Complications of Central Nervous System in Dermatomyositis

The association of DM or PM and nervous system involvement is a very rarely observed and controversial entity. In their report, O'Leary and Waisman noted an asymmetry of the face due to facial nerve palsy in patients with DM [1]. Later, Karajashev et al. [2] reported a 72-year-old man with acute form of DM associated with gastric cancer, in whom the autopsy found morphologic changes in the central nervous system. Histology from brain and spinal cord specimen revealed a dystrophic injury of ganglial cells in brain, loss of dendrites, reduction of the number of Purkinje's cells in the cerebellum, lysis of tigroid substance and lymphocitic infiltrates in the spinal cord [3]. Recently a 50-year-old man with an overlap syndrome of DM and SLE was reported, whose magnetic resonance image of the brain showed a rapidly increasing large tumor in the left frontal lobe [4]. The pathological finding from the brain biopsy was fibrinoid necrosis, inflammatory cell aggregation around blood vessels and many myelin-laden macrophages with central necrosis. Neurologic symptoms in the patient such as paresis were mild and the lesion responded well to steroid treatment [4].

Beloev et al. [5] reported a 42-year-old man with typical cutaneous features of DM, degenerative changes in muscle biopsy, and normal serum enzymes who in the course of the disease developed unilateral damage of right V and VII cranial nerves, presenting with one-sided pains, hypasthesia, and painfulness to the touch in the area of n. trigeminus and facial nerve palsy. Laraki R et al. [6], in their study of four cases, proposed the following criteria of primary nerve involvement in DM/PM patients: early abolition of tendinous reflexes in a patient without notable muscular atrophy and with little or no myalgia, sensitive abnormalities in areas other than those of muscular involvement, early weakness of distal muscles, decrease in nerve conduction speed, target fibers and lesions of nerve trunks. They reported two DM cases with peripheral neuropathy, and two other patients with polyradiculoneuritis and vasculitis [6]. One of the patients had HTLV- I infection confirmed by polymerase chain reaction (PCR), suggesting the direct pathogenic role of certain viruses in those patients [6].