To describe a patient positive for the anti–aquaporin 4 antibody with hypothalamic lesions showing hypothermia, hypotension, hypersomnia, and obesity.
We describe a 21-year-old woman who was positive for anti–aquaporin 4 antibody and presented with hypothermia, hypotension, and hypersomnia owing to bilateral hypothalamic lesions as the only abnormal clinical finding.
Immediate steroid administration resulted in significant improvement of the patient's vital signs and imaging findings; however, her cognitive impairment and sleepiness persisted, and she subsequently developed obesity. Decreased cerebrospinal fluid orexin levels and sleep studies confirmed the diagnosis of narcolepsy due to medical condition. Physicians should be aware that neuromyelitis optica spectrum disorders can initially involve the hypothalamus.
We emphasize that measurement of anti–aquaporin 4 antibody is of clinical importance in the differential diagnosis of hypothalamic lesions.