[Note: The thalamus is a right and left pair of brain structures.]
Chronic fatigue syndrome (CFS) is characterized by disabling fatigue of unknown etiology. Sleep quality is poor in CFS patients. The thalamus is a key subcortical structure in sleep disorders and certain cognitive functions previously shown to be impaired in CFS patients. We investigated the association between subjective sleep quality and thalamic size in CFS.
Twelve right-handed otherwise healthy CFS patients [patients] and 12 age-, gender-, and handedness-matched healthy controls completed the Jenkins Sleep Questionnaire summing up responses on four items asking for a) difficulty in initiating sleep, b) awakening during the night, c) awakening during sleep with difficulty maintaining sleep, and d) awakening exhausted in the morning despite having slept as usual.
Thalamic size was determined by MR-based volumetry.
Logistic regression revealed that sleep problems significantly predicted CFS status (OR = 2.66, 95% CI 1.11-6.38), whereas total thalamic volume and thalamic size of either side did not.
More sleep problems correlated with greater total thalamic volume in patients (r=0.62, 95% CI 0.07-0.88, p=0.032) but not in controls (r=-.034, p=0.30).
In addition, more sleep problems also correlated with right thalamic size in patients (r=0.70, 95% CI 0.21-0.91, p=0.012) but not in controls (r=-.080, p=0.81).
The strength of correlations between sleep problems and total thalamic volume (p=0.028) and right thalamic volume (p=0.046), respectively, differed between patients and controls.
We found a positive relationship between more sleep problems and thalamic volume in CFS patients compared to non-CFS controls.
The finding provides a basis for further studies on a possible role of the thalamus in sleep complaints and fatigue of patients with CFS.
Source: Abstract 1664 from American Psychosomatic Society 65th Annual Meeting, Budapest, Hungary May 7-10, 2007. (From a pdf of all abstracts, only some of which have been published, at http://www.psychosomaticmedicine.org/misc/2007APSabstractsforjournal.pdf), by Lutgert T, von Kanel R, Remonda L, Wiest R, Kiefer C, Begre S. Departments of General Internal Medicine, Neuroradiology and General Internal Medicine, University Hospital, Berne, Switzerland.