A case of acute onset succinic semialdehyde dehydrogenase deficiency: neuroimaging findings and literature review.
BACKGROUND
Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder of γ-aminobutyric acid metabolism, leading to elevated levels of γ-aminobutyric acid and γ-hydroxybutyric acid in cerebrospinal fluid.


METHODS
We describe the neuroimaging findings of a previously healthy 6-month-old girl with acute onset of lethargy, hypotonia, and choreiform movements, and a subsequent diagnosis of SSADH deficiency. Magnetic resonance (MR) imaging of the brain revealed symmetric T2 hyperintense signal abnormalities and reduced diffusivity of the globus pallidi bilaterally. Arterial spin-labeling perfusion MR imaging suggested bilateral hyperperfusion of the globus pallidi. MR spectroscopy of the thalamus and frontal lobe white matter revealed increased signal intensity in the glutamate and glutamine region of the spectra between 2.1 and 2.4 ppm.


CONCLUSIONS
The unique early imaging findings described here may be attributable to bioenergetic failure and deficiency in mitochondrial energy metabolism and are consistent with SSADH-knockout mice studies.
Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Kevin Y
KY
Wang
Divison of Neuroradiology, The Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Peter B
PB
Barker
Divison of Neuroradiology, The Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD, 21287, USA. ddmlin@jhmi.edu.
Doris D M
http://orcid.org/0000-0002-6001-2383
DD
Lin
D000592:Amino Acid Metabolism, Inborn Errors / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002658:Developmental Disabilities / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006885:Hydroxybutyrates / Q000378:metabolism; D007223:Infant; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D050644:Succinate-Semialdehyde Dehydrogenase / Q000172:deficiency* / Q000378:metabolism
D006885:Hydroxybutyrates; C111420:4-hydroxybutyric acid; D050644:Succinate-Semialdehyde Dehydrogenase
4-Hydroxybutyric aciduria; Diffusion-weighted imaging; Magnetic resonance imaging; Magnetic resonance spectroscopy; Perfusion-weighted imaging; Succinic semialdehyde dehydrogenase deficiency