Visual evoked potentials in succinate semialdehyde dehydrogenase (SSADH) deficiency

Area of Science:

• Neuroscience
• Biochemistry
• Ophthalmology

Background:

• Elevated GABA in the central nervous system is linked to visual evoked potential (VEP) abnormalities, specifically increased P100 latency.
• Succinate semialdehyde dehydrogenase (SSADH) deficiency results in supraphysiological accumulation of GABA.

Observation:

• VEPs were evaluated in two patients with confirmed SSADH deficiency.
• While binocular VEPs were normal, monocular VEPs revealed markedly delayed P100 latencies (134-147 ms) in both patients.

Findings:

• Patients with SSADH deficiency exhibit delayed P100 latencies in monocular VEP recordings.
• This suggests potential visual system abnormalities associated with GABA metabolism defects.

Implications:

• Elevated ocular GABA may downregulate GABA(C) receptors, contributing to VEP anomalies.
• VEP analysis could be a useful diagnostic tool for SSADH deficiency.
• Further research in Aldh5a1(-/-) mice is warranted to explore GABA(C) receptor function and SSADH pathophysiology.