Biomedical subjects

Masaru Mimura

Publications and source records attributed to Masaru Mimura.

At least 19 recordsLinked to original sources

PubMed2007

Validity of the Center for Epidemiologic Studies Depression Scale as a screening instrument of major depressive disorder among Japanese workers.

BACKGROUND: The Center for Epidemiologic Studies Depression Scale (CES-D) is used at workplaces to screen depressive disorders. The aim of this study was to examine the validity of the CES-D for depression in a workplace. METHODS: The CES-D was administered to 2,219 workers (84.2% men; age 21-68 years) at a manufacturing company in Japan. Concomitantly all workers had an interview with the Mini International Neuropsychiatric Interview (MINI) as a gold standard for diagnosing major depressive disorder (MDD). The validity was evaluated by a receiver operating characteristic (ROC) curve. RESULTS: The area under the ROC curve of the CES-D was 0.96 [95% Confidence Interval (CI): 0.94-0.99]. The optimal cut-off score of MDD was 19 for screening. CONCLUSIONS: The validity of CES-D is confirmed and it is a valid instrument for detecting MDD in working populations in Japan.

Adult↗

PubMed2006

Impaired decision-making in Parkinson's disease.

The present study demonstrated that individuals with Parkinson's disease display impairments in making profitable decisions, as evidenced by poorer performance on the Iowa Gambling Task relative to matched controls. The ability to make beneficial judgments solely correlates with ability to appropriately attribute internal mental-state to other people, as shown in a mind-reading task. However, decision-making ability for individuals with Parkinson's disease is not associated with effective execution, intellectual function or depressed mood. These findings offer a new perspective on the cognitive impairments that affect social living and adaptive decisions for individuals with Parkinson's disease.

Affect↗

PubMed2006

Right unilateral jargonagraphia as a symptom of callosal disconnection.

We report the case of a right-handed patient who exhibited right unilateral jargonagraphia after a traumatic callosal hemorrhage. The lesions involved the entire corpus callosum, except for the lower part of the genu and the splenium. The patient's right unilateral jargonagraphia was characterized by neologisms and perseveration in kanji and kana, and was more prominent in kana than kanji. The jargonagraphia was similar to that observed in crossed aphasia, except that agraphia occurred only with the right hand. The patient also showed right unilateral tactile anomia and right tactile alexia, along with right-ear extinction on a dichotic listening test for verbal stimuli, which suggested that language function was lateralized to the right hemisphere. Since this patient had learned to write with his right hand, kinesthetic images of characters were thought to be formed and stored dominantly in the left hemisphere. We suggest that the callosal lesions disturbed the interhemispheric transfer of information for the dual-route procedures for writing in the right hemisphere, allowing the kinesthetic images of characters stored in the left hemisphere to be processed freely, resulting in the right unilateral jargonagraphia. At least two factors seem to explain that kana was more defective than kanji. First, writing in kana, which is assumed to be processed mainly via a sub-word phoneme to grapheme conversion route, might depend more strongly on lateralized linguistic processing than writing in kanji. Second, kanji, which represent meaning as well as phonology, with much more complicated graphic patterns than kana, are assumed to be processed in both hemispheres.

Accidents, Traffic↗

PubMed2006

Corticobasal degeneration as cause of progressive non-fluent aphasia: clinical, radiological and pathological study of an autopsy case.

A Japanese male developed gradual loss of spontaneous speech at age 60. Three years later meaningful speech had deteriorated to the point that it had become restricted to monotonous utterances. Neuropsychological examination at age 62 showed that he had severe non-fluent aphasia. A brain MRI demonstrated mild cortical atrophy with ischemic lesions in the cerebral white matter. He was diagnosed as having primary progressive aphasia. At age 63, he was admitted to the hospital to reevaluate the neurological condition. Neurologic examination showed severe non-fluent aphasia, hyperreflexia, snout and sucking reflexes. No alien hand was observed. He was able to walk, dress, wash himself and use chopsticks as well as name real objects. At age 65, 99Tc-hexamethylpropyleneamine oxime single photon emission computed tomography (HMPAO-SPECT) revealed diffuse cerebral hypoperfusion that was particularly prominent in the left frontal lobe. An MRI showed progressive cortical atrophy with the definite atrophy of the left paracentral gyrus. The hippocampal formation and putamen were also atrophic. He died of pneumonia at age 67. The brain weighed 810 g with atrophy of the frontal lobe, globus pallidus, enlargement of the lateral ventricles and depigmentation of the substantia nigra. Microscopic examination showed severe neuronal loss and gliosis in the cerebral cortex, globus pallidus interna and substantia nigra. Ballooned neurons were observed in the cerebral cortex. Gallyas-Braak method revealed numerous astrocytic plaques and argentophilic threads in the cerebrum. Clinical diagnosis of corticobasal degeneration sometimes is difficult in individuals with atypical clinical presentations. More exact clinical and radiological criteria may warrant a diagnosis of corticobasal degeneration.

Aphasia, Primary Progressive↗

PubMed2006

Family history of alcoholism and cognitive recovery in subacute withdrawal.

A family history of alcoholism has been demonstrated to be an important factor affecting cognitive function. However, no studies have yet been conducted to compare cognitive recovery of family history-positive (FH+) and family history-negative (FH-) alcoholics in the subacute withdrawal period. To tackle this problem, a neuropsychological test battery consisting of six computerized tests was administered to 19 FH+ and 20 FH- alcoholics at 2 and 7 weeks after abstinence. At 2 weeks after abstinence, overall performance of both FH+ and FH- groups was significantly poorer than that of healthy controls. At 7 weeks, these performances tended to recover, but in Trail Making A and Figure Position, performances of FH+ alcoholics remained worse than those of controls, while those of FH- alcoholics did not. Thus cognitive recovery during the subacute withdrawal period was worse among FH+ alcoholics than FH- alcoholics, and this finding should be considered when planning alcohol rehabilitation programs.

Adult↗

PubMed2006

Memory impairment and awareness of memory deficits in early-stage Alzheimer's disease.

Recognition memory of auditory verbal learning tests and awareness of memory deficits were examined in 24 individuals with early-stage Alzheimer's disease (AD) using a performance prediction-postdiction paradigm. Individuals with AD displayed impaired recognition memory, and recognition performance correlated positively with regional cerebral blood flow at rest in bilateral prefrontal areas and the left medial temporal area. In addition, underawareness of memory deficits was also marked even at this early stage. Individuals with AD retrospectively overestimated memory performance after actual performance, but appeared to benefit from feedback, and displayed intact online awareness of memory dysfunction, leading to normal prediction of the second session. However, individuals with AD failed to retrospectively incorporate incidents of memory failure into generalized self-belief systems. Brain/ behavior correlational analyses suggest that the prefrontal cortex and posterior dorsomedial regions including the precuneus may be involved in self-awareness.

Aged↗

PubMed2005

Left frontotemporal hyperperfusion in a patient with post-stroke mania.

A 78-year-old housewife with major depression developed a right-sided infarction in the territory of the middle cerebral arteries, followed by acute post-stroke mania. Comparison between pre- and post-stroke SPECT scans demonstrated a unique pattern of left orbitofrontal hyperperfusion with extensive right frontal hypoperfusion. A functional imbalance between right and left orbitofrontal cortices may be important in mania.

Aged↗

PubMed2005

Functional network in the prefrontal cortex during episodic memory retrieval.

A recent consistent finding in neuroimaging studies of human memory is that the prefrontal cortex (PFC) is activated during episodic memory retrieval. To date, however, there has been no direct evidence to explain how activity in the right and left PFC and in the anterior and posterior PFC are functionally interconnected. The goal of the present study was to obtain such evidence by event-related functional magnetic resonance imaging (MRI) and the functional connectivity method. Subjects were first asked to try to remember a series of associate-word lists outside the MRI scanner in preparation for a later recognition test. In the MRI scanning phase, they were asked to make recognition judgments in regard to old words, semantically related lure words, and unrelated new words. The analysis of functional connectivity revealed that the posterior PFC in each hemisphere had strong functional interconnections with the contralateral posterior PFC, whereas the anterior PFC in each hemisphere had only weak functional interconnections with the contralateral anterior PFC. No strong functional interconnections were found between the anterior and posterior PFC in either hemisphere. These findings support the hypothesis of an associative contribution of the bilateral posterior PFC to episodic memory retrieval and a dissociative contribution of the bilateral anterior PFC.

Adult↗

PubMed2005

Constant and severe involvement of Betz cells in corticobasal degeneration is not consistent with pyramidal signs: a clinicopathological study of ten autopsy cases.

This report concerns a clinicopathological study of three additional patients with corticobasal degeneration (CBD), described here for the first time, and a clinicopathological correlation between pyramidal signs and upper motor neuron involvement, in ten autopsy cases of CBD, including seven cases reported by us previously. We investigated pyramidal signs, including hyperreflexia, Babinski sign, and spasticity, and involvement of the primary motor cortex and pyramidal tract, focusing on the astrocytosis of the fifth layer of the primary motor cortex. Pyramidal signs were observed in six (60%) of the ten cases. Hyperreflexia was evident in six patients (60%), with spasticity being observed in three patients (30%). Loss of Betz cells associated with prominent astrocytosis and presence of ballooned neurons in the fifth layer of the primary motor cortex was observed in all ten cases. In all cases, involvement of the pyramidal tract was obvious in the medulla oblongata, without involvement of the pyramidal tract in the midbrain. Constant and severe involvement of the fifth layer of the primary motor cortex, including the Betz cells, has not previously been reported in CBD. We suggest that the pyramidal signs in CBD have been disregarded.

Aged↗

PubMed2005

Prospective studies on mental status and quality of life in patients with head and neck cancer treated by radiation.

Factors affecting the quality of life (QOL) in patients undergoing radiation therapy for head and neck cancer were determined in a prospective study. Full psychiatric interviews and self-report questionnaires concerning patients' QOL, pain, anxiety, mood, coping style and personality were administered to 35 patients with Stage I or II head and neck cancer before radiation therapy (week 0), and approximately one month (week 4) and two months (week 8) after starting of radiation. Anxiety, depression and pain were more severe at week 4 than at baseline. Anxiety was less at week 8, but depressive symptoms remained remarkable. Stepwise regression analyses revealed that changes in depressed mood and pain partially accounted for changes in disease-specific QOL. General health QOL related to a premorbid personality of openness and an emotional aspect of a coping style. Therapeutic interventions including psychiatric management of depression and physical management of pain appear to be crucial for preserving QOL during radiation treatment of patients with head and neck cancer.

Adaptation, Psychological↗

PubMed2005

Further evidence for a comparable memory advantage of self-performed tasks in Korsakoff's syndrome and nonamnesic control subjects.

Two experiments were carried out to examine memory in persons with amnesia using self-performed tasks. In Experiment 1, persons with Korsakoff's syndrome and nonamnesic participants with alcoholism learned action phrases not involving real objects by either self-performed tasks or verbal tasks. As indexed by free recall and recognition tests, a memory advantage favoring self-performed tasks was confirmed in both participant groups. In Experiment 2, persons with Korsakoff's syndrome, nonamnesic alcoholic participants, and young control participants learned object names under three different study conditions that differed from one another as to whether actions for each name were verbally generated and whether actions actually were performed. Verbal generation with or without performing the action facilitated recognition, whereas recall advantage was found only in the verbal generation-plus performance condition. These findings confirm a comparable memory advantage of self-performed tasks for a group with Korsakoff's syndrome and a group of nonamnesic comparison participants. Action memory therefore has potential therapeutic implications for memory rehabilitation.

Adult↗

PubMed2005

Selective memory impairment for personally familiar colors following encephalitis.

A 19-year-old man presented with a peculiar memory impairment following non-herpetic viral encephalitis. He was exclusively impaired in generating images for colors of possessions previously well known to him, and consequently these seemed less familiar. He appeared unable to access personally familiar and autobiographical color attributes. Single-photon emission computed tomography and electroencephalogram findings suggest that the right-sided functional abnormalities, specifically in the frontal and temporal regions, were implicated as the functional locus for the patient's unique problem.

Adult↗

PubMed2005

Reliability and validity of Japanese version of the Mini-International Neuropsychiatric Interview.

The Mini-International Neuropsychiatric Interview (MINI) is a short, structured diagnostic interview used as a tool to diagnose 16 axis I (Diagnostic and Statistical Manual) DSM-IV disorders and one personality disorder. Its original version was developed by Sheehan and Lecrubier. We translated the MINI into Japanese, and investigated the reliability and validity of the Japanese version of MINI. Eighty-two subjects participated in the validation of the MINI versus the Structured Clinical Interview for DSM-III-R (SCID-P). One hundred and sixty-nine subjects participated in the validation of the MINI versus an expert's professional opinion. Seventy-seven subjects were interviewed by two investigators and subsequently readministered by a third interviewer blind to the results of initial evaluation 1-2 days later. In general, kappa values indicated good or excellent agreement between MINI and SCID-P diagnoses. Kappa values indicated poor agreement between MINI and expert's diagnoses for most diagnoses. Interrater and test-retest reliabilities were good or excellent. The mean durations of the interview were 18.8 min for MINI and 45.4 min for corresponding sections of SCID-P. Overall, the results suggest that the MINI Japanese version succeeds in reliably and validly eliciting symptom criteria used in making DSM-III-R diagnoses, and can be performed in less than half the time required for the SCID-P.

Adolescent↗

PubMed2005

High prevalence of Chlamydia pneumoniae antibodies and increased high-sensitive C-reactive protein in patients with vascular dementia.

OBJECTIVES: To determine the relationships between Chlamydia pneumoniae infection, carotid atherosclerosis, and dyslipidemia in patients with vascular dementia (VaD) and Alzheimer's disease (AD). DESIGN: Case control study. SETTING: Showa University Karasuyama Hospital, Tokyo, Japan. PARTICIPANTS: One hundred twenty-four elderly subjects: 31 with VaD, 61 with AD, and 32 age-matched controls without dementia. MEASUREMENTS: Presence of antibodies to C. pneumoniae (immunoglobulin G (IgG) and IgA), the serum concentrations of high-sensitive C-reactive protein (hs-CRP) and atherogenic lipoproteins, and the carotid artery intima-media thickness (IMT) and plaques were determined. RESULTS: Age; body mass index; systolic and diastolic blood pressures; and fasting plasma glucose, hemoglobin A(1c), high-density lipoprotein cholesterol, and apolipoprotein A-I, B, and E concentrations did not differ significantly between the three groups, but the mean IMT and frequency of atherosclerotic plaques in the carotid arteries, as well as the serum concentrations of low-density lipoprotein cholesterol (LDL-C), lipoprotein(a), and lipid peroxides were significantly greater in VaD patients than in AD patients or nondemented controls. Hs-CRP concentrations and prevalence of C. pneumoniae IgG and IgA antibodies also were significantly higher in VaD patients than in AD patients and nondemented controls. Multiple logistic regression analysis revealed that carotid IMT and plaques, LDL-C, lipid peroxides, hs-CRP, and IgG and IgA C. pneumoniae seropositivity were independent risk factors for VaD. CONCLUSION: These results suggest that carotid atherosclerosis, atherogenic lipoproteins, and C. pneumoniae infection (as documented by the IgG and IgA seropositivity together with increased hs-CRP) may be VaD risk factors.

Aged↗

PubMed2004

Impaired pitch production and preserved rhythm production in a right brain-damaged patient with amusia.

Pre- and postmorbid singing of a patient with amusia due to a right-hemispheric infarction was analyzed acoustically. This particular patient had a premorbid tape recording of her own singing without accompaniment. Appropriateness of pitch interval and rhythm was evaluated based on ratios of pitch and duration between neighboring notes. The results showed that melodic contours and rhythm were preserved but individual pitch intervals were conspicuously distorted. Our results support a hypothesis that pitch and rhythm are subserved by independent neural subsystems. We concluded that action-related acoustic information for controlling pitch intervals is stored in the right hemisphere.

Auditory Perception↗

PubMed2003

Comparison of hangover effects among triazolam, flunitrazepam and quazepam in healthy subjects: a preliminary report.

The aim of the present study was to compare the hangover effects of night-time administration of triazolam (0.25 mg), flunitrazepam (1 mg) and quazepam (15 mg) in healthy subjects. Daytime sleepiness and performance level following the night-time administration of the drugs were assessed using Standford Sleepiness Scale (SSS), Sleep Evaluation Questionnaire (SEQ), Multiple Sleep Latency Test (MSLT), actigraphy recordings and Continuous Performance Test (CPT). Fifteen healthy volunteers were given one of the three hypnotics at each drug session, which lasted for 1 week, in a single-blind cross-over fashion. No significant between-drug difference was observed for the psychomotor performance assessed by CPT. Subjective hangover effects assessed by SSS and SEQ in the morning were prominent for flunitrazepam and quazepam relative to triazolam, whereas objective indices such as MSLT or activity counts obtained in actigraphy indicated a marked hangover effect of quazepam compared with the other two compounds restrictively in the afternoon, which were nearly in accordance with their pharmacokinetic profiles.

Activities of Daily Living↗

PubMed2003

Cross-script and within-script priming in alcoholic Korsakoff patients.

In two experiments, alcoholic Korsakoff patients and control subjects studied a list of Japanese nouns written in either Hiragana or Kanji script. Word-fragment completion and recognition tests were then administered in Hiragana. When the writing script was changed between study and test phases, repetition priming in word-fragment completion was significantly attenuated but was still reliable against baseline performance. This was confirmed for both Korsakoff patients and control subjects. In contrast, the script change had little effect on recognition memory, which was severely impaired in Korsakoff patients. The results suggest that repetition priming is mediated by two different implicit processes, one that is script-specific and the other that is assumed to operate at a more abstract level.

Adult↗

PubMed2003

[Amnesia, confabulation and nonaphasic misnaming after left thalamic infarct].

A 72-year-old right handed woman developed amnesia, confabulation and abnormal (bizarre) verbal response after the left thalamic infarction. Clinical features including disorientation, euphoria and various kinds of paraphasia coincided in nonaphasic misnaming. MR images showed that lesions involved the genu of the internal capsule, the anteroventral nucleus, the lateroventral nucleus, intralaminar nuclei, the mamillothalamic tract and the region around the ventral thalamus. 99mTc-HMPAO-SPECT revealed decreased uptake in the left frontal lobe, probably due to the disconnection from the thalamus. These findings suggest that the dysfunction of the thalamus (mainly ventrolateral) and the left frontal lobe caused the disturbance of the self-monitoring in the language use, which generated confabulation and nonaphasic misnaming in our case.

Aged↗