Apathy predicts rate of cognitive decline over 24 months in premanifest Huntington's disease

BACKGROUND

Cognitive impairment is a core feature of Huntington's disease (HD), however, the onset and rate of cognitive decline is highly variable. Apathy is the most common neuropsychiatric symptom of HD, and is associated with cognitive impairment. The aim of this study was to investigate apathy as a predictor of subsequent cognitive decline over 2 years in premanifest and early HD, using a prospective, longitudinal design.

METHODS

A total of 118 premanifest HD gene carriers, 111 early HD and 118 healthy control participants from the multi-centre TRACK-HD study were included. Apathy symptoms were assessed at baseline using the apathy severity rating from the Short Problem Behaviours Assessment. A composite of 12 outcome measures from nine cognitive tasks was used to assess cognitive function at baseline and after 24 months.

RESULTS

In the premanifest group, after controlling for age, depression and motor signs, more apathy symptoms predicted faster cognitive decline over 2 years. In contrast, in the early HD group, more motor signs, but not apathy, predicted faster subsequent cognitive decline. In the control group, only older age predicted cognitive decline.

CONCLUSIONS

Our findings indicate that in premanifest HD, apathy is a harbinger for cognitive decline. In contrast, after motor onset, in early diagnosed HD, motor symptom severity more strongly predicts the rate of cognitive decline.

Interrater Reliability of the Unified Huntington's Disease Rating Scale-Total Motor Score Certification

BACKGROUND

The clinical assessment of motor symptoms in Huntington's disease is usually performed with the Unified Huntington's Disease Rating Scale-Total Motor Score (UHDRS-TMS). A high interrater reliability is desirable to monitor symptom progression. Therefore, a teaching video and a system for annual online certification has been developed and implemented.

OBJECTIVES

The aim of this study is to investigate the interrater reliability of the UHDRS-TMS and of its subitems, and to examine the performance of raters in consecutive years.

METHODS

Data from the online UHDRS-TMS certification were used. The interrater reliability was assessed for all first-time participants (n = 944) between 2009 and 2016. Intraclass correlation coefficients (ICC) were calculated for each year separately and the mean was taken as the total ICC.

RESULTS

The UHDRS-TMS (ICC = 0.847), tandem walking (0.824), pronate/supinate hands left (0.713), and retropulsion pull test (0.706) showed good interrater reliability. Poor interrater reliability was found for maximal dystonia of the left and right upper extremity (0.187 and 0.322, respectively), maximal dystonia of the left and right lower extremity (0.200 and 0.256, respectively), and maximal dystonia of the trunk (0.389), tongue protrusion (0.266), and rigidity arms left (0.390). Raters performed significantly worse on follow-up certification compared to their first certification.

CONCLUSIONS

Our results suggest that the rating of dystonia (absent, slight, mild, moderate, or marked) is subjective and difficult to interpret, especially on video. Therefore, changing the dystonia items of the UHDRS-TMS should be explored. We also recommend that raters should watch the UHDRS-TMS teaching video before each certification.

Structural and functional brain network correlates of depressive symptoms in premanifest Huntington's disease

Depression is common in premanifest Huntington's disease (preHD) and results in significant morbidity. We sought to examine how variations in structural and functional brain networks relate to depressive symptoms in premanifest HD and healthy controls. Brain networks were constructed using diffusion tractography (70 preHD and 81 controls) and resting state fMRI (92 preHD and 94 controls) data. A sub-network associated with depression was identified in a data-driven fashion and network-based statistics was used to investigate which specific connections correlated with depression scores. A replication analysis was then performed using data from a separate study. Correlations between depressive symptoms with increased functional connectivity and decreased structural connectivity were seen for connections in the default mode network (DMN) and basal ganglia in preHD. This study reveals specific connections in the DMN and basal ganglia that are associated with depressive symptoms in preHD. Hum Brain Mapp 38:2819-2829, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Compensation in Preclinical Huntington's Disease: Evidence From the Track-On HD Study

BACKGROUND

Cognitive and motor task performance in premanifest Huntington's disease (HD) gene-carriers is often within normal ranges prior to clinical diagnosis, despite loss of brain volume in regions involved in these tasks. This indicates ongoing compensation, with the brain maintaining function in the presence of neuronal loss. However, thus far, compensatory processes in HD have not been modeled explicitly. Using a new model, which incorporates individual variability related to structural change and behavior, we sought to identify functional correlates of compensation in premanifest-HD gene-carriers.

METHODS

We investigated the modulatory effects of regional brain atrophy, indexed by structural measures of disease load, on the relationship between performance and brain activity (or connectivity) using task-based and resting-state functional MRI.

FINDINGS

Consistent with compensation, as atrophy increased performance-related activity increased in the right parietal cortex during a working memory task. Similarly, increased functional coupling between the right dorsolateral prefrontal cortex and a left hemisphere network in the resting-state predicted better cognitive performance as atrophy increased. Such patterns were not detectable for the left hemisphere or for motor tasks.

INTERPRETATION

Our findings provide evidence for active compensatory processes in premanifest-HD for cognitive demands and suggest a higher vulnerability of the left hemisphere to the effects of regional atrophy.

Neuropsychiatry and White Matter Microstructure in Huntington's Disease

BACKGROUND

Neuropsychiatric symptoms in Huntington's disease (HD) are often evident prior to clinical diagnosis. Apathy is highly correlated with disease progression, while depression and irritability occur at different stages of the disease, both before and after clinical onset. Little is understood about the neural bases of these neuropsychiatric symptoms and to what extent those neural bases are analogous to neuropsychiatric disorders in the general population.

OBJECTIVE

We used Diffusion Tensor Imaging (DTI) to investigate structural connectivity between brain regions and any putative microstructural changes associated with depression, apathy and irritability in HD.

METHODS

DTI data were collected from 39 premanifest and 45 early-HD participants in the Track-HD study and analysed using whole-brain Tract-Based Spatial Statistics. We used regression analyses to identify white matter tracts whose structural integrity (as measured by fractional anisotropy, FA) was correlated with HADS-depression, PBA-apathy or PBA-irritability scores in gene-carriers and related to cumulative probability to onset (CPO).

RESULTS

For those with the highest CPO, we found significant correlations between depression scores and reduced FA in the splenium of the corpus callosum. In contrast, those with lowest CPO demonstrated significant correlations between irritability scores and widespread FA reductions. There was no significant relationship between apathy and FA throughout the whole brain.

CONCLUSIONS

We demonstrate that white matter changes associated with both depression and irritability in HD occur at different stages of disease progression concomitant with their clinical presentation.

Huntingtin with an expanded polyglutamine repeat affects the Jab1-p27(Kip1) pathway

Expansion of polyglutamine repeats is the cause of at least nine inherited human neurodegenerative disorders, including Huntington's disease (HD). It is widely accepted that deregulation of the transcriptional coactivator CBP by expanded huntingtin (htt) plays an important role in HD molecular pathogenesis. In this study, we report on a novel target of expanded polyglutamine stretches, the transcriptional coactivator Jun activation domain-binding protein 1 (Jab1), which shares DNA-sequence-specific transcription factor targets with CBP. Jab1 also plays a major role in the degradation of the cyclin-dependent-kinase inhibitor and putative transcription cofactor p27(Kip1). We found that Jab1 accumulates in aggregates when co-expressed with either expanded polyglutamine stretches or N-terminal fragments of mutant htt. In addition, the coactivator function of Jab1 was suppressed both by aggregated expanded polyglutamine solely and by mutant htt. Inhibition by mutant htt even preceded the appearance of microscopic aggregation. In an exon 1 HD cell model, we found that endogenous Jab1 could be recruited into aggregates and that this was accompanied by the accumulation of p27(Kip1). Accumulation of p27(Kip1) was also found in brains derived from HD patients. The repression of Jab1 by various mechanisms coupled with an increase of p27(Kip1) at late stages may have important transcriptional effects. In addition, the interference with the Jab1-p27(Kip1) pathway may contribute to the observed lower incidence of cancer in HD patients and may also be relevant for the understanding of the molecular pathogenesis of polyglutamine disorders in general.

Enhanced Abeta40 deposition was associated with increased Abeta42-43 in cerebral vasculature with Dutch-type hereditary cerebral hemorrhage with amyloidosis (HCHWA-D)

Cerebrovascular deposition of the amyloid beta-protein (Abeta) is a common pathologic event in patients with Alzheimer's disease (AD) and certain related disorders. Such an Abeta vascular deposition occurs primarily in the medial layer of the cerebral vessel wall in an assembled fibrillar state. These deposits are associated with several pathological responses, including degeneration of the smooth muscle cells in the cerebral vessel wall. Severe cases of cerebrovascular Abeta deposition are also accompanied by loss of vessel wall integrity and hemorrhagic stroke. Although the reasons for this pathological consequence are unclear, altered proteolytic mechanisms within the cerebral vessel wall may be involved. We analyzed cerebral Abeta deposition in brains with AD and Dutch-type hereditary cerebral hemorrhage with amyloidosis (HCHWA-D) on the basis of two amyloid species of Abeta(40) and Abeta(42/43) using specific monoclonal antibodies. Compared to Abeta deposition in senile plaques, the molecular composition of Abeta was distinguishable, indicating that the Abeta(40) species is the main component for vascular amyloid. Furthermore, we found Abeta(42/43) immunoreactivity was also much increased in amyloid angiopathy of all cases with HCHWA-D. Taken together, amyloid angiopathy in HCHWA-D may share an Abeta(42)-driven deposition mechanism with plaque amyloid, resulting in enhanced Abeta(40) deposition.

Dementia in hereditary cerebral hemorrhage with amyloidosis-Dutch type is associated with cerebral amyloid angiopathy but is independent of plaques and neurofibrillary tangles

Cerebral amyloid angiopathy is frequently found in demented and nondemented elderly persons, but its contribution to the causation of dementia is unknown. Therefore, we investigated the relation between the amount of cerebral amyloid angiopathy and the presence of dementia in 19 patients with hereditary cerebral hemorrhage with amyloidosis-Dutch type. The advantage of studying hereditary cerebral hemorrhage in amyloidosis-Dutch type is that patients with this disease consistently have severe cerebral amyloid angiopathy with minimal neurofibrillary pathology. The amount of cerebral amyloid angiopathy, as quantified by computerized morphometry, was strongly associated with the presence of dementia independent of neurofibrillary pathology, plaque density, or age. The number of cortical amyloid beta-laden severely stenotic vessels, vessel-within-vessel configurations, and cerebral amyloid angiopathy-associated microvasculopathies was associated with the amount of cerebral amyloid angiopathy and dementia. A semiquantitative score, based on the number of amyloid beta-laden severely stenotic vessels, completely separated demented from nondemented patients. These results suggest that extensive (more than 15 amyloid beta-laden severely stenotic vessels in five frontal cortical sections) cerebral amyloid angiopathy alone is sufficient to cause dementia in hereditary cerebral hemorrhage with amyloidosis-Dutch type. This may have implications for clinicopathological correlations in Alzheimer's disease and other dementias with cerebral amyloid angiopathy.

Risk of extrapyramidal syndromes with haloperidol, risperidone, or olanzapine

OBJECTIVE

To compare the risk of extrapyramidal syndrome (EPS) between risperidone, olanzapine, and haloperidol, taking into account patients' past antipsychotic drug use and past EPS.

METHODS

Data were obtained from the PHARMO-database, containing filled prescriptions of 450,000 community-dwelling people in the Netherlands from 1986 through 1999. We defined cohorts of first-time users of haloperidol, risperidone, or olanzapine aged 15 to 54 years. In the first 90 days of treatment, we assessed the occurrence of EPS, defined as first use of any antiparkinsonian agent. We estimated relative risks of EPS for risperidone and olanzapine versus haloperidol using a Cox proportional hazards model. Patients were subdivided according to prior use of antipsychotic and antiparkinsonian drugs.

RESULTS

We identified 424 patients starting treatment with haloperidol, 243 with risperidone, and 181 with olanzapine. Prior use of antipsychotic plus antiparkinsonian medication was significantly more frequent among users of risperidone and olanzapine than in those using haloperidol (36.2%, 40.3%, and 4.5%, respectively; p < 0.001). Within most subgroups of comparable treatment history, patients using risperidone and olanzapine showed reduced risks of EPS compared with haloperidol, although some of these findings did not reach statistical significance (RR 0.03-0.22). However, this was not observed for patients using risperidone who had experienced EPS in the past (RR 1.30; 95% CI 0.24 to 7.18).

CONCLUSIONS

In general, we observed reduced risks of EPS for risperidone and olanzapine compared with haloperidol within subgroups of patients with a similar treatment history. However, the added value of risperidone in patients who have experienced EPS in the past needs further study.

[From gene to disease; HD gene and Huntington disease]

Huntington's disease (HD) is a late onset, incurable, autosomal dominantly-inherited, progressive neuropsychiatric disease, characterised by chorea, changes in personality, mood and behaviour, and dementia. Huntington's disease is a clinical diagnosis. The advent of DNA diagnosis has made predictive, prenatal and preimplantation testing possible for at-risk persons or asymptomatic carriers. The prevalence is estimated to be 3-10/100,000 among individuals of European descent; HD is less common in other ethnic groups. Huntington's disease is caused by an expanded trinucleotide CAG repeat in the HD gene on chromosome 4. The gene encodes for the protein huntingtin, with an as yet unknown function. The mutated huntingtin has an elongated stretch of glutamines which leads to a gain of function such as overactivity, excitotoxicity, or to interactions with other proteins.

[From gene to disease; presenilins and Alzheimer disease]

A very small percentage (less than 5%) of all cases of Alzheimer's disease are autosomal dominant inherited and caused by a mutation in the presenilin protein (PS). The mutations are found on chromosome 14 (PS1) and chromosome 1 (PS2). Although the exact function of presenilin is still unknown, it seems to function as gamma-secretase or as a cofactor for it. This upsets the metabolic balance around the beta-amyloid precursor protein, which leads to the formation of senile amyloid plaques.

Estimation of incidence and prevalence of Parkinson's disease in the elderly using pharmacy records

PURPOSE

We determined the prevalence and incidence of Parkinson's disease among persons aged 55 years and older in pharmacy records.

METHODS

Data came from the PHARMO database which includes information on drug dispensing for all residents of six Dutch cities. We selected all persons aged 55 years and older who had used antiparkinsonian drugs, and calculated a chance for having Parkinson's disease with use of a previously validated logistic regression model. We used a cut-off of 0.5 (sensitivity 62%, positive predictive value 92%). Prevalence was estimated on the first Wednesday of October 1997, incidence on the first Wednesday of October 1993 until 1997. A patient was incident, if the first prescription for an anti-parkinsonian drug was dispensed at least 180 days after entry into PHARMO. Prevalence and incidence were standardized to the Netherlands population of 1 January 1998. The prevalence was adjusted for the sensitivity and positive predictive value of the model.

RESULTS

The unadjusted prevalence (per 100,000) for those aged 55-64 years was 111, 65-74 years 598, 75-84 years 1551 and for persons aged 85 years and older 1847. The adjusted and standardized prevalence was 970 per 100,000 (95% confidence interval 869 to 1071). The incidence (per 100,000 person years) for persons aged 55-64 years was 12, 65-74 years 108, 75-84 years 257 and for persons aged 85 years and older 247. The standardized incidence was 109 per 100,000 person years (96 to 121).

CONCLUSIONS

Prevalence and incidence were in range with the literature. Pharmacy records therefore seem to be a useful tool for continuous monitoring of incidence and prevalence of Parkinson's disease.

[From gene to disease; amyloid-beta precursor protein gene instrumental in hereditary cerebral amyloid angiopathies]

Hereditary cerebral haemorrhage with amyloidosis-Dutch type (HCHWA-D) is an autosomal dominant disease caused by a mutation in the amyloid precursor protein gene on chromosome 21. The disease is characterised by amyloid deposition in cerebral blood vessels, which results in cerebral haemorrhages, leucencephalopathy, dementia and death. In the same gene, mutations have also been found for other rare diseases which also result in dementia and haemorrhages, as well as familial Alzheimer's disease (different mutations in different families). The majority of familial Alzheimer cases, however, are associated with mutations in the PS1 gene (more than 70 different mutations) or the PS2 gene (4 mutations).

Evaluation of antiparkinsonian drugs in pharmacy records as a marker for Parkinson's disease

AIM

The aim of this study was to determine whether use of antiparkinsonian drugs in pharmacy records can be used as a marker for patients with Parkinson's disease (PD).

METHOD

Data were obtained from the Rotterdam Study, a community-based prospective cohort study among people aged 55 years or older who were all screened for PD. For 5510 persons, of whom 74 had PD, pharmacy records were available. Stepwise logistic regression analysis was used to evaluate whether age, sex and use of the antiparkinsonian drugs amantadine, anticholinergics, dopamine agonists, levodopa and selegiline, were predictive variables for PD. For each individual a probability for having PD was calculated. Sensitivity, specificity and positive predictive value (PPV) were calculated at different cut-off values based on calculated probabilities.

RESULTS

More than 90% of the users of levodopa, bromocriptine, selegiline, and users of at least two different antiparkinsonian drugs had PD. Age, use of amantadine, anticholinergics, bromocriptine, levodopa, and selegiline were predictive variables for PD. After application of different cut-off values, sensitivity was at most 66.2%, and specificity was at least 99.8%. A PPV of higher than 90% was obtained at higher probabilities.

CONCLUSION

Based on the high PPV of our predictive model, antiparkinsonian drugs can be used as a reliable marker for PD in pharmacy records. Because sensitivity is low, pharmacy records cannot be used to estimate prevalence of PD.

Antipsychotic-induced extrapyramidal syndromes. Risperidone compared with low- and high-potency conventional antipsychotic drugs

AIM

To compare the risk of extrapyramidal syndromes (EPS) between patients using risperidone and those using low-potency conventional antipsychotic drugs (APDs) in outpatient clinical practice, as measured by the use of anticholinergic medication. We tried to replicate results from previous clinical trials that compared risperidone with high-potency APDs.

METHOD

Data was obtained from the PHARMO database containing filled prescriptions of 450,000 community-dwelling people in The Netherlands from 1986 to 1998. From the patients aged 15-54 years who had been newly treated with APDs, we defined mutually exclusive cohorts according to the APD first prescribed to a patient. APD exposure was followed until the first prescription of anticholinergic medication and was censored when APD prescribing was interrupted or switched. We estimated relative risks between risperidone and commonly used low-potency and high-potency APDs using Cox proportional hazards models, adjusting for age, gender, dose and other potential confounders.

RESULTS

In 4094 patients who had been newly prescribed antipsychotic drugs, the overall incidence rate of anticholinergic drug therapy was 556 per 1000 person-years, which was dose dependent. Prescribed doses of all antipsychotics were low. While, in accordance with previous trials, risperidone showed a lower risk of EPS than the high potency APDs such as haloperidol (RR 0.26; 95% CI 0.10-0.64), we did not observe a lower EPS rate than low-potency APDs (risperidone vs thioridazine RR 1.73, 95% CI 0.49-6.13; risperidone vs pipamperone RR 2.50, 95% CI 0.78-8.04).

CONCLUSION

The reduced EPS rates observed when comparing risperidone with high-potency antipsychotics such as haloperidol may not apply to comparisons with low-potency drugs.

Quantitative assessment of daytime motor activity provides a responsive measure of functional decline in patients with Huntington's disease

Voluntary motor impairment is a functionally important aspect of Huntington's disease (HD). Therefore, quantitative assessment of disturbed voluntary movement might be important in follow-up. We investigated the relation between quantitatively assessed daytime motor activity and symptom severity in HD and evaluated whether assessment of daytime motor activity is a responsive measure in the follow-up of patients. Sixty-four consecutive HD patients and 67 age- and sex-matched healthy controls were studied. Daytime motor activity was recorded using a wrist-worn activity monitor that counts all movements during a period of five consecutive days. Patients were rated clinically for voluntary motor impairment, dyskinesias, posture & gait, depression, cognitive impairment and functional capacity. Follow-up was available from 40 patients (mean follow-up 2.0 years) and 29 controls (mean follow-up 5.9 years). Despite chorea, patients had less daytime motor activity than controls (P < 0.005). This hypokinesia correlated with impaired voluntary movements (r = 0.37; P < 0.01), disturbed posture & gait (r = 0.38; P < 0.005) and especially with reduced functional capacity (r = 0.51; P < 0.0005). During follow-up, hypokinesia remained unchanged in clinically stable patients, but became worse in those whose functional disability progressed (P < 0.005). Hypokinesia seems a core symptom of HD which is related to functional capacity. Actimetric assessment of hypokinesia is responsive to disease progression and can be used as an objective tool for follow-up.

Gilles de la Tourette's syndrome with and without obsessive-compulsive disorder compared with obsessive-compulsive disorder without tics: which symptoms discriminate?

Stereotyped repetitive behaviors occur in Gilles de la Tourette's Syndrome (GTS) and obsessive-compulsive disorder (OCD). The present study was undertaken to compare the distribution of obsessive-compulsive and Tourette-related impulsive behaviors in GTS with (+) OCD, GTS without (-) OCD, tic-free OCD, and control subjects. Fourteen GTS + OCD, 18 GTS-OCD, 21 OCD-tic, and 29 control subjects were evaluated using a semistructured interview designed to assess GTS and OCD-related repetitive behaviors. Each reported item was evaluated on the presence of anxiety and goal-directedness. This information was subsequently used to define whether the repetitive behavior was an (anxiety-related) obsession or compulsion, or a (non-anxiety-related) OC-like behavior, impulsion. GTS + OCD subjects reported more overall Tourette-related impulsions than OCD-tic subjects, i.e., more mental play, echophenomena, and touching behaviors but similar frequencies of typical obsessive-compulsive behaviors. Further, GTS + OCD subjects exhibited more overall repetitive behaviors than GTS-OCD subjects, i.e., more Tourette-related impulsions as well as more obsessive-compulsive behaviors. The distribution of symptoms is similar in GTS with and without OCD, and differs from tic-free OCD. These differences suggest that GTS with OCD constitutes a form of GTS, not of OCD, although the possibility that GTS + OCD patients constitute a subgroup distinct from GTS and from OCD can not be excluded by this phenomenological study. Specific non-anxiety-related impulsions seem to discriminate between GTS and OCD-tic individuals. These impulsions possibly reflect differences in underlying mechanisms between GTS and OCD-tics.

Repetitive behaviors in Tourette's syndrome and OCD with and without tics: what are the differences?

Gilles de la Tourette Syndrome (GTS) and obsessive-compulsive disorder (OCD) share obsessive-compulsive phenomena. The aims of this study were to compare the OC symptom distribution between GTS and OCD and to investigate whether a subdivision of these phenomena into obsessions, compulsions and 'impulsions' is useful in distinguishing GTS and OCD patients. Thirty-two GTS, 31 OCD (10 with tics, 21 without tics) and 29 control subjects were studied using the Leiden repetitive behaviors semi-structured interview to assess GTS as well as OCD-related behaviors. Each reported repetitive thought or action was evaluated on the presence of anxiety and on goal-directedness. This information was used to define whether the behavior was an obsession, compulsion, or 'impulsion'. Both the GTS and OCD study groups showed higher scores than control subjects on rating scales measuring depression, OC behavior and anxiety. In GTS, Y-BOCS severity scores and trait anxiety were lower than in the OCD groups. Furthermore, GTS patients differed from OCD patients in the distribution of symptoms. Aggressive repetitive thoughts, contamination worries and washing behaviors were reported more frequently by tic-free OCD, while mental play, echophenomena, touching and (self)-injurious behaviors were reported more frequently by GTS. OCD individuals with tics were intermediate, but closer to tic-free OCD. GTS individuals reported significantly more 'impulsions' and fewer obsessions and compulsions than OCD individuals with and without tics. Factor analysis revealed three factors accounting for 44% of the variance, resulting in an 'impulsive' factor related to GTS, a 'compulsive' factor related to OCD and an 'obsessive' factor related to tic-free OCD. In conclusion, OCD individuals reported more anxiety and goal-directedness associated with their behaviors than did GTS subjects. The distinction between obsessions, compulsions and impulsions is of importance in identifying Tourette-related vs. non-Tourette-related repetitions.

Impact of Huntington's disease on quality of life

The purpose of this study was to systematically assess the impact of Huntington's disease (HD) on patients' health-related quality of life (QOL). Seventy-seven patients with a clinically confirmed diagnosis of HD were interviewed by means of the Sickness Impact Profile (SIP). Additional data were gathered on patients' motor performance by means of the motor section of the Unified Huntington Disease Rating Scale (UHDRS), and cognitive performance by means of the Mini-Mental State (MMS). Patients had high scores on the SIP subscales, indicating moderate to severe functional impairment. Total Motor Score (TMS), MMS scores, and the duration of HD were significantly correlated with patients' scores on the SIP, and predicted a significant amount of variance of the Physical Dimension of the SIP, but not of the Psychosocial Dimension. We conclude that HD has a great impact on patients' physical and psychosocial well-being, the latter being more severely affected. Implications for further research and clinical practice are discussed.

Amyloid beta protein (Abeta) starts to deposit as plasma membrane-bound form in diffuse plaques of brains from hereditary cerebral hemorrhage with amyloidosis-Dutch type, Alzheimer disease and nondemented aged subjects

To clarify where and how beta-amyloid begins to deposit in senile plaques, we examined the ultrastructural localization of amyloid beta protein (Abeta) in diffuse plaques of brains with hereditary cerebral hemorrhage with amyloidosis-Dutch type. Alzheimer disease (AD), and from nondemented aged subjects. Serial ultrathin sections of osmium-plastic blocks were immunogold-labeled for Abetax-42 (Abeta42), and sections on grids were observed under the electron microscope (EM) after observing the exact localization of the diffuse plaques in sections on glass slides by the reflection contrast microscope. Abeta42 deposition, which was decollated with gold particles, appeared in 3 forms in all subjects under the EM: 1) Scattered small bundles of amyloid fibrils between cell processes, frequently seen in the densely stained area of diffuse plaques. 2) Scattered small foci of nonfibrillar materials between cell processes as a relatively minor form. 3) Abeta42 on a part of the cell surface plasma membrane of normal appearing cell processes, a major form in weakly immunostained areas. The last form was not associated with degenerative neurites or reactive glia. Abeta42 deposition on the cell surface plasma membrane appears to be an initial event in diffuse plaques, and then it develops into amorphous/fibrillar amyloid between cell processes.

The relationship between types and severity of repetitive behaviors in Gilles de la Tourette's disorder and obsessive-compulsive disorder

BACKGROUND

This study investigated which categories of obsessive-compulsive and Tourette-related behaviors in Gilles de la Tourette's disorder and obsessive-compulsive disorder (OCD) without tics are experienced as most severe across the study groups and what the differences are in symptom distribution between the study groups.

METHOD

Fourteen subjects with both Tourette's disorder and OCD, 18 subjects with Tourette's only, 21 subjects with OCD (no tics), and 29 control subjects were studied using a semistructured interview designed to equally assess Tourette- and OCD-related behaviors according to DSM-III-R criteria. Each reported repetitive behavior was evaluated on the presence of anxiety and on goal-directedness. Anxiety-related items were categorized as obsessions or compulsions and non-anxiety-related items as impulsions. Severity of each reported item was assessed with respect to time per day consumed and amount of distress and interference induced by the item. Following these criteria, each reported item was classified as a symptom, a subthreshold symptom, or just as being present.

RESULTS

Across the study groups, obsessions were experienced as more severe than (Tourette-related) impulsions and compulsions. Within the study groups, patients with both Tourette's disorder and OCD reported more symptomatic Tourette-related impulsions, such as mental play, echophenomena, and impulsive or self-injurious behaviors; less overall symptomatic obsessions; and less symptomatic washing than patients with OCD (no tics). The differences among individuals with Tourette's with or without OCD reflected differences in symptom severity rather than differences in symptom distribution.

CONCLUSION

Obsessions are more time consuming, distressing, and interfering than compulsions and impulsions. Furthermore, the symptomatic repetitive behaviors were distributed differently among patients with both Tourette's disorder and OCD and patients with OCD (no tics). Patients with Tourette's and OCD are phenomenologically more similar to Tourette's than to OCD. These differences possibly represent differences in underlying pathophysiology between Tourette's and tic-free OCD.

Family history and DNA analysis in patients with suspected Huntington's disease

OBJECTIVES

Until recently a definite diagnosis of Huntington's disease could be made by a combination of clinical findings, a positive family history, and pathological confirmation. Prevalence data are based on these criteria. After finding the gene and its pathogenic mutation direct diagnostic confirmation became available. The aim of this study was to determine to what extent the direct assessment of CAG repeat length has allowed the diagnoses of additional patients, with atypical psychiatric or neurological disease, or those without a family history, that could otherwise not be diagnosed using traditional criteria.

PATIENTS AND METHODS

From all 191 referred patients suspected of having Huntington's disease between July 1993 and January 1996 CAG repeat length was determined and the family history was reviewed in the Leiden roster. After a retrospective search the patients were subdivided in positive, negative, suspect, and unknown family histories. Patients with an expanded repeat (>35) were finally diagnosed as having Huntington's disease. The family history was compared with the repeat length and the clinical features.

RESULTS

Clinical information was obtained for 172 patients. Of these, 126 patients had an expanded repeat, 77 had a positive, eight a negative, 40 a suspect, and one an unknown family history. Of the 44 patients with a normal repeat length four had a positive family history. Of the two patients with an intermediate repeat (between 30-36 repeats), one with a negative family history received a clinical diagnosis of Gilles de la Tourette's syndrome. The other had an unknown family history.

CONCLUSION

Despite verification of the family history through the Leiden roster, many more patients and families could be diagnosed with the new approach than would have been possible with the traditional criteria. Because prevalence studies have been based on this type of information, the data suggest an underestimation of the prevalence of Huntington's disease in the community of 14%.

Age-related plaque morphology and C-terminal heterogeneity of amyloid beta in Dutch-type hereditary cerebral hemorrhage with amyloidosis

The evolvement of amyloid beta (Abeta) deposition in the frontal cerebral cortex of 24 patients of increasing age with Dutch-type hereditary cerebral hemorrhage with amyloidosis (HCHWA-D) was studied using end-specific monoclonal antibodies to Abetax-42 (Abeta42) or Abetax-40 (Abeta40) and markers for degenerating neurites. Abeta42 immunostaining revealed parenchymal Abeta deposits with a heterogeneous morphology and distribution, i.e., clouds, fine/dense diffuse, coarse, and homogeneous plaques. Clouds and diffuse plaques were associated with glial Abeta granules. Abeta40 labeling was absent in clouds/fine diffuse plaques, inconsistent and variably intense in dense diffuse/coarse plaques and consistent in homogeneous plaques. In a subset of Abeta40-positive plaques, degenerating neurites--without tauopathy--and/or amyloid cores were observed. Electron microscopy revealed no apparent amyloid fibrils in fine diffuse plaques, small bundles of fibrils in dense diffuse/homogeneous plaques, and amyloid masses in coarse plaques. The parenchymal Abeta pathology was age-related: the ratio of fine to dense diffuse plaques decreased with age, clouds were limited to younger patients; coarse plaques to the oldest old. Homogeneous/cored plaques were present most consistently in older patients. Plaque density did not increase with age. Vascular Abeta deposits stained for both Abeta species, but exclusively Abeta42-positive, presumably recent deposits were also observed. This study suggests that HCHWA-D is a model of plaque evolution in which clouds leave fine diffuse plaques, which may become dense diffuse and ultimately coarse or homogeneous plaques.

Predictive testing of 25 percent at-risk individuals for Huntington disease (1987-1997)

Before the mutation causing Huntington disease was identified, predictive testing of 25% at-risk persons with a 50% at-risk parent who did not wish to know his/her genetic status, was only possible by exclusion testing. The exclusion test, using linked markers, ensures the parent's wish not to know because the parent's risk is not changed. When mutation analysis became available in 1993, new testing options for 25% at-risk persons emerged: viz., the exclusion-definitive test and direct mutation analysis. These new tests not only disclose the risk of the test candidate, but may also change the risk of the at-risk parent and siblings. The testing options for 25% at-risk test applicants and their consequences are discussed and the testing procedures and results of testing 64 25% at-risk persons in the period 1987 to 1997 are described. Relatives received unsought information in 56% of the test procedures before and 34% after the mutation was identified. A decision tree and guidelines for predictive testing of 25% at-risk test applicants are proposed. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:662-668, 1999.

Memory and learning are not impaired in presymptomatic individuals with an increased risk of Huntington's disease

Retrieval from long-term memory in patients with brain injuries was investigated with a memory scanning paradigm (Conway & Engle, 1994), that allows dissociation of scanning processes within short-term memory and memory retrieval processes from long-term memory. The study focused on the influence of brain injury on memory retrieval processes that are assumed to be automatic. Thirteen patients with memory impairment and 13 healthy matched control subjects were tested. In general, patients showed increased reaction times, but they showed set size independent retrieval from long-term memory indicating preserved automatic retrieval processes. In a subgroup of patients with more severe memory deficits, however, automatic retrieval processes appeared not to be intact. Learning profiles of the patients were characterized by smaller item chunks, indicating differences in the process of information acquisition.

Ultrastructural evidence of early non-fibrillar Abeta42 in the capillary basement membrane of patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type

The C-terminal profile and ultrastructure of small and presumably early capillary amyloid beta protein (Abeta) deposits were investigated in four patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type. The C terminus of the 40 (Abeta40) or the 42 (Abeta42) amino acid form of Abeta was gold labeled in serial, ultrathin sections on glass slides for reflection contrast microscopy and on grids for electron microscopy. In all studied subjects, reflection contrast microscopy revealed capillaries with focal Abeta42 immunolabeling in the absence of Abeta40 labeling. In the adjacent electron microscopic section, Abeta42 labeling was confined to the capillary basement membrane. The majority of Abeta42(+)40(-) deposits showed no amyloid fibrils. Abeta42(+)40(-) deposits were sometimes observed in an unremarkable basement membrane but usually showed increased electron density and reticular structures. A small subset of Abeta42(+)40(-) deposits with basement membrane changes showed few amyloid fibrils. Abeta42(+)40(+) capillary deposits always showed definite fibrils and were larger than Abeta42(+)40(-) capillary deposits. The present findings suggest that in capillaries the accumulation and subsequent polymerization of Abeta42, possibly in conjunction with basement membrane changes, precedes the definite fibril formation with Abeta40.

Two centuries of mortality in ten large families with Huntington disease: a rising impact of gene carriership

To estimate the impact of the Huntington gene on mortality, we studied ten families with Huntington disease, whose records started before 1800. We investigated mortality from 1800 to 1997 in 257 carriers of the Huntington gene and 474 potential carriers. Follow-up extended from age 20 years to the date of death or end-of-study date. The observed deaths were compared with those expected on the basis of the general population, adjusted for sex, age, and calendar time. To study the influence of the family and parental transmission, we calculated hazard ratios adjusted for sex, probability of carrying the gene, and year of birth. In 25,013 person-years, 420 deaths occurred, whereas 278 deaths were expected [standardized mortality ratio = 1.5; 95% confidence interval (CI) = 1.4-1.7]. Excess mortality was confined to ages 40-70 years (standardized mortality ratio = 2.2; 95% CI = 1.9-2.4). To study the evolution of mortality over time in this age group, we calculated absolute mortality rates per calendar period. From 1800 onward, mortality rates in the general population continuously declined, but among the families with Huntington disease this decline was absent. There were only small differences in risk between families, and the relative risk for paternal over maternal transmission was 1.2 (95% CI = 0.9-1.5). Our main finding is that persons who carry the Huntington gene and reach middle age have not benefited from advances in medical care and overall increase in life expectancy.