Spontaneous oscillatory markers of cognitive status in two forms of dementia

AbstractAbnormal oscillatory brain activity in dementia may indicate incipient neuronal/synaptic dysfunction, rather than frank structural atrophy. Leveraging a potential link between the degree of abnormal oscillatory activity and cognitive symptom severity, one could localize brain regions in a diseased but pre ‐atrophic state, which may be more amenable to interventions. In the current study, we evaluated the relationships among cognitive deficits, regional volumetric changes, and resting‐state magnetoencephalography abnormalities in patients with mild cognitive impairment (MCI;N  = 10; age: 75.9  ± 7.3) or primary progressive aphasia (PPA;N  = 12; 69.7  ± 8.0), and compared them to normal aging [young (N  = 18; 24.6  ± 3.5), older controls (N  = 24; 67.2  ± 9.7]. Whole‐brain source‐level resting‐state estimates of relative oscillatory power in the delta (1–4 Hz), theta (4–7 Hz), alpha (8–12 Hz), and beta (15–30 Hz) bands were combined with gray matter volumes and cognitive scores to examine between‐group differences and brai n–behavior correlations. Language and executive function (EF) abilities were impaired in patients with PPA, while episodic memory was impaired in MCI. Widespread oscillatory speeding and volumetric shrinkage was associated with normal aging, whereas the trajectory in PPA indicated widespread oscil latory slowing with additional volumetric reductions. Increases in delta and decreases in alpha power ...

Source: Human Brain Mapping - November 12, 2018 Category: Neurology Authors: Priyanka P. Shah ‐Basak, Aneta Kielar, Tiffany Deschamps, Nicolaas Paul Verhoeff, Regina Jokel, Jed Meltzer Tags: RESEARCH ARTICLE Source Type: research