Unawareness of dyskinesias in Parkinson's and Huntington's diseases

We performed a clinical study to evaluate the unawareness of dyskinesias in patients affected by Parkinson's disease (PD) and Huntington's disease (HD). Thirteen PD patients with levodopa-induced dyskinesias and 9 HD patients were enrolled. Patients were asked to evaluate the presence of dyskinesias while performing specific motor tasks. The Abnormal Involuntary Movement Scale (AIMS) and Goetz dyskinesia rating scale were administered to determine the severity of dyskinesias. The Unified Parkinson's disease rating scale (UPDRS) and Unified Huntington's Disease Rating Scale (UHDRS) were used in PD and HD patients, respectively. In PD we found a significant negative relationship between unawareness score at hand pronation-supination and AIMS score for upper limbs. In HD we found a significant positive relationship between total unawareness score and disease duration. In PD the unawareness seems to be inversely related with severity of dyskinesias, while in HD it is directly related to disease duration and severity.     

Assessment of simple movements and progression of Huntington's disease

Instrumental measurement of simple motion sequences reflects impairment in patients with Huntington's disease (HD). The objectives were to study the progress of symptoms of HD and tapping results in 42 patients with HD, without symptomatic drug treatment over 3 years. Assessment moments were at baseline, and at years 1, 2 and 3. Unified Huntington's Disease Rating Scale (UHDRS) total score and UHDRS arm score significantly increased. Motor test outcomes considerably worsened. Instrumental test results significantly correlated with both UHDRS scores at each assessment. Assessment of simple movement sequences is an additional simple method to follow impairment in patients with HD in addition to clinical rating.     

Clinical markers of early disease in persons near onset of Huntington's disease

OBJECTIVE: There is increasing evidence that neuron loss precedes the phenotypic expression of Huntington's disease (HD). As genes for late-onset neurodegenerative diseases are identified, the need for accurate assessment of phenoconversion (i.e., the transition from health to the disease phenotype) will be important. METHODS: Prospective longitudinal evaluation using the Unified Huntington's Disease Rating Scale (UHDRS) was conducted by Huntington Study Group members from 36 sites. There were 260 persons considered "at risk" for HD who initially did not have manifest disease and had at least one subsequent evaluation. Repeat UHDRS data, obtained an average of 2 years later, showed that 70 persons were given a diagnosis of definite HD based on the quantified neurologic examination. RESULTS: Baseline cognitive performances were consistently worse for the at-risk group who demonstrated conversion to a definitive diagnosis compared with those who did not. Longitudinal change scores showed that the at-risk group who did not demonstrate manifest disease during the follow-up study period demonstrated improvements in all cognitive tests, whereas performances in the at-risk group demonstrating conversion to disease during the study declined across cognitive domains. CONCLUSIONS: Neuropsychological measures show impairment 2 years before the development of more manifest motor disease. Findings suggest that these brief cognitive measures administered over time may capture early striatal neural loss in HD.     

Health-related quality of life in Huntington’s disease patients: a comparison of proxy assessment and patient self-rating using the disease-specific Huntington’s disease health-related quality of life questionnaire (HDQoL)

Huntington's disease (HD) is a fatal, neurodegenerative disease for which there is no known cure. Proxy evaluation is relevant for HD as its manifestation might limit the ability of persons to report their health-related quality of life (HrQoL). This study explored patient-proxy ratings of HrQoL of persons at different stages of HD, and examined factors that may affect proxy ratings. A total of 105 patient-proxy pairs completed the Huntington's disease health-related quality of life questionnaire (HDQoL) and other established HrQoL measures (EQ-5D and SF-12v2). Proxy-patient agreement was assessed in terms of absolute level (mean ratings) and intraclass correlation. Proxies' ratings were at a similar level to patients' self-ratings on an overall Summary Score and on most of the six Specific Scales of the HDQoL. On the Specific Hopes and Worries Scale, proxies on average rated HrQoL as better than patients' self-ratings, while on both the Specific Cognitive Scale and Specific Physical and Functional Scale proxies tended to rate HrQoL more poorly than patients themselves. The patient's disease stage and mental wellbeing (SF-12 Mental Component scale) were the two factors that primarily affected proxy assessment. Proxy scores were strongly correlated with patients' self-ratings of HrQoL, on the Summary Scale and all Specific Scales. The patient-proxy correlation was lower for patients at moderate stages of HD compared to patients at early and advanced stages. The proxy report version of the HDQoL is a useful complementary tool to self-assessment, and a promising alternative when individual patients with advanced HD are unable to self-report.     

Olanzapine in Huntington's disease

OBJECTIVES: To study the effect of olanzapine (OL) in Huntington's disease (HD) patients. DESIGN AND METHODS: Eleven HD patients (five men), aged 47.6 +/- 11.4 years and with disease duration of 11.2 +/- 3.3 years received OL. Assessment was carried out using the Clinical Global Impression of Change Scale (CGIC) and the Unified Huntington's Disease Rating Scale behavioral (UHDRS - b) and motor (UHDRS - m) at 6 month intervals. RESULTS: Nine patients were treated for 9.8 +/- 5.9 months. The mean OL dose/patient was 11.4 +/- 8.5 mg/day (median 10 mg/day). Mean CGIC was 2.1 +/- 0.8. UHDRS - b improved significantly (P < 0.0001) and UHDRS - m did not change. Chorea improved in five patients and two dropped out because of drug eruption and lack of efficacy. CONCLUSION: OL is a good alternative treatment in HD, mainly for the psychiatric symptoms and moderately effective for the motor symptoms, possibly because of its effect on chorea. We suggest OL should be used in HD patients with the adult onset form, severe chorea and/or severe psychiatric disturbances.     

Short-term continuous infusion of apomorphine hydrochloride for treatment of Huntington's chorea: A double blind, randomized cross-over trial.

We evaluated tolerability and the efficacy of continuous infusion of apomorphine hydrochloride on involuntary movements and mood disorder in Huntington's disease (HD) patients in a pilot, single center, double-blind, randomized, crossover, and controlled versus placebo study. Nine patients with a molecular diagnosis of HD were screened for response to acute apomorphine injection. Four of them, not ameliorating at the acute test, were discontinued. Five patients, responding to acute apomorphine, received continuous infusion of either apomorphine or placebo for 5 days. After 2 days of washout, the alternative treatment was administered. Primary endpoint measures were scores of the Unified Huntington's Disease Rating Scale (UHDRS "motor section") and of the Abnormal Involuntary Movement Scale (AIMS). Secondary endpoint measures were the Hamilton Depression Rating Scale (HAD) score and safety parameters. Both UHDRS and AIMS scores significantly decreased in all patients after apomorphine. The beneficial effect of apomorphine was recorded throughout the 5 treatment days. The HAD score did not change after infusion of either treatment. No serious adverse events were reported by either group during the study. Our results suggest that continuous infusion of apomorphine might be considered for the treatment of involuntary movements in some HD patients.     

Electrophysiological deterioration over time in patients with Huntington's disease.

In recent studies aimed at assessing the effects of original therapeutic strategies applied to patients with Huntington's disease (HD), we observed informative changes in electrophysiological results that recovered normal values in coherence with clinical improvement. However, longitudinal studies were lacking for determining whether electrophysiological test results evolve in parallel with clinical markers of the natural course of the disease and could consequently provide objective quantifiable markers of disease progression. For this purpose, electrophysiological testing was performed annually in a cohort of 20 patients with HD over a 2-year period (three examinations). The study included the recording of sympathetic skin responses and blink reflexes (BRs) to supraorbital nerve stimulation, long latency reflexes (LLRs) and somatosensory evoked potentials (SEPs) to median nerve stimulation, and cortical silent periods (CSPs) to transcranial magnetic stimulation. Clinical evaluation was based on the Total Functional Capacity scale (TFC) and the Motor part of the Unified Huntington's Disease Rating Scale (UHDRS). A significant deterioration with time was found for BR latency, LLR presence, various SEP parameters (parietal N20 peak amplitude and frontal N30 presence) and CSP duration. Attenuation of the N20 peak and CSP shortening correlated with functional decline, as assessed by the TFC score, whereas delayed BR and LLR abolition correlated with UHDRS Motor score deterioration. This study shows that several electrophysiological parameters are closely associated with dysfunction of various neural circuits in HD and could be useful markers of disease progression.     

Effects of depression on working memory in presymptomatic Huntington's disease

Cognitive decline may precede motor symptoms in Huntington's disease (HD). Depression is common in HD and has also been linked with cognitive impairment. The contribution of depression to cognition in individuals presymptomatic for HD (N=15) was investigated. Tests from the Cambridge Automated Neuropsychological Assessment Battery measured visual and working memory. Depression was assessed with the Beck Depression Inventory and the Unified Huntington's Disease Rating Scale. Depressed mood and estimated time to disease onset, calculated by using DNA mutation length, both were significant predictors of working memory performance. Findings are consistent with and contribute to existing research with individuals presymptomatic for HD, identifying a potentially remediable contribution to cognitive decline (i.e., depressed mood).     

Clinical severity of Huntington's disease does not always correlate with neuropathologic stage

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by a triplet-repeat, CAG expansion mutation. Although CAG repeat length is thought to correlate with pathologic burden and disease severity, considerable variability in clinical phenotype remains. This study examined whether neuropathologic burden at autopsy corresponded with severity of clinical phenotype in HD. The brains of 24 patients with a clinical and genetic diagnosis of HD were analyzed at autopsy. Subjects were stratified on the basis of Vonsattel staging as mild/moderate (stage 1-2; n = 7) or severe (stage 3-4; n = 17). Clinical severity was assessed on the basis of the Mini-Mental State Examination (MMSE; 0-30) and two Unified Huntington's Disease Rating Scale (UHDRS) functional components: the Independence Scale (10-100) and the Total Functional Capacity (0-13). Mild/moderate subjects were significantly older, had lower CAG repeat lengths, and greater fixed brain weights than those classified as severe. Patients who were pathologically classified as severe at autopsy were, on average, younger at age of onset and death and less well educated. Despite obvious clinical and pathological differences between mild-moderate and severe HD subjects at autopsy, mean MMSE scores of the two groups before death were surprisingly similar. Correlations between Vonsattel stage and functional assessment scores before death were low and not statistically significant. Our results suggest that the extent of striatal changes in HD may not always correlate with clinical disease severity as measured by UHDRS functional scales. ? 2012 Movement Disorder Society.     

Objective assessment of progression in Huntington's disease: a 3-year follow-up study

Objective measures to assess progression of Huntington's disease (HD) are desirable. The authors have previously found that patients with HD with higher Unified Huntington's Disease Rating Scale (UHDRS) motor scores exhibited higher variability of isometric grip forces while grasping an object. Therefore, the authors assessed grip force variability during this task in 10 HD patients with a 3-year follow-up. Grip force variability increased in all patients at the follow-up. Thus, grip force variability during grasping might be an objective and quantitative measure to assess motor deficits associated with the progression of HD.     

Motor cortical excitability studied with repetitive transcranial magnetic stimulation in patients with Huntington's disease.

OBJECTIVE: TMS techniques have provided controversial information on motor cortical function in Huntington's disease (HD). We investigated the excitability of motor cortex in patients with HD using repetitive transcranial magnetic stimulation (rTMS). METHODS: Eleven patients with HD, and 11 age-matched healthy subjects participated in the study. The clinical features of patients with HD were evaluated with the United Huntington's Disease Rating Scale (UHDRS). rTMS was delivered with a Magstim Repetitive Magnetic Stimulator through a figure-of-8 coil placed over the motor area of the first dorsal interosseus (FDI) muscle. Trains of 10 stimuli were delivered at 5 Hz frequency and suprathreshold intensity (120% resting motor threshold) with the subjects at rest and during voluntary contraction of the target muscle. RESULTS: In healthy subjects at rest, rTMS produced motor evoked potentials (MEPs) that increased in amplitude over the course of the trains. Conversely in patients, rTMS left the MEP size almost unchanged. In both groups, during voluntary contraction rTMS increased the silent period (SP) duration. CONCLUSIONS: Because rTMS modulates motor cortical excitability by activating cortical excitatory and inhibitory interneurons these findings suggest that in patients with HD the excitability of facilitatory intracortical interneurones is decreased. SIGNIFICANCE: We suggest that depressed excitability of the motor cortex in patients with HD reflects a disease-related weakening of cortical facilitatory mechanisms.     

Open-label pilot study of levetiracetam (Keppra) for the treatment of chorea in Huntington's disease.

The objective of this study is to evaluate the tolerability and preliminary efficacy of levetiracetam (LEV) in reducing chorea in Huntington's disease (HD) patients in a prospective open-label pilot study. Nine HD patients with chorea were treated with LEV in doses up to 3,000 mg/day for up to 48 days. The primary endpoint measure was the Unified Huntington's Disease Rating Scale (UHDRS) chorea subscore. The mean dose (+/-SD) of LEV at endpoint was 2,583.3 +/- 1,020.6 mg/day. Mean UHDRS chorea score decreased from 12.6 +/- 3.0 at baseline to 6.7 +/- 4.3 at endpoint (P = 0.01). There was no significant change in UHDRS total motor scores (38.8 +/- 11.4 at baseline and 33.6 +/- 26.7 at endpoint; P = 0.24). Somnolence contributed to a 33% drop-out rate, and 3 patients developed Parkinsonism. Results of this open label study suggest that LEV may be efficacious in reducing chorea in HD patients.     

Probability of obsessive and compulsive symptoms in Huntington's disease.

BACKGROUND: The purpose of this study was to examine the probability of obsessive and compulsive (OC) symptoms across stages of Huntington's disease (HD) with both cross sectional and longitudinal data. METHODS: We present the largest sample to date of individuals at risk for HD (N = 3964). Obsessive and compulsive symptoms were assessed with the Unified Huntington's Disease Rating Scale OC items. RESULTS: The probability of meeting the threshold for obsessions and compulsions increased with greater disease severity. Those with no motor abnormalities ("at risk") had a 7% probability of obsessions and a 3.5% probability of compulsions; the peak probability for obsessions (24%) and compulsions (12%) occurred in patients with advanced disease with significant functional disability. CONCLUSIONS: The probability of OC symptoms is more than three times greater by stages 3 and 4 (clearly manifest disease) than in our at-risk group with no apparent motor abnormalities.     

Functional and motor response to low dose olanzapine in Huntington's disease: case report

Previous reports on the use of olanzapine in Huntington's disease (HD) used doses ranging from 10-30 mg. We report a case of HD with marked delusions and behavioral impairment assessed by the Unified Huntington's Disease Rating Scale at baseline and four months later treated with a low dose of olanzapine. The patient improved in motor, psychiatric and activity of daily living symptoms after four months of treatment. The response to a low dose of olanzapine in HD may be an indicator of efficacy in similar cases. Further randomized controlled trials can properly assess these findings.     

Preparing for preventive clinical trials: the Predict-HD study

BACKGROUND: The optimal design and outcome measures for preventive clinical trials in neurodegenerative diseases are unknown. OBJECTIVE: To examine measures that may be associated with disease in the largest cohort ever recruited of prediagnosed individuals carrying the gene expansion for Huntington disease (HD). DESIGN: The Predict-HD study is a multicenter observational research study in progress at 17 sites in the United States, 4 in Canada, and 3 in Australia. SETTING: Genetics and HD outpatient clinics. PARTICIPANTS: Five hundred five at-risk individuals who had previously undergone elective DNA analyses for the CAG expansion in the HD gene (predictive testing) and did not currently have a clinical diagnosis of HD. MAIN OUTCOME MEASURES: Basal ganglia volumes on magnetic resonance images, estimated probability of diagnosis (based on CAG repeat length), performances on 21 standardized cognitive tasks, total scores on 3 scales of psychiatric distress, and motor diagnosis based on the Unified Huntington's Disease Rating Scale. RESULTS: Several variables showed progressive decline as the diagnostic ratings advanced toward manifest disease. Estimated probability of diagnosis was associated with Unified Huntington's Disease Rating Scale prediagnostic stages and varied from 15% in persons with no motor abnormalities to nearly 40% in those with abnormalities suggestive of probable disease. Striatal volumes, cognitive performances, and even psychiatric ratings declined significantly with motor manifestations of disease. CONCLUSIONS: The documentation of biological and refined clinical markers suggests several clinical end points for preventive clinical trials. Longitudinal study is critical to further validate possible markers for prediagnosed HD.     

Recognition memory for hand positions and spatial locations in patients with Huntington's disease: differential visuospatial memory impairment?

Allocentric and egocentric memory was investigated in patients with Huntington's disease (HD) and matched controls. Patients with HD and age- and education-matched healthy normal controls (NC) were administered two visuospatial recognition memory tasks, one assessing memory for hand positions (egocentric) and the other assessing memory for spatial locations (allocentric). HD patients showed normal primacy and recency effects, but their overall performance was impaired relative to controls on both tasks. Correlation analyses indicated that HD patients' performance on the Hand Position Memory task, but not the Spatial Location Memory task, was associated with global cognitive status (Mattis Dementia Rating Scale) and disease severity (Shoulson and Fahn Rating Scale), and HD patients' performances on the two tasks were not associated. Results provide preliminary support for the role of the caudate nucleus in both allocentric and egocentric spatial memory.     

Differentiation of Alzheimer's disease and Huntington's disease with the Dementia Rating Scale

Patients with dementia of the Alzheimer type (DAT) and Huntington's disease (HD) were assessed with the Dementia Rating Scale, a brief mental status examination that provides a global dementia score and subtest scores for attention, initiation, construction, conceptualization, and memory capacities. Although the patients with DAT and the patients with HD were precisely matched in terms of total Dementia Rating Scale score, different subtest score profiles emerged. Patients with DAT were more impaired than patients with HD on the Memory subtest, whereas patients with HD were more impaired than patients with DAT on the initiation subtest. These results are indicative of qualitative differences in the cognitive impairment of the two disorders and demonstrate that such differences can be elucidated with brief mental status examinations.     

Minocycline enhances MPTP toxicity to dopaminergic neurons

Minocycline has been shown previously to have beneficial effects against ischemia in rats as well as neuroprotective properties against excitotoxic damage in vitro, nigral cell loss via 6-hydroxydopamine, and to prolong the life-span of transgenic mouse models of Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). We investigated whether minocycline would protect against toxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a toxin that selectively destroys nigrostriatal dopaminergic (DA) neurons and produces a clinical state similar to Parkinson's disease (PD) in rodents and primates. We found that although minocycline inhibited microglial activation, it significantly exacerbated MPTP-induced damage to DA neurons. We present evidence suggesting that this effect may be due to inhibition of DA and 1-methyl-4-phenylpridium (MPP+) uptake into striatal vesicles.     

A randomised, placebo-controlled, double blind study of treatment of Huntington's disease with unsaturated fatty acids

Huntington's Disease (HD) is a serious dominantly inherited neurodegenerative disorder for which there are no current treatments. Open label and animal studies have suggested that highly unsaturated fatty acids (HUFAs) may be beneficial. Seventeen patients with HD were entered into a randomised, placebo-controlled, double blind trial of HUFA therapy. Patients were assessed on the Rockland-Simpson Dyskinesia Rating Scale (RSDRS) and the Unified Huntington's Disease Rating Scale (UHDRS). On the RSDRS and the UHDRs motor scale patients on HUFA treatment improved while those on placebo deteriorated, with a significant difference between the two groups on the RSDRS. A similar trend was noted on the UHDRS functional performance scales. Little change was seen on the neuropsychology scales. There were no treatment-related adverse events. This is the first time that a significant improvement has been noted in a randomised trial in HD. The results are consistent with open label observations; a second placebo-controlled study in end-stage patients, and a study in a transgenic mouse model of HD.     

White matter volume and cognitive dysfunction in early Huntington's disease.

BACKGROUND: Structural abnormalities of the striatum and cognitive impairments have consistently been shown in patients with Huntington's disease (HD). Fewer studies have examined other cerebral structures in early HD and potential associations with cognition. METHOD: Ten patients with early HD and 10 matched control subjects underwent magnetic resonance imaging to provide quantitative measures (volumes) of cortical gray and white matter and the caudate, putamen, and thalamus. Patients completed the Unified Huntington's Disease Rating Scale, including three cognitive tasks. RESULTS: Although striatal volumes were clearly reduced, white matter was also morphologically abnormal. Cortical gray matter volume was not significantly correlated with cognitive performance. However, the cognitive tasks were most highly correlated with cerebral white matter and, to a lesser degree, striatal volume. CONCLUSIONS: Cerebral white matter volume may be an important variable to examine in future studies of HD.