Chronic Progressive Inflammatory Demyelinating Polyneuropathy In Childhood: Clinical And Electrophysiological Features

Chronic inflammatory demyelinating neuropathy (CIDP) occurring in childhood is rare and the diagnosis in indolently progressive cases may be difficult. We report 7 children (age 8–12 years) with insidiously progressive weakness and atrophy (in 3 cases) predominantly involving the lower limbs and mimicking a genetically determined neuropathy. Family history was negative in all cases. Numbness and paresthesias were present in 1/7 and mild sensory signs in 3/7 patients. Motor conductions were slowed in at least two nerves in 6/7, distal motor latencies prolonged in 4/7 and F waves delayed in 6/7 children, but these findings, although characteristic of a demyelinating neuropathy, did not help in the differential diagnosis with an inherited disorder. The following features documenting focal and non-uniform nerve conduction abnormalities indicated an acquired demyelinating disorder: 1) abnormal terminal latency index in at least one nerve in 5/7 children, 2) conduction block (reduction of proximal CMAP area> 50%) in at least one nerve in 5/7 children, 3)> 10 m/s conduction velocity difference among nerves of upper limbs or nerves of lower limbs in 4/7 children, 4) abnormal median sensory in presence of normal sural sensory conduction in 3/7 children. CSF protein concentration was increased in 5/7 (59–120 mg/dl). One patient had a self-limited course and recovered spontaneously in 10 months. Three children had a monophasic course, improved with steroids and had little or no residual disability. The remaining three with the longest disease duration before diagnosis (>2 years) improved with steroids but showed some residual distal weakness and atrophy and two developed foot deformities. Three children had at least one relapse at steroid tapering or discontinuation. Because of therapeutic implication the possibility of a CIDP occurring in childhood should always be kept in mind. An extensive electrophysiological study searching for indicators of non-uniform nerve conduction abnormalities may suggest the diagnosis in most cases. When the diagnosis is doubtful and genetic studies are negative we recommend a therapeutic trial of steroids for at least four weeks.