Search

Alcohol neuropathy has been thought to involve decreased nerve function following chronic ethanol consumption. However, there is no reliably successful therapy, largely due to a lack of understanding of the central underlying mechanisms. The aim of this study was to investigate the mechanisms that contribute to the neuropathic pain-like state induced by chronic ethanol treatment in rats. Rats were chronically treated with ethanol diet (1.25-5% of ethanol) for over 70 days. Mechanical hyperalgesia was observed during ethanol consumption and even after ethanol withdrawal. Under these conditions, an immunohistochemical study showed an increase in metabotropic glutamate receptor 5 (mGluR5) immunoreactivity in the superficial spinal dorsal horn of chronic ethanol-fed rats. Furthermore, immunoblot analysis revealed that the protein level of mGluR5 was clearly increased following chronic ethanol consumption. These findings support the idea that the increased levels of mGluR5 in the spinal cord may be, at least in part, involved in the induction of ethanol-dependent neuropathic pain-like state.

Neurophysiological study of all links of afferent somatosensory systems in neuropathies of different genesis was conducted. Patients with alcoholic (APN) and diabetic (DNP) polyneuropathies have been examined and selected as follows: 19 patients with intensive spontaneous pain syndrome (scoring over 6 on VAS); 20--without pain; 22 patients with allodiny caused by neuropathic pain and 38--without allodiny. Control group included 20 healthy subjects. Symptom complex of pain syndrome encompassed pronounced disorders of cutaneous sensitivity, minus symptoms in deep sensory sphere and high depression level. Neurophisiological appearances of spontaneous pain syndrome in APN and DPN are characterized by generalized mixed damage of peripheral sensible nerves and of 1 beta-afferents of H-reflex arch. Insufficiency of function of pain control system was mainly of deafferent character. Allodiny and spontaneous pain syndrome are reciprocally combined, the former being distinguished by involvement in pathology of 1-[symbol: see text] fibers (motor nerves and efferent links of H-reflex).