Parkinson's disease and the skin.

The concept that the skin is a mirror of Parkinson's disease dates to the start of the last century. Despite dermatological disorders being recognised as a common non-motor symptom of Parkinson's disease, they are often overlooked. This article reviews the various skin disorders seen in Parkinson's disease and addresses the other dermatological questions that are frequently raised by those attending Parkinson's disease clinics.

Permanent tremor reduction during thalamic stimulation in multiple sclerosis.

Background: Unlike thalamic lesioning, thalamic stimulation is considered a reversible treatment for tremor. However, tremor in multiple sclerosis (MS) can sometimes permanently improve during thalamic stimulation. Such 'permanent tremor reduction' (PTR) has been attributed to limb weakness preventing tremor expression.

Perceptual bias for affective and nonaffective information in asymmetric Parkinson's disease.

Objective: To relate lateralized impairments of visual perception in Parkinson's disease to asymmetries in the severity of motor symptoms.

Method: Ten patients with worse left-sided motor symptoms (LPD), 15 with worse right-sided (RPD), and 13 healthy age-matched controls (all right-handed) viewed mirror-imaged pairs of emotional chimeric faces, (left side smiling, right neutral, and vice versa), of greyscales (strips whose luminance varied smoothly from black on the left to white on the right, and vice versa) and of gender chimeric faces (left side male, right female, and vice versa). Participants signaled which stimulus appeared happier, brighter, or more feminine, respectively, so showing which side received more attention.

Deep brain stimulation for movement disorders.

Deep brain stimulation is now considered a routine treatment option for selected patients with advanced Parkinson's disease, primary segmental and generalised dystonia, and essential tremor. The neurosurgeon is responsible for the accurate and safe placement of the electrodes and the neurologist for the careful selection of patients and titration of medication against the effects of stimulation. A multidisciplinary team approach involving specialist nurses, neuropsychologists and neurophysiologists is required for a successful outcome.

Pedunculopontine nucleus stimulation for people with Parkinson's disease? A clinical perspective.

Subthalamic deep brain stimulation is now well established as a treatment for the dopaminergic motor symptoms of Parkinson's disease. It has little effect on postural instability and "on-state" gait freezing. Animal experiments and early human pilot studies suggest that Pedunculopontine nucleus stimulation may alleviate these phenomenon, consistent with the hypothesis that these disabling symptoms are secondary to degeneration in non-dopaminergic pathways.

Anatomy, physiology, and pathophysiology of the pedunculopontine nucleus.

The pedunculopontine nucleus is composed of cholinergic and non-cholinergic neurones and is located in the caudal pontomesencephalic tegmentum. Evidence suggests that the nucleus plays a role in the production and control of movement. The nucleus has dense interconnections with the basal ganglia, as well as with other areas of the brain associated with motor control.

Changes in cognition and health-related quality of life with unilateral thalamotomy for Parkinsonian tremor.

Cognitive functioning and health-related quality of life were assessed pre- and post-operatively in a consecutive series of 31 Parkinson's disease patients who underwent stereotactic unilateral thalamotomy (22 left-sided, 9 right-sided) for tremor alleviation. Neuropsychological functions assessed included verbal and visual memory, language and speech production, verbal and non-verbal reasoning, and attention and working memory. Health-related quality of life measures included both general and disease-specific questionnaires.

The sensory and motor representation of synchronized oscillations in the globus pallidus in patients with primary dystonia.

In 15 patients with primary dystonia (six cervical and nine generalized dystonias) who were treated with bilateral chronic pallidal stimulation, we investigated the sensorimotor modulation of the oscillatory local field potentials (LFPs) recorded from the pallidal electrodes. We correlated these with the surface electromyograms in the affected muscles. The effects of involuntary, passive and voluntary movement and muscle-tendon vibration on frequency ranges of 0-3 Hz, theta (3-8 Hz), alpha (8-12 Hz), low (12-20 Hz) and high beta (20-30 Hz), and low (30-60 Hz) and high gamma (60-90 Hz) power were recorded and compared between cervical and generalized dystonia groups.

Deep brain stimulation in childhood: an effective treatment for early onset idiopathic generalised dystonia.

Background: Early onset idiopathic generalised dystonia is a progressive and profoundly disabling condition. Medical treatment may ameliorate symptoms. However, many children have profound, intractable disability including the loss of ambulation and speech, and difficulties with feeding.

Use of surface electromyography to assess and select patients with idiopathic dystonia for bilateral pallidal stimulation.

Object: The object of this study was to identify a preoperative physiological index by using surface electromyography (EMG) signals that would correlate with clinical outcome in dystonic patients following bilateral pallidal stimulation.

Methods: In 14 patients with spasmodic torticollis, generalized dystonia, and myoclonic dystonia, surface EMG signals were recorded from the most affected muscle groups. Although the dystonia affected different body segments, the EMG signals in all patients could be decomposed into bursting and sustained components.

A dominant bursting electromyograph pattern in dystonic conditions predicts an early response to pallidal stimulation.

Although chronic pallidal deep brain stimulation (DBS) is effective in the treatment of medically intractable dystonia, there is no way of predicting the variations in clinical outcome, partly due to our limited understanding of the pathophysiological mechanisms underlying this condition. We recorded electromyographic (EMG) activity from the most severely affected muscle groups in seven dystonia patients before and after pallidal DBS. Patient EMG recordings could be classified into two groups: one consisting of patients who at rest demonstrated a dominant low frequency component of activity on power spectral analysis (ranging from 2 to 5 Hz), and one group in which this dominant pattern was absent.

STN vs. Pallidal Stimulation in Parkinson Disease: Improvement With Experience and Better Patient Selection.

Objectives.  This is a prospective study to determine the outcomes of subthalamic nucleus (STN) vs. globus pallidus internus (GPi) deep brain stimulation (DBS) at our institution.

Camptocormia treated with bilateral pallidal stimulation: case report.

The authors report the neurological, neurophysiological, and neuropsychological effects of using chronic bilateral pallidal high-frequency deep brain stimulation (DBS) in a case of disabling camptocormia. Deep brain stimulation electrodes were implanted stereotactically to target the globus pallidus internus (GPi) bilaterally. Local field potentials (FPs) were recorded using the DBS electrodes and concurrent abdominal flexor electromyography (EMG) potentials during camptocormic episodes.

Thalamotomy versus thalamic stimulation for multiple sclerosis tremor.

Disabling intractable tremor occurs frequently in patients with multiple sclerosis (MS). There is currently no effective medical treatment available, and the results of surgical intervention have been variable. Thalamotomy has been the mainstay of neurosurgical therapy for intractable MS tremor, however the popularisation of deep brain stimulation (DBS) has led to the adoption of chronic thalamic stimulation in an attempt to ameliorate this condition.

The costs and benefits of deep brain stimulation surgery for patients with dystonia: an initial exploration.

Objectives.  To perform a preliminary cost-utility and cost-benefit of deep brain stimulation (DBS) in the treatment of dystonia, Materials and Methods.  We conducted a prospective study of 26 patients undergoing DBS for the treatment of dystonia.

Effect of GPi DBS on functional imaging of the brain in dystonia.

Five patients with idiopathic dystonic conditions, treated successfully with deep brain stimulation (DBS) of the globus pallidus internus (GPi), were studied using single-photon emission tomography (SPET) in order to evaluate brain perfusion in the presence and absence of DBS. Comparison was made between the "on" and "off" DBS scans on an individual basis and also as part of a group analysis. Whilst the individual data suggested great regional variation in cerebral perfusion between individuals, the results of the group analysis revealed several topographically similar areas of the brain where relative hyperperfusion in the absence of DBS was common to all patients.

Deep brain stimulation for generalised dystonia and spasmodic torticollis.

Dystonia appears distinct from the other tremulous disorders in that improvement following deep brain stimulation frequently appears in a delayed and progressive manner. The rate of this improvement and the point at which no further progress can be expected are presently unknown. The establishment of these parameters is important in the provision of accurate and relevant prognostic information to these patients, their carers, and their treating physicians.

Senile chorea treated by deep brain stimulation: a clinical, neurophysiological and functional imaging study.

We report on a patient with senile chorea, treated with deep brain stimulation of the left globus pallidus internus and subsequently the left ventralis oralis posterior nucleus of the thalamus. Deep brain field potential recordings and functional imaging using single photon emission tomography enabled us to suggest pathophysiological mechanisms for the symptoms.

Reversal of hypertonic co-contraction after bilateral pallidal stimulation in generalised dystonia: a clinical and electromyogram case study.

In a patient of generalised dystonia treated with bilateral pallidal stimulation, serial surface EMGs recorded from the neck muscles during alternating head movements revealed progressive reduction in hypertonic activity and reversal of co-contraction to reciprocal contraction, which preceded clinical improvement.

Increased risk of lead fracture and migration in dystonia compared with other movement disorders following deep brain stimulation.

Deep brain stimulation (DBS) therapy is a continually expanding field in the functional neurosurgical treatment of movement disorders. However, the occurrence of adverse events related to implanted hardware cannot be overlooked. We report on a specific feature noted in our experience of DBS-related complications.

Failure of chronic pallidal stimulation in dystonic patients is a medical emergency.

Deep brain stimulation (DBS) therapy is a continually expanding field of functional neurosurgery for the treatment of movement disorders and neuropathic pain. However, occurrence of adverse events related to implanted hardware cannot be ignored, particularly in patients with dystonic conditions. We report on two such patients who required emergency hospital admission and pulse generator re-implantation following sudden and unexpected cessation of DBS effectiveness resulting from battery failure.