[Anti-NMDA receptor antibody-positive meningoencephalitis with SIADH and CNS demyelination: A case report].

After a 34-year-old female developed a headache and high fever, she was diagnosed with aseptic meningitis. On admission, neurological examinations revealed cerebellar limb ataxia, horizontal gaze paretic nystagmus, and pyramidal tract signs. Laboratory tests showed hyponatremia (129 mEq/l). Five days after admission, convulsions in the upper limbs due to the severe hyponatremia (108 mEq/l) were noted. In addition, serum antidiuretic hormone levels were markedly increased to 18.5 pg/ml. Brain MRI showed multiple small inflammatory lesions in the subcortical cerebral white matter, thalamus, and around the third ventricular diencephalic regions. Pulse corticosteroid treatment promptly improved her symptoms. Although tests for serum anti-aquaporin 4, anti-myelin oligodendrocyte glycoprotein, and anti-voltage-gated potassium channel antibodies were negative, cerebrospinal fluid samples tested positive for anti-N-methyl-D-aspartate (NMDA) receptor antibodies. Oral prednisolone administration was continued, but she developed paresthesia in her upper and lower extremities and gaze-evoked nystagmus three months after the first attack. MRI showed that the previously observed high-intensity regions were decreased, but a new area of high intensity was observed in ventral regions through the lower midbrain to the pons. Because pulse corticosteroid treatment was again effective, we continued the oral prednisolone treatment. This case presented none of the characteristic symptoms of anti-NMDA receptor antibody encephalitis during the clinical course other than repeated demyelinating encephalitis and severe syndrome of inappropriate antidiuretic hormone secretion (SIADH). Additional clinical observations are needed to better understand the underlying pathology of the NMDA receptor antibodies in the cerebrospinal fluid in this case.

Preliminary study on the association of AQP4 promoter polymorphism with anti-aquaporin-4 antibody positivity in southern Han Chinese patients with idiopathic demyelinating disorders of central nervous system.

OBJECTIVES: To identify the association of aquaporin-4 (AQP4) promoter polymorphism with the presence of anti-aquaporin-4 antibody (AQP4-Ab) in Southern Han Chinese patients with idiopathic demyelinating disorders of central nervous system. METHODS: Eighteen neuromyelitis optica (NMO), thirty-eight conventional MS (CMS), thirteen recurrent myelitis (RM), six recurrent optic neuritis (RON) patients and thirty-nine matched controls were enrolled. Polymorphisms of AQP4 promoters 0 and 1 were determined by sequencing-based typing. RESULTS: Fourteen polymorphism loci were observed in AQP4-promoter 0, while the six ones were observed in AQP4-promoter 1. Among them, the frequency of polymorphism at position -1003bp (A-G) of AQP4-promoter 0 in AQP4-Ab-positive patients was significantly higher than that in AQP4-Ab-negative patients and controls (former: 13/18 vs 20/45, P=0.046; latter: 13/18 vs 10/39, P=.001). The frequency of polymorphism at position between -401bp and -400bp (C inserted) of AQP4-promoter 1 in AQP4-Ab-positive and -negative patients was significantly higher than that in controls (former: 5/16 vs 0/28, P=0.008; latter: 8/38 vs 0/28, P=0.027). CONCLUSIONS: Polymorphism at position -1003bp (A-G) of AQP4-promoter 0 is associated with the presence of anti-AQP4 antibody. Genetic variation in AQP4 may account for the susceptibility to AQP4-Ab-positive NMO and NMO spectrum disorders in Southern Han Chinese population.