A patient with anti-aquaporin 4 antibody who presented with recurrent hypersomnia, reduced orexin (hypocretin) level, and symmetrical hypothalamic lesions.
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.
Nozaki
Hiroaki
H
Department of Neurology, Brain Research Institute, Niigata University, 1-757 Asahi-machi-dori Niigata, Niigata 951-8585, Japan.
Shimohata
Takayoshi
T
Kanbayashi
Takashi
T
Sagawa
Youhei
Y
Katada
Shin-Ichi
S
Satoh
Masahisa
M
Onodera
Osamu
O
Tanaka
Keiko
K
Nishizawa
Masatoyo
M
D000328:Adult; D000906:Antibodies / Q000097:blood*; D051401:Aquaporin 4 / Q000276:immunology*; D002574:Cervical Vertebrae; D006970:Disorders of Excessive Somnolence / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000473:pathology*; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D000068797:Orexins; D013116:Spinal Cord / Q000473:pathology; D013904:Thoracic Vertebrae
C496030:AQP4 protein, human; D000906:Antibodies; D051401:Aquaporin 4; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins