Nerve Conduction Velocity in Diabetic Children

Diabetes mellitus type 1 is a chronic disease in which the pancreas no longer produces enough insulin and the glucose in the blood cannot be absorbed into the cells of the body. The main symptom is hyperglycemia. After 10 to 15 years of disease long-term vascular complications including retinopathy, nephropathy, neuropathy, and macrovascular disease are seen. Among the most common long-term complications of diabetes, diabetic neuropathy (DN) is a significant source of morbidity and mortality. There is considerable uncertainty about the prevalence of DN due to a lack of large epidemiological studies and consensus on diagnostic criteria with data variation ranging from 5% to 100%. DN is thought to result from diabetic microvascular injury involving small blood vessels that supply nerves (vasa nervorum). It is a set of heterogeneous clinical syndromes that affect distinct regions of the nervous system, individually or combined. The investigators differentiate autonomic and peripheral neuropathy: Clinical presentation of autonomic neuropathy includes postural hypotension, vomiting, diarrhea, bladder paresis, impotence, sweating abnormalities, and gastric fullness. Peripheral neuropathy presents as altered pain sensations (dys-, para-, hypo- or hyperesthesia), burning, and either superficial or deep pain. The examination of choice for the diagnosis of peripheral neuropathy is to determine nerve conduction velocity.

One of the main goals in treating children and adolescents suffering from diabetes mellitus type I is to avoid long-term complications by early detection of clinical or, even better, subclinical signs. For this reason, the International Society for Pediatric and Adolescent Diabetes (ISPAD) periodically issues Clinical Practice Consensus Guidelines, particularly for screening for vascular complications. With regard to DN there is still uncertainty about the time frame, intensity and diagnostic method of choice.

The investigators aim to examine children and adolescents from 8 to 18 years suffering from diabetes mellitus type I for more than one year with an insulin requirement of more than 0.5 IU/kg/d. The investigators will exclude children with other chronic diseases, handicapped children or children suffering from cancer or chronic renal impairment, as well as children with other neurological diseases which can also cause a change in nerve conduction velocity, and children with blood glucose levels below 50 or above 350 mg/dl. At the time of the annual check-up the patients will undergo a detailed examination for anthropometric data, blood pressure, blood and urine. Thereafter, motor and sensory nerve conduction velocity will be determined by electrical stimulation using surface patch electrodes. The nerves to be investigated are the nervus tibialis anterior, nervus medianus and nervus peroneus. Finally, the patient will undergo a neurological investigation to calculate his Young Score (Neuropathy Symptom Score).