2025 年 42 巻 4 号 p. 733-737
The prevalence of polyneuropathy is around 1–3% and increases with age, so it can be said that polyneuropathy is one of the most common diseases in neurology. On the other hand, we neurologists do not often see polyneuropathy in our daily practice, but it is important to understand the typical symptoms and pathology and to make an accurate diagnosis. In this lecture we will outline the most common types of neuropathies : 1) diabetic polyneuropathy (DPN), 2) chemotherapy–induced polyneuropathy (CIPN) and 3) alcoholic neuropathy.
These three neuropathies have in common that they are symmetrical, distal and sensory–dominant conditions with no established diagnostic criteria and are diagnosed on the basis of history and symptoms. Although they are common condition, easy diagnosis must be avoided and especially atypical cases should be carefully differentiated from other conditions. In DPN, small–fiber sensory nerves are predominantly affected, but as the disease progresses, large–fiber, motor and vibration or touch sensation and autonomic symptoms may also occur. In severe DPN, nerve conduction studies also show reduced action potentials and delayed conduction velocity in both sensory and motor nerves. In CIPN, symptoms appear and worsen with increasing cumulative doses of the causative agent and tend to improve with cessation of treatment. However, positive symptoms such as neuropathic pain are also influenced by other factors, so progression should be assessed by negative symptoms such as dysesthesia. Alcoholic neuropathy is a chronic condition with predominance of small fibers and pain, but attention should be paid as motor neuropathy may also occur and the progression may be more rapid when accompanied by nutritional disorders such as thiamine deficiency. It is important to make the diagnosis by careful interview and examine, understanding the typical patterns of disease.
