Encephalopathy

Encephalopathy is the name of any one of several conditions of the brain associated with AIDS. These include:

• HIV encephalopathy
• HIV-associated progressive encephalopathy, which is seen in children
• AIDS dementia complex is a group of nerve problems due to HIV infection

With the use of highly active antiretroviral therapy, these disorders are much less widespread and severe than they used to be. 

Symptoms

The signs of encephalopathy affect thinking, behavior and movement.  The symptoms include:

• Apathy
• Difficulty concentrating
• Difficulty finding words when speaking
• Forgetfulness
• Loss of bladder control
• Loss of interest in sex
• Slow hand movements
• Unsteady, clumsy movements of the arms, legs and torso
• Withdrawal from hobbies or social activities

The symptoms at first are vague and easy to overlook.  The symptoms grow worse and can lead to a vegetative state. An infant with HIV-associated progressive encephalopathy is slow to develop. In older children or teens, the signs are more like those of AIDS dementia complex. 

Causes

Usually nerve or brain disorders are due to the death of nerve cells. HIV doesn’t directly infect nerve cells. HIV may either infect or disturb cells (macrophages and microglia) that nurture and maintain the brain. The infected macrophages and microglia then produce toxins that set off a chain reaction that kill neurons (brain cells).

Another possibility is that the body’s immune system attacks the brain and spinal cord (an autoimmune response). Yet another possibility is that HIV infection disturbs the release of chemicals that allow cells of the brain to talk to each other. 

Prevention

The best defense against encephalopathy is highly active antiretroviral therapy. 

Diagnosis

In addition to taking a medical history and doing a physical exam, a doctor will do a neurological evaluation. Several types of tests or scans may be done to help diagnose encephalopathy.  They include:

• A mental status exam.  These are tests designed to show how well the thought processes are working.  They focus on issues such as memory, concentration, coordination, learning ability, speech and language abilities and abstract thinking.
• A spinal tap.  A sample of the fluid that surrounds the brain and spinal cord is taken for study under a microscope.  This not only helps pinpoint encephalopathy, it can rule out other possible reasons for the symptoms.
• Blood tests
• Computed tomography (CT) or magnetic resonance imaging (MRI) scans. CT scans can show signs of destroyed brain tissue. An MRI may be done if the CT scan is not clear. Both can help rule out other conditions that might be causing the symptoms.
• Electroencephalogram.  This test creates an image of the electrical activity in the brain.  In the late stages of AIDS dementia, the activity of the brain slows down. 

Treatment

The best way to prevent or treat encephalopathy is highly active antiretroviral therapy. Antiretrovirals that can cross the blood-brain barrier are preferred.  They include lamivudine (Epivir®), stravudine (Zerit®), zidovudine (Retrovir®), efavirenz (Sustiva®), nevirapine and indinavir (Crixivan®).

Any infections, vitamin deficiencies, thyroid problems or liver and kidney problems need to be treated as well.

Depression and behavioral disturbances can sometimes be helped with drug therapy. These include antidepressants or antipsychotics. (Antipsychotics help improve agitation, aggression, hallucinations or delusions.)

A doctor has to balance HAART with drugs to treat dementia. Sometimes these drugs interact badly when taken together.

A person with encephalopathy needs to:

• Stay active. Daily exercise helps the brain work better. It also reduces depression and anxiety.
• Challenge the mind. Working puzzles, games, reading and safe hobbies and crafts are like exercise for the brain.
• Stay socially active. See friends and relatives. This keeps the mind active and emotions balanced.
• Eat a balanced, nutritious diet with plenty of fruits and vegetables. This helps keep weight at a healthy level. It also prevents malnutrition and constipation.
• Give up smoking or using tobacco products. The nicotine in tobacco cuts down the flow of blood through the body. Smoking can be dangerous for someone who is forgetful or can’t concentrate.