RT Journal Article SR Electronic T1 Extreme sleep pattern in Lewy body dementia: a hypothalamic matter? JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e228177 DO 10.1136/bcr-2018-228177 VO 12 IS 3 A1 Elisabet Londos A1 Oskar Hansson A1 Ingmar Rosén A1 Elisabet Englund YR 2019 UL http://casereports.bmj.com/content/12/3/e228177.abstract AB Excessive sleep during the night and for >2 hours during the day is part of the fluctuating wakefulness criterion of dementia with Lewy bodies (DLB). The phenomenon ‘sleep days’ is not uncommon in nursing homes. Here, we describe a woman who, for months, slept for 3 days and nights in a row and thereafter was awake for 3 days and nights. Electroencephalogram (EEG) showed slow background activity and increased delta activity. No epileptiform activity was detected. Polysomnography showed a severely disturbed, markedly fragmented sleep pattern. On her death, neuropathology revealed degeneration and loss of neurons along with α-synuclein-containing Lewy body inclusions and neurites in the substantia nigra, locus coeruleus, hypothalamus, and neocortex, thus fulfilling the criteria of DLB, cortical type. We propose that the hypothalamic degeneration contributed significantly to the clinical profile in this case. We suggest that patients with sleep days should be investigated for other DLB signs.