Biomedical subjects

Pierre R Burkhard

Publications and source records attributed to Pierre R Burkhard.

25 records · Page 2Linked to original sources

PubMed2003

[Parkinson disease: description of an interdisciplinary program of functional group rehabilitation].

Neurorehabilitation for Parkinson's disease, in the form of physical and occupational therapy, has long been advocated but also seriously questioned with respect to its specific content, its mechanisms, its efficacy and its costs. Many factors may be put forward to explain the lack of consensus surrounding these interventions, including the multiplicity of different programs proposed, the scarcity of controlled studies available and the inadequacy of some assessment methods used. In this article, we describe a new neurorehabilitation program for Parkinson's disease which is characterized by some original features. In particular, the specific functional patients' needs were taken into account instead of the symptoms related to the condition, therapeutic interventions favoured a multidisciplinary approach, patients trained in groups rather than individually, the program combined different methods and was continuously evolving over time, and finally we used simple but goal-oriented measurement methods to assess efficacy. The study included 22 patients. Statistically significant positive results were obtained by the end of the program, suggesting that the program in its current form was indeed capable to generate a functional benefit of sufficient magnitude to be objectively detected by the assessment methods used. In our opinion, our data emphasizes the usefulness of specific neurorehabilitation programs in the global management of Parkinson's disease.

Aged↗

PubMed2003

[Kinesiologic analysis of gait and abnormal movements].

Gait disorders, postural instability and movement disorders, such as tremor, chorea or dystonia, are common complaints in day-to-day neurological practice. These conditions are quite difficult to appreciate objectively when relying on clinical observation only, yet a correct assessment of their phenomenology and an accurate measurement of their main characteristics are required to address the questions of both the underlying diagnosis and the functional impairment they may generate. By contrast, kinesiological analyses allow qualitative and quantitative studies of gait, posture and movements and may lead to specific therapeutic interventions. kinesiological analyses, which requires a high-technology laboratory conducted by a trained staff, is based on the sequential or simultaneous use of various and complementary measurement methods, whose choice is problem-oriented. Hence, the use of specific observational analysis, three-dimensional kinematic recordings, poly-electromyography and electro goniometry for the analysis of gait, the use of force plate for the analysis of postural stability and the use of electromyography and multiaxial accelerometers or gyroscopes for the analysis of movement disorders. In the present article, we review the particular features of these measurement tools and the clinical usefulness of their routine use illustrated by case reports.

Dyskinesias↗

PubMed2003

[Unusual causes of gait disorders].

Gait disorder is a common complaint in general practice, in particular in the elderly, and more than one cause frequently interact to produce various abnormalities of gait, including neurological, orthopedic, rhumatologic or ophthalmologic conditions, among others. The most frequent etiologies of gait impairment include sensory deficits, cervical myelopathy, vascular encephalopathy, parkinsonism and normal pressure hydrocephalus. In a particular individual, several of them may contribute to alter gait and, as a general rule, the treatment of these well-established conditions is generally considered difficult. Besides them, a number of rare and underrecognized neurological conditions may also produce a gait disorder as their initial, main or exclusive feature, including dopa-responsive dystonia, stiff-person syndrome, orthostatic tremor, primary progressive freezing gait and cursive epilepsy. In this review article, the clinical, therapeutic and other characteristics of these conditions are revisited and a typical illustrative case is reported for each. Since most of these conditions are responsive to specific treatments, we believe that a better knowledge of these unusual forms of gait disorder may allow general practitioners to identify them more accurately, to assess them and to improve therapeutic strategies.

Adult↗

PubMed2003

[Quiz case].

Explore the source record for details and available documents.

Humans↗

PubMed2002

Voluntarily simulated tremor in normal subjects.

Based on the hypothesis that rhythmical, tremor-like movements produced by normal subjects might be influenced by similar central oscillatory neuronal networks believed to determine the features of the pathologic tremors of Parkinson's disease (PD) or Essential Tremor (ET) patients, we examined the neurophysiological characteristics of a tremor mimicked by normal volunteers and compare this data with those from PD or ET tremors. Voluntarily simulated tremor (VST) was studied in 47 neurologically intact subjects, resting tremor in 10 patients with PD and postural tremor in 10 patients with ET. Using a tremor analysis system based on a solid state gyroscopic sensor sensitive to angular rate, the following parameters were determined: frequency, amplitude (angular displacement) and regularity (Q coefficient of constancy). We also performed an inertial loading test and a test-retest analysis. Nearly all normal subjects were able to simulate a tremor that was indistinguishable, in frequency and regularity, from that of PD or ET, although the amplitude was significantly higher in normal subjects. As in pathological tremors, the VST frequency was significantly influenced by age, but not by gender, handedness or previous knowledge of tremor. Inertial load did not modify the tremor frequency, suggesting that mechanical factors were minor. We also found a logarithmic inverse relationship between frequency and amplitude of the VST. We concluded that VST shares many similarities with pathological tremors. It is therefore possible that all tremors are somehow influenced by the same central oscillators which may become disinhibited and clinically apparent in pathological conditions such as PD or ET.

Aged↗

PubMed2002

Clinical significance of basal ganglia alterations at brain MRI and 1H MRS in cirrhosis and role in the pathogenesis of hepatic encephalopathy.

In hepatic encephalopathy, a progressive and diffuse impairment in brain function is associated with gradual alterations that can be detected by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS). In some patients, a variety of movement disorders suggestive of extrapyramidal impairment points toward basal ganglia (BG) alterations. Accordingly, (i) hyperintensities at MRI predominant in the pallidum, an important region of BG involved in the motor control, (ii) redistribution of cerebral blood flow from cortical areas to BG structures observed using positron emission tomography studies, and (iii) the preferential pallidal location of Alzheimer astrocytosis, all support this hypothesis. In most clinical studies, little if any correlations have been found between cerebral hyperintensities and neurological manifestations. The application of a test designed to evaluate patients with Parkinson's disease (where extrapyramidal signs are typical) showed significant clinical correlations both with pallidal hyperintensity and with choline/creatine ratio at 1H MRS in BG structures. Because of complex neuronal connections between BG and many cortical areas, BG dysfunction may influence the neurocognitive manifestations of hepatic encephalopathy. Similarities between chronic Mn intoxication and cirrhosis suggest common pathophysiological mechanisms including altered dopaminergic neurotransmission, although information in chronic liver failure is limited. Clinical observations are presented regarding the evolution of parkinsonian signs in various situations.

Basal Ganglia↗

PubMed2002

TNF-alpha and psychologically stressful events in healthy subjects: potential relevance for multiple sclerosis relapse.

The authors conducted a prospective and descriptive pilot study in 14 healthy medical students, investigating whether a psychologically stressful event (final examination) may modify serum tumor necrosis factor alpha (TNF-alpha) levels. There was a dramatic and sustained decrease of phytohemagglutinin (PHA)-induced TNF-alpha several weeks before and the day of the examination, followed by a significant increase of TNF-alpha starting the next day. Examination-induced stress was confirmed by both elevated urinary cortisol concentration and significant increase in stress scale scores. Extending these results to patients suffering from multiple sclerosis (MS) leads to the hypothesis that psychological stress may influence the course of MS by substantially altering TNF-alpha levels, and suggests the need for further studies in MS patients exposed to stressful conditions.

Adult↗