Frequency variations of discrete cranial traits in major human populations. III. Hyperostotic variations.

Seven discrete cranial traits usually categorised as hyperostotic characters, the medial palatine canal, hypoglossal canal bridging, precondylar tubercle, condylus tertius, jugular foramen bridging, auditory exostosis, and mylohyoid bridging were investigated in 81 major human population samples from around the world. Significant asymmetric occurrences of the bilateral traits were detected in the medial palatine canal and jugular foramen bridging in several samples. Significant intertrait associations were found between some pairs of the traits, but not consistently across the large geographical samples. The auditory exostosis showed a predominant occurrence in males. With the exception of the auditory exostosis and mylohyoid bridging in a few samples, significant sex differences were slight. The frequency distributions of the traits (except for the auditory exostosis) showed some interregional clinality and intraregional discontinuity, suggesting that genetic drift could have contributed to the observed pattern of variation.

Frequency variations of discrete cranial traits in major human populations. IV. Vessel and nerve related variations.

This concludes a series of descriptive statistical reports on discrete cranial traits in 81 human populations from around the world. Four variants classified as vessel and nerve related characters were investigated: patent condylar canal, supraorbital foramen; accessory infraorbital foramen; and accessory mental foramen. A significant asymmetric occurrence without any side preference was detected for the accessory mental foramen. Significant intertrait associations were found between the accessory infraorbital and supraorbital foramina in the panPacific region and Subsaharan African samples. The intertrait associations between the accessory infraorbital foramen and some traits classified as hypostotic were found mainly in the samples from the western part of the Old World, and those as hyperostotic traits in the samples from eastern Asian and the related population samples. With a few exceptions. the occurrence of a patent condylar canal and a supraorbital foramen was predominant in females, but the accessory infraorbital and accessory mental foramina were predominant in males. The frequency distributions of the traits showed interregional clinality and intraregional discontinuity. A temporal trend was found in the Northeast Asian region in the frequencies of the accessory infraorbital and accessory mental foramina. The diversity of modern human discrete cranial traits may at least in part be attributable to differential retention or intensification from an ancestral pattern.

Frequency variations of discrete cranial traits in major human populations. I. Supernumerary ossicle variations.

Four supernumerary ossicle variations-the ossicle at the lambda, the parietal notch bone, the asterionic bone, and the occipitomastoid bone-were examined for laterality differences, intertrait correlations, sex differences, and between group variations in the samples from around the world. Significant laterality differences were not detected in almost all samples. In some pairs of traits, significant association of occurrence were found. Several geographic samples were sexually dimorphic with respect to the asterionic bone and to a lesser extent for the parietal notch bone. East/Northeast Asians including the Arctic populations in general had lower frequencies of the 4 accessory ossicles. Australians, Melanesians and the majority of the New World peoples, on the other hand, generally had high frequencies. In the western hemisphere of the Old World, Subsaharan Africans had relatively high frequencies. Except for the ossicle at the lambda, the distribution pattern in incidence showed clinal variation from south to north. Any identifiable adaptive value related to environmental or subsistence factors may be expressed in such clinal variation. This may allow us to hypothesise that not only mechanical factors but a founder effect, genetic drift, and population structure could have been the underlying causes for interregional variation and possible clines in the incidences of the accessory ossicles.

Frequency variations of discrete cranial traits in major human populations. II. Hypostotic variations.

Five discrete hypostotic cranial traits, tympanic dehiscence, ovale-spinosum confluence, metopism, transverse zygomatic suture vestige, and biasterionic suture, were investigated in 81 human population samples. Except for ovale-spinosum confluence, marked asymmetric occurrences of the bilateral traits were not detected in the majority of the samples. Significant intertrait association was observed mainly between the biasterionic suture and other sutural variations including accessory ossicles. The traits showing relatively consistent sex differences across diverse populations were tympanic dehiscence, which is predominant in females, and biasterionic suture in males. On a world scale, the 5 hypostotic cranial traits showed distinctive patterns of geographical variation. Different clinal variations within and between macrogeographical areas such as western and eastern parts of the Old World were found for the frequencies of the traits. The Ainu may be the most distinct outlier in the eastern Asian region on the basis of the incidence of the traits, especially the transverse zygomatic suture vestige. The interregional variation without reasonable adaptive value and nonadaptive shift of the possible outliers presented in this study suggest that the genetic background for the occurrence of these traits cannot be excluded completely.

Occipital glucose metabolism in dementia with lewy bodies with and without Parkinsonism: a study using positron emission tomography.

Reduction of glucose metabolism in the occipital lobe is reported in dementia with Lewy bodies (DLB) and Parkinson's disease. If dysfunction of the nigrostriatal system is responsible for occipital hypometabolism, (1) DLB patients with parkinsonism would show a lower occipital metabolism than do patients without parkinsonism, and (2) DLB patients without parkinsonism would show an occipital metabolism comparable to those of normal subjects and patients with Alzheimer's disease (AD). To examine these hypotheses, we studied the regional cerebral metabolic rate of glucose (rCMRglc) in patients with a clinical diagnosis of DLB or AD, using (18)F-fluorodeoxyglucose and positron emission tomography. The subjects consisted of 15 DLB patients with parkinsonism, 7 DLB patients without parkinsonism and 7 AD patients without parkinsonism. The medial and lateral occipital rCMRglc was significantly lower in the DLB patients without parkinsonism than in the AD patients. There were no significant differences in occipital metabolic rates between the DLB groups with and without parkinsonism. DLB patients without parkinsonism showed a significant reduction of occipital glucose metabolism which is comparable with that of DLB patients with parkinsonism. The neurobiological bases of occipital hypometabolism in DLB may be pathological processes in the brainstem or basal forebrain structures other than the nigrostriatal system.

Os incae: variation in frequency in major human population groups.

The variation in frequency of the Inca bone was examined in major human populations around the world. The New World populations have generally high frequencies of the Inca bone, whereas lower frequencies occur in northeast Asians and Australians. Tibetan/Nepalese and Assam/Sikkim populations in northeast India have more Inca bones than do neighbouring populations. Among modern populations originally derived from eastern Asian population stock, the frequencies are highest in some of the marginal isolated groups. In Central and West Asia as well as in Europe, frequency of the Inca bone is relatively low. The incidence of the complete Inca bone is, moreover, very low in the western hemisphere of the Old World except for Subsaharan Africa. Subsaharan Africans show as a whole a second peak in the occurrence of the Inca bone. Geographical and ethnographical patterns of the frequency variation of the Inca bone found in this study indicate that the possible genetic background for the occurrence of this bone cannot be completely excluded. Relatively high frequencies of the Inca bone in Subsaharan Africans indicate that this trait is not a uniquely eastern Asian regional character.

Impact of emotion on memory. Controlled study of the influence of emotionally charged material on declarative memory in Alzheimer's disease.

BACKGROUND: In an earlier study we showed that a powerful emotional experience (the Kobe earthquake) reinforced memory retention in patients with Alzheimer's disease, but we could not control factors other than the emotional impact of the earthquake. AIMS: To test our previous findings in a controlled experimental study. METHOD: Recall tests consisting of two short stories were administered to 34 patients with Alzheimer's disease and 10 normal subjects. The two stories were identical except for one passage in each story: one was emotionally charged (arousing story) and the other (neutral story) was not. RESULTS: In both groups, the emotionally charged passage in the arousing story was remembered better than the counterpart in the neutral story. In addition, the extent of the memory improvement was similar in the subjects and in the controls. CONCLUSIONS: The results provide further evidence that emotional arousal enhances declarative memory in patients with Alzheimer's disease, and give a clue to the management of people with dementia.

Fall-related injuries in dementia with Lewy bodies (DLB) and Alzheimer's disease.

Repeated falls are reported as one of the clinical characteristics in dementia with Lewy bodies (DLB). We examined the incidence of fall-related injuries in 561 dementia patients with various clinical diagnoses, including DLB and Alzheimer's disease (AD), in a ward established for dementia research. The incidence of fall-related injuries was significantly higher in DLB patients (10.7%) than in AD patients (1.1%) (P < 0.001). The high incidence in those patients with DLB cannot be attributed to Parkinsonism because none of the DLB patients with injuries showed extrapyramidal sign. Our observations suggest that patients with a clinical diagnosis of DLB have a high risk of fall-related injuries, even though they do not show Parkinsonism. An appropriate clinical discrimination between DLB and AD is recommended to manage and prevent fall-related injuries.

Visuoperceptual impairment in dementia with Lewy bodies.

BACKGROUND: In dementia with Lewy bodies (DLB), vision-related cognitive and behavioral symptoms are common, and involvement of the occipital visual cortices has been demonstrated in functional neuroimaging studies. OBJECTIVES: To delineate visuoperceptual disturbance in patients with DLB in comparison with that in patients with Alzheimer disease and to explore the relationship between visuoperceptual disturbance and the vision-related cognitive and behavioral symptoms. DESIGN: Case-control study. SETTING: Research-oriented hospital. PATIENTS: Twenty-four patients with probable DLB (based on criteria of the Consortium on DLB International Workshop) and 48 patients with probable Alzheimer disease (based on criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) who were matched to those with DLB 2:1 by age, sex, education, and Mini-Mental State Examination score. MAIN OUTCOME MEASURES: Four test items to examine visuoperceptual functions, including the object size discrimination, form discrimination, overlapping figure identification, and visual counting tasks. RESULTS: Compared with patients with probable Alzheimer disease, patients with probable DLB scored significantly lower on all the visuoperceptive tasks (P<.04 to P<.001). In the DLB group, patients with visual hallucinations (n = 18) scored significantly lower on the overlapping figure identification (P = .01) than those without them (n = 6), and patients with television misidentifications (n = 5) scored significantly lower on the size discrimination (P<.001), form discrimination (P = .01), and visual counting (P = .007) than those without them (n = 19). CONCLUSIONS: Visual perception is defective in probable DLB. The defective visual perception plays a role in development of visual hallucinations, delusional misidentifications, visual agnosias, and visuoconstructive disability charcteristic of DLB.

Features of regional cerebral glucose metabolism abnormality in corticobasal degeneration.

We studied regional cerebral glucose metabolism in 15 patients with a clinical diagnosis of corticobasal degeneration (CBD), 15 patients with probable Alzheimer's disease (AD), and 15 healthy controls for 19 brain regions. Asymmetry in regional glucose metabolism was found in the central and frontal cortices in patients with CBD as compared with either the normal controls or the patients with AD. Regional glucose metabolism in CBD patients was significantly lower in the paracentral and superior parietal areas and thalamus than in patients with AD. Relative glucose metabolism in patients with CBD was significantly higher in the posterior cingulate, medial temporal and basal frontal areas, and significantly lower in the paracentral and superior parietal areas than in those with AD. These features of regional glucose metabolic abnormality in CBD may correspond to neurological and cognitive disturbances peculiar to CBD.

A study of remote memory impairment in Alzheimer's disease by using the family line test.

We evaluated remote autobiographical memory impairment in 25 patients with probable Alzheimer's disease (AD) and 25 sex-, age- and education-matched healthy subjects by using a newly developed, highly effective assessment tool for remote memory, the Family Line Test (FLT). The FLT yields a total score, scores for 3 lifetime periods and the duration of remote memory impairment. In the patients with AD, the total score was significantly lower and the duration of remote memory impairment was significantly longer than in the healthy controls. A prominent temporal gradient in remote memory impairment was documented in the patients with AD. The total FLT score and duration of remote memory impairment correlated with recent memory and general cognitive dysfunctions.

Frontal and facial flatness of major human populations.

In the present study, the frontal and facial features of 112 populations from around the world are compared in terms of frontal and facial flatness measurements. Univariate analyses and canonical correlation analysis were applied to six indices representing flatness of frontal and facial bones. The deep infraglabellar notch, marked prognathism, and flat frontal bone show distinctive Australian/Melanesian characters among recent populations. Very flat faces in the transverse plane are the most common condition in eastern Asians. Some subSaharan Africans share similar characteristics with Australians in terms of marked prognathism and flat frontal bones in the sagittal plane on the one hand, and with eastern Asians on the other hand, for flat nasal and zygomaxillary regions. These results are not necessarily inconsistent with the evidence for regional continuity. The examination of relationships between frontal and facial flatness through canonical correlation analysis reveals a significant association between morphological features such as a deep infraglabellar notch, prognathism, flat frontal bone, and flat faces in the transverse plane. In this context, together with the generalized features of the late Pleistocene fossil record, the features of Australians having transversely projecting faces and of eastern Asians showing weak infraglabellar notches, ortho-/mosognathism, and rounded frontal bones can be interpreted as a differential retention of ancestral traits of anatomically modern humans. This may allow us to suppose that the frontal and facial flatness features treated herein can be explained by the hypothesis of a single origin of anatomically modern humans.

Distinctive neurobehavioral features among neurodegenerative dementias.

The distinctive neuropsychiatric features of Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD) were investigated by using the Neuropsychiatric Inventory. The patients with FTD had significantly more euphoria, aberrant motor activity, and disinhibition and significantly fewer delusions compared with the patients with AD or DLB. The patients with DLB had significantly more hallucinations compared with the AD or FTD patients. The findings clearly demonstrate that AD, DLB, and FTD have distinctive neuropsychiatric features, which may correspond to different patterns of cerebral involvement characteristic of these three major degenerative dementias.

Visual hallucinations and regional cerebral metabolism in dementia with Lewy bodies (DLB).

To investigate the neurobiological bases of visual hallucinations in dementia with Lewy bodies (DLB), regional cerebral glucose metabolism was compared among three patient groups; DLB with visual hallucinations, DLB without visual hallucinations and Alzheimer's disease (AD) without visual hallucinations. The regional metabolism was significantly lower in both DLB groups than in the AD group in the primary visual area and the posterior temporal, parietal and lateral occipital association areas. The hypometabolism in the right posterior temporal and parietal areas was significantly milder in DLB with visual hallucinations than in DLB without hallucinations. The hypometabolism in the primary visual cortex and the relatively preserved metabolism in the right temporoparietal association cortices may be associated with the occurrence of visual hallucinations in DLB patients.

Diffusion-weighted magnetic resonance imaging: detection of ischemic injury 39 minutes after onset in a stroke patient.

A neurologist witnessed the in-hospital onset of an ischemic stroke in a 71-year-old right-handed male who suddenly developed global aphasia and right hemiplegia. Diffusion-weighted magnetic resonance imaging (DWI) 39 minutes after the ictus demonstrated high signals in the left internal carotid artery territory. T1- and T2-weighted images failed to detect this change. Magnetic resonance angiography showed occlusions in branches of the left anterior and middle cerebral arteries and an atheromatous stenotic lesion in the ipsilateral proximal internal carotid artery. The patient was treated with intravenous heparin and low molecular dextran solution. Repeated magnetic resonance imagings identified an infarction slightly smaller than the abnormality demonstrated by the initial DWI. DWI detects hyperacute ischemic injury within 1 hour of symptom onset in human ischemic stroke.

Clinical diagnosis of dementia with Lewy bodies in a Japanese dementia registry.

We found 15 patients with dementia with Lewy bodies (DLB) and 232 patients with Alzheimer's disease (AD) among 327 consecutive patients with mild to moderate dementia in a Japanese dementia registry, using the clinical criteria of the Consortium on DLB International Workshop. The percentage of females was significantly lower in DLB than in AD (p < 0.01), while age at examination, Mini-Mental State Examination score and duration of cognitive symptoms were comparable between the two diseases. Eight of the 15 DLB patients (53%) had spontaneous parkinsonism, which was observed in 6 of the 232 AD patients (2.6%). Visual hallucinations were reported by 11 of the 15 DLB patients (73%) and 8 of the 232 AD patients (3.4%). Cognitive fluctuation was positive in 13 of the 15 DLB patients (87%). We found two types of episodic cognitive deterioration: one was characterized by pronounced disturbances of attention and alertness (inattention type), and the other was characterized by marked and bizarre disturbances of orientation in time and places, and misidentification of persons (disorientation type). Systematized delusion was observed in 8 DLB patients, and 5 patients showed neuroleptic sensitivity. Patients with DLB have a unique dementia syndrome even in the stage of mild to moderate cognitive impairments. Further studies are recommended to establish diagnosis, treatment and management.

Cognitive loss in dementia with Lewy bodies and Alzheimer disease.

BACKGROUND: Dementia with Lewy bodies (DLB) is emerging as a common cause of degenerative dementia. Some preliminary evidence exists that the pattern of cognitive impairment in DLB is different from that in Alzheimer disease (AD). OBJECTIVE: To delineate features of cognitive impairment of DLB on standardized neuropsychological tests. METHODS: We performed neuropsychological assessments of 26 patients with probable DLB (based on criteria of the consortium on DLB international workshop) and of 52 patients with probable AD (based on criteria of the National Institute of Neurological and Communicative Disorders and Stroke [now the National Institute of Neurological Disorders and Stroke])-Alzheimer's Disease and Related Disorders Association) who were matched to the patients with DLB 2:1 by age, sex, education, and Mini-Mental State Examination score. RESULTS: Compared with the group with probable AD, the group with probable DLB scored significantly lower on the picture arrangement, block design, object assembly, and digit symbol substitution subtests of the Wechsler Adult Intelligence Scale-Revised and on the Raven Colored Progressive Matrices test and significantly higher on the Mini-Mental State Examination locational orientation subtest and the Alzheimer's Disease Assessment Scale word recall subtest. A discriminant analysis revealed that the word recall score on the Alzheimer's Disease Assessment Scale and the block design score on the Wechsler Adult Intelligence Scale-Revised were the best discriminant factors. CONCLUSIONS: The disproportionately severe visuoperceptual, visuoconstructive, and visuospatial dysfunction and the disproportionately mild memory impairment in DLB compared with AD, which likely reflect the distribution of the pathologic changes in DLB, can help to differentiate DLB from AD.

Place of the Hokkaido Ainu (northern Japan) among circumpolar and other peoples of the world. A comparison of the frequency variations of discrete cranial traits.

Fifteen discrete cranial variations were studied in Ainu and a number of populations from around the world. The major findings, extracted by B-squared distance analysis and Fisher's exact probability test, are as follows: A) The five key traits which distinguish Ainu from the predominant eastern Asians are (1) medial palatine canal, (2) hypoglossal canal bridging, (3) supraorbital foramen, (4) transverse zygomatic suture vestige, and (5) mylohyoid bridging. The frequency of the first trait is comparable to those of Africans, especially Subsaharan Africans, the second and fifth conform to those of the New World peoples, the third is similar to Australians and Subsaharan Africans, and the fourth is the only one aligning the Ainu to Northeast Asians. B) The frequencies of a few wormian bones in Ainu are significantly different from those of many Southeast Asians. The frequencies favour rough clinality from the south to as far north as the arctic area of Northeast Asia in the regions of western Oceania and eastern Asia. The present study confirms that Ainu and Jomon are certainly members of populations originated in Asia but possibly outliers of more predominant Asian populations.

Mutation involving cytochrome P450IID6 in two Japanese patients with neuroleptic malignant syndrome.

Cytochrome P450IID6 (CYP2D6) plays an important role in the hepatic metabolism of various psychotropic drugs. We detected a mutation of the CYP2D6 gene in two patients who previously had episodes of neuroleptic malignant syndrome (NMS). They were homozygous for a mutated CYP2D6J allele conferring a poor-metabolizer phenotype. Possession of this trait may contribute to susceptibility to NMS.