Background: The neurophysiological examination provides valuable pathophysiological information for the diagnosis, prognosis, and therapy of patients with polyneuropathy (Fuglsang-Fredriksen A., Pugdahl K. Clin Neurophysilogy 122: 440-455, 2011). Nerve conduction study (NCS) is the most objective and reliable measure of peripheral nerve function and is considered the gold standard for the diagnosis of most neuropathies. Aim of the study: To evaluate the clinical usefulness of nerve conduction study (NCS) in the differentiation between axonal and demyelinating polyneuropathies. Methods: In the present study, 125 patients with polyneuropathy were studied ranging age from 9 to 79 years. Thirtysix patients were classified as axonal polyneuropathy, 23 patients as demyelinating, and 9 as mixed, while 57 patients were classified as neuropathic. Nerve conduction study (NCS) and electromyography (EMG) were performed using Nihon Kochden electromyography machine with surface recording and stimulating electrodes. Results: There is statistically significant linear correlation between reduction in sensory nerve action potential (SNAP) amplitude and decrease in sensory conduction velocity (SCV) of median and ulnar nerves. Also, there is statistically significant inverse correlation between reduction in compound motor action potential (CMAP) amplitude and increase in distal motor latency (DML). There is statistically significant linear correlation between reduction in compound motor action potential (CMAP) amplitude and decrease in motor conduction velocity (MCV). There is statistically significant linear correlation between reduction in compound motor action potential (CMAP) amplitude and decreased grade of power in both axonal and demyelinating polyneuropathy; statistically significant linear correlation was found between decrease in conduction velocity and decrease in grade of power. Conclusion: The present study demonstrates significant correlation between amplitude reduction and conduction slowing in demyelinating as well as axonal polyneuropathy.

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Background Idiopathic polyneuropathy is an asymmetrical, length-dependent neuropathy in which neurophysiology demonstrates axonal damage involving large fibers, along with insidious onset and slow progression over 6 months, with no identified etiology in spite of thorough investigations. This study aimed to evaluate the diagnostic role of clinical, electrophysiological, and histopathological studies in patients with idiopathic polyneuropathy. Methods Case–control study included 20 patients with clinical and neurophysiological evidence of sensory or sensory–motor neuropathy with no apparent etiology after laboratory investigation were recruited from 127 patients with sensory–motor neuropathy of unknown etiology (the patients group). Twenty apparently healthy individuals, age- and sex-matched, with no neuropathy symptoms (the control group), were recruited from the Neurology Clinic of Al-Azhar University, Assuit. Results Age of onset of patients with idiopathic polyneuropathy (44–70) years, duration of illness (1–6) years, 60% had painful neuropathy, diagnostic neuropathic pain questioner (DN4 score) (5–7), abnormal pin brick (80%), abnormal vibration (90%), abnormal fine touch (75%), distal weakness (70%), and lost ankle reflex (90%). In the control group, there were substantial differences with respect to prolonged latency, diminished sympathetic skin response amplitude, and significant intraepidermal nerve fiber density reduction in skin biopsy cases. In diagnosing idiopathic polyneuropathy, the specificity and sensitivity of sympathetic skin response were (80–86)% and (81–89.5)%, respectively, whereas those of diminished intraepidermal nerve fiber density were (92.5%) and (97.5%), respectively. Conclusion The assessment of intraepidermal nerve fiber density had an important good diagnostic role in cases presented with polyneuropathy.

Background: Chronic idiopathic polyneuropathy is asymmetrical, axonal damage involving large fibres of insidious onsets is disclosed in neurophysiologic long-dependent neuropathy and slowly progressive course over a minimum of six months without aetiology can be identified despite the appropriate investigations. This research was designed to investigate idiopathic polyneuropathy individuals. Methods: The comparative patient control research comprised 20 patients selected from 127 polyneuropathic and 20 matching age or sex controls from the Al-Azhar University Neurology Clinic at Assuit Hospitals, April 2019 to May 2021. Results: Age of onset of idiopathic polyneuropathy patients (47-73), length of disease (1-6) years (60%), DN4 score (5-7), abnormal pine brick (80%), abnormal vibrations (90%), abnormal fine touch (75%), distal weaknesses (70%) losing ankle (90%) and wasting (20 percent ). This represents significant variations in the amplitude of decreased motor-action compounds and the reduced speed of median,ulnar, tibial peroneal nerves across the tested groups. Significant variations between tibial and peroneal tissues are also seen in prolonged distal latency, decreased sensory amplitude and extended latency between sensory (median, ulnar, and sural) nerves. The delay differences and a reduced amplitude of sympathetic cutaneous response across the investigated groups are significant. There are also substantial differences in the intraepidermal nerve fibre density decrease in skin biopsy from the distal leg between idiopathic polyneuropathical patients and control groups. Conclusion: Intraepidermal nerve fibre density in skin biopsy is responsive to idiopathic polyneuropathy than standard neurophyological investigations.

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