Biomedical subjects

W G Friedli

Publications and source records attributed to W G Friedli.

10 recordsLinked to original sources

PubMed1992

[Bell's palsy--a field of controversies. I. Etiology and pathogenesis--diagnostic delimitation--prognosis].

Facial paresis as a sign or symptom is caused by a number of different conditions. Although being the most common type of facial paresis, Bell's palsy represents a diagnosis of exclusion characterized by an acute, unilateral peripheral facial palsy of unknown etiology. Clinical features and laboratory findings are considered with regard to their diagnostic as well as prognostic significance.

Adolescent↗

PubMed1992

Lipoma of the cauda equina selectively involving lower sacral roots. Case report.

A 44-year-old male patient suffering from sexual and voiding dysfunction did not exhibit any sensorimotor deficit except for a lax anal sphincter with loss of the bulbocavernosus reflex (BCR). The absence of both the electrically induced BCR and cortical evoked responses to stimulation of the dorsal penile nerve as well as partial denervation of the pelvic floor musculature suggested damage to the lower sacral roots. The site of the lesion as indicated by electrophysiological findings was confirmed by computerized tomography and magnetic resonance imaging. The operation revealed a lipoma involving a few cauda fibers which produced a distension in the region of the conus medullaris.

Adult↗

PubMed1990

Electrocutaneous reflexes and multimodality evoked potentials in multiple sclerosis.

Electrical stimulation of the digital nerves of the index finger produces changes in the EMG signal during steady voluntary contraction of the first dorsal interosseous muscle. This electrocutaneous reflex (ECR) was studied in 90 patients classified into different categories according to diagnostic criteria for multiple sclerosis. In addition, pattern reversal visual evoked responses (VER), brainstem auditory evoked responses (BAER) as well as spinal and scalp recorded somatosensory evoked potentials (SSEP) were investigated by stimulating both the index finger and the posterior tibial nerve. The reflex response was altered uni- or bilaterally in 56 per cent of the patients and the abnormalities of the ECR were related to the categories of diagnostic probability. Pathological results were found in 28 per cent of the hands without clinical evidence of sensorimotor deficit. Although ECR abnormalities were often associated with clinical signs, significant correlation was found only with hyperreflexia and/or increased muscle tone in the corresponding upper limb. Pathological ECR were more common than pathological SSEPs with finger stimulation recorded under identical stimulus conditions. Fewer abnormalities were found by ECR testing than with VER, but the proportion of abnormal ECR was higher than that of BAER. ECR provides a valuable supplement to existing electrophysiological procedures for detecting lesions in the central nervous system.

Adolescent↗

PubMed1989

[Diagnostic aspects of myasthenia gravis].

Myasthenia gravis is described on the basis of both the physiological mechanisms of neuromuscular transmission and the current knowledge of the pathogenesis of the disease. The different laboratory tests in use are considered with regard to their diagnostic significance, in addition to the clinical features of the disease. Differential diagnosis has to include myasthenic syndromes of different origin, periodic paralysis, diseases of the peripheral motor neuron as well as certain myopathies.

Biopsy↗

PubMed1988

[Plexus lesions, rhabdomyolysis and heroin].

Of five patients admitted to hospital after heroin injection, three had injected heroin exclusively, and two had taken several other drugs orally in addition to heroin. All patients developed severe rhabdomyolysis as well as lesions of the brachial or lumbosacral plexus or both, affecting more than one extremity in three cases. The neurologic symptomatology occurred with variable latency after heroin injection. Additionally, one patient presented a bilateral compartment syndrome in the lower extremities. While CK values normalized within 2-3 weeks, even severe pareses markedly improved within only a few months. Current knowledge of these complications is summarized from the literature and several pathophysiological hypotheses are derived from the present case histories. In the light of theoretical considerations and our own observations of comparable clinical features in patients who had not consumed opiates, the question arises whether the syndrome is heroin specific or not.

Adolescent↗

PubMed1988

Postural adjustments associated with rapid voluntary arm movements. II. Biomechanical analysis.

Normal subjects performed bilaterally symmetric rapid elbow flexions or extensions ("focal movements") while standing. Specific patterns of electromyographic activity in leg and trunk muscles ("associated postural adjustments") were seen for each type of movement. The biomechanical significance of these postural adjustments was analysed by means of the ground reaction forces and motion of the various body segments. Experimental data were compared with that from a theoretical model of the body consisting of a six segment kinetic chain with rigid links. Distinct patterns of the ground reaction forces with elbow flexion were opposite in direction to those seen with elbow extension. Movements of the various body segments were small and specific for a certain focal movement. Dynamic perturbations arising from the arm movement in an anteroposterior direction were found to be compensated by postural adjustments, whereas vertical perturbations were not compensated. The muscular activity acting about different joints in the different movements was found to correlate with the predictions of activity needed to compensate for net joint reaction moments arising from the focal movement. Motion of the various body segments could be understood as resulting from the interplay of the net reaction moments and the net muscular moments at the different joints. Dynamic postural requirements are accomplished by a precise active compensation initiated before the focal movement.

Adult↗

PubMed1987

Detection threshold for percutaneous electrical stimuli: asymmetry with respect to handedness.

Sensory strength-duration curves were obtained using percutaneous true square-wave pulses ranging from 0.1 to 20.0 ms produced by an isolated constant current stimulator. In 119 healthy volunteers sensory thresholds were measured bilaterally by stimulating the distal phalange of the little finger. In order to examine the relationship of sensory threshold and handedness the latter was assessed by means of the Edinburgh Inventory. An asymmetry of sensory threshold was found for all the subjects and this was more pronounced with shorter stimuli. Of right-handers tested 73.5% had a lower threshold on the left side while 70.8% of left-handers had a lower threshold on the right side. Although threshold asymmetry is associated with handedness this is not necessarily due to cerebral lateralization.

Adolescent↗

PubMed1987

Electrocutaneous reflexes in upper limbs--reliability and normal values in adults.

The present study provides information as to both the range of normality and reliability of the electrocutaneous reflex (ECR) in upper limbs as a routine diagnostic procedure. Measurements were performed on 70 adult volunteers under optimized and standardized conditions. The mean latency was 40.3 +/- 3.2, 50.9 +/- 3.5 and 65.8 +/- 5.8 ms for E1, I1 and E2, respectively, and 21.9 +/- 1.6 ms for N22 of the cortical somatosensory-evoked potentials as recorded under identical stimulus conditions. Arm length represented the most important factor of interindividual variability while age was of minor and sex of no importance after normalization of the latencies for arm length.

Adult↗

PubMed1984

Strength-duration curve: a measure for assessing sensory deficit in peripheral neuropathy.

By using an isolated constant current stimulator producing true square-wave pulses, sensory strength-duration curves were obtained at various sites by percutaneous electrical stimulation. Strength-duration curves derived from normal groups were compared to those of patients with peripheral neuropathy. Stimulus strength at sensory threshold was shown to be a reproducible measure of sensory deficit, increasing parallel to the degree of axonal failure found by conventional methods. This may be useful as a complementary method in assessing peripheral neuropathy.

Adult↗

PubMed1984

Postural adjustments associated with rapid voluntary arm movements 1. Electromyographic data.

Normal subjects made bilaterally symmetric rapid elbow flexions or extensions ("focal movement") while free standing or when supported by being strapped to a firm wall behind them (different "postural set"). In some trials a load opposed the movement two thirds of the way into its course. Electromyographic activity in leg and trunk muscles ("associated postural adjustments") demonstrated specific patterns for each type of movement. Activity in these muscles began prior to activity in the arm muscles and demonstrated a distal-to-proximal order of activation. The EMG patterns were characterised by alternating activity in the antagonist pairs similar to the triphasic pattern seen in the arm muscles. When the movement type was changed change of the pattern of the postural muscles occurred over several trials. It is concluded that the associated postural adjustments are pre-programmed motor activity linked to the focal movement, specific for the focal movement including anticipated events and the postural set.

Adult↗