A magnetic resonance spectroscopy study on cerebellar nuclei in patients with insomnia disorder / 中国神经精神疾病杂志

ABSTRACT

Objective The objective of this study was to utilize proton magnetic resonance spectroscopy (1H-MRS) to assess metabolites in cerebellar nuclei in unmedicated patients with insomnia disorder. Methods 1H-MRS was performed on cerebellar nuclei in 23 unmedicated patients with insomnia disorder (insomnia group) and 18 normal sleepers (control group). N-acetylaspartate (NAA), choline-containing compound (Cho) and creatine (Cr) were measured and the ratios of NAA/Cr and Cho/Cr were determined.Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were used to assess the subjective sleep quality and insomnia severity of all subjects, while State-Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI) were used to assess the levels of anxiety and depression of all subjects. Sleep parameters of all subjects were measured by polysomnography (PSG). Results Mean NAA/Cr ratio of right cerebellar nuclei in insomnia group was significantly lower than that in control group (1.72±0.37 vs. 2.03±0.50, t=2.280, P=0.028). Mean NAA/Cr ratio of right cerebellar nuclei was significantly higher than that of left cerebellar nuclei within control group (2.03±0.50 vs. 1.68±0.21, t=3.386, P=0.004). There was no significant difference with regard to NAA/Cr ratio between bilateral cerebellar nuclei within insomnia group (t=1.416, P=0.171). Across all subjects, PSQI global scores (r=-0.369, P=0.018), and sleep latency (r=-0.437, P=0.004) and number of awakenings after sleep onset (r=-0.432, P=0.005) measured by PSG were negatively correlated with NAA/Cr ratios of right cerebellar nuclei, while percentages of stage 3 sleep (r=0.377,P=0.015) measured by PSG were positively correlated with NAA/Cr ratios of right cerebellar nuclei,respectively. Conclusion Patients with insomnia disorder have a hemispherically lateralized metabolic disturbance of NAA/Cr in right cerebellar nuclei,indicating that patients with insomnia disorder have neuronal damage in right cerebellar nuclei.