REM SLEEP DISORDERS IN LEWY BODY DISEASE—OR MAY THERE BE ANOTHER REASON?

Abstract

In 2017 a 68 year old patient came together with his wife to our outpatient memory department to have his cognitive functions evaluated. The wife complained about a very annoying aggressive sleep behavior, e.g. boxing in the night. This aggressive sleep disorder had been present for about one year. On inspection the patient showed movement disorders like in Parkinson's disease. Patient history, medication and other exams were collected. Moreover neuropsychological tests were done. Apart from an arterial hypertension and a diabetes mellitus type II no further diseases were known. The medication consisted in pantoprazol, citalopram 40 mg once daily, metamizol, candesartan and magnesium. The neurological examination showed a slow moving patient without tremor or rigor and without really typical symptoms for Parkinson's disease. The cognitive testing disclosed deficits in memory and visual construction (for example: clock drawing test score 4, MMSE 23 points, MoCA 17 points). The MRI showed a slight reduction of brain volume and only a few microvascular lesions. The Beta-Cit-SPECT did not point in the direction of Parkinson's disease. In the face of these results Lewy body disease was assumed, where REM sleep disorders are typical. But due to the fact that drugs like selective serotonin reuptake inhibitors (SSRI) may also induce aggressive sleep behavior, the family was advised to first reduce citalopram, but of course slowly to avoid a SSRI discontinuation syndrome. Despite this citalopram the patient discontinued citalopram rapidly and with the end of the citalopram therapy the aggressive sleep disorder disappeared. It was concluded that the first and very evident reason for the REM sleep disorders, the probable Lewy body disease, was not the only reason and that a methodical workup of the patient is important. The Lewy body disease may have laid the ground for a higher susceptibility for REM sleep disorders and that the SSRI had initiated the symptoms.