Expanding the phenotype of SCA19/22: Parkinsonism, cognitive impairment and epilepsy

INTRODUCTION

Spinocerebellar ataxia types 19 and 22 (SCA19/22) are rare conditions in which relatively isolated cerebellar involvement is frequently associated with cognitive impairment. Here, we report on new clinical features and provide details of the cognitive profile in two SCA19/22 families.

METHODS

Two families displaying an autosomal-dominant form of cerebellar ataxia underwent clinical examinations and genetic testing.

RESULTS

In addition to the classical clinical features of SCA, a wide spectrum of cognitive disorders (including visuospatial impairments) was observed. Eight patients had mild Parkinsonism, and five had epilepsy. Genetic testing showed that the KCND3 mutation (c.679_681delTTC, p.F227del) was present in both families.

CONCLUSIONS

Our findings broaden the phenotypic spectrum of SCA19/22, and suggest that KCND3 should be included in the list of candidate genes for epilepsy, Parkinsonism and cognitive impairment.

Are Upper-Body Axial Symptoms a Feature of Early Parkinson's Disease?

BACKGROUND

Axial disorders are considered to appear late in the course of Parkinson's disease (PD). The associated impact on quality of life (QoL) and survival and the lack of an effective treatment mean that understanding and treating axial disorders is a key challenge. However, upper-body axial disorders (namely dysarthria, swallowing and breathing disorders) have never been prospectively assessed in early-stage PD patients.

OBJECTIVES

To characterize upper-body axial symptoms and QoL in consecutive patients with early-stage PD.

METHODS

We prospectively enrolled 66 consecutive patients with early-stage PD (less than 3 years of disease progression) and assessed dysarthria, dysphagia and respiratory function (relative to 36 controls) using both objective and patient-reported outcomes.

RESULTS

The mean disease duration was 1.26 years and the mean UPDRS motor score was 19.4 out of 108. 74% of the patients presented slight dysarthria (primarily dysprosodia). Men appeared to be more severely affected (i.e. dysphonia). This dysfunction was strongly correlated with low swallowing speed (despite the absence of complaints about dysphagia), respiratory insufficiency and poor QoL. Videofluorography showed that oral-phase swallowing disorders affected 60% of the 31 tested patients and that pharyngeal-phase disorders affected 21%. 24% of the patients reported occasional dyspnea, which was correlated with anxiety in women but not in men. Marked diaphragmatic dysfunction was suspected in 42% of the patients (predominantly in men).

CONCLUSION

Upper body axial symptoms were frequent in men with early-stage PD, whereas women presented worst non-motor impairments. New assessment methods are required because currently available tools do not reliably detect these upper-body axial disorders.

Rivastigmine in apathetic but dementia and depression-free patients with Parkinson's disease: a double-blind, placebo-controlled, randomised clinical trial

BACKGROUND

Even with optimal dopaminergic treatments, many patients with Parkinson's disease (PD) are frequently incapacitated by apathy prior to the development of dementia. We sought to establish whether rivastigmine's ability to inhibit acetyl- and butyrylcholinesterases could relieve the symptoms of apathy in dementia-free, non-depressed patients with advanced PD.

METHODS

We performed a multicentre, parallel, double-blind, placebo-controlled, randomised clinical trial (Protocol ID: 2008-002578-36; clinicaltrials.gov reference: NCT00767091) in patients with PD with moderate to severe apathy (despite optimised dopaminergic treatment) and without dementia. Patients from five French university hospitals were randomly assigned 1:1 to rivastigmine (transdermal patch of 9.5 mg/day) or placebo for 6 months. The primary efficacy criterion was the change over time in the Lille Apathy Rating Scale (LARS) score.

FINDING

101 consecutive patients were screened, 31 were eligible and 16 and 14 participants were randomised into the rivastigmine and placebo groups, respectively. Compared with placebo, rivastigmine improved the LARS score (from -11.5 (-15/-7) at baseline to -20 (-25/-12) after treatment; F(1, 25)=5.2; p=0.031; adjusted size effect: -0.9). Rivastigmine also improved the caregiver burden and instrumental activities of daily living but failed to improve quality of life. No severe adverse events occurred in the rivastigmine group.

INTERPRETATION

Rivastigmine may represent a new therapeutic option for moderate to severe apathy in advanced PD patients with optimised dopaminergic treatment and without depression dementia. These findings require confirmation in a larger clinical trial. Our results also confirmed that the presence of apathy can herald a pre-dementia state in PD.

REGISTRATION

Clinicaltrials.gov reference: NCT00767091.

Are gait initiation parameters early markers of Huntington's disease in pre-manifest mutation carriers?

Huntington's disease (HD) pre-manifest mutation carriers (PMCs) present early-onset gait disturbances. Gait initiation encompasses the preparation and execution of the first step. By using paradigms with and without external cues, a gait initiation analysis can highlight the interaction between motor and cognitive aspects of movement preparation and execution. Hence, gait initiation disorders may constitute particularly interesting early markers of HD. The objective of the present study was to quantify gait initiation in PMCs. In a case-control study, 17 PMCs (median age: 36.5) were compared with a group of 25 healthy controls (HCs, median age: 36) for gait initiation and a group of 57 HCs (median age: 38) for gait. Presymptomatic mutation carriers displayed a shorter first step duration and lower-amplitude postural adjustments. For the first step duration and speed, these impairments were more pronounced under self-triggered (ST) conditions. The PMCs displayed a lower gait speed, cadence and stride length and higher stride-to-stride variability. The latter parameter seemed capable of differentiating between PMCs and HCs with adequate sensitivity (0.81) and specificity (0.87). We confirmed the early-onset impairment of gait in general and first step execution in particular in PMCs (particularly under ST conditions). The temporal parameters of step execution (e.g. duration) and spatial parameters of postural adjustment (e.g. a backward shift in the centre of pressure) may be worth investigating as early markers of HD. However, two such parameters (stride-to-stride variability and first step duration under ST conditions) already appear to be sufficiently reliable diagnostic tools for differentiating between PMCs and HCs.

Diagnostic criteria for apathy in clinical practice

BACKGROUND

Apathy is an important and distressing behavioural symptom in Alzheimer's disease and in various neuropsychiatric disorders. Recently, diagnostic criteria for apathy have been proposed.

OBJECTIVES

In groups of patients suffering from different neuropsychiatric diseases, (i) to estimate the prevalence of patients meeting the proposed diagnostic criteria; (ii) to estimate the concurrent validity of the criteria with the neuropsychiatric inventory (NPI) apathy item; (iii) to identify the most frequently met criteria or sub-criteria in each specific neuropsychiatric disease and (iv) to estimate the inter-observer reliability of the diagnostic criteria for apathy.

METHODS

This cross-sectional, multicentric, observational study was performed on 306 patients. Each of the participating centres had to check the presence of apathy according to the diagnostic criteria for apathy in consecutive patients belonging to the following diagnoses list: Alzheimer disease (AD), mixed dementia, mild cognitive impairment (MCI), Parkinson's disease (PD), Schizophrenia (DSM-IV) and major depressive episode. In addition to the clinical interview, the assessment included the Mini Mental Score Examination (MMSE) and the NPI. At the end of the visit, clinicians were required to check the diagnostic criteria for apathy.

RESULTS

Using the diagnostic criteria for apathy, the frequency of apathy was of 53% in the whole population, 55% in AD, 70% in mixed dementia, 43% in MCI, 27% in PD, 53% in schizophrenia and 94% in major depressive episode. In AD, mixed dementia, MCI and PD, the NPI apathy score was significantly higher for patient fulfilling the apathy criteria. Goal-directed cognitive activity (criteria B2-Cognition) was the most frequently observed domain followed by goal-directed behaviour (criteria B1-Behaviour) and emotion (criteria B3), respectively. Inter-rater reliability was high for the overall diagnostic (κ coefficient = 0.93; p = 0.0001) and for each criteria.

CONCLUSION

This study is the first one to test the diagnostic criteria for apathy in clinical practice. Results make the diagnostic criteria useful for clinical practice and research.

External globus pallidus stimulation modulates brain connectivity in Huntington's disease

Positron emission tomography with O-15-labeled water was used to study at rest the neurophysiological effects of bilateral external globus pallidus (GPe) deep brain stimulation in patients with Huntington's disease (HD). Five patients were compared with a control group in the on and off states of the stimulator. External globus pallidus stimulation decreased neuronal activity and modulated cerebral connectivity within the basal ganglia-thalamocortical circuitry, the sensorimotor, and the default-mode networks. These data indicate that GPe stimulation modulates functional integration in HD patients in accordance with the basal ganglia-thalamocortical circuit model.

Apathy may herald cognitive decline and dementia in Parkinson's disease

Apathy is usually defined as a lack of motivation. It may occur as part of another disorder (notably depression and dementia) or as an isolated syndrome. In Parkinson's disease (PD), apathy is common and several studies have reported an association between this condition and more severe cognitive symptoms, such as executive dysfunction. However, this association has not been thoroughly investigated. The aim of this study (in nondepressed, nondemented PD patients) was to examine whether or not cognitive decline and/or dementia occurred more frequently in apathetic subjects than in nonapathetic subjects. Forty consecutive PD patients participated in the study (20 with apathy and 20 without). None of the subjects were either demented or depressed at the time of study entry. The patients' cognitive functions were extensively assessed twice: at study entry and after an 18-month follow-up period. At study entry, the apathetic PD patients had significantly lower global cognitive status and executive function scores than the nonapathetic subjects. After a median period of 18 months, the rate of conversion to dementia was found to be significantly higher in the apathetic group than in the nonapathetic group (8 of 20 and 1 of 20, respectively). Even in nondemented patients, the decrease over time in cognitive performance (mainly executive function but also memory impairment) was significantly greater in apathetic subjects than in nonapathetic subjects. These findings suggest that in nondemented, nondepressed PD patients, apathy may be a predictive factor for dementia and cognitive decline over time.

Role of attentional resources on gait performance in Huntington's disease

Patients with Huntington's disease (HD) suffer from cognitive deficits with impaired executive functions, including limited attentional resources. We sought to use a dual-task paradigm to evaluate attentional demands and the ability of patients with HD to concentrate on two tasks simultaneously. We analyzed the interference effects of cognitive and motor tasks on walking in HD and the contribution of clinical symptoms to gait disturbances. Patients and controls were asked to perform either a motor task (carrying a tray with four glasses), a cognitive task (counting backwards), or no task at all while walking at their preferred speed. Kinematic spatial parameters, temporal parameters, and angular parameters related to gait were recorded in 15 patients and 15 controls by means of a videomotion analysis system. Gait instability was assessed using the stride-to-stride variability of the various gait parameters. For patients with HD, performing a concurrent cognitive task resulted in a lower gait speed (compared with free walking), with decreased cadence and stride length. However, this effect was not observed in controls. Performing a motor task did not change any kinematic gait parameters in either HD or control subjects. We found correlations between gait speed in the dual cognitive/walking task on one hand and the motor UHDRS score, cognitive status and executive function on the other. Patients with HD had greater difficulty walking while performing a concurrent cognitive task; the drain on attentional resources deteriorated walking performance.

[About Huntington's disease: role of families and health professionals in information transmission]

INTRODUCTION

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder. However, little information is available concerning the way each patient learns about the existence of Huntington's disease in his family and the way he transmits the information to his descendants. This study aims to specify the role of families and healthcare professionals in delivering information about the disease and its hereditary risk.

PATIENTS AND METHODS

Data from 105 consecutive patients were analyzed. The patients were categorized in four classes according to the way they received information about HD in their family: firstly, families where the disease was known; secondly, families where the HD was "poorly known"; thirdly, families where no antecedent could be found; fourthly, families where the disease was voluntarily hidden. The majority (52%) of the patients did not know the name of HD before being diagnosed. The patient choices for disclosure of hereditary risks to their relatives were influenced by the information they received about the disease in their own family. Patients from the second category (disease "poorly known") had the most difficulty in transmitting the information.

DISCUSSION

Despite the high risk of transmission, information about the disease is poorly known and transmitted in families concerned by HD. Although healthcare professionals confronted with the question of information delivery to relatives must always respect patient confidentiality, our results underline the need to more fully inform patients about the disease and transmission patterns. More help from healthcare professionals is needed to accompany HD patients concerning the question of transmitting information. The efficacy of a specific educational program should be assessed.

Characteristics of apathy in Parkinson's disease

The objective of this study was to use the Lille Apathy Rating Scale to assess apathy in a large population of Parkinson's disease (PD) patients and identify several different apathy profiles. One hundred fifty-nine patients with probable PD and 58 healthy controls participated in the study. Apathy was assessed using the Lille Apathy Rating Scale. Motor, cognitive, and depressive symptoms were rated on standardized scales. Data were analyzed using linear regression and multivariate analyses of variance. Thirty-two percent of the PD patients were classified as apathetic. Apathy was more frequent in patients with dementia. The four apathy dimensions contributed differently to the overall severity of the apathetic condition. Action initiation and intellectual curiosity had a marked influence. Linear regression analysis revealed that the apathy level was mainly determined by cognitive impairment, not associated with the severity of motor symptoms, and only associated with the apathy subcomponent of the Montgomery and Asberg Depression Rating Scale. Apathy is highly prevalent in PD patients. Apathy profiles vary according to the clinical presentation of PD. The high prevalence of apathy in PD suggests the involvement of frontal-subcortical circuits. Although the neurochemical substrate of apathy remains poorly characterized, the strong link between apathy and cognitive impairment observed in several studies suggests the participation of nondopaminergic circuits.