Complicated Seronegative Neuromyelitis Optica Longitudinally Extensive Transverse Myelitis in Elderly: A Diagnostic...

A 69-year-old gentleman without any previous comorbidities presented with complaints of acute-onset low-grade fever, one episode of loss of consciousness, and weakness of both legs with urinary and stool retention for 1 day. He had an episode of generalized tonic-clonic seizure 3 hours after admission. On examination, he had tachycardia and hypotension; Glasgow Coma Scale (GCS) was E3V2M4, and neurological examination was suggestive of bilateral lower limb upper motor neuron lesion in the shock stage. Blood investigation revealed severe hyponatremia, and magnetic resonance imaging (MRI) with contrast of the dorsolumbar spine revealed longitudinally extensive transverse myelitis (LETM). Blood investigation for antineuromyelitis optica (anti-NMO) antibody was negative. Other investigations revealed low serum osmolality, raised urine osmolality, and spot sodium. Cerebrospinal fluid (CSF) viral panel detected human herpesvirus 6 (HHV6). He was treated with a pulse dose of IV methylprednisolone, hypertonic saline, and IV levetiracetam. He had symptomatic improvement and was discharged with a tapering dose of oral prednisolone. He had a complete recovery after 3 months of regular follow-up. Thus, we report a case of HHV6-induced LETM complicated with cerebral salt wasting syndrome and hyponatremic seizures.