GIN Test: A Meta-Analysis on Its Neurodiagnostic Value.

Purpose: A meta-analysis was conducted to evaluate how effective the Gaps-in-Noise (GIN) test is in separating populations who are and who are not at risk of having neurological damage related to the central auditory nervous system (CANS). This was investigated by asking three specific questions: (1) Does ear and side of lesion have an effect over the individual's performance? (2) How large is the difference in performance between control and neurological groups? (3) What are the diagnostic indices related to the GIN test?

Data Collection And Analysis: A literature review was performed between April 2016 and April 2017. The eligibility criteria for inclusion were as follows: (1) studies that used the GIN test as an outcome measure, (2) studies that included adult participants who either had confirmed lesions or were at risk of having lesions to the CANS or related regions, and (3) studies that had a neurologically normal control group. From relevant studies that met eligibility criteria, information regarding study design, participants, lesion details and origins, use of additional assessments, GIN performance scores for both control (CTRL) and neurological (NRLG) groups, GIN cutoff scores and proportion of individuals with normal and abnormal performances were all included.

Results: Nine studies were included, totaling 221 participants in NRLG (stroke = 90, epilepsy = 67, and blast exposure [BLST] = 64) and 262 in CTRL (Stroke = 106, Epilepsy = 98, and BLST = 58). No significant ear effects related to side of lesion were observed for the GIN test in neurological patients nor were there significant ear differences for normal individuals with symmetrically normal hearing. The GIN demonstrated consistency among different neurological populations, presented good sensitivity and specificity rates, and was overall accurate in discriminating between participants with neuroauditory lesions from neurologically normal individuals.

Conclusions: The GIN is thus a clinically effective measure that provides insight into the CANS integrity and may aid in clinical diagnosis by distinguishing between populations who are and who are not at risk of having neurological damage affecting the CANS.