Dementia and the Neurovirulence of HIV-1

HIV-1-Associated Cognitive-Motor Disorders: A Research-Based Approach to Diagnosis and Treatment

The diagnosis of human immunodeficiency virus type 1 (HIV-1)-associated cognitive-motor disorder--either minor cognitive-motor disorder (MCMD) or HIV-1-associated dementia (HAD)--is fraught with potential pitfalls for the clinician. Before making such a diagnosis, clinicians should exclude other etiologies by using neuroimaging, lumbar puncture, and serum chemistries to screen for opportunistic and non-opportunistic infections of the brain and meninges. Clinicians should also consider psychoneurotoxicity (caused from the use of psychoactive substances and prescribed medications) and psychopathology, such as mood, anxiety, and other disorders. In addition, a thorough medical history and physical examination, including a complete neurologic and neuropsychiatric mental status examination, are necessary for an accurate diagnosis. There is also a need for standardized neuropsychological and functional status tests, since the diagnostic criteria for these disorders are partly based on these criteria. Treatment targets should include subclinical cognitive-motor impairment and neuroprotection, as well as MCMD and HAD. Currently, zidovudine remains the best proven treatment for these disorders, but other nucleoside reverse transcriptase inhibitors, as well as nonnucleoside reverse transcriptase inhibitors and protease inhibitors, show promise, and selected agents from these classes are being tested in clinical trials. Other areas that should be investigated are the modulation of inflammatory mediators (such as tumor necrosis factor alpha), neurotransmitter manipulation (especially of dopamine), and nutritional interventions.

HIV-1 Infection, Neuroendocrine Abnormalities, and Clinical Outcomes

Different lines of evidence suggest that human immunodeficiency virus type 1 (HIV-1) infection is complicated by a variety of adverse effects on neuroendocrine systems. Soon after the discovery of HIV-1, reports began to appear suggesting that a number of neurotransmitter and neuroendocrine activities were negatively impacted by this infection. In 1987 it was observed that fine-needle aspiration of the lung in patients with acquired immunodeficiency syndrome resulted in syncopal reactions. Subsequently, an abnormality in the autonomic nervous system was reported in these patients. However, investigations in this area have remained limited due to the assumption that HIV-1-mediated activation of various endocrine systems was related to the major life stressor of living with a fatal disease. Evidence accumulated over the years has indicated, instead, that there are various other mechanisms in addition to life stressors that also play an important role in negatively impacting the neuroendocrine systems in this infection. This article examines various developments that have taken place in this area in order to provide avenues for future research.