Large-fiber neuropathy in distal sensory neuropathy with normal routine nerve conduction.

Near-nerve needle sensory nerve conduction of plantar nerves in 100 patients with distal sensory neuropathy with normal routine nerve conduction (DSN-NNC) found the definite neuropathy pattern (abnormality in more than three of six tested nerves) in 65%, axonal neuropathy in 35%, and the known cause in 37% of patients. Absent or diminished reflexes were a reliable indicator for large fiber neuropathy (LFN). This near-nerve needle plantar nerve study provides useful and unequivocal evidence of its value in identifying neuropathy in DSN-NNC by finding LFN in 65% of patients.

[Effects of age and body height on somatosensory evoked potentials]. / Wplyw wieku i wzrostu na somatosensoryczne potencjaly wywolane.

The influence of age and height on somatosensory evoked potentials (SEP) following median and tibial nerve stimulation was studied. Age correlated with increase of latencies and decrease of amplitudes; exceptionally the amplitude of cortical N20 component increased with age. The central conduction time P31-P40 (tibial nerve stimulation) was longer in elderly subjects, whereas the time N13-N20 (median nerve stimulation) was independent of age. Height showed a positive correlation with latencies and peripheral conduction times; central conduction times (N13-N20 and P31-P40) were independent on height. The correlations of SEP parameters with age and height were expressed quantitatively by regression equations. The presented equations should be treated as a valuable complement to normative data in interpretation of SEP testing results.

[Routine study of somatosensory evoked potentials in healthy persons. I. Median nerve]. / Rutynowe badanie somatosensorycznych potencjalów wywolanych u osobników zdrowych. Czesc I. Nerw posrodkowy.

The study was performed on 62 healthy volunteers (123 nerves) using standard technical parameters. In every case the median nerve was stimulated at the level of II + III fingers and at the wrist. This enabled us to compare potentials evoked by sensory versus mixed nerve stimulation. It has been shown that a reliable evaluation of the somatosensory system is provided by stimulation of mixed nerve. The following montage seems to be the most useful in routine diagnosis. Erb's point - Erb's point, C VII - Fz, Fz - Shoulder, C3,4 - Fz. Additionally, according to clinical situation. C VII - Shoulder and C II - Fz derivations may be used. The Fz - Shoulder derivation enables to record far-field potentials and to control the effect of Fz reference on the waveform of potentials in order derivations. In the study normal values of the main median nerve SEP parameters are presented.

[Routine study of somatosensory evoked potentials in healthy persons. II. Tibial nerve]. / Rutynowe badanie somatosensorycznych potencjalów wywolanych u osobników zdrowych. Czesc II. Nerw piszczelowy.

60 healthy volunteers ranging in age from 15 to 75 years participated in the study. Tibial nerve was stimulated unilaterally or bilaterally at the ankle and SEPs were recorded along the somatosensory pathway. Determination and readability of the potentials were evaluated according to the stimulating and recording method. After unilateral stimulation, the following derivation system was regarded as most useful in routine testing: L4 - Ic (iliac crest), Th12 - Ic, Cz' - Fz, Fz - Shoulder (and, if possible C7 - Fz). When more detailed spinal cord diagnosis is indicated, bilateral stimulation and recording in montage: Th6 - Shoulder, C7 - Shoulder, C7 - Fz, Fz - Shoulder may be helpful. In the study normal values of parameters of the potentials from certain derivations were presented: latencies, amplitudes, peripheral conduction velocities and central conduction times were taken into account. According to our own results (correlative analysis of SEP parameters) and the results of other authors, interpretation of the potentials on various levels of the ascending somatosensory pathway was discussed.