Dorsolateral prefrontal cortex connectivity in patients with primary insomnia: evidence from resting state functional magnetic resonance imaging / 中华神经科杂志

ABSTRACT

Objective To investigate cognitive impairment mechanism by studying dorsolateral prefrontal cortex connectivity in patients with primary insomnia.Methods Forty patients with primary insomnia and 50 healthy subjects from the Department of Neurology,People's Hospital of Zhengzhou University during the period April 2011 through April 2013 were included.The World Health OrganizationUniversity of California Los Angeles Auditory Verbal Learning Test (WHO-UCLA AVLT) and the digital pin test were applied to evaluate the subjects' word study ability and vigilance.Resting state functional magnetic resonance imaging was used to observe the connectivity of dorsolateral prefrontal cortex.Results The Pittsburgh Sleep Quality Index (2.00 (1.00,3.00)) and the Hamilton Anxiety Scale scores (13.00 (11.25,15.75)) of primary insomnia patients were significantly higher than that of healthy controls (11.00(9.00,13.00),1.00 (0,2.00),Z=-5.517,Z=-5.525,P＜0.01).Digital pin test efficiency (60.03％ ± 13.95％ vs 66.32％ ± 13.73％,t =2.142,P＜0.05) and WHO-UCLA word learning (10.11 ± 2.29 vs 11.95 ± 2.42,t =-3.493,P ＜ 0.01) of primary insomnia patients were significantly lower than that of healthy controls.Compared to the healthy controls,the right dorsolateral prefrontal cortex of primary insomnia patients exhibited decreased functional connectivity of the right prefrontal lobe (-2.610 3 ± 0.172 6,t =-3.504,P ＜ 0.05).The left dorsolateral prefrontal cortex of primary insomnia patients exhibited increased functional connectivity of the bilateral insular lobes and right prefrontal lobe (2.8204±0.326 5,2.371 7 ±0.106 6,2.492 6 ±0.052 8,t =4.032,t =3.340,t =3.037,P ＜0.05).Conclusions The ability of WHO-UCLA word study and the digital pin test efficiency have been shown to decline in patients with primary insomnia.The possible mechanism of cognitive impairment may be the abnormal dorsolateral prefrontal cortex connectivity in patients with primary insomnia.