Risk factors for silent cerebral infarcts in subcortical white matter and basal ganglia

BACKGROUND AND PURPOSE

The purpose of this study was to clarify whether the relevant risk factors for silent cerebral infarcts (SCIs) in subcortical white matter (WM) are different from those in the basal ganglia (BG).

METHODS

Subjects of this study were 219 adults without a history of stroke or transient ischemic attack and without any abnormality on a neurological examination who consecutively visited the neurology service in our hospital between January 1994 and November 1997 requesting medical evaluation for possible cerebrovascular diseases. Subjects included 141 men and 78 women ranging in age from 33 to 83 years (mean+/-SD, 63.2+/-9.5 years). We performed brain MRIs and cervical/cranial MR angiographies on all subjects. In this study, SCI was defined as a focal lesion >5 mm in diameter that was prolonged on both T2-weighted and proton density images.

RESULTS

SCIs in the WM and/or BG were detected in 88 (40.2%) of the 219 subjects. No SCI >15 mm was observed in this series. Fifty of the subjects had SCIs only in the WM, 32 subjects had SCIs in both the WM and BG, and 6 subjects had SCIs only in the BG. Thus, 82 (93.2%) of 88 subjects with SCIs had lesions in the WM. Most subjects with SCIs in the BG also had SCIs in the WM. Multiple logistic regression analyses revealed that age, female sex, and hypertension were significant and independent predictors of SCIs in the WM, and that age, a history of ischemic heart disease, and carotid artery stenosis were significant and independent predictors of SCIs in the BG.

CONCLUSIONS

The present study indicated that the relevant risk factors for SCIs in the WM and those for SCI in the BG were different. Our results suggest that SCIs are prone to first appear in the WM in association with aging and hypertension, and the additional appearance of SCIs in the BG predicts a progression of generalized atherosclerosis that is manifested in the carotid and coronary arteries.

Violence and epilepsy: a close relation between violence and postictal psychosis

PURPOSE

We investigated the incidence of well-directed violent behavior and suicide attempts in patients with temporal lobe epilepsy, with special attention to postictal psychosis.

METHODS

We compared 57 episodes of postictal psychosis with 62 episodes of acute interictal (or alternative) psychosis and with 134 complex partial seizures. All patients were matched for age and for age at onset of seizures.

RESULTS

The incidence of well-directed violent behavior against human beings was significantly higher (23%) during postictal psychotic episodes than during acute interictal episodes (5%) and postictal confusion (1%). Suicide attempts were also more frequent during postictal psychosis (7%) than during either acute interictal psychosis (2%) or postictal confusion (0%).

CONCLUSIONS

Our study showed that well-directed violent and self-destructive behavior was not a feature of epileptic psychosis in general but a specific hallmark of postictal psychosis.

Single tottering mutations responsible for the neuropathic phenotype of the P-type calcium channel

Recent genetic and molecular biological analyses have revealed many forms of inherited channelopathies. Homozygous ataxic mice, tottering (tg) and leaner (tgla) mice, have mutations in the P/Q-type Ca2+ channel alpha1A subunit gene. Although their clinical phenotypes, histological changes, and locations of gene mutations are known, it remains unclear what phenotypes the mutant Ca2+ channels manifest, or whether the altered channel properties are the primary consequence of the mutations. To address these questions, we have characterized the electrophysiological properties of Ca2+ channels in cerebellar Purkinje cells, where the P-type is the dominant Ca2+ channel, dissociated from the normal, tg, and tgla mice, and compared them with the properties of the wild-type and mutant alpha1A channels recombinantly expressed with the alpha2 and beta subunits in baby hamster kidney cells. The most striking feature of Ca2+ channel currents of mutant Purkinje cells was a marked reduction in current density, being reduced to approximately 60 and approximately 40% of control in tg and tgla mice, respectively, without changes of cell size. The Ca2+ channel currents in the tg Purkinje cells showed a relative increase in non-inactivating component in voltage-dependent inactivation. Besides the same change, those of the tgla mice showed a more distinct change in voltage dependence of activation and inactivation, being shifted in the depolarizing direction by approximately 10 mV, with a broader voltage dependence of inactivation. In the recombinant expression system, the tg channel with a missense mutation (P601L) and one form of the two possible tgla aberrant splicing products, tgla (short) channel, showed a significant reduction in current density, while the other form of the tgla channels, tgla (long), had a current density comparable to the normal control. On the other hand, the shift in voltage dependence of activation and inactivation was observed only for the tgla (long) channel. Comparison of properties of the native and recombinant mutant channels suggests that single tottering mutations are directly responsible for the neuropathic phenotypes of reduction in current density and deviations in gating behavior, which lead to neuronal death and cerebellar atrophy.

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.

Lack of association of apolipoprotein E epsilon4 allele dose with cerebral glucose metabolism in Alzheimer disease

Parietal cerebral glucose metabolism is reduced before substantial impairments appeared in subjects carrying the apolipoprotein E (APOE) epsilon4 allele, but the effect of the APOE epsilon4 allele on cerebral metabolism in Alzheimer disease (AD) is still undetermined. To investigate the effect of the APOE epsilon4 allele on cerebral metabolism in AD, we examined regional cerebral glucose metabolism in 83 patients with AD by using 18F-fluorodeoxyglucose and positron emission tomography. Cerebral glucose metabolism in the fronto-parieto-temporal association and limbic cortices was significantly decreased in the AD patients compared with 26 age- and sex-matched normal controls. Regional cerebral glucose metabolic rate was not correlated significantly with the number of APOE epsilon4 alleles in any region, which was consistent even after controlling the effects of age, sex, and severity of dementia, and in a subgroup analysis of those aged between 60 and 75. These results supported the view that the APOE epsilon4 allele is not associated with specific deficits in brain metabolism in AD despite evidence of preclinical alterations.

Regional metabolism: associations with dyscalculia in Alzheimer's disease

OBJECTIVES

The ability to calculate, which is an important aspect of social daily living, is commonly impaired in patients with Alzheimer's disease even early in the course of the disease. Dyscalculia is often accompanied by focal brain damage, and has been argued to be an independent sign localised around the left temporoparietal region. However, the region most responsible for dyscalculia in Alzheimer's disease has not been determined. The relation between calculation ability and regional cerebral glucose metabolism in Alzheimer's disease was therefore examined.

METHODS

The calculation ability, In 91 patients with probable Alzheimer's disease of minimal to moderate severity, was assessed using the arithmetic subtest of the Wechsler adult intelligence scale-revised and the performance correlated with regional cerebral glucose metabolism determined by "F-fluorodeoxyglucose and PET.

RESULTS

Regional glucose metabolism in the left inferior parietal lobule and in the left inferior temporal gyrus was significantly correlated with the calculation performance irrespective of age, sex, education, and severity of disease.

CONCLUSIONS

The results suggest that dysfunction of the left inferior parietal lobule and the left inferior temporal gyrus plays an important part in producing dyscalculia in patients with Alzheimer's disease.

Identification of mRNAs differentially expressed in lymphocytes following interleukin-2 activation

We investigated genes involved in the interleukin-2 activation of cultured lymphocytes using a differential display reverse transcription PCR technique. Three cDNA fragments corresponding to mRNAs differentially amplified in the activated lymphocytes were sequenced and identified. These fragments were identical to the 3' region of the mRNAs encoding for the tumor rejection antigen TRA 1 that is the human homologue of the murine heat shock protein gp96, the DAP12 protein that possesses an immunoreceptor tyrosine-based activation motif, and the human motor protein p87/89 expressed in the heart. These proteins are involved, respectively, in cellular communication, in signal transduction, and in cellular movements. Our findings suggest that the activation of cellular immune response by interleukin-2 is a process analogous to other known phenomena of activation of catabolic reactions of energy transduction for activities which allow adaptation of cells to stress conditions.

Alteration of regional cerebral glucose utilization with delusions in Alzheimer's disease

The authors examined 65 patients with Alzheimer's disease for delusions and explored the relationship of delusions with regional cerebral glucose metabolism determined by [18F]fluorodeoxyglucose PET. In patients with delusions (n = 26), normalized glucose metabolism was significantly increased in the left inferior temporal gyrus and significantly decreased in the left medial occipital region as compared with those without delusions (n = 39). The two groups were similar in age, sex, and dementia severity. These results suggest that delusions in Alzheimer's disease are attributable to a dysfunction in specific brain areas rather than a simple reaction to intellectual deficits.

Aberrant expression and dysfunction of Fas antigen in MRL/MpJ-lpr/lpr murine ovary

In lpr mice the insertion of an early transposable element (ETn) into intron 2 of the Fas gene, which mediates apoptosis, causes the development of massive lymphadenopathy, splenomegaly and autoimmune disease. In the present study we investigated the influence of this mutation on ovarian development of lpr mice. By means of in situ hybridisation, the expression of Fas mRNA was detected at the same levels in the ovarian cells of MRL/MpJ-lpr/lpr (MRL/lpr) mice as in those of MRL/MpJ-(+)/+ (MRL/+) mice. However, indirect immunofluorescence (IIF) staining with anti-Fas monoclonal antibody (mAb) on the membrane of follicle and egg of MRL/lpr mice was significantly weaker than that of MRL/+ mice. Furthermore, the expression level of Fas protein at the 45 kDa band from ovarian cell lysates of MRL/lpr mice was much lower than that of MRL/+ mice. The co-incubation of Spodoptera frugiperda (Sf9)-Fas lig- and (L) cells with eggs of MRL/+ mice resulted in apoptosis of eggs, as detected by the terminal deoxynucleotide transferase mediated dUPT-nick end labelled (TUNEL) method. In contrast the co-incubation of Sf9-FasL cells with eggs of MRL/lpr mice did not generate apoptosis in eggs. Following intraperitoneal administration of anti-Fas mAb into both types of mice, most oocytes, a proportion of granulosa cells in the ovary and hepatocytes in liver of MRL/+ mice were positively stained by the TUNEL method, corresponding to the appearance of DNA fragmented ladders by DNA fragmentation assay, while negative signals were obtained in those cells of MRL/lpr mice. As the mice aged, the ovarian size of MRL/lpr mice was found to be much larger than that of MRL/+ mice due to the increased number of ovarian follicles. Therefore, the ovarian adenopathy in MRL/lpr mice was strongly suggested to be caused by the dysfunction of Fas antigen in the ovary.

Relatively preserved hippocampal glucose metabolism in mild Alzheimer's disease

The purpose of this study was to clarify the changes in hippocampal glucose metabolism in mild Alzheimer's disease (AD) using positron emission tomography (PET) and 2-(18F)fluoro-2-deoxy-D-glucose (FDG). Forty-one patients with probable mild AD (age: 69.0 +/- 8.0 years; MMSE: 22.6 +/- 2.1) and 22 normal volunteers (age: 67.7 +/- 7.1 years) were studied. The regional cerebral metabolic rate for glucose (CMRglc) was measured using FDG and PET. Although the mean CMRglc in the parietal region was significantly lower in the AD group (right: 6.35 +/- 1.26 mg/100 g/min; left: 6.37 +/- 1.21 mg/100 g/min) than in the control group (right: 7.73 +/- 1.02 mg/100 g/min; left: 7.63 +/- 0.95 mg/100 g/min), the mean CMRglc in the hippocampus did not show a significant difference between the AD group (right: 4.58 +/- 0.70 mg/100 g/min; left: 4.63 +/- 0.67 mg/100 g/min) and the control group (right: 5.22 +/- 0.65 mg/100 g/min; left: 5.22 +/- 0.67 mg/100 g/min) by analysis of variance and post-hoc Tukey's test. The magnitude of the hippocampal CMRglc reduction was not as large as that of parietal CMRglc reduction. Statistical parametric maps (SPM) analysis also did not significantly demonstrate reduced hippocampal CMRglc in AD patients, although it did show a significant reduction in parietal CMRglc in AD patients. Hippocampal CMRglc was not significantly decreased in mild AD. This was unexpected in view of previous studies that have shown atrophy and clinical dysfunction concerning hippocampus in AD, and suggests that the pathophysiology of the hippocampus in AD may be more complex than was previously thought.

Cerebral glucose metabolism in patients with frontotemporal dementia

Frontotemporal dementia (FTD) is a dementia syndrome characterized by peculiar behavioral changes arising from frontotemporal involvement and distinct from Alzheimer's disease (AD). The purpose of this study was to elucidate the specific patterns in cerebral glucose metabolism in patients with FTD and to compare them with the patterns in patients with AD and normal elderly subjects using fluorodeoxyglucose (FDG) and PET.

METHODS

Twenty-one patients with a clinical diagnosis of FTD [mean age 67.0 +/- 7.0 yr, Mini Mental State Examination (MMSE) score 18.7 +/- 5.7], 21 age-, sex- and dementia-severity-matched patients with probable AD (mean age 66.9 +/- 7.1 yr, MMSE score 20.2 +/- 5.5) and 21 age- and sex-matched normal control subjects (mean age 66.8 +/- 5.7 yr) were studied. The cerebral metabolic rate for glucose (CMRglc) was measured with FDG and PET. Absolute measures of regional CMRglc were compared among the three groups. One-way ANOVA and the posthoc Tukey HSD test were used for statistical analyses.

RESULTS

In the FTD group, CMRglc was preserved only in the left cerebellum, right sensorimotor area and occipital lobes. The CMRglc was significantly lower in the FTD group as opposed to the AD group in the hippocampi, orbital gyri, anterior temporal lobes, anterior cingulate gyri, basal ganglia, thalami, middle and superior frontal gyri and left inferior frontal gyrus.

CONCLUSION

Although metabolic abnormality in FTD is predominant in the frontal and anterior temporal lobes and the subcortical structures, it is more widespread than has been previously stressed. These findings document an FTD-specific cerebral involvement and facilitate differential diagnosis of degenerative dementias.

Isolation and identification of apoptosis inducing nucleosides from CD57(+)HLA-DRbright natural suppressor cell line

The CD57(+)HLA-DRbright natural suppressor (57.DR-NS) cell line derived from human decidual tissue generated the apoptosis in K562/Molt4 target cells mediated by soluble factors released into the culture supernatant. The factors in the culture fluid of the 57. DR-NS cell line were isolated by the physicochemical procedures as follows, first by a preparative octadecyl sorbent column, further by thin-layer-chromatography (TLC), finally by reverse-phase high-performance liquid chromatography (HPLC). The six major components (P1-P6) obtained by HPLC demonstrated the generation of apoptotic cell death of target cells. The physicochemical characters of six active components were strongly suggested to be nucleosides and their modified forms in nature. Then, the physicochemical structures of the six active components were finally determined by fast atom bombardment-mass spectrometry (FAB-MS) and nuclear magnetic resonance (1H NMR) spectrometry as follows: P1, 2'-deoxyuridine; P2, ribothymidine; P3, 2'-O-methyluridine; P4, thymidine; P5, 2'-O-methylinosine; P6, 2'-O-methylguanosine. Thus, we collectively named them "apoptosis inducing nucleosides (AINs)." Then, we demonstrated that the induction of apoptosis in target cells by the 57.DR-NS cell line was mediated by a series of AINs.

Intra-coronary administration of L-arginine aggravates myocardial stunning through production of peroxynitrite in dogs

OBJECTIVE

The aim of this study was to investigate how the enhanced nitric oxide (NO) production by intra-coronary infusion of L-arginine acts in myocardial stunning in dogs by focusing on the involvement of peroxynitrite, a reaction product of NO and superoxide anion.

METHODS AND RESULTS

Dogs were divided into six groups; a control non-treated group (CON, n = 9), and NG-nitro L-arginine methyl ester (L-NAME, n = 6), 1 mM L-arginine (L-ARG, n = 8), D-arginine (D-ARG, n = 6), L-arginine plus superoxide dismutase (L-ARG + SOD, n = 6), and SOD alone (SOD, n = 6) treated groups. L-NAME, or L- or D-arginine was continuously infused into the left anterior descending coronary artery (LAD) starting just prior to reperfusion, whereas SOD was intravenously injected before occlusion. During 120 min of reperfusion after 15 min occlusion of LAD, myocardial contractile function in the ischemic region gradually recovered and reached approximately 70% of the preischemic level in CON, D-ARG and SOD, but it remained dyskinetic (-46%) in L-ARG. On the other hand, it was improved in L-NAME (90%). Tissue malondialdehyde was elevated (p < 0.005) after reperfusion, and myocardial NO metabolites measured by an intratissue-microdialyzer increased (approximately 150%, p < 0.05) in the ischemic region during reperfusion in L-ARG but not in the CON, L-NAME, D-ARG or SOD groups. In the L-ARG + SOD group, L-arginine-induced contractile dysfunction and elevation of malondialdehyde were prevented, but the increase in NO metabolites remained. These results suggest that L-arginine aggravated myocardial stunning through oxidative stress and the cytotoxicity was caused by NO derivatives but not by NO itself. The formation of nitrotyrosine, a footprint of peroxynitrite, was immunohistochemically confirmed in the ischemic region of L-ARG.

CONCLUSIONS

Our results demonstrate for the first time in vivo that NO has a detrimental role in myocardial stunning through the production of peroxynitrite.

Evolution of the structure and chromosomal distribution of histidine biosynthetic genes

A database of more than 100 histidine biosynthetic genes from different organisms belonging to the three primary domains has been analyzed, including those found in the now completely sequenced genomes of Haemophilus influenzae, Mycoplasma genitalium, Synechocystis sp., Methanococcus jannaschii, and Saccharomyces cerevisiae. The ubiquity of his genes suggests that it is a highly conserved pathway that was probably already present in the last common ancestor of all extant life. The chromosomal distribution of the his genes shows that the enterobacterial histidine operon structure is not the only possible organization, and that there is a diversity of gene arrays for the his pathway. Analysis of the available sequences shows that gene fusions (like those involved in the origin of the Escherichia coli and Salmonella typhimurium hisIE and hisB gene structures) are not universal. In contrast, the elongation event that led to the extant hisA gene from two homologous ancestral modules, as well as the subsequent paralogous duplication that originated hisF, appear to be irreversible and are conserved in all known organisms. The available evidence supports the hypothesis that histidine biosynthesis was assembled by a gene recruitment process.

Postictal psychosis as a risk factor for mood disorders after temporal lobe surgery

This study investigated the psychiatric consequences of 38 consecutive patients who had surgery for intractable temporal lobe epilepsy with special attention to postoperative mood disorders. A close interrelation between preoperative postictal psychosis and postoperative manic or depressive episodes was suggested. Left sided lobectomy augmented this correlation. Because the first sign of postoperative manic and depressive episodes appeared within 1 month and 2 months respectively, cautious psychiatric follow up for several months after surgery proved to be crucial to prevent postoperative suicides. Postoperative manic depressive episodes disappeared within the first 2 years after operation without exception, if treated suitably. This suggests that we do not have to preclude patients with postictal psychosis as surgical candidates, but measures must be taken to prevent postoperative depressions.

Age at onset and visuocognitive disturbances in Alzheimer disease

We examined the relation of age at onset and visuocognitive disturbances in Alzheimer disease (AD) using a large sample of patients, quantitative neuropsychological measures, and multivariate statistics controlling for gender, education, stage of dementia, and disease duration. Significant positive coefficients were obtained with forward and backward digit and visual spans, visual counting, copying Rey complex figure, and block design task. The results indicated that patients with early-onset AD performed worse than late-onset AD patients on these tasks. There was no significant effect of age at onset on identification of overlapping figures, visual form discrimination, or Raven's colored progressive matrices. These findings confirm the greater attentional and visuospatial impairments in early onset patients when these confounding factors were controlled for, although no significant effect of age at onset in visuoperceptual function was observed.

Frequency and clinical correlates of occlusive lesions of cerebral arteries in Japanese patients without stroke. Evaluation by MR angiography

To determine the frequency and clinical correlates of intra- and extracranial arterial occlusive lesions in a stroke-free population, we studied cerebral arteries in 156 subjects with no evidence of stroke who presented at a neurologic clinic with concerns about a possible stroke (104 males ranging in age from 37 to 83 years, with a mean age of 63.0) by using MR angiographies (MRAs). According to a validated rating scheme of MRAs for occlusive lesions, the degree of stenoses in the cervical portion of the carotid artery and of the intracranial arteries including the intracranial portion of the internal carotid artery, the middle cerebral artery stem, and the basilar artery were evaluated. Stenoses (>25% narrowing in diameter) were found in 18 patients (11.5%) in the cervical carotid artery, and in 23 patients (14.7%) in the intracranial arteries. Multiple logistic regression analysis showed that age and hyperlipidemia were significant and independent predictors for cervical carotid artery stenoses, and that age and hypertension were predictors for intracranial artery stenoses. Our data based on this special cohort of stroke-free patients suggested that the risk factors for extra- and intracranial artery lesions were different, and that MRA is possibly efficient in those patients in whom cerebral artery occlusive lesions may be suspected. e.g. in hyperlipidemic or hypertensive elderly. Larger population-based studies are needed to confirm these results.

Development of Wernicke-Korsakoff syndrome after long intervals following gastrectomy

BACKGROUND

Surgical exclusion of portions of the gastrointestinal tract is a predisposing risk factor for the development of Wernicke-Korsakoff syndrome. When this disease occurs, it is usually within weeks after the gastrointestinal surgery. However, it is not well known that Wernicke-Korsakoff syndrome may occur after a long latent interval following gastrectomy.

SETTING

A research-oriented hospital.

PATIENTS

Three patients without a history of alcoholism or dietary deprivation developed Wernicke-Korsakoff syndrome 2 to 20 years after undergoing gastrectomy. In these patients, minor changes in dietary habit led to the development of Wernicke-Korsakoff syndrome.

CONCLUSIONS

In addition to a long-standing latent deficiency in thiamin levels due to defective absorption following gastrectomy or gastrojejunostomy, other minor factors that may influence the intake of thiamin and the need for thiamin in subjects who have undergone gastrectomy may cause a state of thiamin deficiency resulting in Wernicke-Korsakoff syndrome. Results from our study indicate that the following measures are mandatory: educating patients about proper dietary habits, carefully monitoring their thiamin intake, recognizing Wernicke-Korsakoff syndrome early, and treating it immediately with appropriate measures.

Heterologous gene expression in an Escherichia coli population under starvation stress conditions

A novel system to study the evolution of transcription signals in heterologous systems under selective starvation conditions is described. It is based on the plasmid-mediated transfer of his biosynthetic genes from Azospirillum brasilense into a heterologous Escherichia coli mutant population lacking histidine biosynthetic ability. We show that under highly selective stressful conditions, genetic changes in the donor plasmid lead to mutated sequences that are efficiently recognized as promoters by the E. coli RNA polymerase.

Age at onset and language disturbances in Alzheimer's disease

This study examined the effect of age at symptom onset of Alzheimer's disease (AD) on the pattern of language disturbance. We assessed 150 consecutive patients with a clinical diagnosis of mild-to-moderate AD using the Western Aphasia Battery and a 100-item picture-naming test. A multivariate linear regression analysis examined the effect of age at onset after controlling for gender, education, severity of dementia and duration of the disease. Patients with early onset performed significantly worse than did patients with late onset on the word comprehension and sequential commands subtests. On the other hand, late-onset patients performed more poorly than early-onset patients on the picture-naming test in a subgroup with mild language deficits. However, the trend disappeared in other subgroups with more degraded language function. We consider that the concomitant effects of normal aging worsened the picture-naming deficits in the late-onset patients, and the rapid decline of naming ability in the early-onset patients masked the aging effect with the progression of language deficits. The deterioration of word comprehension and the rapid decline of naming ability are the characteristics of early-onset patients. The different patterns of language deficits between early- and late-onset patients may correspond to the genetic heterogeneity of AD.

Frontotemporal dementia and Alzheimer disease: evaluation of cortical atrophy with automated hemispheric surface display generated with MR images

PURPOSE

To determine the features of cortical atrophy in frontotemporal dementia (FTD) and Alzheimer disease by using a hemispheric surface display generated with magnetic resonance (MR) images.

MATERIALS AND METHODS

The extent of cortical atrophy was evaluated with automated MR hemispheric surface display and volumetry in 18 patients with FTD and in 18 matched patients with Alzheimer disease. Results were compared with those in 18 healthy, matched control subjects.

RESULTS

Most cortical regions were significantly atrophic in FTD and Alzheimer disease. The frontal and anterior temporal lobes were significantly more atrophic in FTD than in Alzheimer disease. The mean hemispheric-to-intracranial volume ratio in patients with FTD (56.2%) and those with Alzheimer disease (58.4%) was significantly smaller than the ratio in the control subjects (66.0%). Asymmetry of hemispheric volume was significantly larger in the FTD group than in the Alzheimer disease and control groups.

CONCLUSION

Cortical atrophy in FTD is more widespread than was previously thought. Asymmetric frontal and anterior temporal atrophy is a distinctive feature of FTD and distinguishes it from Alzheimer disease. Hemispheric surface display is a useful complement to tomographic images and is useful for the evaluation of focal cortical atrophy in degenerative dementias, especially FTD.

CSF spaces in idiopathic normal pressure hydrocephalus: morphology and volumetry

PURPOSE

Idiopathic normal pressure hydrocephalus (NPH) is an important cause of dementia in the elderly; however, idiopathic NPH is often difficult to differentiate from normal aging and vascular dementias in which brain atrophy with ventricular dilatation (hydrocephalus ex vacuo or central atrophy) is present. To elucidate the distinctive features of the distribution of CSF in idiopathic NPH, we used MR imaging to investigate the morphologic features and volume of the CSF space in patients with idiopathic NPH compared with those with other dementias.

METHODS

We assessed the size of four CSF compartments (the ventricle, basal cistern, sylvian space, and suprasylvian subarachnoid space) in 11 shunt-responsive patients with idiopathic NPH by semiquantitative and volumetric analyses of coronal T1-weighted MR images. The results were compared with those in 11 age- and sex-matched patients with Alzheimer disease and in 11 patients with vascular dementia.

RESULTS

In patients with idiopathic NPH, the CSF volume was significantly increased in the ventricles and decreased in the superior convexity and medial subarachnoid spaces as compared with patients with other dementias. The sylvian CSF volume in patients with idiopathic NPH was significantly greater than in patients with Alzheimer disease. The volume of the basal cistern was comparable among the three groups. In several patients with idiopathic NPH, focally dilated sulci were observed over the convexity or medial surface of the hemisphere.

CONCLUSION

Our results indicate that findings of enlarged basal cisterns and sylvian fissures and of focally dilated sulci support, rather than exclude, the diagnosis of shunt-responsive idiopathic NPH and suggest that this condition is caused by a suprasylvian subarachnoid block.

Medial temporal and whole-brain atrophy in dementia with Lewy bodies: a volumetric MRI study

OBJECTIVE

Dementia with Lewy bodies (DLB) is emerging as a common cause of degenerative dementia. A recent pathologic study has indicated that the medial temporal lobe in patients with DLB was less atrophic than that in patients with AD. The purpose of this study was to examine whether medial temporal MRI volumetry was useful to differentiate DLB from AD clinically.

METHODS

We compared the volumes of the hippocampal formation, amygdaloid complex, and whole brain in 27 patients with probable DLB (based on the criteria of the Consortium on DLB International Workshop), 27 patients with probable AD (based on criteria of the National Institute of Neurological Disease and Stroke/Alzheimer's Disease and Related Disorders Association), and 27 normal elderly subjects using an MRI-based volumetric technique. The three groups were matched for age and sex. Severity of cognitive disturbances represented by their Mini-Mental State Examination score was comparable between the DLB and AD groups.

RESULTS

Hippocampal volume (normalized to intracranial volume) in the DLB group was significantly larger than that in the AD group, but significantly smaller than that in the normal control group. There were no significant differences in the amygdala and whole-brain volume between the DLB group and the AD group, but the atrophies of the amygdala and whole brain were more severe in the DLB group than those in the control group.

CONCLUSIONS

These findings indicate the usefulness of MRI hippocampal volumetry in clinically discriminating patients with DLB from patients with AD.