Extreme sleep pattern in Lewy body dementia: a hypothalamic matter?

Area of Science:

• Neurology
• Sleep Medicine

Background:

• Excessive sleep, including prolonged daytime napping, is a recognized symptom of fluctuating wakefulness in dementia with Lewy bodies (DLB).
• The phenomenon of 'sleep days,' characterized by prolonged sleep episodes, is observed in long-term care facilities.

Observation:

• A case study describes a woman experiencing cyclical sleep patterns of 3 days of continuous sleep followed by 3 days of wakefulness.
• Electroencephalogram (EEG) revealed slow background activity and increased delta activity, without epileptiform discharges.
• Polysomnography indicated severely disturbed and fragmented sleep architecture.

Findings:

• Neuropathological examination post-mortem confirmed cortical type dementia with Lewy bodies (DLB).
• Degeneration and neuronal loss were observed in the substantia nigra, locus coeruleus, hypothalamus, and neocortex, with α-synuclein Lewy bodies and neurites.
• Hypothalamic degeneration is proposed as a significant contributor to the patient's clinical presentation, particularly the sleep-wake cycle disturbances.

Implications:

• This case suggests a strong link between hypothalamic degeneration and the severe sleep disturbances seen in some DLB patients.
• It is recommended that individuals exhibiting 'sleep days' undergo thorough investigation for other clinical signs indicative of DLB.
• Early identification of DLB, even with atypical presentations like profound sleep disturbances, is crucial for patient management and care planning.