Spanish Validation of the Problem Behaviors Assessment-Short (PBA-s) for Huntington's Disease

Obsessive-compulsive and perseverative behaviors in Huntington's disease

Obsessive-compulsive and perseverative behaviors (OCBs/PBs) are characteristic features of Huntington's Disease (HD). Although a few recent research have attempted to discriminate between OCBs and PBs, most of the available evidence on OCBs does not consistently make this distinction. In this article, we aimed to explore the current inconsistencies in assessing and reporting OCBs/PBs and map the body of existing evidence. Up to half of the patients with motor manifest HD can experience OCBs. Separate reporting of PBs in HD patients has been uncommon among the studies and was frequently reported as a part of obsessive-compulsive symptoms. The structural limitation of the currently used rating scales and the overlaps in neuropathology and definition of OCBs and PBs are among the main reasons for the mixed reporting of OCBs/PBs. Perseverative thinking or behavior as a separate item is found in a few assessment tools, such as the Problem Behaviors Assessment - Short form (PBA-s). Even when the item exists, it is commonly reported as a composite score in combination with the obsessive-compulsive item. In addition to the significant psychological burden in individuals with HD, PBs are associated with somatic effects (e.g., cardiovascular symptoms) and high-risk behaviors (e.g., suicide). Recognition and monitoring of PBs in HD can aid in early detection of concerning symptoms and differentiating overlapping illnesses.

Huntington's Disease in Chile: Epidemiological and Genetic Aspects

INTRODUCTION

Huntington's disease (HD) is a neurodegenerative, autosomal dominant disabling condition due to an expansion of the CAG trinucleotide in the HTT gene. Motor, psychiatric, and cognitive disorders characterize it. Chilean reports on HD in the era of molecular diagnosis were wanted.

METHODS

This is a retrospective analysis of a prospective cohort of patients with HD seen at the Center for Movement Disorders (CETRAM) in Chile between 2013 and 2019. Sociodemographic, genotype, and neuropsychiatric features were investigated.

RESULTS

One hundred three probands with HD were identified. The majority (63.1%) were born in the metropolitan region, followed by the VIII and V regions with 8.73% and 7.76%, respectively. When pedigrees were analyzed, ninety unrelated families encompassing 1,007 individuals were identified; among relatives, other 35 manifested HD, and 106 died of HD. Besides, five hundred seventy-nine individuals were at genetic risk. The minimum estimated prevalence of HD in Chile in 2019 was 0.72 × 100,000 inhabitants. The mean CAG repeats (CAGR) of 47.2 ± 10.74 for the expanded allele and 17.93 ± 2.05 for the normal allele. The mean age of onset was 41.39 ± 13.47 years. Juvenile cases represented 7.8% of this cohort, and 4.9% had a late onset. There was a negative correlation between the age of onset and the CAGR of the expanded allele (r =-0.84 p < 0.0001). Besides, 79.6% had a family history of HD.

CONCLUSIONS

This is the first report characterizing genetics, motor, and neuropsychiatric features in patients with HD in Chile. The mean length of CAGR expansion of the abnormal allele was similar to previous reports in North America (i.e., Mexico and Canada) and higher than that reported in the neighboring country of Argentina. According to previous estimations, the minimal prevalence of HD in Chile may be lower than expected.

Longitudinal analysis of neuropsychiatric symptoms in a large cohort of early-moderate manifest Huntington's disease patients

BACKGROUND

The relationship between neuropsychiatric symptoms (NPS) and other clinical dimensions in Huntington's disease (HD) is controversial. This longitudinal study analyzed the association between NPS and motor, cognitive and functional aspects of the disease along with other variables related to its clinical onset and progression.

METHODS

639 early-moderate HD patients were assessed longitudinally (mean: 4.95 visits/5 years). Generalized linear mixed models were used to explore associations between NPS and the aforementioned aspects. Other variables previously reported as significant in smaller or cross-sectional studies were included in the models.

RESULTS

Significant associations found included a negative linear relationship between presence of depressed mood and illness duration (7.2% odds reduction of being depressed per year), a 7.6% increase in the odds of having irritability with increased chorea scores, a negative association (4.3% reduction in odds) between age at onset and aggression (i.e. earlier onset was related to a higher probability of having aggressive behaviors) and a negative association between irritability and the interference component of the Stroop test (3% odds change). Total functional capacity (TFC) was the most frequently associated factor with NPS, with apathy and perseverative behavior having the strongest relations with TFC (22% and 18% increases in odds per unit reduction in TFC respectively).

CONCLUSIONS

With the exception of irritability, NPS are not related to motor or cognitive variables in early-moderate HD. Total functional capacity (TFC) is the most frequently associated factor with NPS, with apathy and perseverative behavior having the strongest relations with TFC.

Frequency and Pathophysiology of Apathy in Huntington Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

Apathy is a common behavioral symptom of Huntington disease (HD). This systematic review describes current evidence on the pathophysiology, assessment, and frequency of apathy in HD.

METHODS

This systematic review was conducted in accordance with PRISMA guidelines. Using a comprehensive search strategy, the investigators searched the MEDLINE, Embase, and PsycINFO databases. All studies that evaluated apathy in HD patients with a valid scale and reported apathy frequency or scores were included. Apathy scores were analyzed by mean or standardized mean differences in accordance with Cochrane guidelines.

RESULTS

A total of 1,085 records were screened and 80 studies were ultimately included. The Problem Behaviors Assessment-Short was the most frequently used apathy assessment tool. Apathy frequency generally ranged from 10%-33% in premanifest HD to 24%-76% in manifest HD. A meta-analysis of 5,311 records of patients with premanifest HD showed significantly higher apathy scores, with a standardized mean difference of 0.41 (CI=0.29-0.52; p<0.001). A comparison of 1,247 patients showed significantly higher apathy scores in manifest than premanifest HD, with a mean difference of 1.87 (CI=1.48-2.26; p<0.001). There was evidence of involvement of various cortical and subcortical brain regions in HD patients with apathy.

CONCLUSIONS

Apathy was more frequent among individuals with premanifest HD compared with those in a control group and among individuals with manifest HD compared with those with premanifest HD. Considering the complexity and unique pattern of development in neurodegenerative disease, further studies are required to explore the pathophysiology of apathy in HD.

The structure of mental health symptoms in Huntington's disease: Comparisons with healthy populations

INTRODUCTION

Mental health difficulties are common among people with Huntington's disease (HD). However, such difficulties are only weakly associated with HD progression, suggesting their causes may be multifactorial rather than purely disease-related. Genetically unaffected family members have been shown to experience similar levels of mental distress to people with HD, potentially due to systemic stressors and life disruption. These factors may also influence mental wellbeing in people with HD. Accordingly, this study aimed to compare patterns and occurrence of mental distress between people with HD and genetically unaffected control groups, to determine systemic and environmental contributions to HD-related distress.

METHOD

Exploratory and confirmatory factor analysis was used to compare the structure of mental distress in 5,294 individuals from four groups: manifest or premanifest HD, family control, and genotype-negative. Data were from the Enroll-HD study, using scores from the Problem Behaviors Assessment, the Hospital Anxiety and Depression Scale, and the Snaith Irritability Scale. We then evaluated consistency of the identified constructs over three annual assessments using analysis of variance.

RESULTS

Four factors consistently emerged across all groups, comprising depression, anxiety, temper and self-harm; these remained stable across time. People with HD did not report significantly different anxiety scores to control groups. The manifest group reported significantly higher depression, temper and self-harm than the genotype-negative group, but only differed in some cases from family-controls.

CONCLUSIONS

The findings suggest greater similarity in the severity and structure of mental health symptoms between people with and without HD than previously believed. This suggests contributions from systemic as well as genetic factors in families affected by HD, especially in terms of anxiety symptoms.

Validity of irritability in Huntington's disease: A scoping review

PURPOSE

To scope the literature concerning irritability in Huntington's disease to determine whether or not irritability is a valid and meaningful construct within this population.

METHOD

A scoping literature review was conducted based on findings from a search of five databases (Academic Search Ultimate, PsycINFO, CINAHL, Scopus and Web of Science) in November 2018. From an initial return of 453 papers, 40 were found suitable for review.

RESULTS

Review of the 40 studies highlighted several aspects of irritability in people with HD which influence its validity as an independent construct in context of the disease. While various measures are used to assess irritability, a gold standard has yet to be identified and consequently irritability is assessed inconsistently across the literature. In addition, the results suggest that irritability may not reflect pathological disease processes in HD, but rather comprises a multidimensional construct which appears to be strongly associated with other psychological difficulties such as depression and anxiety.

CONCLUSIONS

The current concept of irritability in people with HD continues to lack a general consensus in the clinical literature, in terms of both operationalisation and assessment. Consequently, further research is warranted in order to determine the extent to which irritability is a valid construct within the context of HD, including its associated behavioural, cognitive and affective dimensions.

Adult-onset Huntington disease: An update

Appropriate nursing-care strategies depend on the early recognition of Huntington disease (HD) to prioritize a plan of care. This article offers perspective on the clinical presentation, prognosis, diagnosis, and management of adult-onset HD.