0855 A challenging case of nocturnal visual hallucinations in an elderly woman

Abstract

Introduction Nocturnal hallucinations can be part of a wide array of different disorders, like sleep disorders (e.g. narcolepsy), visual impairment (e.g. Charles-Bonnet syndrome), neurodegenerative disorders (e.g. Lewy Body Dementia) and psychiatric disorders (e.g. schizophrenia). We explore the differential diagnosis, the challenging diagnostic workup and the limited therapeutic options in this patient with complex visual nocturnal hallucinations. Report of Cases: A 64 year old woman was referred with detailed and vivid visual nocturnal hallucinations (seeing her dog smoking a cigar, seeing someone in the room moving her bed, etc.). The hallucinations started 1-2 months ago, were mainly present at night (both when falling asleep and during the night) but occasionally also during the day. She had also been suffering from worsening daytime sleepiness for 3-4 months, and from memory problems for 1 year. Cataplexy and sleep paralysis were absent. Clinical neurological examination was normal. The patient had been diagnosed in the past with OSAS. She had been treated with CPAP for 3 years and recent polysomnography showed good control of her apnea. She had also been diagnosed with Crohn’s disease, COPD and cardiomyopathy. Because of her age, the vivid hallucinations, and the memory problems, we first wanted to rule out Lewy Body Dementia. Neuropsychological testing ruled out dementia. MRI of the brain showed some white matter lesions, without substantial atrophy. At a subsequent multidisciplinary consultation, her cardiologist considered her cardiomyopathy as a contraindication for stimulants. Therefore, and because we believed the a priori probability for narcolepsy to be low, an additional MSLT was not considered useful. Based on further pulmonary tests, we hypothesized that hypoxia could play a role in the hallucinations and hypersomnolence. The hallucinations improved over time, the hypersomnolence remained, but we found there were no good treatment options available, considering the cardiac contraindications for stimulants. Conclusion There is a wide-ranging differential diagnosis for nocturnal visual hallucinations. The specific patient characteristics are important both for further diagnosis and treatment options. Support (If Any) Supported by the Funds Malou Malou, Perano, Georgette Paulus, JMJS Breugelmans and Gabrielle, François and Christian De Mesmaeker, Managed by the King Baudouin Foundation of Belgium, No. 2021-J1990130-222081.