[New trends in neuropathy practice: clinical approach to CIDP]

Our recent study showed that the overall prevalence of CIDP was estimated as 2.2 per 100,000 population in Aomori Prefecture, in Northan Honshu of Japan. In our series of more than 80 cases with CIDP, a chronic acquired inflammatory demyelinating polyneuropathy, nearly 30% showed clear laterality of weakness, and electrophysiologic laterality or multifocality was apparent in almost all cases. Nearly 90% of patients were able to walk without walking aids or other assistance. Sixty% showed distal dominant muscular weakness. In 12 patients with age of onset under 15, pes cavus deformity was seen in 5. Two thirds complained numbness in the extremities during progressive phase. Four cases initially showed severe sensory ataxia associated with motor conduction block. It should be, thus, reminded that clinical spectrum of CIDP is enormously wide: chronic acquired demyelinating multiple mononeuropathy showing asymmetric involvement (Lewis-Summer syndrome) should be put on one side of the clinical presentation of CIDP. Multifocal motor neuropathy (MMN) is, on the other hand, an unique syndrome mimicking amyotrophic lateral sclerosis (ALS). There may be, however, true association syndrome of CIDP and ALS presenting both peripheral nerve demyelination and pyramidal sign with progressive bulbar involvement. Recently, several atypical varieties of CIDP showing only one-limb involvement, upper limb weakness rather than lower limb power loss, or proximal weakness, etc ... have been reported in the literature. To realize such clinical variations of chronic acquired demyelinating neuropathy is important for early diagnosis and commencement of treatment of CIDP. Clinical guideline for suspicion of CIDP could be useful for general physicians and neurologists unfamiliar to peripheral neuropathies.