Study of Abnormalities of the Nervous System in the Occurrence of Intradialytic Arterial Hypotension

Intradialytic hypotension is a common complication of hemodialysis sessions in patients with chronic renal failure, with an estimated prevalence of 10 to 30%. This hypotensopn is classically defined by a decrease in systolic blood pressure greater than 30 mmHg associated with clinical signs (cramps, abdominal pain, unconsciousness, convulsions). Its repetition is correlated with cardiovascular events, neurological events and excess mortality. Several clinical factors have been proposed to predict the risk of intradialytic hypotension such as age, certain comorbidities (diabetes, ischemic heart disease...), dialysis modalities (hemodialysis), ultrafiltration, conductivity but also alterations of the autonomic nervous system (especially the sympathetic system). In recent years, the study of vegetative functions has been facilitated by the use of SUDOSCAN® (Impeto, Paris, France) which is a simple, non-invasive tool that allows the study of Chlorine conductance directly reflecting the activity of small non-myelinated C fibers that innervate the sweat glands. SUDOSCAN® has shown good sensitivity and specificity in the diagnosis of vegetative damage in diabetic patients and also a good correlation with cardiac autonomic neuropathy. More recently, SUDOSCAN® has shown good sensitivity in the detection of neuropathies small fibers especially in diabetic patients. This sensitivity is comparable to QST-type quantitative tests and the correlation with cardiovascular dysautonomia tests is good. This test, simple and fast realization, does not require the active participation of the patient. There is a good correlation between the results of SUDOSCAN® and the reduction of intra-dermal fiber density at cutaneous biopsy. Hemodialysis patients are at risk of peripheral neurological involvement not only because of an increasing incidence of diabetes (30-40%) but also because of the abnormal production and elimination of certain uremic toxins. Few studies exist on the anomalies of