Perception of dreams and subjective sleep quality in patients with myasthenia gravis

Recent reports have led to the hypothesis of a central nervous system involvement in myasthenia gravis (MG). As the central cholinergic system also plays an important role in sleep/wake rhythms and in the regulation of REM sleep, sleep perception and dreaming may be altered in MG patients.

Seventeen consecutive patients with MG (mean age 49.5 +/- 13.6 years) and 14 healthy controls (mean age 50.5 +/- 16.0 years) were investigated by means of the Self-Rating Depression Scale, Self-Rating Anxiety Scale, Quality of Life Index, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale as well as a self-rating questionnaire for sleep and awakening quality and dreaming for 2 weeks.

Subjective sleep and awakening quality and sleep efficiency were reduced (p < 0.05), and the number of nocturnal awakenings (p = 0.02) as well as dream recall frequency (p = 0.02) were increased in patients with MG. Patients reported more often body-related and tactile sensations during dreaming (p = 0.001) and dreamed less often visually (p = 0.04). Dream content, emotions, and dream sources did not differ between both groups. Whereas the number of awakenings was related to dream recall frequency in healthy controls, no such a relationship was found in the patient group.

There is no clear evidence for the arousal-retrieval model of dream recall in patients with MG, but more for the continuity hypothesis of dreaming. Other factors such as the functional state of the brain, possibly related to a central cholinergic involvement in MG or its anticholinesterase treatment, may be important in explaining dream recall in this patient group.