV) was very low (<5%). A linear relationship was observed between the partition coefficient (chloroform/water) and CSF/unbound plasma concentration in 6 of 9 agents. The exceptions were DDI, AZT and ACV, which showed much lower concentrations in the CSF than expected from their hydrophobicity and protein binding activities. The effects of probenecid treatment on the CSF and plasma concentrations were measured with continuous intravenous administration of ACV, AZT, araC and 5F-araSC. Probenecid markedly increased the CSF concentrations of ACV and AZT, although the effect was minimal in araC and 5F-araSC. These results may provide useful information for molecular design of nucleoside analogues with better transport to the brain.

Prognosis of Parkinson's disease in Japan. Tottori University Parkinson's Disease Epidemiology (TUPDE) Study Group.

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.

Clinical usefulness of electrically elicited pain-related evoked potentials.

In 14 patients with sensory disturbance, the clinical usefulness of electrical pain-related evoked potentials (EPREPs) were studied. In four patients with deep sensation disturbance, conventional somatosensory evoked potentials (SEPs) were abnormal. However, EPREPs were abnormal only in one of the patients. In nine patients with pain-temperature sensation disturbance, SEPs were normal except for only one patient and EPREPs were abnormal in seven of the nine patients. In a patient with herpes zoster myelitis, EPREPs elicited by electrical stimulation below the disturbed spinal level were delayed. After symptomatic improvement, EPREPs recovered. EPREPs are useful in the clinical field.

Epidemiology of Parkinson's disease in Yonago City, Japan: comparison with a study carried out 12 years ago.

A study of the prevalence of Parkinson's disease (PD) was conducted in a Japanese city in 1992, and the data compared with those of a similar study performed in 1980. On the prevalence day, April 1, 1992, a total of 156 patients (46 males and 110 females) were found to be living in the investigated area, which had a population of 132,315. The prevalence per 100,000 population was 117.9 (72.8 in males and 159.1 in females), and the incidence during the period 1989 through 1992 was 15.0 per 100,000 population per year. The age- and sex-adjusted prevalence per 100,000 population was 99.5 in 1992 and 103.9 in 1980, as calculated using the 1990 Japanese population as the standard. The age-adjusted prevalence in the population under 60 years of age and the incidence in those under 55 years of age in 1992 were lower than in those under 55 in 1980. These results revealed that changes in the age structure of the population were the main contributors to the increased incidence of PD.

Indocyanine green angiographic aspects of multiple evanescent white dot syndrome.

PURPOSE: The authors investigated the indocyanine green angiography findings of multiple evanescent white dot syndrome (MEWDS). METHODS: Four patients with MEWDS underwent examination by indocyanine green angiography, conventional ophthalmoscopy, and fluorescein angiography. RESULTS: Fundus examination showed multiple white dots in the retinal pigment epithelium of the unilateral eye of each patient. Fluorescein angiography demonstrated early hyperfluorescence corresponding to the white dots. In the early phase, indocyanine green angiography showed no abnormal signs in the large choroidal vessels, but in the late phase, hypofluorescent lesions appeared, corresponding to the white dots. The hypofluorescent dots were clustered in the posterior pole and sporadic in the peripheral region, appearing to radiate away from the optic disc or fovea. The hypofluorescent dots disappeared at the recovery stage. CONCLUSIONS: Previous fluorescein angiographic and electrophysiologic studies have demonstrated the involvement of the retinal pigment epithelium (RPE) and photoreceptors in MEWDS: The current findings on indocyanine green angiography suggest that MEWDS affects the choriocapillaris or precapillary arterioles as well as the RPE and photoreceptors, and that the lesions spread to the midperipheral region, centering on the optic disc or fovea.

Epidemiological and genetic studies of Huntington's disease in the San-in area of Japan.

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 065/100,000 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.

[Prevalence and founder effect of Huntington's disease in the San-in area of Japan].

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. The population of the area was 1,387,000 on October 1st, 1993. There were 10 patients with HD in the San-in area, who were diagnosed clinically. They all had involuntary movement, mental disturbance, changes of character and atrophy of the caudate nucleus. However, one of the patients showed no positive family history of HD. The other nine patients had members with HD in their families, although those family members of the patients had already died. The expansion of the CAG repeat was observed in nine of the patients. In the patient who had no positive family history, expansion of the CAG repeat was not seen. According to the nine patients with expansion of the CAG repeat, the prevalence was 0.65/100,000. Haplotypes using polymorphism markers of D4S111 and D4 S136 were studied. The haplotypes which were observed in only 2.7% of the normal population were shown in all nine HD patients. Thus, the obvious disequilibrium was seen. These results suggested a common ancestor of these HD patients.

Prevalence of focal dystonias in the western area of Tottori Prefecture in Japan.

We evaluated the prevalence of focal dystonias in the western area of Tottori Prefecture in Japan. The population of the area was 244,935 on October 1, 1992. Because four patients with blepharospasm and three patients with writer's cramp did not visit any hospitals or clinics in 1993 and did not reply to our question letter, we could not confirm their present condition: with or without focal dystonia in 1993. Four patients with facial dystonia including blepharospasm and oromandibular dystonia, seven with spasmodic torticollis, and four with writer's cramp were observed. The prevalence of focal dystonias was 6.12 per 100,000 persons, which may be lower than that in western countries. Although the reasons for this difference are still unclear, a genetic factor may be one implication.

Epidemiology of inflammatory neurological and inflammatory neuromuscular diseases in Tottori Prefecture, Japan.

We investigated the incidence of the following conditions: inflammatory neurological and neuromuscular diseases, adult meningitis and adult encephalitis in Yonago City, and Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), polymyositis/dermatomyositis (PM/DM), periarteritis nodosa (PN) and HTLV-1 associated myelopathy (HAM) during the period 1988-1992 in Tottori Prefecture, Japan. The annual incidence per 100,000 population was as follows: meningitis, 4.38; encephalitis, 0.90; GBS, 1.14; PM/DM, 1.01; and PN, 0.32. The prevalence per 100,000 population CIDP, 0.81; PM/DM, 9.92; PN, 2.59; and HAM, 1.30. There were marked localization of HAM in western Tottori, and there was seasonal variation in the prevalence of meningitis, encephalitis and GBS. The mean age at onset of meningitis was lower than that for encephalitis. Comparison with reported data revealed interracial differences in the epidemiology of PM/DM and PN.