Category: Brain Injury; Clinical Practice (assessment, diagnosis, treatment, knowledge translation/EBP, implementation science, program development)
Objective : To evaluate the use of the Montreal Cognitive Assessment (MOCA) for cognitive assessment in moderate to severe traumatic brain injury (TBI).
Design : This was a cross-sectional of adult subjects wtith moderate to severe TBI.
Setting : Tertiary rehabilitation centre
Participants (or Animals, Specimens, Cadavers) : Adult subjects (21-89 years) with moderate to severeTBI were consecutively recruited. Subjects with disorders of consciousness, who were still in posttraumatic amnesia, had a major and active psychiatric illness or had pre-existing dementia were excluded. Severity of TBI was classified according to Veterans Affairs and Department of Defense guidelines.
The MOCA was validated against 2 commonly used neuropsychological tests in TBI, the Color Trail Test (CTT) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).
Main Outcome Measure(s) :
Receiver operating characteristics (ROC) curves were constructed to examine the ability of MoCA to identify patients with at least mild-moderate impairment on CTT and RBANS. Cut-off values were then derived at ROC co-ordinate points where both sensitivity and specificity were optimized. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) and diagnostic accuracy at the optimal cutoffs were calculated. The area under the curve (AUC) was calculated for each ROC curve, with a larger AUC denoting better correlation.
Results : 61 subjects (mean age 52.3 years, 49 male) were recruited. The mean Glasgow Coma Scale (GCS) score on arrival to hospital was 10.4, the mean post-traumatic amnesia (PTA) duration was 30.0 days and the mean (SD) interval between TBI and assessment was 17.5 (18.0) months.
ROC analysis for the MoCA revealed an optimal balance of sensitivity and specificity at 24/25 to discriminate subjects who were classified as less than 5th centile on the Total Scale Index on the RBANS. This achieved a sensitivity, specificity, PPV and NPV of 73.9%, 86.5%, 77.3% and 84.2% respectively.
The use of MOCA displayed good validity in identifying patients with clinically significant impairment on a standard neuropsychological assessment battery in this study population of moderate to severe TBI. Larger prospective studies will be useful to examine the use of MoCA in a more heterogeneous population including mild TBI patients.