Potential utility of resting-state magnetoencephalography as a biomarker of CNS abnormality in HIV disease

There is a lack of a neuroimaging biomarker for HIV-Associated Neurocognitive Disorder. We report magnetoencephalography (MEG) data from patients with HIV disease and risk-group appropriate controls that were collected to determine the MEG frequency profile during the resting state, and the stability of the profile over 24 weeks. 17 individuals (10 HIV+, 7 HIV-) completed detailed neurobehavioral evaluations and 10 min of resting-state MEG acquisition with a 306-channel whole-head system. The entire evaluation and MEG measurement were repeated 24 weeks later. Relative MEG power in the delta (0-4 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (12-30 Hz) and low gamma (30-50 Hz) bands was computed for 8 predefined sensor groups. The median stability of resting-state relative power over 24 weeks of follow-up was .80 with eyes closed, and .72 with eyes open. The relative gamma power in the right occipital (t(15)= 1.99, p < .06, r = -.46) and right frontal (t(15) = 2.15, p<.05, r = -.48) regions was associated with serostatus. The effect of age on delta power was greater in the seropositive subjects (r(2) = .51) than in the seronegative subjects (r(2) = .11). Individuals with high theta-to-gamma ratios tended to have lower cognitive test performance, regardless of serostatus. The stability of the wide-band MEG frequency profiles over 24 weeks supports the utility of MEG as a biomarker. The links between the MEG profile, serostatus, and cognition suggest further research on its potential in HAND is needed. (C) 2012 Elsevier B.V. All rights reserved.