12. Co-existence of primary progressive MS and CMT1A

Abstract

A 48-year old man presented with a 20-year history of neurological symptoms. He reported slowly progressive changes in gait, mild right leg weakness and subtle short-term memory problems. There was no history of discrete relapses and no family history of neurological disease. The neurological examination revealed upper and lower limb weakness, marked lower limb spasticity, globally brisk reflexes and extensor plantar responses. MRI of the brain demonstrated white matter T2/FLAIR hyperintensities with extensive pericallosal involvement and MRI of the spinal cord revealed lesions in the thoracic cord suggestive of demyelination. Somatosensory and visual evoked potentials were markedly delayed and oligoclonal bands were detected in cerebrospinal fluid, consistent with multiple sclerosis. Nerve conduction studies demonstrated electrophysiological evidence of a generalised demyelinating, sensorimotor neuropathy, without temporal dispersion or conduction block, suggestive of an inherited cause. Genetic testing revealed PMP22 duplication, confirming Charcot-Marie-Tooth disease type 1A. This case highlights the rare co-existence of acquired central demyelination (i.e. primary progressive MS) in conjunction with inherited peripheral demyelination (CMT 1A).