HIV-associated neurocognitive disorder
HIV-associated neurocognitive disorders, often abbreviated as HAND, are a result of inflammatory and neurotoxic responses in the brain following infection with HIV. The condition can cause a variety of behavioral, cognitive, and motor difficulties that can range from mild to severe. The condition is estimated to affect between 30 and 50 percent of those living long-term with HIV.
Definition & Facts
Even in the early days of the AIDS epidemic, those living with the disease or who treated or cared for those with AIDS noticed that individuals with HIV or AIDS often experienced a decline in cognitive and motor skills as well as behavioral changes and mood changes. The condition was given the name HIV-associated neurocognitive disorder.
Today, the American Academy of Neurology recognizes three categories of the condition. The most severe form is HIV-associated dementia, which is characterized by significant impairment that limits daily functioning. Individuals with mild neurocognitive disorder (MND) have impairment that is evident in neuropsychological testing, but the impairment only moderately interferes with daily life. Asymptomatic neurocognitive impairment (ANI) does not impact everyday functioning, but cognitive decline is apparent on neuropsychological tests.
Symptoms & Complaints
The effect of HAND on motor skills typically includes weakness, loss of coordination, difficulties with balance, dropping things frequently, loss of bowel control (fecal incontinence) or bladder control (urinary incontinence), and changes in handwriting. Individuals with HAND may also demonstrate personality changes, impulsive behavior, mood swings, and symptoms of psychosis.
The condition can be difficult to diagnose and manage since some of the same symptoms can be the result of medication side effects, opportunistic HIV-related infections, nutritional imbalances, or other unrelated health conditions. Since the symptoms can develop gradually, it can be difficult to determine the point at which isolated symptoms should be classified as HAND.
Shortly after infection, HIV enters the body’s central nervous system. Normally, the tissues surrounding the brain, referred to as the blood-brain barrier, protect the brain from invading viruses but allow macrophages and other immune cells to cross.
Instead of helping to fight infection, these immune cells actually carry the HIV infection. Once the virus crosses the blood-brain barrier, it triggers an inflammatory response that damages the nerve cells. Those at greatest risk for developing HAND include:
- Older adults
- Individuals with high viral loads
- Those with low CD4 counts (CD4 cells are white blood cells that help fight infections
- People with a history of intravenous drug use
- Individuals with a history of delirium
- Those with comorbid health conditions, including anemia or cytomegalovirus (CMV) infection.
Since individuals with HIV are living longer, the risk of cognitive decline, including HIV-associated mild neurocognitive disorder has increased. With the increased use of antiretroviral therapy (ART), the incidence of HIV-associated dementia, the most severe form of the condition, has decreased. In the 1990s, HIV-associated dementia was common during the late stages of AIDS. Today, less than 5 percent of those on antiretroviral therapy develop this form of the condition.
Diagnosis & Tests
Individuals with HIV are highly susceptible to infections, cancers, and other problems that can affect cognition, behavior, and motor ability. A diagnosis of HAND requires thorough physical examinations and neuropsychological evaluations. Various blood tests can help identify infections, measure CD4 and viral load levels, and abnormalities in thyroid, kidney, or liver function. Toxicology tests may be used to rule out substance abuse or drug toxicity.
Computed tomography (CT) scan and magnetic resonance imaging (MRI) of the brain will typically show significant atrophy or shrinkage of the brain in advanced cases of HAND. Tests of the cerebrospinal fluid may be necessary if infection is suspected. A mental status exam will identify if the individual is suffering from memory loss, difficulty concentrating, mood swings, or other issues with thought and behavior processes.
Caregivers, friends, and family members are a vital part of the diagnostic process since they are often the first to notice the changes in the patient. There is no single test to confirm whether a person has HAND. The diagnosis is usually reached after considering the results of the various tests in combination.
Evidence of decline over repeated tests makes the diagnosis more likely. After the initial diagnosis, most patients with HAND benefit from a referral to a neuropsychologist, neurologist, or psychiatrist with specific experience in treating HAND.
Treatment & Therapy
At this time, there is not a specific treatment for HAND. The best results are obtained using a multidisciplinary approach that involves a number of different specialists. The first step in treatment is to address any underlying medical conditions, including psychiatric disorders, endocrine abnormalities, and nutritional deficiencies, that can affect the brain. Individuals with HAND should avoid illicit drugs and alcohol that can further impair cognitive function.
Antiretroviral therapy is the primary method of preventing and treating HAND. These drugs prevent HIV from replicating and may be able to at least partially reverse the symptoms of HAND. Antiretroviral medications can vary as to the extent to which they are able to penetrate the blood-brain barrier, so those medications with the most central nervous system penetration may provide the most protection against HAND.
Stimulant medications may help fight fatigue and improve concentration, but these medications may not be appropriate for patients with a history of abusing stimulants. Antidepressants should be considered for patients experiencing depression in addition to HAND. Antipsychotic medications may alleviate symptoms of agitation and hallucinations, but they generally are only used when non-pharmacological measures are not enough to manage the symptoms.
Prevention & Prophylaxis
Following a structured routine, simplifying tasks, and using memory aids can make daily life easier for individuals with mild cognitive impairment. Those with HIV-associated dementia will need increased supervision and assistance to ensure their safety.