Neurocognitive disorders associated with the human immunodeficiency virus (HIV), also known as HIV-associated neurocognitive disorders (HAND), are some of the lesser-known side effects of the disease. Once infected with HIV, a patient may experience neurocognitive problems, such as impaired memory and difficulty processing information.

With the improvement of HIV antiretroviral therapy in the past two decades, however, severe forms of HAND have declined along with the most debilitating and fatal effects of HIV, allowing patients to live long and otherwise normal lives.

According to the new study which was completed at St. Michael’s Hospital in Toronto, though severe forms of HAND have decreased, there continues to be an incidence of the milder form, affecting 50 to 60 percent of people with HIV and AIDS. Dr. Sean B. Rourke, the author of the study, notes that the incidence of the mild form of HAND may actually be increasing.

The study reviewed previous studies to see how effectively common tests, such as the HIV Dementia Scale and the International HIV Dementia Scale, were used in detecting HAND in HIV patients. Rourke found that though these tests were able to identify severe forms of HAND, they were not as effective in recognizing milder forms of HAND.

The International HIV Dementia Scale (IHDS) measures memory registration, motor speed, and memory recall (in which patients are asked to complete tasks such as recalling words or tapping their fingers as quickly as they can).

According to the National Institutes of Health, HIV-associated neurocognitive disorders occur when the HIV virus affects the nerve cells, causing forgetfulness, confusion, headaches, and behavioral changes. "Identifying that patients have a mild form of this condition is critical," Rourke said in a press release about the study. "Even mild neurocognitive problems can have a significant impact on a person's everyday functioning, affecting his or her ability to take medications or ability to perform at work, and may also lead to more social isolation and withdrawal."