Dorsal rather than ventral visual pathways discriminate freezing status in Parkinson's disease.

Background: Although visuospatial deficits have been linked with freezing of gait (FOG) in Parkinson's disease (PD), the specific effects of dorsal and ventral visual pathway dysfunction on FOG is not well understood.

Method: We assessed visuospatial function in FOG using an angle discrimination test (dorsal visual pathway bias) and overlapping figure test (ventral visual pathway bias), and recorded overall response time, mean fixation duration and dwell time. Covariate analysis was conducted controlling for disease duration, motor severity, contrast sensitivity and attention with Bonferroni adjustments for multiple comparisons.

Cognition, coping, and outcome in Parkinson's disease.

Background: Cognitive impairment and depression are common and disabling non-motor symptoms of Parkinson's disease (PD). Previous studies have shown associations between them but the nature of the relationship remains unclear. In chronic illness, problem- or task-oriented coping strategies are associated with better outcome but often require higher level cognitive functioning.

Frontotemporal dementia in elderly individuals.

Objective: To determine whether cases of frontotemporal lobar degeneration (FTLD) do exist in elderly individuals and have clinical and neuropathological features distinct from those with presenile onset.

Design: Retrospective matched cohort study.

Setting: Regional Neuroscience Centre, North East England.

Identifying prodromal Parkinson's disease: pre-motor disorders in Parkinson's disease.

Increasing recognition that Parkinson's disease (PD) may start outside of the substantia nigra has led to a rapidly expanding effort to define prodromal stages of PD, before motor signs permit classical diagnosis. Many of these efforts center around the identification of clinical non-motor symptoms and signs of disease. There is now direct evidence that olfaction, rapid eye movement (REM) sleep behavior disorder (RBD), constipation, and depression can be present in prodromal PD.

Conventional magnetic resonance imaging in confirmed progressive supranuclear palsy and multiple system atrophy.

Conventional magnetic resonance imaging (cMRI) is often used to aid the diagnosis of progressive supranuclear palsy (PSP) and multiple system atrophy (MSA), but its ability to predict the histopathological diagnosis has not been systematically studied. cMRI from 48 neuropathologically confirmed cases, including PSP (n = 22), MSA (n = 13), Parkinson's disease (PD) (n = 7), and corticobasal degeneration (n = 6), and controls (n = 9) were assessed blinded to clinical details and systematically rated for reported abnormalities. Clinical diagnosis and macroscopic postmortem findings were retrospectively assessed.

Amantadine-induced myoclonus in a patient with progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a tauopathy that generally results in a hypokinetic disorder. Treatment is largely symptomatic, with some small studies indicating a benefit with dopaminergic therapy. Myoclonus is a hyperkinetic disorder that can be seen as part of later stage Parkinson's disease and in multiple system atrophy, but is rarely seen in PSP.

Diagnostic criteria for mild cognitive impairment in Parkinson's disease: Movement Disorder Society Task Force guidelines.

Mild cognitive impairment is common in nondemented Parkinson's disease (PD) patients and may be a harbinger of dementia. In view of its importance, the Movement Disorder Society commissioned a task force to delineate diagnostic criteria for mild cognitive impairment in PD. The proposed diagnostic criteria are based on a literature review and expert consensus.

Tau acts as an independent genetic risk factor in pathologically proven PD.

MAPT has been repeatedly linked with Parkinson's disease (PD) in association studies. Although tau deposition may be seen in PD, its relevance to the pathogenesis of the condition remains unclear. The presence of tau-positive inclusions is, however, the defining feature of progressive supranuclear palsy (PSP), which may often be clinically misdiagnosed as idiopathic PD.

Synaptic protein alterations in Parkinson's disease.

Alterations occur within distal neuronal compartments, including axons and synapses, during the course of neurodegenerative diseases such as Parkinson's disease (PD). These changes could hold important implications for the functioning of neural networks, especially since research studies have shown a loss of dendritic spines locating to medium spiny projection neurons and impaired axonal transport in PD-affected brains. However, despite ever-increasing awareness of the vulnerability of synapses and axons, inadequate understanding of the independent mechanisms regulating non-somatic neurodegeneration prevails.

Cognitive impairment in nondemented Parkinson's disease.

A substantial percentage of patients with newly diagnosed Parkinson's disease without dementia are reported to be affected by cognitive impairment (CI). In practice, however, CI is underrecognized, as the signs may not be apparent in early-stage disease and many routine assessment tools lack the sensitivity to detect subtle cognitive dysfunction. Patients with PD and mild CI (MCI) may have a higher risk of developing dementia than cognitively intact PD patients; however, it is not currently known which patients with CI are at increased risk of developing dementia.

The Wilson films--post encephalitic Parkinsonism.

Three cases of postencephalitic parkinsonism that were originally described by Kinnier Wilson are reviewed and some general comments made upon their presentation. A differential diagnosis that might now be appropriate in the 21(st) Century is given, in the light of recent literature on the topic and so-called "sporadic" cases.

Parkinson's disease motor subtypes and mood.

Parkinson's disease is heterogeneous, both in terms of motor symptoms and mood. Identifying associations between phenotypic variants of motor and mood subtypes may provide clues to understand mechanisms underlying mood disorder and symptoms in Parkinson's disease. A total of 513 patients were assessed using the Hospital Anxiety and Depression Scale, and separately classified into anxious, depressed, and anxious-depressed mood classes based on latent class analysis of a semistructured interview.

Genetic and pathological links between Parkinson's disease and the lysosomal disorder Sanfilippo syndrome.

Background: Parkinson's disease (PD) is a common neurodegenerative disorder of unknown etiology. The characteristic α-synuclein aggregation of PD is also a feature of Sanfilippo syndrome, a storage disorder caused by α-N-acetylglucosaminidase (NAGLU) gene mutations. We explored genetic links between these disorders and studied the pathology of Sanfilippo syndrome to investigate a common pathway toward α-synuclein aggregation.

Understanding the impact of deep brain stimulation on ambulatory activity in advanced Parkinson's disease.

Whilst deep brain stimulation of the subthalamic nucleus (DBS-STN) improves the motor symptoms of Parkinson's disease (PD), its effect on daily activity is unknown. We aimed to quantify changes in ambulatory activity following DBS-STN in advanced PD using novel accelerometry based measures that describe changes to the volume and pattern of walking. Seventeen participants with advanced PD were measured over a 7-day period using an activPAL (™) activity monitor.

Visual symptoms in Parkinson's disease and Parkinson's disease dementia.

Visual symptoms are common in PD and PD dementia and include difficulty reading, double vision, illusions, feelings of presence and passage, and complex visual hallucinations. Despite the established prognostic implications of complex visual hallucinations, the interaction between cognitive decline, visual impairment, and other visual symptoms remains poorly understood. Our aim was to characterize the spectrum of visual symptomatology in PD and examine clinical predictors for their occurrence.

The interplay of cholinergic function, attention, and falls in Parkinson's disease.

Dopamine loss in the substantia nigra causes several of the motor signs seen in Parkinson's disease, but there is now increasing evidence highlighting the importance of cholinergic loss in the pathophysiology of nonmotor symptoms. The nucleus basalis of Meynert supplies the majority of the cholinergic input to the cerebral cortex, with the pedunculopontine nucleus providing many subcortical structures with acetylcholine. Both these structures undergo degeneration in Parkinson's disease (PD), with more severe loss associated with cognitive impairment.

No evidence of substantia nigra telomere shortening in Parkinson's disease.

Telomeres are repetitive tracts of DNA which protect chromosomal integrity. Increased oxidative stress leads to shorter telomeres, which have been associated with several late-onset human diseases. Given independent evidence of oxidative stress and Parkinson's disease (PD), and conflicting reports of the role of telomere length in PD, we measured telomere length in both PD peripheral blood monocytes and in substantia nigra from affected individuals and controls.

Parkinson's disease: the quintessential neuropsychiatric disorder.

Although diagnosed by characteristic motor features, Parkinson's disease may be preceded, and is frequently accompanied by, a wide range of cognitive and neuropsychiatric features. In addition to the most commonly studied disorders of dementia, depression, and psychosis, other relatively common and clinically significant psychiatric complications include impulse control disorders, anxiety symptoms, disorders of sleep and wakefulness, and apathy. These problems may be underrecognized and are frequently undertreated.

Targeting dopa-sensitive and dopa-resistant gait dysfunction in Parkinson's disease: selective responses to internal and external cues.

Background: Independence of certain gait characteristics from dopamine replacement therapies highlights its complex pathophysiology in Parkinson's disease (PD). We explored the effect of two different cue strategies on gait characteristics in relation to their response to dopaminergic medications.

Patients And Methods: Fifty people with PD (age 69.

Retinal thickness in Parkinson's disease.

Background: Visual symptoms are common in Parkinson's disease with studies consistently demonstrating reductions in visual acuity, contrast sensitivity, colour and motion perception as well as alterations in electroretinogram latencies and amplitudes. Optical coherence tomography can examine retinal structure non-invasively and retinal thinning has been suggested as a potential biomarker for neurodegeneration in Parkinson's disease. Our aim was to examine the retinal thickness of a cohort of Parkinson's disease subjects (and age-matched controls) to establish the practical utility of optical coherence tomography in a representative older Parkinson's disease group.

Depression and anxiety related subtypes in Parkinson's disease.

Background: Depression and anxiety are common in Parkinson's disease (PD) and although clinically important remain poorly understood and managed. To date, research has tended to treat depression and anxiety as distinct phenomena. There is growing evidence for heterogeneity in PD in the motor and cognitive domains, with implications for pathophysiology and outcome.

Gait variability in Parkinson's disease: an indicator of non-dopaminergic contributors to gait dysfunction?

Gait variability has potential utility as a predictive measure of dysfunction in Parkinson's disease (PD). Current understanding implicates non-dopaminergic pathways. This study investigated the explanatory characteristics of gait variability in PD on and off medication under single and dual task conditions.