A case of succinic semialdehyde dehydrogenase deficiency with status epilepticus and rapid regression.
BACKGROUND
Clinical phenotypic expression of SSADH deficiency is highly heterogeneous, and some infants may develop refractory secondary generalized seizures.


METHODS
A 9-month-old boy manifested partial seizures, developing severe status epilepticus, and conventional antiepileptic drugs were ineffective. Use of ketamine contributed to the control of status epilepticus, achieving a reduction in frequency of partial seizures, and improving EEG findings without apparent complications. Diffusion-weighted images showed hyperintensities in the bilateral basal ganglia and fornix, and multiple T2 hyperintensity lesions were detected. (123)I-iomazenil (IMZ) SPECT revealed a decrease in binding of (123)I-iomazenil predominantly in the left temporal region by the 18th day of hospitalization. However, repeated IMZ-SPECT on the 46th day of hospitalization demonstrated almost no accumulation across a broad region, sparing the left temporal region. The patient showed rapid regression, refractory myoclonus, and severe progressive brain atrophy.


CONCLUSIONS
IMZ-SPECT findings demonstrated reduced benzodiazepine receptor binding and its dynamic changes in an SSADH-deficient patient. Considering the down regulation of the GABAA receptor, ketamine should be included in pharmacotherapeutic strategies for treatment of refractory status epilepticus in SSADH-deficient patients.
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan. Electronic address: holiday0530@yahoo.co.jp.
Asako
A
Horino
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Hisashi
H
Kawawaki
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Masataka
M
Fukuoka
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Hitomi
H
Tsuji
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Yuka
Y
Hattori
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Takeshi
T
Inoue
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Megumi
M
Nukui
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Ichiro
I
Kuki
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Shin
S
Okazaki
Departments of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, Japan.
Kiyotaka
K
Tomiwa
Department of Pediatric, Fukuoka University, School of Medicine, Japan.
Shinichi
S
Hirose
D000592:Amino Acid Metabolism, Inborn Errors / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D001284:Atrophy; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D002658:Developmental Disabilities / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D004569:Electroencephalography; D005442:Flumazenil / Q000031:analogs & derivatives; D006801:Humans; D007223:Infant; D008297:Male; D019275:Radiopharmaceuticals; D013226:Status Epilepticus / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D050644:Succinate-Semialdehyde Dehydrogenase / Q000172:deficiency*; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D005442:Flumazenil; C063038:iomazenil; D050644:Succinate-Semialdehyde Dehydrogenase
(123)4-Hydroxybutyric aciduria; Gamma-hydroxybutyric aciduria; Ketamine; Refractory status epilepticus; SSADH deficiency