Biomedical subjects

W Tackmann

Publications and source records attributed to W Tackmann.

At least 37 records · Page 2Linked to original sources

PubMed1985

Homozygous hypobetalipoproteinaemia and phenylketonuria.

Two patients, aged 0.1 and 2 years, with homozygous hypobetalipoproteinaemia, one with PKU in addition are described. The clinical evaluation showed no neurologic abnormalities. Treatment with a fat-reduced, protein and carbohydrate-enriched diet was combined with vitamin A and E supplementation, according to the suggestions for classical abetalipoproteinaemia. In the patient with PKU the protein intake was increased by using a phenylalanine-free, amino acid mixture. Only by this, were normal growth and weight gain achieved.

Adult↗

PubMed1985

[Motor, sensory electroneurographic and electromyographic results as well as somatosensory evoked potentials in comparison to clinical findings following nerve suture].

A group of 37 patients (total 41 nerves) with a traumatic transection of median or ulnar nerves at the wrist were reinvestigated clinically and electrophysiologically 4-59 months after primary or secondary suture or grafting. Clinically there was no relation between the time after the operation, and sensory recovery determined according to the schedule of Nicholson and Seddon (1957), two-point discrimination, vibration threshold. There was also no relationship between the time after suture, and the motor latencies as well as amplitudes of evoked muscle action potentials from the abductor pollicis brevis or hypothenar muscles. In sensory nerve fibres there was a statistically significant increase of the maximum amplitude and of the cumulative amplitude during the period after operation, due to an increasing number of regenerated nerve fibres. Sensory nerve conduction velocities showed no relation to the time after suture. Cumulative amplitudes were significantly related to two-point discrimination and to restitution of sensibility. As indicated by the great scatter, however, this parameter is merely a moderate predictor for the degree of clinical recovery. Somatosensory evoked potentials can be helpful in some cases to indicate nerve regeneration when nerve action potentials in peripheral nerves cannot be recorded. However, latencies and amplitudes of the individual peaks did not reveal any relationship to either clinical findings or to period of time after operation. Needle electromyography also yielded highly variable findings. A constant finding was a persistent loss of motor units. Most of these were increased sin size, as indicated by prolonged duration of their action potentials during slight voluntary effort.

Adolescent↗

PubMed1985

[Clinical aspects and diagnosis of acoustic neurinomas].

The application of microsurgical techniques for the removal of acoustic neuromas has evidenced greatly improved postoperative results. Therefore the early detection of an acoustic neuroma is a special need for every neurologist. The development of new electrophysiological and radiological procedures now allows a far better approach in the diagnosis of acoustic neuromas. Brain stem auditory evoked potentials as well as acoustic reflex testing have shown to be rather sensitive tools in the diagnosis of retrocochlear pathology. Other electrophysiological procedures have been widely replaced by these techniques. Gasmeatocisternography in combination with cranial computed tomography is the method of choice in the detection of small acoustic neuromas. The current status in the application of different techniques for the diagnosis of acoustic neuromas is reviewed.

Audiometry, Pure-Tone↗

PubMed1979

Evoked potentials in neuronal ceroid lipofuscinosis.

Nerve conduction, EEG, visual evoked potentials, electroretinograms and somatosensory evoked potentials were investigated in 3 children with the Bielschowsky-Jansky-type and in 1 child diagnosed as Spielmeyer-Vogt-type of neuronal ceroid lipofuscinosis. Electroretinographic responses were abolished in all of them. Electroencephalograms showed high amplitude, irregular delta-theta activity and spike- or polyspike-wave discharges without localized preponderance. As a characteristic feature for the Bielschowsky-Jansky type grossly enlarged evoked responses to single light flashes were recorded. Somatosensory evoked potentials were increased in amplitude in 2 patients. Myoclonic jerks of the pyramidal type could be elicited by electrical stimuli to the median nerve. The possibility to differentiate certain neurometabolic disorders of childhood by simple electrophysiological parameters is discussed.

Cerebral Cortex↗

PubMed1979

Diagnostic validity for different components of pattern shift visual evoked potentials in multiple sclerosis.

Visual evoked potentials, elicited by checkerboard-pattern reversal were recorded from multiple sclerosis patients with different probabilities of diagnosis. Latencies and amplitudes of the different components were analyzed for diagnostic validity. It was demonstrated that the latency of the main positive peak (P2) was the most sensitive parameter. But in a few cases determination of P2 latency and interocular difference of this peak alone failed to detect involvement of the visual system. Additional evaluation of absolute latencies, asymmetries in latency and amplitudes of other components would give evidence in predicting abnormalities of the visual pathways.

Adolescent↗

PubMed1979

[Basic conditions for electromyographic examination. Part I: EMG, nerve conduction velocity and test of motor end-plate function (author's transl)].

The purpose of the following contribution is to give a survey about the basic conditions of electromyographic examination. The necessary apparatus will be described as well as the course of examination. Moreover the parameter for the evaluation will be explained together with exogenous falsifying influences. This contribution is thought to be a guide for orientation to improve electromyographic recording and evaluation.

Electric Stimulation↗

PubMed1979

[Neurological symptoms in a-beta-lipoproteinemia (author's transl)].

Abetalipoproteinaemia (Bassen-Kornzweig syndrome), an autosomal recessive inherited disease, up to now has been described in 53 instances in the world literature. Neurological symptoms were reported in 34 of them. Ataxia, loss of proprioceptive sensation, and areflexia characterize this disorder, resembling Friedreich's ataxia. Other signs, which may be inconstantly found, are weakness, diminution of cutaneous sensation, and in the later course an atypical retinitis pigmentosa. Laboratory examinations show acanthocytosis, lowered concentrations of serum cholesterol, triglycerides and phospholipids and as the pathognomonic feature of this disease absence of beta-lipoproteins. Reduced serum concentrations of fat soluble vitamin are secondary effects of this metabolic disorder. In a few cases there are connections to familial hypobeta-lipoproteinaemia, which is autosomal dominantly inherited. Therapeutic trials with a controlled dietary intake of fat may cause an improvement of clinical symptoms, additional doses of fat-soluble vitamin, if given during the early stages of the disease are said to prevent from retinopathy but do not seem to influence the development and course of neuropathy.

Abetalipoproteinemia↗

PubMed1979

[Cortical somatosensory evoked potentials in patients with thalamic lesions (author's transl)].

The influence of thalamic lesions on the configuration of the somatosensory evoked cortical potential is studied on the basis of two own observations and of the literature. An increased latency of the initial component N1 and a reduced voltage in the beginning of the potential recorded on the side of the thalamic lesion are the most frequent findings in patients with thalamic syndromes. Most dramatic changes of the evoked response occur in cases with lesions of the VPL nucleus and with proprioceptive sensory disturbances. Considering the morphological basis of the normally configurated potential possible developmental mechanisms of the pathological evoked response are discussed.

Adult↗

PubMed1978

[The motor response potential after distal and proximal stimulation: studies in healthy volunteers and in polyneuropathies (author's transl)].

Muscle responses evoked distally and proximally were recorded in median and in peroneal nerves from controls and patients with polyneuropathies of different origin. The following parameters were studied in the individual muscle response: 1. the amplitude of the potential, measured peak to peak, 2. the amplitude of the negative phase, 3. the total duration of the potential, 4. the duration of the negative phase, 5. the area covered by the negative phase. Results of the proximal measurements were divided by those of the distal records. Distal motor latencies and nerve conduction velocities were also determined. In controls a loss of amplitude of 10-15% and an equal reduction of the area covered by the negative phase was noted in proximally evoked responses and the duration of the negative phase was increased by 2-7% when compared with distal measurements. In some polyneuropathies these parameters showed significantly pathological changes, although distal motor latency, amplitude and nerve conduction velocity were still within the normal range. Comparison of distally and proximally evoked muscle potentials may thus lead to further information about the mode of conduction in altered motor nerves.

Adolescent↗

PubMed1977

Correlation of electrophysiological and quantitative histological findings in the sural nerve of man. Studies on alcoholic neuropathy.

Electrophysiological results of sural nerve conduction studies were compared with quantitative histological data from the same nerve in 27 patients with alcoholic neuropathy. Diminution of amplitude and/or conduction velocity of the main component was seen in 14 nerves. Minimum nerve conduction velocity, which was studied in 11 nerves, was lowered in eight cases. Histological investigations revealed that nerve fibers of different diameter were involved to a variable extent, so at least four different types of fiber loss could be distingusihed. Relation of nerve conduction velocity to external fiber diameter revealed a conversion factor within normal range in 13 nerves, indicating axonal degeneration. A borderline value was found in four of the nerves, teased fiber studied showed demyelination in three nerves and axonal degeneration in one of the four. It was impossible in 10 nerves to relate external fiber diameter to nerve conduction velocities of the different components of the potential caused by demyelination or extensive remyelination.

Adult↗

PubMed1977

Nerve conduction velocity of small components in human sensory nerves. Studies in normal and diseased nerves.

Slow conducted components of sensory nerve action potentials were investigated in median and in sural nerves of controls and in patients with peripheral nerve diseases. In the normal group the slow components showed no relation to age which is in contrast to the maximum velocity. In both the median nerve and sural nerve of about 20% of the patients with neuropathy exclusively a decrease of the conduction velocity of slow components was found, the other investigated parameters were normal. Possible causes are an alternation of the myelin sheath or changes in the properties of the nodal gap membrane.

Action Potentials↗

PubMed1976

Quantitative histometric studies and relation of number and diameter of myelinated fibres to electrophysiological parameters in normal sensory nerves of man.

Quantitative histometric investigations were made in 6 radial and in 12 sural nerves of subjects without signs of a neuromuscular disorder. Nerve conduction velocities and amplitudes were studied on the same nerves. A linear relationship between the nerve fibre diameter and the conduction velocity of the fastest fibres was found. The conversion factor had a mean of 4.67, S.D. 0.16 in the radial nerves and an average value of 4.55, S.D. 0.19 in the sural nerves. Correlating the amplitudes of the compound nerve action potentials and the fibre number there was a linear proportionality between the log10 of number of fibres with a diameter of 11 mum and more, and the amplitude.

Action Potentials↗

PubMed1974