[Cortical somatosensory evoked potentials following median and tibial nerve stimulation in multiple sclerosis; relation to sensory disorders and duration of the disease]. / Kortikale somato-sensorisch evozierte Potentiale nach Medianus- und Tibialis-Stimulation bei multipler Sklerose; Beziehung zur Sensibilitätsstörung und Dauer der Erkrankung.

In 40 patients with multiple sclerosis, 11 of whom presented with their first disease manifestation, cortical somatosensory evoked potentials following median and tibial nerve stimulation were examined. 45 percent of the patients with first manifestation had at least one pathological SEP, while 79 percent of the patients with longer course of the illness showed pathological SEPs. The group of patients with first manifestation differs significantly in this aspect from the group of those patients with longer duration of the illness. The occurrence of pathological SEPs was associated significantly more often with impairment of joint position and vibration sense, than with nonspecific sensory disturbances. Not only in some patients with first manifestation, but also in some patients with long, but mild courses, there were nonspecific sensory disturbances in association with normal SEPs. One should not underestimate the complaints in such cases.

[Cortical SEP of early and intermediate latency following stimulation of the median and tibial nerves in disseminated encephalomyelitis--relation to findings in cerebral nuclear magnetic resonance tomography]. / Kortikale SEP früher und mittlerer Latenz nach Medianus-und Tibialisstimulation bei Encephalomyelitis disseminata--Beziehung zu Befunden der zerebralen Magnetischen Resonanztomographie.

Cortical somatosensory evoked potentials following median and tibial nerve stimulation were compared with the findings in nuclear magnetic resonance imaging in 23 patients with multiple sclerosis, 11 of whom presented with their first disease manifestation. Pathological SEP's were found in 55 percent of patients presenting with first manifestation and in 83 percent of those with a longer duration of illness. Except for one patient with spinal cord involvement only, in whom no cerebral lesions were seen, all patients showed periventricular lesions in NMR. Between 1 and 16 (4.7 +/- 3.5) non-periventricular isolated lesions were found per patient. Cortical SEP's are affected differently by lesions within the thalamocortical system: Plaques within the internal capsule may result in SEP-changes as seen in other causes of damage to this region. However, lesions in this strategic area may also remain clinically and electrophysiologically silent. Nevertheless, the size of the lesion seen in NMR is not relevant, as observed in one case of an extensive plaque within the centrum semiovale. Correlations between the lesions near the parietal cortex or within the parietal white matter and SEP-component alterations of intermediate latency (N55, N75) remained insignificant.

[Habituation of the human orbicularis oculi reflex]. / Habituation des menschlichen Orbicularis oculi-Reflexes.

The habituation of the electrically (stimulation of the supraorbital nerve) elicited orbicularis oculi reflex (OOR) was investigated in 51 healthy volunteers (average age: 39 years). Ten reflex responses were registered from the left and right side including eyes open, eyes closed, and during task performance. The stimulus frequency was 1/s. The data were transmitted to an LAB 8e computer and statistically treated. The influence of stimulus frequency on habituation was examined separately. The following parameters of habituation as devised by Thompson and Spencer were demonstrable: dishabituation, habituation of dishabituation, spontaneous recovery, and influence of stimulus intensity. The analysis of habituation during task performance with the Kruskal-Wallis test revealed a statistically significant decrease of habituation. The early reflex component (R1) amplitudes increased during the 1/s stimulation. This effect was also statistically significant. The increase in R1 amplitude during 1/s stimulation was interpreted as "facilitation".

Failure to show a correlation between serum parathyroid hormone, nerve conduction velocity and serum lipids in hemodialysis patients.

The proposed role of parathyroid hormone as an important agent for the development of certain uremic complications could not be confirmed in studies correlating, in dialysis patients, the nerve conduction velocity and the serum lipids with four different immunochemically defined forms of circulating parathyroid hormone. To a certain extent the data invalidate suggestions which favor parathyroid hormone as a leading uremic toxin.

[Alteration of the early R1-component of the blink reflex in coma: topographical and prognostic value (author's transl)]. / Veränderungen des Blinkreflexes (Orbicularis-oculi-Reflexes) im Koma: lokalisatorische und prognostische Bedeutung.

Alteration of the early component of the blink reflex (delayed latency or abolished reflex) is considered to be relatively specific for pontine lesions (multiple sclerosis, vacular lesions of the brain-stem, neoplasms, syringes); provided, the trigeminal and facial nerve are unaffected. In comatose patients the electrically, by stimulation of the supraorbital nerve elicited blink reflex was super-imposed (50 or 100 responses) with the LAB 8/e-computer (off-line). It was found that the R1 component was abolished even in cases with supratentorial lesions and secondary brain-stem alterations, while no specific pontine lesions were demonstrated by neuropathological examination. Therefore it is suggested that delayed or abolished blink reflexes in coma due to supratentorial mass lesions are not concluslive for pontine lesions: they rather may reflect an unspecific secondary brain-stem alteration. Recording of the EEG reveals that in some cases the extinction of the early blink reflex precedes corresponding EEG alterations; this may be a matter of prognostic value.

[Basic conditions for electromyographic examination. Part I: EMG, nerve conduction velocity and test of motor end-plate function (author's transl)]. / Grundbedingungen für die Durchführung elektromyographischer Untersuchungen. Teil I: EMG, Nervenleitgeschwindigkeit und Endplattenbelastung.

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.