Search PubMed⌕ Search

Biomedical subjects

E Brunko

Publications and source records attributed to E Brunko.

At least 37 records · Page 2Linked to original sources
PubMed1987

Prognostic value of early cortical somatosensory evoked potentials after resuscitation from cardiac arrest.

Short-latency somatosensory evoked potentials (SEPs) were evaluated in patients after cardiorespiratory arrest to study their pattern of recovery in the acute stage of anoxic-ischaemic coma. Fifty consecutive comatose patients were investigated within 8 h after cardiorespiratory resuscitation. In 30 patients no cortical SEPs were recorded and none of the patients recovered cognition. In 20 patients cortical SEPs were recorded and 5 recovered. The different susceptibility of frontal and parietal cortical structures to anoxia was reflected by the dissociated loss of parietal or frontal potentials in 6 patients. Post-mortem pathology in 15 patients confirmed extensive anoxic-ischaemic damage of cerebral and cerebellar cortex and thalamus in patients without cortical SEPs whereas the histological lesions were restricted to Sommer's sector and Purkinje cells in those with preserved SEPs. SEPs thus reflect the extent of brain damage after cardiorespiratory resuscitation.

Adult↗
PubMed1987

Femoral versus peroneal neuropathy in diabetic children and adolescents--relationships to clinical status, metabolic control and retinopathy.

In order to estimate the prevalence of diabetic neuropathy in proximal and distal peripheral nerves, femoral and peroneal motor conduction was evaluated in 61 diabetic children, adolescents and young adults whose type 1 diabetes had become clinically apparent before the age of 14 years. Femoral motor nerve conduction velocity (FMNCV) in diabetic patients (63.8 +/- 10.4 m/sec) was not significantly different from FMNCV in control subjects (65.6 +/- 7.1 m/sec). By contrast, peroneal motor nerve conduction velocity (PMNCV) in diabetic patients (50.2 +/- 6.9 m/sec) was significantly lower than in controls (54.1 +/- 3.5 m/sec). Distal motor weakness, sensory deficit and absent Achilles reflexes were strongly correlated to impaired motor conduction in peroneal and also in femoral nerve. Peroneal nerve abnormality was negatively correlated with HbA1 levels, while femoral nerve abnormality was positively correlated with the presence of retinopathy. This discrepancy is not fully understood. Age and duration of diabetes were unrelated to femoral or peroneal motor nerve conduction velocity. Our data emphasize the frequent occurrence of subclinical proximal neuropathy in diabetic children and adolescents.

Adolescent↗
PubMed1985

Unusual pattern of somatosensory and brain-stem auditory evoked potentials after cardio-respiratory arrest.

Two patients in coma after cardio-pulmonary arrest showed bilateral absence of all brain-stem auditory evoked potentials contrasting with normal brain-stem reflexes and normal somatosensory cortical evoked potentials. In both patients pre-existing dysfunction of peripheral auditory structures could be ruled out. Subsequent neuropathological analysis showed that the anoxic-ischaemic lesions were restricted to Sommer's sector and the Purkinje cells. These unusual data suggest the hypothesis that a severe hypoxic-ischaemic insult may impair cochlear function and interfere with the activation of the intact auditory pathways.

Aged↗
PubMed1984

[Motor conduction in the femoral nerve in healthy subjects].

A method of neurophysiological evaluation of the motor conduction in the femoral nerve is reported. The range of normal values is determined in 20 subjects, 23-82 years old. It is different from the conduction velocity in the peroneal nerve. These data can be useful in the evaluation of lesions of the femoral nerve.

Adult↗
PubMed1976

Maturation of the somatosensory evoked potentials in normal infants and children, with special reference to the early N1 component.

The early components of the somatosensory evoked potential (SEP) were analysed in 39 normal newborns in REM sleep, 35 normal awake children between 1 month and 9 years and 16 normal awake adults. Electrical pulses were delivered at random intervals to fingers of the contralateral hand. The SEP were averaged from several electrodes in the parietal scalp focus and several runs were compared to estimate precise latencies and durations (Fig. 5, 6, 7). The system bandpass extended to 3 kc and many precautions were taken to exclude interference. The limb temperature was carefully maintained at normal value in order to avoid undue slowing of peripheral conduction velocity. The SEP presented markedly increased latencies for near-threshold stimuli (Fig. 3) while becoming even more focalised (Fig. 1). Background data were obtained in order to standardize the parameters for the maturation study (Fig. 2, 3, 4). In the children, the early negative component was found to undergo progressive changes. It was only at the age of about 8 years that the adult pattern was approached (Fig. 8, 9, 10, 11). The duration of the early negative N1 component decreased quite progressively. The latencies to onset and to peak were also shown to follow a highly consistent pattern when the body length of the subjects was taken into account (Fig. 9, 10). By dividing the data by the body length, functions were obtained which could be said to apply to a "standard" individual whose body length did not change from birth to adulthood and remained at one meter. Such plots made it possible to appreciate the true extent of the SEP maturational changes from birth. The quantitative data thus provided should serve as a useful reference for subsequent studies on developmental changes of the brain and for clinical applications to diseased children.

Adult↗
PubMedDate not supplied

The somatosensory central conduction time: physiological considerations and normative data.

The somatosensory central conduction time (CCT) can be measured from the peak of N13 to the peak of N20 (peak CCT) or from the onset of N11 to the onset of N20 (onset CCT). The onset and peak CCT were measured concomitantly in 40 normal subjects and the mean peak CCT was significantly shorter than the mean onset CCT. Records with different reference electrodes (linked earlobes, F3, over the ipsilateral parietal scalp, non-cephalic reference in some subjects) showed no significant latency change of the N11 onset, the N20 onset, the peak and onset CCT in contrast with the significant latency changes of the N13 and N20 peak with different montages. The onset CCT was divided by the onset of the P14 far-field in 2 parameters, the N11-P14 interval predominantly concerned with spinal conduction and the P14-N20 interval which reflected only supraspinal conduction. The onset and peak CCT, the N11-P14 and P14-N20 intervals were not correlated with height or age. Three independent recording sessions over 1 year in 16 subjects showed that the parameters were reproducible. From the physiological point of view the onset and peak CCT are different parameters and the anatomical correlates of both parameters are discussed.

Adult↗
PubMedDate not supplied

The effect of stimulus frequency on post- and pre-central short-latency somatosensory evoked potentials (SEPs).

We assessed the influence of the stimulus frequency on short-latency SEPs recorded over the parietal and frontal scalp of 26 subjects to median nerve stimulation and 16 subjects to digital nerve stimulation. When the stimulus frequency is increased from 1.6 Hz to 5.7 Hz, the amplitude of the N13 potential decreases whereas the P14 remains stable. The amplitude of the N20 is not changed significantly whereas the P22, the P27 and the N30 decrease significantly. In 50% of the subjects 2 components can be seen within the frontal negativity that follows the P22: an early 'N24' component, which is not affected by the stimulus rate, and the later N30, which is highly sensitive to the stimulus frequency. The distinct amplitude changes of the N20 and P22 with increasing stimulus frequency is one among other arguments to show that these potentials arise from separate generators.

Adult↗
PubMedDate not supplied

Dissociation of P13-P14 far-field potentials: clinical and MRI correlation.

P13 and P14 far-field potentials are recorded over the scalp with median nerve stimulation when non-cephalic reference is used to measure somatosensory evoked potentials. The dissociation of these 2 potentials is exceptional. Only 2 cases subsequent to pontine lesions have been described hitherto. We report the case of a 31-year-old woman with a low grade glioma located at the spino-medullary junction who presented a P13-P14 far-field dissociation. This case fully supports the independent nature of the P13 and P14 potential generators.

Adult↗
PubMedDate not supplied

Topographic analysis of the effects of isoflurane anesthesia on SEP.

Isoflurane anesthesia induces a striking increase in the P22 potential recorded over the precentral scalp whereas the amplitude of the N20 is reduced. It is not known whether the increased "P22" enhanced by isoflurane arises from the same generator as the small precentral P22 potential recorded in the normal awake subject. Multi-channel recordings of SEP before and during isoflurane anesthesia were performed in 13 normal subjects. Isopotential topographic maps showed that isoflurane did not change the distribution of the precentral "P22" despite its clear amplitude increase. Our data confirm that isoflurane enhances the precentral P22 and that the enhanced "P22" arises from the same generator as the P22 recorded before isoflurane anesthesia.

Adult↗