Is International HIV Dementia Scale good enough to diagnose HIV-associated neurocognitive disorders?

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) comprise impairment of multiple cognitive domains and cause significant morbidity. International HIV Dementia Scale (IHDS) is a quite sensitive and specific method for screening for HAND, and Modified Mini-Mental State Examination (3MS), though nonspecific, contains more parameters for screening for neurocognition. Hence, we compared 3MS and IHDS as screening tools for HAND with an aim to find out which was a better screening tool for HAND.

Using 3MS and IHDS, we assessed the cognitive status of 200 HIV-positive patients (65% males) and 84 controls, presenting to the Department of Medicine, King George's Medical University, Lucknow, India from September 2015 to September 2019.

According to 3MS, 42 (21%) HIV-positive patients were neurocognitively impaired (mean 76.24 ± 1.51), and 158 (79%) patients were not (mean 87.02 ± 4.16). As per IHDS, 185 (92.5%) HIV patients were neurocognitively impaired (mean 8.45 ± 0.88), and 15 (7.5%) patients were not (mean 11.13 ± 0.35). The mean 3MS score of controls was 87.56 ± 4.26, and the IHDS score was 9.73 ± 1.00. According to Patient Health Questionnaire-9 (PHQ-9), moderate depression occurred in only 3.5% of the patients, and the rest had only minimal or mild depression. In IHDS, psychomotor speed was the most affected parameter, whereas in 3MS, similarities were the most affected.

IHDS may be over diagnosing neurocognitive impairment in HIV patients due to difficulty in understanding the test, especially psychomotor speed testing. 3MS may be more accurate for detecting neurocognitive impairment in HIV patients, and scale combining both these methods may be a still better choice.