A patient with anti-aquaporin 4 antibody who presented with recurrent hypersomnia, reduced orexin (hypocretin) level, and symmetrical hypothalamic lesions

• DOI: 10.1016/j.sleep.2007.11.022
• Publication Date: 2008-01-30T15:11:55Z
• Authors: Hiroaki Nozaki; Takayoshi Shimohata; Takashi Kanbayashi; Youhei Sagawa; Shin-ichi Katada; Masahisa Satoh; Osamu Onodera; Keiko Tanaka; Masatoyo Nishizawa
• Keywords: Adult; Aquaporin 4; Orexins; Neuropeptides; Hypothalamus; Intracellular Signaling Peptides and Proteins; Disorders of Excessive Somnolence; Antibodies; Thoracic Vertebrae; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Spinal Cord; Cervical Vertebrae; Humans; Female

Recent studies have demonstrated that hypothalamic lesions associated with brain tumor, head trauma, and encephalopathy can cause symptomatic hypersomnia with a reduced orexin (hypocretin) level in the cerebrospinal fluid (CSF). Aquaporin 4 (AQP4), a member of the AQP superfamily, is strongly expressed in the hypothalamus in which orexin (hypocretin)-containing neurons are primarily concentrated. We report the case of a patient with a serum anti-AQP4 antibody who presented with recurrent hypersomnia, symmetrical hypothalamic lesions with long spinal cord lesions on MRI, and a reduced CSF orexin (hypocretin) level, all of which were improved simultaneously by steroid therapy. Further studies should be performed to determine the roles of anti-AQP4 antibody positivity in patients with hypersomnia associated with orexin (hypocretin) deficiency and hypothalamic lesions.