Demyelinating motor Guillain-Barré syndrome following Rubella

Case report. A 20-year-old man developed weakness without sensory complaints 10 days after rubella. He had fever, typical rubella rash, and suboccipital lymphadenopathy during an epidemic outbreak in his school. Examination showed symmetric weakness of forearm and intrinsic hand muscles, tibioperoneal muscles, and triceps surae (grade 4/5, Medical Research Council scale) and hyperactive tendon reflexes. He could not get up from squatting or walk on heels and toes. Cranial nerves and sensory examination were normal. Serum creatine kinase was normal. Serologic tests revealed immunoglobulin (Ig) G and IgM antirubella. CSF protein content was increased (0.8 g/L). Electrophysiologic examination showed partial motor conduction blocks (CBs) in eight nerves, prolonged distal motor latencies in tibial nerves, and normal sensory conductions even across the sites of CB (figure). EMG of distal muscles of limbs showed reduced recruitment with high frequency discharging motor units. Brain and spinal MRI and median and tibial somatosensory evoked potentials were normal. A diagnosis of Guillain–Barré syndrome (GBS) was made, and the patient was treated with four plasmaphereses with complete recovery in 6 months. On serial electrophysiologic examination, CBs disappeared in 8 to 16 weeks, and abnormal temporal dispersion occurred in four nerves, indicating that demyelination was the pathophysiologic basis (see figure). Sensory conductions remained normal, and fibrillation potentials were not detected through the entire course of the illness.