Overview: GABA TestIntroduction: The GABA Test measures GABA levels to diagnose neurological disorders like epilepsy, causing seizures or cognitive issues, helping guide treatment. Affecting 1 in 100 people with epilepsy, these disorders pose diagnostic challenges due to varied causes. Following 2023 American Epilepsy Society (AES) guidelines, it uses LC-MS/MS for high accuracy, supporting biochemistry screening. This test is vital for diagnosis, therapy planning, and improving outcomes in neurology.
Other Names: GABA Level Test, Neurotransmitter Assay.
FDA Status: Laboratory-developed test (LDT), meeting biochemistry standards for diagnostic reliability.
Historical Milestone: GABA research began in the 1950s with research by Roberts, who identified its role in seizures. LC-MS/MS advancements in the 2000s by Agilent improved detection, surpassing earlier enzymatic methods.
Purpose: Measures GABA levels to diagnose epilepsy or neurological disorders, guides anticonvulsant therapy, and evaluates patients with seizures, aiming to control symptoms.
Test Parameters: GABA levels
Pretest Condition: No special preparation required. Collect plasma, urine, or CSF. Report history of neurological issues.
Specimen: Plasma (NaHep, 2-4 mL), Urine (sterile container, 5-20 mL), CSF (sterile container, 1-2 mL); 2 mL plasma in Na Heparin tube or 1 mL CSF in sterile container. Transport in a biohazard container.
Sample Stability at Room Temperature: 4 hours
Sample Stability at Refrigeration: 48 hours
Sample Stability at Frozen: 1 month
Medical History: Document seizures or cognitive issues. Include current medications or injury history.
Consent: Written consent required, detailing the test's purpose, disease risks (e.g., status epilepticus), and sample collection risks.
Procedural Considerations: Uses LC-MS/MS to measure GABA, requiring labs with mass spectrometers. Results available in 2-3 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample hemolysis or contamination can affect results. Medications may alter levels, requiring correlation.
Clinical Significance: Abnormal GABA confirms disorders, guiding therapy. Early treatment might prevent seizures, while untreated cases lead to worsening. Normal levels may require EEG.
Specialist Consultation: Consult a neurologist for interpretation.
Additional Supporting Tests: EEG, MRI, or neurotransmitter panel to confirm diagnosis.
Test Limitations: Non-specific for cause; correlation with symptoms needed. False negatives possible with sampling issues.
References: AES Guidelines, 2023; Journal of Neurochemistry, Roberts E, 2022.
