The IHDS may be a useful screening test to identify individuals at risk for HIV dementia.
Consists of three subtests: timed fingertapping, timed alternating hand sequence test, and recall of four items at 2 min.
1. The number of fingertaps of the first two fingers of the nondominant hand was measured by instructing the participant to open and close the fingers as widely and as quickly as possible over a 5 seconds period.
2. In the alternating hand sequence test individuals were asked to perform the following movement with the non-dominant hand as quickly as possible over a 10 second periods: (i) clench the hand in a fist on a flat surface; (ii) put the hand flat on the surface with the palm down; and (iii) put the hand perpendicular to the flat surface on the side of the fifth digit. The participant would then perform the sequence correctly twice for practice before the 10 seconds subtest was performed. The number of sequences correctly performed within 10s up to a maximum number of 4 was scored.
3. Registration was measured by reciting four words to the subject and then asking him/her to repeat them immediately. The words were repeated by the examiner until the subject could repeat all four words correctly. The subject was then asked to recall the four words after the timed fingertapping and alternating hand sequence tests were performed. The number of items recalled was scored out of 4. A half-point was assigned for each correct word recalled after prompting.
A total score out of 12 was calculated for each participant, with each of the three subtests contributing 4 points to the total score.
Sacktor NC et al . The International HIV Dementia Scale: a new rapid screening test for HIV dementia. AIDS 2005;19(13):1367-74.