Diagnostic efficiency and treatment strategy in chronic axonal polyneuropathy

Polyneuropathy is a common peripheral nerve disorder that often has a well known cause such as diabetes, chronic renal disease, alcohol abuse, vitamin deficiency, hypothyroidism, or use of toxic medication. Elderly people are more often affected, but the differentiation from signs of normal ageing can be difficult. It is important to diagnose a polyneuropathy and establish the cause at an early stage, because treatment can ameliorate symptoms and prevent progression. Because of the ageing population, the number of people affected by a polyneuropathy can be expected to increase. This thesis deals with questions regarding the efficient work-up and treatment strategies for chronic axonal polyneuropathy. A succinct description of the main study results is as follows. In about 25% of healthy elderly people older than 60 years the vibration sense at the big toes or ankles and the ankle jerks can be absent, and this should be taken into account when developing a clinical diagnostic definition for polyneuropathy. Implementation of a restrictive guideline for the workup of polyneuropathy leads to less diagnostic delay (on average 2 weeks), fewer investigations and less costs (about 30%), whilst retaining diagnostic reliability. For chronic idiopathic axonal polyneuropathy, the sural and superficial peroneal SNAP have complementary diagnostic value and equal diagnostic accuracy. Neither ageing nor disease duration have an important influence on the disease course or prognosis of chronic idiopathic axonal polyneuropathy. Sural nerve biopsies in progressive idiopathic axonal neuropathy often demonstrate inflammatory abnormalities suggestive of vasculitis (i.e. an inflammation of arterial blood vessels), but the absence of these findings does not preclude an immune-mediated origin of this neuropathy. Based on a literature review according to the methods of The Cochrane Collaboration there is no evidence from randomized trials on which to base treatment for chronic idiopathic axonal polyneuropathy and non-systemic vasculitic neuropath