Multifocal inflammatory demyelinating neuropathy: a distinct clinical entity?

BACKGROUND: Several patients have been reported with an asymmetric sensory or sensorimotor demyelinating neuropathy not fulfilling the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy or multifocal motor neuropathy.
OBJECTIVE: To present the clinical, electrophysiologic, radiologic, and pathologic features of six patients with an asymmetric sensory or sensorimotor demyelinating neuropathy.
RESULTS: All six patients were initially affected in only one limb; in four patients the neuropathy progressed to other limbs in an asymmetric fashion during several years. On electrophysiologic examination, evidence of multifocal demyelination and conduction block in motor and sensory nerves was found in all patients. MRI of the brachial plexus revealed swollen nerves and an increased signal intensity on T2-weighted imaging in four patients. A biopsy sample taken from the brachial plexus of one patient revealed evidence of inflammation. All patients showed a beneficial response to IV immunoglobulin treatment. Thirty-four similar patients have been reported previously, many of whom were initially diagnosed as having various other (nontreatable) diseases.
CONCLUSIONS: The authors propose calling this neuropathy "multifocal inflammatory demyelinating neuropathy" and considering it as a distinct clinical entity to facilitate early diagnosis of this treatable disorder.