Affective behavioural disturbances in Alzheimer's disease and ischaemic vascular disease

OBJECTIVES: To investigate affective change in Alzheimer's disease and ischaemic vascular disease and examine the contribution of white matter disease to psychopathology in these dementias. Based on earlier studies, it was predicted that: (1) depression would be more prevalent and severe in ischaemic vascular disease; (2) psychomotor slowing would be more prevalent in ischaemic vascular disease; (3) apathy would be more prevalent in ischaemic vascular disease; and (4) The degree of white matter disease would be positively correlated with the severity of psychomotor slowing. METHODS: Ratings of affective/behavioural states and white matter disease were compared in 256 patients with Alzheimer's disease and 36 patients with ischaemic vascular disease or mixed dementia with an ischaemic vascular component using analysis of variance (ANOVA) and linear regression models. RESULTS: The findings were: (1) decreased affect/withdrawal was more prevalent and severe in patients with ischaemic vascular disease and patients with white matter disease; (2) psychomotor slowing was more severe in patients with ischaemic vascular disease and patients with white matter disease; and (3) differences between Alzheimer's disease and ischaemic vascular dementia groups in the degree of psychomotor slowing were independent of the severity of white matter disease. CONCLUSIONS: Future studies using structural and functional neuroimaging techniques would be helpful for examining the relation between neurobiological factors and affective/behavioural disturbances in dementia.     

Sleep disturbances by disease type and stage in Huntington's disease

IntroductionSleep disturbances are a common symptom in patients with Huntington's disease (HD). However, it is unclear when in the disease course of HD sleep disturbances become more frequent compared to the general population. This study investigated the frequency and odds of developing sleep disturbances between adults with HD or at-risk for HD and non-HD controls.MethodsParticipants from the Enroll-HD study were split by both disease type and disease severity using CAG length, diagnostic confidence level, and total functional capacity score. Multivariate logistic regression was used to calculate odds ratios adjusted for age, sex, tobacco and alcohol use, depression and psychosis scores, and cognition to compare HD groups to non-HD controls. Cox proportional hazards models and Kaplan Meier curves were used to determine differences in probabilities of developing sleep disturbances and how sleep disturbances are related to age at motor onset.ResultsThere were significant differences between HD participants and non-HD controls in both the disease type and disease stage analyses (p < 0.001). The odds of a sleep disturbance increased with worsening disease stage and was highest in those with juvenile HD. The development of a sleep disorder in manifest HD participants was observed to be around the time of disease onset.ConclusionsSleep disturbances are more frequent in HD patients than those without HD. There are also differences based on disease type and stage. This is supplemented by the finding that the onset of sleep disturbances occurs near the time of motor onset of HD.     

Inhibitory control during smooth pursuit in Parkinson's disease and Huntington's disease

The basal ganglia are involved in the preferential selection and suppression of competing responses. Parkinson's disease and Huntington's disease are 2 prototypical basal ganglia disorders that feature impaired inhibitory control, a function of poor conflict resolution. Previous saccadic studies showed that individuals with Parkinson's disease experience difficulty suppressing unwanted ocular motor responses, whereas evidence for a similar difficulty in Huntington's disease is more equivocal. Relative to saccades, few research studies have examined inhibitory control processes in the context of an ongoing smooth pursuit task. In this study, we examined the ability of 16 patients with Parkinson's disease and 12 patients with Huntington's disease to suppress automatic responses to irrelevant distracters that transiently appeared during the tracking of a moving visual stimulus. Compared with an equivalent number of age‐matched controls, patients with Parkinson's disease generated proportionately more saccades to distracter stimuli. This was particularly evident for distracters appearing far away from the target. Conversely, whereas individuals with early‐stage Huntington's disease and healthy controls made a comparable number of errors toward distracter stimuli, those in a more advanced clinical stage demonstrated significantly poorer inhibitory control. The current findings in parkinsonian patients replicate those previously reported in the saccadic and manual response literature, demonstrating difficulty inhibiting a competing motor response. However, in Huntington's disease we demonstrate for the first time that inhibitory control declines in more advanced‐disease stages. This suggests that ocular motility may provide a sensitive marker of clinical disease progression in Huntington's disease. © 2011 Movement Disorder Society     

Colonic diverticular disease: A new risk factor for Parkinson's disease?

BackgroundColonic diverticular disease is a chronic gastrointestinal disorder. Previous studies have suggested that chronic gastrointestinal tract is involved in the pathophysiology of Parkinson's disease.ObjectThis study investigated the potential link between colonic diverticular disease and risk of Parkinson's disease.MethodsData in this nationwide population-based cohort study were obtained from the National Health Insurance Research Database. Patients with colonic diverticular disease were identified from among 23.22 million insured Taiwanese residents who had been diagnosed between 2000 and 2005 and were aged ≥20 years (n = 23367). The comparison cohort included patients without colonic diverticular disease, matched by sex, age, and all comorbidities with the colonic diverticular disease patients cohort (n = 23367). Using univariable and multivariable Cox proportional hazard regression models, we estimated the adjusted hazard ratio (aHR) for PD with a 95% confidence interval (CI) after adjusting for age, sex, and all of comorbidities.ResultsThe risk of Parkinson's disease was higher in the CDD cohort than in the comparison cohort (HR = 1.27, 95%CI = 1.10–1.47). Compared with patients aged ≥65 years without CDD, the CDD patients in the equal age group had a 1.25-fold increased risk of PD (95% CI = 1.07–1.46).ConclusionColonic diverticular disease may be associated with an increased risk of Parkinson's disease. Thus, the risk of this neurodegenerative disease should be considered in patients with colonic diverticular disease.     

Lyme disease

Lyme disease is due to infection with a tick-borne spirochete, Borrelia burgdorferi. Risk for infection is confined to regions that contain the Ixodid tick vector. Characteristic skin, musculoskeletal, cardiac, ocular, and neurologic disorders are associated with the local, early dissemination and late stages of infection. Neurologic involvement can be seen at all stages, and involves both central and peripheral nervous system syndromes. The inability to easily culture B. burgdorferi and the lack of a reliable active infection assay have contributed to controversies in diagnosis and management. Because the vast majority of patients are seropositive, however, antibody testing is helpful to support the diagnosis of Lyme disease. With appropriate antibiotics, most patients do well. This infection provides an important model system to understand how interactions between an organism, vector, and host lead to disease. It also provides a model to study how infectious agents lead to neurologic disease.     

Alexander's disease

Summary This is the first pathologic report of an infant at 37 weeks' gestation with Alexander's disease. The findings demonstrate that the disease can arisein utero and be extensive at birth before myelination begins.     

Is celiac disease associated with Alzheimer's disease?

An increased prevalence of celiac disease has been reported in neurological disorders of unknown etiology. A large proportion of Alzheimer's cases is still of unexplained etiology. Thirty-three Alzheimer's patients and 24 elderly controls were screened for celiac disease. IgA and IgG antigliadin antibodies were assayed in serum samples with enzyme-linked immunoassay. Confirmation of celiac disease in positive subjects was made by assaying IgA anti-endomysium antibodies by indirect immunofluorescence. Two Alzheimer's patients and 2 controls were positive for antigliadin antibodies (6 versus 8%; NS). None was positive for anti-endomysium antibodies. We conclude that the prevalence of celiac disease in Alzheimer's disease is not higher than in cognitively unimpaired elders, suggesting that the immune changes in celiac disease are unlikely to play a role in Alzheimer's disease.     

Leber's disease and dystonia: a mitochondrial disease

We studied a kindred in which 8 members had the neuroretinopathy of Leber's disease; 14 had a progressive, generalized dystonia attributed to striatal degeneration; and 1 had both disorders. The mode of inheritance was compatible with maternal transmission. This neurologic disorder may be a mitochondrial disease.     

Autonomic dysfunction according to disease progression in Parkinson's disease

BackgroundAlthough autonomic dysfunction is common in patients with Parkinson’s disease (PD), few data are available regarding its pattern and quantitative severity with increasing Hoehn and Yahr (H&Y) stage. We conducted autonomic function tests to quantify autonomic dysfunction in PD patients and to elucidate its possible relationship with disease progression.MethodsWe performed autonomic function tests including Valsalva ratio, heart rate response to deep breathing, quantitative sudomotor axon reflex test, and head-up tilt test in 66 patients with PD. We compared clinical characteristics and results of autonomic function tests between stages, and correlated the proportion of abnormal patients in each test with their H&Y stage. In addition, logistic regression analyses were conducted to examine the contribution of increasing H&Y stage to impairments of each domain of the autonomic nervous system.ResultsWe found that PD patients with higher disease stage tended to have impairments in cardiovagal and sudomotor domains of the autonomic nervous system. Cardiovagal function was the domain most influenced by disease progression. Our findings also demonstrated that the pattern of sudomotor impairment in PD was similar to that in patients with peripheral autonomic neuropathy.ConclusionsOur study demonstrates that autonomic dysfunction is not only common in early stage PD but it increases in severity with increasing disease stage. Given that the patterns of sudomotor impairments in PD are similar to those in peripheral neuropathy, our data support a previous hypothesis that pathophysiology of PD involves both the central and peripheral nervous systems.     

Parkinson's disease: medical treatment of moderate to advanced disease

Parkinson’s disease, a common neurodegenerative disorder, results in significant morbidity 10 to 15 years after disease onset and increased mortality. Levodopa is the mainstay of therapy and provides benefit for the duration of the illness. However, within 5 years, up to 50% of individuals develop fluctuations, including dyskinesias, wearing off, and "on/off" effects. Optimal management of Parkinson’s disease patients requires careful titration of medications, with use of polypharmacy, including levodopa, dopamine agonists, catechol-O-methyltransferase inhibitors, amantadine, and anticholinergics in order to maintain good motor function and quality of life. With advancing disease, problems such as dysphagia, dysarthria, and gait and balance abnormalities occur, which are not responsive to dopaminergic medication. Due to extradopaminergic neuronal system degeneration, autonomic dysfunction can also be prominent. Recognition and management of these problems is helpful in improving quality of life in late-stage disease. In very late stages, dementia may complicate treatment, requiring discontinuation of combination therapy and use of low-dose levodopa with atypical neuroleptics.     

The role of disease duration and severity on novel clinical subtypes of Parkinson disease

IntroductionOne of the latest subtyping systems of Parkinson disease (PD) identifies motor severity, cognitive dysfunction, dysautonomia, and rapid eye movement behavior disorder as key features for phenotyping patients into three different subtypes (i.e., mild motor-predominant, diffuse-malignant and intermediate). Since PD subtypes are clinically most relevant if they are mutually exclusive and consistent over-time, we explored the impact of disease stage and duration on these novel subtypes.MethodsOne-hundred-twenty-two consecutive patients, with a disease duration ranging from 0 to 20 years, were allocated as suggested into these three subtypes. The relationship between either disease duration or stage, as measured by the Hoehn and Yahr staging, and subtype allocation was explored.ResultsSignificant differences in subtype distribution were observed across patients stratified according to either disease duration or staging, with the diffuse-malignant subtypes increasing in prevalence as the disease advanced. Both disease duration and staging were independent predictors of subtype allocation.ConclusionsThese novel PD subtypes are significantly influenced by disease duration and staging, which might suggest that they do not represent mutually exclusive disease pathways. This should be taken into account when attempting correlations with putative biomarkers of disease progression.     

Olfaction differentiates parkin disease from early-onset parkinsonism and Parkinson disease

The authors studied whether olfactory dysfunction is present in parkin disease using the University of Pennsylvania Smell Identification Test (UPSIT). The mean UPSIT score in parkin patients was 27.3 (95% CI 24.4 to 30.2). This did not differ from the normal group mean of 29.4 (95% CI 28.0 to 30.7; p = 0.22) but was higher than the Parkinson disease group (mean 14.3; 95% CI 12.2 to 19.5; p < 0.0001) and the parkin-negative group (mean 17.1; 95% CI 14.8 to 16.3; p < 0.0001) values. Parkin disease may be a distinct and separate entity from Parkinson disease.     

Lysosomal trafficking defects link Parkinson's disease with Gaucher's disease

Lysosomal dysfunction has been implicated in multiple diseases, including lysosomal storage disorders such as Gaucher's disease, in which loss‐of‐function mutations in the GBA1 gene encoding the lysosomal hydrolase β‐glucocerebrosidase result in lipid substrate accumulation. In Parkinson's disease, α‐synuclein accumulates in Lewy bodies and neurites contributing to neuronal death. Previous clinical and genetic evidence has demonstrated an important link between Parkinson's and Gaucher's disease, as GBA1 mutations and variants increase the risk of Parkinson's and Parkinson's patients exhibit decreased β‐glucocerebrosidase activity. Using human midbrain neuron cultures, we have found that loss of β‐glucocerebrosidase activity promotes α‐synuclein accumulation and toxicity, whereas α‐synuclein accumulation further contributes to decreased lysosomal β‐glucocerebrosidase activity by disrupting β‐glucocerebrosidase trafficking to lysosomes. Moreover, α‐synuclein accumulation disrupts trafficking of additional lysosomal hydrolases, further contributing to lysosomal dysfunction and neuronal dyshomeostasis. Importantly, promoting β‐glucocerebrosidase activity reduces α‐synuclein accumulation and rescues lysosomal and neuronal dysfunction, suggesting that β‐glucocerebrosidase may be an important therapeutic target for advancing drug discovery in synucleinopathies including Parkinson's disease. © 2016 International Parkinson and Movement Disorder Society.     

Hallucinosis in idiopathic Parkinson's disease

BACKGROUND—Hallucinosis is a complication ofthe treatment of idiopathic Parkinson's disease commonly thought toafflict older, chronically medicated, cognitively impaired patients.However, patients with idiopathic Parkinson's disease of shortduration experiencing hallucinosis on relatively low doses ofdopaminergic medication have been found. The aim, therefore,was to investigate the homogeneity of a population of patients withidiopathic Parkinson's disease and hallucinosis.
METHODS—The clinical, demographic, and cognitivecorrelates of hallucinosis were investigated in a sample of 129 patients with idiopathic Parkinson's disease.
RESULTS—There were two subgroups of patientswith idiopathic Parkinson's disease experiencing hallucinosis. Inpatients with a disease duration of five years or less, hallucinosiswas associated with rapid progression of the motor component of thedisease but not cognitive impairment. In patients with idiopathicParkinson's disease of longer than five years duration, hallucinosiswas associated with postural instability, global cognitiveimpairment, and lack of depressive affect. In all patients withidiopathic Parkinson's disease, hallucinosis was more prevalent whenthey were treated with a direct acting dopamine receptor agonist.Hallucinosis was not associated with age at onset of idiopathicParkinson's disease or dosage of dopaminergic medication.
CONCLUSION—Hallucinosis in idiopathic Parkinson'sdisease is heterogeneous, falling into two groups. The difference inthe pathophysiological basis of hallucinosis in these two groups ofpatients is discussed.

     

Parkinson disease

Parkinson disease (PD) is the most common neurodegenerative movement disorder. In Europe, prevalence and incidence rates for PD are estimated at approximately 108–257/100 000 and 11–19/100 000 per year, respectively. Risk factors include age, male gender and some environmental factors. The aetiology of the disease in most patients is unknown, but different genetic causes have been identified. Although familial forms of PD account for only 5%–15% of cases, studies on these families provided interesting insight on the genetics and the pathogenesis of the disease allowing the identification of genes implicated in its pathogenesis and offering critical insights into the mechanisms of disease. The cardinal motor symptoms of PD are tremor, rigidity, bradykinesia/akinesia and postural instability, but the clinical picture includes other motor and non‐motor symptoms. Its diagnosis is principally clinical, although specific investigations can help the differential diagnosis from other forms of parkinsonism. Pathologically, PD is characterized by the loss of dopaminergic neurons in the pars compacta of the substantia nigra and by accumulation of misfolded α‐synuclein, which is found in intra‐cytoplasmic inclusions called Lewy bodies. Currently available treatments offer good control of motor symptoms but do not modify the evolution of the disease. This article is intended to provide a comprehensive, general and practical review of PD for the general neurologist.     

Lysosomal storage disorders and Parkinson's disease: Gaucher disease and beyond

Parkinson's disease is associated with mutations in the glucocerebrosidase gene, which result in the enzyme deficiency causing Gaucher disease, the most common lysosomal storage disorder. We have performed an exhaustive literature search and found that additional lysosomal storage disorders might be associated with Parkinson's disease, based on case reports, the appearance of pathological features such as α‐synuclein deposits in the brain, and substantia nigra pathology. Our findings suggest that the search for biochemical and cellular pathways that link Parkinson's disease with lysosomal storage disorders should not be limited exclusively to changes that occur in Gaucher disease, such as changes in glucocerebrosidase activity or in glucosylceramide levels, but rather include changes that might be common to a wide variety of lysosomal storage disorders. Moreover, we propose that additional genetic, epidemiological, and clinical studies should be performed to check the precise incidence of mutations in genes encoding lysosomal proteins in patients displaying Parkinson's symptoms. © 2011 Movement Disorder Society     

Milestones in Huntington disease

There have been extraordinary advances in our knowledge of the underlying gene, the protein it encodes, various models of disease, and potential targets for effective therapies for Huntington disease. Huntington disease research has increased exponentially in the past 25 years, and we now understand many of the molecular mechanisms underlying the disease. Still, more work needs to be done before we have a full understanding of the pathophysiology of the disease. Clinical research on biomarkers and clinical trials on potential neuroprotective agents are underway. Here we review our progress in these areas over the last 25 years and speculate on what the next 25 years may hold. © 2011 Movement Disorder Society     

Seeking progress in disease modification in Parkinson disease

ObjectiveDisease modification in Parkinson disease (PD) has remained an elusive goal, in spite of large investments over several decades. Following a large meeting of experts, this review article discusses the state of the science, possible reasons for past PD trials’ failures to demonstrate disease-modifying benefit, and potential solutions.MethodsThe National Institute of Neurological Disorders and Stroke (NINDS) convened a meeting including leaders in the field and representatives of key stakeholder groups to discuss drug therapy with the goal of disease modification in PD.ResultsImportant lessons can be learned from previous attempts, as well as from other fields. The selection process for therapeutic targets and agents differs among various organizations committed to therapeutic development. The areas identified as critical to target in future research include the development of relevant biomarkers, refinements of the targeted patient populations, considerations of novel trial designs, and improving collaborations between all stakeholders.ConclusionsWe identify potential barriers to progress in disease modification for Parkinson's and propose a set of research priorities that may improve the likelihood of success.     

Is Parkinson's disease of early onset a separate disease entity?

Summary Two groups of patients suffering from Parkinson's disease were studied. The first group consisted of 23 patients with an onset age before 40 years; in the second group of 21 patients the onset was after age 50. The clinical findings and the course of the disease were very similar in each group. In spite of a longer disease duration in the patients with early onset of the disease there was no difference in motor impairment; the younger patients did better in mental testing and they were taking less dopaminergic medication. These differences are thought to be due to the age difference rather than to the existence of different disease entities. In the early onset group more familial cases (mostly affecting siblings) were found than in the older ones. The points in favour of there being a hereditary subgroup of early onset Parkinson's disease or of environmental factors causing the disease are reviewed.     

Genetic dissection of neurodegenerative disease

The clinical and molecular of Alzheimer's disease, Parkinson's disease, Pick's disease, progressive supranuclear palsy, corticobasal degeneration, multiple system atrophy and prion disease are reviewed. The hypothesis that these diseases share pathogenic pathways to cell death which involve either the tau or the α-synuclein proteins is propounded. The production and use of transgenic animal models of these disease, based on the genetic findings are briefly reviewed in the context of the development of treatments for these prevalent and distressing disorders.