Background: Cognitive dysfunction is a feature of many diseases and the impact is especially relevant in the young. While there are many sophisticated tests of cognitive function, the shorter Mini Mental State examination (MMSE) is the most widely used screening test. In Nigeria where cognitive function is not routinely assessed in the management of cases, the MMSE is probably the most practical test of cognitive function to be promoted. This is because it is easy to administer and to interpret. There is however a need to define the performance of normal Nigerian subjects on the MMSE to make its use more relevant.
Methodology: Seventy normal adolescents attending a secondary school in Ibadan, Nigeria, were administered the MMSE. Excluded were subjects with a history of mental impairment or medical disorders known to influence cognitive function. All subjects were tested only once.
Results: Normal MMSE scores were obtained by 88.6% of subjects while 11.4% of the subjects were found to be mildly or moderately cognitively impaired. More than 55% of the subjects did not obtain full scores with test of orientation in place while 30% and 34.3% respectively did not obtain full scores with tests of orientation in time and of attention respectively. Males and females performed equally with regard to the test items except for a non-statistically significant better performance of the females with test of three-item recall (p = 0.09).
Conclusion: Abnormalities on the MMSE in Nigerians should be interpreted with caution as more than 10% of subjects may have abnormal scores. Tests of orientation and of attention are particularly likely to indicate abnormal cognitive function even in subjects with overall scores in the normal range. There may be a need to modify the MMSE to make it more applicable to young Nigerian subjects.