333. Covert Cognitive Impairment in Asymptomatic ART-Nave HIV-Infected Patients a Clinical and fMRI Study
Session: Poster Abstract Session: HIV Co-morbidities
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
  • Poster_Print.pdf (1.2 MB)
  • Background:

    HIV causes a range of neurological and neuro-cognitive disorders. While severe disorders have become uncommon in the ART (Anti-Retroviral Therapy) era, mild cognitive decline is still documented in 21-30% of ART- treated patients. However, the influence of the virus on the brain of neurologically asymptomatic unmedicated HIV–infected patients with a CD4 T cell count above 350/mm3 has not been studied. We hypothesized that the presence of HIV in the brain of these patients may impair brain activity well before the emergence of clinically detectable cognitive deficits. 


    Twelve otherwise healthy asymptomatic unmedicated male HIV–infected patients with a CD4 T cell count above 350/mm3and twelve sero-negative age-matched healthy male controls underwent a clinical and fMRI examination while performing the N-back task, which is an extensively-studied test of working memory and executive functions. Analysis was focused on task-relevant brain activity and functional connectivity.


    Both groups performed the N-back task with equal accuracy, precision and reaction times. Additionally, all participants displayed activations in the expected task-relevant brain areas, including the supplementary motor area, the pre-motor area, the lateral prefrontal cortex and the posterior parietal cortex. However, these activations were significantly reduced in patients. Furthermore, patients displayed right lateralization of brain activity with increasing task difficulty, known to signify increased cognitive and attentional load. Finally, there was significantly reduced functional connectivity in working memory networks in patients relative to controls. 


    Our results demonstrate that HIV adversely affects brain function in clinically asymptomatic, untreated patients with a seemingly normally functioning immune system. Interestingly, similar brain abnormalities have been described in patients suffering from symptomatic HIV associated neuro-cognitive dysfunction. Thus, they may be an early biomarker for HIV infection of the brain which can later develop into cognitive impairment. If so, they may provide an additional reason for early initiation of ART in HIV-infected patients, regardless of the CD4 T cell counts.

    Haggai Sharon, MD1,2,3, Sari Ziv, MD3, Dan Turner, MD2,4, Talma Hendler, MD PhD1,2,5 and David Hassin, MD2,3,4, (1)Functional Brain Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, (2)Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel, (3)Internal Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, (4)Infectious Diseases Unit and HIV Clinic, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, (5)Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel


    H. Sharon, None

    S. Ziv, None

    D. Turner, None

    T. Hendler, None

    D. Hassin, None

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