Extrapyramidal signs in Alzheimer's disease: A 3-year follow-up study

Advanced Immunolabeling Method for Optical Volumetric Imaging Reveals Dystrophic Neurites of Dopaminergic Neurons in Alzheimer's Disease Mouse Brain

Optical brain clearing combined with immunolabeling is valuable for analyzing molecular tissue structures, including complex synaptic connectivity. However, the presence of aberrant lipid deposition due to aging and brain disorders poses a challenge for achieving antibody penetration throughout the entire brain volume. Herein, we present an efficient brain-wide immunolabeling method, the immuno-active clearing technique (iACT). The treatment of brain tissues with a zwitterionic detergent, specifically SB3-12, significantly enhanced tissue permeability by effectively mitigating lipid barriers. Notably, Quadrol treatment further refines the methodology by effectively eliminating residual detergents from cleared brain tissues, subsequently amplifying volumetric fluorescence signals. Employing iACT, we uncover disrupted axonal projections within the mesolimbic dopaminergic (DA) circuits in 5xFAD mice. Subsequent characterization of DA neural circuits in 5xFAD mice revealed proximal axonal swelling and misrouting of distal axonal compartments in proximity to amyloid-beta plaques. Importantly, these structural anomalies in DA axons correlate with a marked reduction in DA release within the nucleus accumbens. Collectively, our findings highlight the efficacy of optical volumetric imaging with iACT in resolving intricate structural alterations in deep brain neural circuits. Furthermore, we unveil the compromised integrity of DA pathways, contributing to the underlying neuropathology of Alzheimer's disease. The iACT technique thus holds significant promise as a valuable asset for advancing our understanding of complex neurodegenerative disorders and may pave the way for targeted therapeutic interventions.

Facial emotion expressivity in patients with Parkinson's and Alzheimer's disease

Parkinson's disease (PD) and Alzheimer's disease (AD) are neurodegenerative disorders with some overlapping clinical features. Hypomimia (reduced facial expressivity) is a prominent sign of PD and it is also present in AD. However, no study has experimentally assessed hypomimia in AD and compared facial expressivity between PD and AD patients. We compared facial emotion expressivity in patients with PD, AD, and healthy controls (HCs). Twenty-four PD patients, 24 AD patients and 24 HCs were videotaped during neutral facial expressions and while posing six facial emotions (anger, surprise, disgust, fear, happiness, and sadness). Fifteen raters were asked to evaluate the videos using MDS-UPDRS-III (item 3.2) and to identify the corresponding emotion from a seven-forced-choice response format. We measured the percentage of accuracy, the reaction time (RT), and the confidence level (CL) in the perceived accuracy of the raters' responses. We found the highest MDS-UPDRS 3.2 scores in PD, and higher in AD than HCs. When evaluating the posed expression captures, raters identified a lower percentage of correct answers in the PD and AD groups than HCs. There was no difference in raters' response accuracy between the PD and AD. No difference was observed in RT and CL data between groups. Hypomimia in patients correlated positively with the global MDS-UPDRS-III and negatively with Mini Mental State Examination scores. PD and AD patients have a similar pattern of reduced facial emotion expressivity compared to controls. These findings hold potential pathophysiological and clinical implications.

Age related weight loss in female 5xFAD mice from 3 to 12 months of age

In addition to cognitive decline, patients with Alzheimer's disease (AD) exhibit sensory, motor, and neuropsychiatric deficits. Many AD patients also show weight loss, suggesting that AD may involve a metabolic syndrome. The 5xFAD mouse model shows age-related weight loss compared to wildtype controls, and thus may exhibit metabolic dysfunction. This longitudinal study measured age-related weight loss in female 5xFAD and B6SJL/JF2 wild-type mice from 3 to 12 months of age, and examines some of the behavioural and physiological phenotypes in these mice that have been proposed to contribute to this weight loss. Because some mice had to be singly housed during the study, we also examined genotype by housing interactions. The 5xFAD mice weighed less and ate less than WT littermates starting at 6 months of age, exhibited less home cage activity, had higher frailty scores, less white adipose tissue, and lower leptin expression. At 9 and 12 months of age, heavier 5xFAD mice performed better on the rotarod, suggesting that metabolic deficits which begin between 6 and 9 months of age may exacerbate the behavioural deficits in 5xFAD mice. These results indicate that the 5xFAD mouse is a useful model to study the behavioural and metabolic changes in AD.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Case report of first-episode psychotic symptoms in a patient with early-onset Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder featuring the behavioral and psychological symptoms of dementia. Patients with early-onset AD that exhibits first as psychotic symptoms usually lack obvious cognitive impairment, so they may be misdiagnosed with late-onset schizophrenia.

CASE PRESENTATION

We report a patient who had prominent psychotic symptoms at the age of 60 and was initially diagnosed with very-late-onset-schizophrenia-like psychosis. Psychotic symptoms disappeared rapidly after treatment with olanzapine, and the patient later showed extrapyramidal symptoms and decline in cognitive function. Brain magnetic resonance imaging (MRI) showed frontotemporal atrophy, and positron emission tomography (PET) showed extensive areas of hypometabolism in the frontal cortex and head of the caudate nucleus. The patient's SORL1 gene was found to carry a heterozygrous mutation (c.296A > G). The patient was eventually diagnosed with early-onset AD.

CONCLUSIONS

Our case suggests that clinicians should consider the possibility of early-onset AD in middle-aged or elderly patients whose first symptoms are the behavioral and psychological symptoms of dementia. To distinguish early-onset AD from late-onset schizophrenia, clinicians should evaluate cognitive function, perform MRI and PET, and search for SORL1 mutations.

Extrapyramidal Signs and Cognitive Subdomains in Alzheimer Disease

OBJECTIVE

Extrapyramidal signs (EPS), commonly observed in Alzheimer disease (AD), predict cognitive impairment and functional decline. This study investigated the association between EPS and five cognitive subdomains in a large number of participants with AD.

DESIGN

Cross-sectional analyses of the nationwide Clinical Research of Dementia of South Korea (CREDOS) study, 2005-2012.

SETTING

Multicenter clinical settings.

PARTICIPANTS

1,737 participants with AD drawn from the CREDOS study.

MEASUREMENTS

The EPS group was defined by the presence of at least one EPS based on neurologic examination. We assessed five cognitive subdomains: attention, language, visuospatial function, memory, and frontal/executive function using the Seoul Neuropsychological Screening Battery-Dementia version. The associations of EPS with each cognitive subdomain were analyzed with a multiple linear regression model after controlling for confounding factors: sex, age, years of education, severity of dementia (Clinical Dementia Rating Sum of Boxes), and white matter hyperintensities.

RESULTS

164 AD participants (9.4%) had EPS. AD participants with EPS showed lower performance compared with those without EPS in two cognitive subdomains: attention and visuospatial function. The language, memory, and frontal/executive subdomains did not differ between the EPS-positive and the EPS-negative groups. In addition, we found a significant moderating relationship between EPS and deep white matter hyperintensities on visuospatial function score.

CONCLUSIONS

EPS in AD are associated with severe cognitive impairment in attention and visuospatial function. Careful screening for EPS in patients with AD may assist in prediction of cognitive profile.

Opposing effects of APP/PS1 and TrkB.T1 genotypes on midbrain dopamine neurons and stimulated dopamine release in vivo

Brain derived neurotrophic factor (BDNF) signaling disturbances in Alzheimer׳s disease (AD) have been demonstrated. BDNF levels fall in AD, but the ratio between truncated and full-length BDNF receptors TrkB.T1 and TrkB.TK, respectively, increases in brains of AD patients and APPswe/PS1dE9 (APP/PS1) AD model mice. Dopaminergic (DAergic) system disturbances in AD and detrimental effects of BDNF signaling deficits on DAergic system functions have also been indicated. Against this, we investigated changes in nigrostriatal dopamine (DA) system in mice carrying APP/PS1 and/or TrkB.T1 transgenes, the latter line modeling the TrkB.T1/TK ratio change in AD. Employing in vivo voltammetry, we found normal short-term DA release in caudate-putamen of mice carrying APP/PS1 or TrkB.T1 transgenes but impaired capacity to recruit more DA upon prolonged stimulation. However, mice carrying both transgenes did not differ from wild-type controls. Immunohistochemistry revealed normal density of tyrosine hydroxylase positive axon terminals in caudate-putamen in all genotypes and intact presynaptic machinery for DA release and reuptake, as shown by unchanged levels of SNAP-25, α-synuclein and DA transporter. However, we observed increased DAergic neurons in substantia nigra of TrkB.T1 mice resulting in decreased tyrosine hydroxylase per neuron in TrkB.T1 mice. The finding of unchanged nigral DAergic neurons in APP/PS1 mice largely confirms earlier reports, but the unexpected increase in midbrain DA neurons in TrkB.T1 mice is a novel finding. We suggest that both APP/PS1 and TrkB.T1 genotypes disrupt DAergic signaling, but via separate mechanisms.

Prevalence, incidence and risk factors of paratonia in patients with dementia: a one-year follow-up study

BACKGROUND

Paratonia is a progressive motor problem that is observed in individuals with dementia and is not a well-known phenomenon. This study explores the development and risk factors of paratonia in moderate stage dementia patients.

METHODS

A multi-center, longitudinal, one-year follow-up cohort study was performed. Patients with an established diagnosis of dementia, with a score of 6 or lower on the Global Deterioration Scale (GDS) were included. The participants were assessed using the Paratonia Assessment Instrument (PAI), the Timed Up and GO test, the Qualidem, the Global Deterioration Scale (Reisberg et al., 1982) and the Mini-mental State Examination. Information about each patient's diagnosis of dementia, comorbidities and use of medication were obtained from the participant's medical file. The PAI was assessed every three months, the other variables at baseline and after 12 months. Cross-tabulation χ2 and logistic regression tests were used for the statistical analyses.

RESULTS

Baseline measures were assessed in the 204 participants - 111 (54%) female and 93 (46%) male, with a mean age of 79.8 years (56-97). Seventy-one patients (34.8%) were diagnosed with paratonia at baseline, and 51 patients developed paratonia over one year. The highest hazard ratio (3.1) for developing paratonia within one year was observed in the vascular dementia group. The logistic regression analysis revealed that the presence of diabetes mellitus (OR = 10.7) was significantly related to the development of paratonia (Wald χ2 p-value < 0.01).

CONCLUSIONS

Diabetes mellitus and likely vascular damage are risk factors for the development of paratonia.

Extrapyramidal signs, primitive reflexes and incontinence in fronto-temporal dementia

According to the diagnostic consensus criteria [1] akinesia, rigidity and tremor as well as primitive reflexes and incontinence support the diagnosis of fronto-temporal dementia (FTD). However, the prevalence of extrapyramidal signs (EPMS), primitive reflexes and incontinence in FTD has not yet been systematically studied. In the present study, thirty-one patients with mild or moderate FTD without previous or present antipsychotic medication underwent a detailed neurological exam including the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS). The average total score on the motor subscale of the UPDRS was 14.0 points. Akinesia and Parkinsonian gait or posture were found frequently but were mild in most instances. Rigidity was found in 36% of the patients. Resting tremor was a rare symptom. The only primitive reflex that occurred was a positive palmomental that was found in 7% of the patients. Urinary incontinence was present in 26%. The results have to be confirmed with larger or pooled patient samples from different ascertainment scenarios. If the results of the present study can be replicated, a revision of the consensus criteria from 1998 might be considered.

Motor signs predict poor outcomes in Alzheimer disease

OBJECTIVE

To examine whether the presence of motor signs has predictive value for important outcomes in Alzheimer disease (AD).

METHODS

A total of 533 patients with AD at early stages (mean Folstein Mini-Mental State Examination [MMSE] 21/30 at entry) were recruited and followed semiannually for up to 13.1 years (mean 3) in five University-based AD centers in the United States and European Union. Four outcomes, assessed every 6 months, were used in Cox models: cognitive endpoint (Columbia Mini-Mental State Examination < or = 20/57 [ approximately MMSE < or = 10/30]), functional endpoint (Blessed Dementia Rating Scale > or = 10), institutionalization equivalent index, and death. Using a standardized portion of the Unified PD Rating Scale (administered every 6 months for a total of 3,149 visit-assessments, average 5.9 per patient), the presence of motor signs, as well as of individual motor sign domains, was examined as time-dependent predictor. The models controlled for cohort, recruitment center, sex, age, education, a comorbidity index, and baseline cognitive and functional performance.

RESULTS

A total of 39% of the patients reached the cognitive, 41% the functional, 54% the institutionalization, and 47% the mortality endpoint. Motor signs were noted for 14% of patients at baseline and for 45% at any evaluation. Their presence was associated with increased risk for cognitive decline (RR, 1.72; 95% CI, 1.24 to 2.38), functional decline (1.80 [1.33 to 2.45]), institutionalization (1.68 [1.26 to 2.25]), and death (1.38 [1.05 to 1.82]). Tremor was associated with increased risk for reaching the cognitive and bradykinesia for reaching the functional endpoints. Postural-gait abnormalities carried increased risk for institutionalization and mortality. Faster rates of motor sign accumulation were associated with increased risk for all outcomes.

CONCLUSIONS

Motor signs predict cognitive and functional decline, institutionalization, and mortality in Alzheimer disease. Different motor sign domains predict different outcomes.

Motor signs during the course of Alzheimer disease

BACKGROUND

Motor signs (MOSIs) are common in Alzheimer disease (AD) and may be associated with rates of cognitive decline, mortality, and cost of care.

OBJECTIVE

To describe the progression and identify predictors of individual MOSIs in AD.

METHODS

A cohort of 474 patients with AD at early stages was followed semiannually for up to 13.1 years (mean 3.6 years) in five centers in Europe and the United States. MOSIs were rated using a standardized portion of the Unified Parkinson's Disease Rating Scale. Overall, 3,030 visits/assessments of MOSIs (average 6.4/patient) were performed. Prevalence and incidence rates were calculated, and cumulative risk graphs were plotted for individual non-drug-induced MOSI domains. Rates of change over time taking into account potential covariates were also estimated. With use of each MOSI domain as outcome in Cox models, predictors of MOSI incidence were identified.

RESULTS

At least one MOSI was detected in 13% of patients at first examination and in 36% for the last evaluation. Total MOSI score increased at an annual rate of 3% of total possible score. Rates of annual change for speech/facial expression (4%), rigidity (2.45%), posture/gait (3.9%), and bradykinesia (3.75%) were of similar magnitude, and their occurrence increased from first (3 to 6%) to last (22 to 29%) evaluation. Tremor was less frequent throughout the course of the disease (4% at first and 7% at last evaluation) and worsened less (0.75% increase/year).

CONCLUSIONS

Most motor signs occur frequently and progress rapidly in Alzheimer disease. Tremor is an exception in that it occurs less frequently and advances at slower rates.

Assessment of diffuse Lewy body disease by 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET)

BACKGROUND: Lewy body disease is, after Alzheimer's disease, the second most common cause of senile degenerative dementia with progressive cognitive deterioration, fluctuation of cognitive and motoric functions and psychotic symptoms. It is characterized histologically by the occurrence of Lewy bodies in allocortical, neocortical and subcortical structures. The aim of this study was to measure the cortical glucose metabolism using FDG PET (2-[18F]fluoro-2-deoxy-D-glucose position emission tomography) compared to normal subjects. PATIENTS AND METHODS: Five patients (5 m, mean age 75 y) with clinically suspected diffuse Lewy body disease (DLB) were studied with FDG PET. PET studies of the head were performed with a Siemens ECAT-ART PET-scanner with attenuation correction using 137-Cs point sources. RESULTS: We found the same distribution pattern of diffuse glucose hypometabolism in the entire cortical region with relative sparing of the primary sensory-motor cortex in all the patients. The few cases reported in the literature so far describe findings similar to ours. CONCLUSION: The pattern of diffuse glucose hypometabolism in the entire cortex including the occipital region seems to be a typical feature of DLB that is distinctive from dementia of Alzheimer's disease.

Extrapyramidal signs and cognitive abilities in Alzheimer's disease

OBJECTIVE

To evaluate whether the relationship between extrapyramidal signs (EPS) and cognitive disturbances in Alzheimer's disease (AD) is influenced by illness duration.

METHODS

A multivariate regression analysis was used to study the relationships between EPS, illness duration and five cognitive ability areas based on the Mattis Dementia Rating Scale (DRS) in 89 clinically diagnosed AD patients with extrapyramidal motor involvement.

RESULTS

Severity of EPS was statistically associated with performance on four cognitive ability areas from the DRS including: attention, initiation and perseveration, construction and memory. Age was a significant factor related to severity of EPS. However illness duration did not contribute to the strength of the association between EPS and cognitive disturbances in patients with AD.

CONCLUSIONS

The findings of the present study support the notion that while neuropsychological and motor functions often coexist in patients with AD, their relationship seems to be unrelated to degenerative processes that accumulate throughout the illness.

Extrapyramidal symptoms and signs in Alzheimer's disease: prevalence and correlation with the first symptom

OBJECTIVES

To determine the prevalence and clinical correlates of extrapyramidal signs (EPS) in outpatients with probable Alzheimer's disease (AD); to examine the appearance of EPS in association with the first symptom that led the patient or family to ask for medical help; to examine the association of the prevalence of EPS with gender, age at onset of the disease, duration of the disease, severity of dementia, functional disability, and potential use of neuroleptics; and to address the issue of the possible role of EPS as a predictive factor for the clinical course of the disease.

PATIENTS AND METHODS

We examined 126 patients meeting NINCDS-ADRDA* criteria for probable AD and 29 healthy, nondementia controls of comparable age and gender. Thirteen of the patients taking neuroleptics at the time of the examination were excluded from the main study group and formed a separate subgroup of AD/neuroleptics-positive. Twenty-eight of the AD/neuroleptics-free patients were re-examined during an 18-month period in order to determine the possible role of EPS as a predictive factor of the clinical course of the disease.

RESULTS

Only 8 percent of the AD/neuroleptics-free patients were free of EPS, while the corresponding percentage in the control group was 61.5 percent. The most common types of EPS presented in the patient group were hypomimia ([facial mask] 60 percent), difficulty in talking (53.66 percent), bradykinesia (51.4 percent), postural instability (47.33 percent), abnormal gait (34.66), and rigidity (26 percent), respectively. No significant differences were found when examining for the presence of resting tremor, other tremors, dystonias, and dyskinesias. With regard to the presence of EPS and the first symptom, no significant difference was found among patients whose first complaint was memory disorder (probable AD) and patients with other symptoms. When examining the association between the prevalence of EPS and gender or age at onset of the disease, no special correlation was detected. However, such a correlation was found between the prevalence of EPS and duration of the disease, as indicated by the fact that EPS appear in 78.9 percent of the patients with a duration of illness less than two years, but in 97 percent of the patients with a corresponding duration of two years or more. The mean duration of the disease in patients appearing with EPS is found to be 2.68 +/- 1.98 years. The presence of EPS increases proportionally with the progression of the disease and cognitive and functional decline. Patients with poor results in the MMSE (score of less than 11) appear to present EPS at a greater percentage than those with better performance on the examination (MMSE scores greater than 11). With regard to the association between EPS and functional ability in AD, it seems that the presence of EPS imposes difficulties in daily activities, as seen by the fact that patients with EPS have lower FRSSD scores (mean +/- SD: 14.87 +/- 10.53) than patients without EPS (5 +/- 2.58). After controlling for duration of the disease, the use of neuroleptics is found to influence the appearance of EPS in patients with AD. Almost all of the patients AD/neuroleptics-positive patients presented EPS (100 percent), while 92 percent of the AD/neuroleptics-free patients manifested such symptoms. Finally, we re-evaluated 28 patients, who were part of the initial AD/neuroleptics-free group, in order to determine whether the appearance of EPS could have prognostic value for the clinical course of the disease. Patients who presented EPS at initial examination appeared to deteriorate faster, mainly cognitively, but also functionally. The mean decrease in MMSE scores in patients with EPS was found to be 2.65 +/- 3.46; while in patients without EPS at initial visit, MMSE scores were 0.63 +/- 3.88. The functional decline seems to be less influenced by the presence of EPS. The corresponding mean decrease in FRSSD scores of the two groups was 2.1 +/- 5.55 and 1.8 +/- 2.1, respectively.

The association between parkinsonism, Alzheimer's disease, and mortality: a comprehensive approach

BACKGROUND

The impact of parkinsonism on survival in older persons independent of dementia is not well understood.

METHODS

Participants in the clinical examination of the Canadian Study of Health and Aging who had parkinsonism and were older than age 65 were identified. The impact of parkinsonism on 5-year survival was determined for a combined cohort with and without dementia, and a stratified analysis was then conducted for the subgroups with Alzheimer's disease (AD) and those without dementia. Subjects with a previous diagnosis of Parkinson's disease and those prescribed drugs causing extrapyramidal side effects were excluded.

FINDINGS

A total of 721 subjects with AD and 1705 subjects without dementia were examined. After adjusting for age and residential status (community vs institution), parkinsonism was associated with poorer survival in the combined cohort (risk ratio 1.51; 95% CI, 1.22-1.85), in those with AD (risk ratio 1.34; 95% CI, 1.02-1.76), and those without dementia (risk ratio 1.54; 95% CI, 1.11-2.15). In the combined cohort, parkinsonism remained independently associated with higher mortality after adjusting for AD status (risk ratio 1.39; 95% CI, 1.13-1.72). In the subgroup with AD, parkinsonism remained associated with poorer survival after adjusting for severity of cognitive impairment (risk ratio 1.33; 95% CI. 1.04-1.74).

INTERPRETATION

Parkinsonism is significantly associated with poorer survival in older persons, regardless of whether they have dementia.

Choline acetyltransferase mRNA expression in the striatal neurons of patients with Alzheimer's disease

Besides cortical pathology, Alzheimer's disease (AD) is associated with a massive loss of cholinergic neurons in the basal forebrain. The resulting cortical cholinergic depletion is thought to contribute to the major cognitive impairment described in Ad. A selective loss of cholinergic neurons has also been observed in the ventral striatum, despite the lack of any major neurochemical dysfunction in the striatum of patients with AD. To examined possible changes in the functional activity of the neurons that remain in the striatum of AD patients, the expression level of the gene coding for choline acetyltransferase (ChAT) was evaluated using in situ hybridization in the caudate nucleus, putamen and ventral striatum. Quantitative analysis showed (i) a marked decrease in the number of ChAT mRNA-positive neurons in the ventral striatum, and (ii) significantly reduced ChAT mRNA expression in the surviving cholinergic neurons of the ventral striatum, whereas it was only slightly decreased in those of the dorsal striatum. Our data support the hypothesis of a down-regulated expression of ChAT in striatal cholinergic neurons, especially in those most vulnerable to the neurodegenerative process. The subnormal ChAT mRNA content may be the consequence of changes in the level of transcription of the ChAT gene, possibly in relation to sustained suffering still present at the late stages of this disease. Furthermore, the involvement of the ventral striatum in Alzheimer's disease may account for some of the behavioral and motor dysfunctions often observed in patients with AD.

Specific patterns of cortical dysfunction in dementia and Parkinson's disease demonstrated by the acceleration spectrum entropy of the EEG

Acceleration spectrum entropy (ASE) was used to quantify EEG desynchronization, which is related to cortical activation. We investigated the ASE in control and patient groups with dementia (AD) and Parkinson's disease (PD). Both patient groups had significantly lower ASE scores corresponding with less desynchronization in all cortical regions. In the AD group, the ASE was significantly lower in the parietal region. ASE was found to be a sensitive and specific measure for differentiating patient groups with AD and PD from controls and from each other.

Discontinuation of Antipsychotics in Nursing Home Patients With Dementia

The authors assessed the consequences of stopping antipsychotic medication in nursing home patients with dementia, as mandated by federal regulations (OBRA 87). They studied three patient groups: 1) a group ("clinical judgment") whose antipsychotics were discontinued at the discretion of their physicians; 2) a group ("empirical") with mandated cessation of antipsychotics in the facility; and 3) a comparison group of patients not receiving medication. The primary outcome measure was the necessity to resume antipsychotic or other psychotropic medication ("failure"). Also, assessments of behavior, function, neurologic status, and cognition were performed by blind raters. The failure rate in the empirical withdrawal group was 50%, 10 times that of the clinical judgment group. Among failures, the most striking result was increased verbal and physical aggression. No failures occurred in the comparison group. There were no benefits of antipsychotic withdrawal in terms of neurological performance, functional status, or cognition.

Regional cerebral blood flow measured by 99mTc-HMPAO SPECT differs in subgroups of Alzheimer's disease

Alzheimer's disease (AD) is a heterogeneous entity. Identifying AD subtypes might have impact in patients' response to different treatment strategies. We designed a study to examine regional cerebral blood flow (rCBF) in AD subtypes. To identify AD subtypes, we performed a cluster analysis including performance on memory, language, visuospatial, praxic, and executive functions. The rCBF measured by 99mTc-HMPAO SPECT was referred to the cerebellum. We examined 35 patients fulfilling the NINCDS-ADRDA criteria of probable AD and 13 age and sex-matched healthy cognitively intact controls. AD patients were at the early stage of the disease, their mean Mini-Mental Status (MMS) score (S.D.) was 22.5 (3.6). The cluster analysis revealed two AD subgroups: AD1 (N = 12) and AD2 (N = 23). The subgroups did not differ in age, sex, or global clinical severity as assessed by MMS and Brief Cognitive Rating Scale (BCRS). Both subgroups had equally impaired memory. The AD2 group was inferior to the AD1 group on verbal, visuospatial, praxic, and executive functions. The AD1 group showed reduced rCBF ratios in the temporal and parietal cortices and the amygdala compared to controls. The AD2 group differed from controls in the rCBF ratios of frontal, temporal, parietal, occipital, basal ganglia, and amygdaloid regions bilateral and from AD1 in the rCBF ratios of frontal and temporal cortices. In AD patients, the rCBF ratios did not correlate with MMS or BCRS scores. In contrast, several significant correlations were found between decreases rCBF ratios and impairment of memory and other cognitive functions. In conclusion, a cluster analysis on neuropsychological test performance identified two AD subgroups that differed on the neuropsychological profile and on the rCBF in spite of similar global clinical severity.

Human striatum: chemoarchitecture of the caudate nucleus, putamen and ventral striatum in health and Alzheimer's disease

The morphology and distribution of perikarya positive for choline acetyltransferase, somatostatin, calcium binding protein (calbindin D28K) and nicotinamide adenine dinucleotide phosphate diaphorase were surveyed in the human striatum. Choline acetyltransferase and somatostatin antibodies labeled separate populations of large striatal interneurons. Somatostatin immunoreactivity and nicotinamide adenine dinucleotide phosphate diaphorase (nitric oxide synthase) activity were completely co-localized. Calbindin antibody identified two distinct groups of striatal neurons: (1) numerous medium-sized, lightly stained neurons, probably analogous to striatopallidal projection neurons in the rat, and (2) much less numerous, large, darkly stained neurons. Half of the latter group, but none of the former, were also nicotinamide adenine dinucleotide phosphate diaphorase-positive. Somatostatin-positive and medium-sized, calbindin-positive neurons were more numerous in the caudate nucleus than in the putamen or ventral striatum. By contrast, large calbindin-immunoreactive neurons were more frequently encountered in the putamen. Choline acetyltransferase-positive neurons were evenly distributed across striatal components. In aged control subjects, the size of large, darkly stained calbindin-positive neurons was reduced relative to young subjects. Aging had no effect on somatostatin-, medium-sized calbindin-, or choline acetyltransferase-positive neurons. However, in histologically confirmed cases of Alzheimer's disease, there was a selective, 75% loss of choline acetyltransferase-immunoreactive perikarya from the ventral striatum, but not from the dorsal striatum, compared to aged controls. Furthermore, the remaining cholinergic neurons in the ventral striatum of Alzheimer's disease cases were significantly smaller than similar neurons in controls. These results indicate that various striatal components which have been shown to differ in their anatomical connectivity and functional specialization, also differ in their neurochemical signatures. The specific and marked loss of choline acetyltransferase-positive neurons from the ventral striatum in Alzheimer's disease is consistent with the characteristic cholinergic and 'limbic' pathology in this disease.