Peripheral motor nerve conduction velocities in children undergoing chronic hemodialysis

Peripheral nerve disease secondary to systemic conditions in children

This review is an overview of systemic conditions that can be associated with peripheral nervous system dysfunction. Children may present with neuropathic symptoms for which, unless considered, a causative systemic condition may not be recognized. Similarly, some systemic conditions may be complicated by comorbid peripheral neuropathies, surveillance for which is indicated. The systemic conditions addressed in this review are critical illness polyneuropathy, chronic renal failure, endocrine disorders such as insulin-dependent diabetes mellitus and multiple endocrine neoplasia type 2b, vitamin deficiency states, malignancies and reticuloses, sickle cell disease, neurofibromatosis, connective tissue disorders, bowel dysmotility and enteropathy, and sarcoidosis. In some disorders presymptomatic screening should be undertaken, while in others there is no benefit from early detection of neuropathy. In children with idiopathic peripheral neuropathies, systemic disorders such as celiac disease should be actively excluded. While management is predominantly focused on symptomatic care through pain control and rehabilitation, some neuropathies improve with effective control of the underlying etiology and in a small proportion a more targeted approach is possible. In conclusion, peripheral neuropathies can be associated with a diverse range of medical conditions and unless actively considered may not be recognized and inadequately managed.

Uremic neuropathy

Polyneuropathy is a common complication of end-stage renal failure especially when treatment with periodic hemodialysis is started too late. Large myelinated fibers bear the brunt of the many biological changes associated with renal failure. Nerve conduction slowing is common in this setting. Compression of the median nerve in the carpal tunnel commonly occurs in these patients, as a result of amyloid deposits at this site. End-stage renal failure in diabetic patients is often associated with severe distal motor and sensory deficits. Improved quality of periodic hemodialysis and renal transplantation have dramatically reduced the prevalence and severity of peripheral neuropathy in these patients.

Topical anaesthesia in haemodialysis: evaluation of topical anaesthesia with lidocaine during vascular access in children undergoing long-term haemodialysis for chronic renal failure

Children with chronic renal failure are frequently exposed to painful invasive procedures. Ointments containing lignocaine-prilocaine, when used before intravenous punctures, have been reported to lessen the pain sensation. The aim of this study was to interpret the effectiveness of lidocaine 2.5% ointment in preventing pain when used before venous and arterial punctures in children undergoing a haemodialysis programme for chronic renal failure. Eight children were included in this study. The pain level was identified by the patients using a linear analogue scale. When topical anaesthetic and placebo were compared, there was no statistical difference in interpretation of pain during arterial (P > 0.4), venous (P > 0.375) or both (P > 0.4) procedures. We conclude that lidocaine 2.5% ointment is not effective in preventing pain in children undergoing long-term haemodialysis. In these patients some other factors, like psychological factors, puncture technique and needle size must be taken into consideration for the prevention of pain.

Are nerve conduction studies useful for monitoring the adequacy of renal dialysis?

When hemodialysis was first used clinically, a peripheral neuropathy frequently emerged. The discovery that sufficient dialysis time would prevent the emergence of symptomatic neuropathy led to the routine use of nerve conduction studies (NCS) to monitor the "adequacy" of dialysis. Modern dialysis practice has evolved since then, and the patient population is markedly different. This report addresses the question of whether there is evidence to indicate that routine use of NCS is helpful to monitor the adequacy of present-day dialysis. A critical review of the available literature reveals that there is insufficient evidence to allow one to answer the question.