Bilateral thalamic stroke transiently reduces arousals and NREM sleep instability

Area of Science:

• Neuroscience
• Vascular Neurology
• Sleep Medicine

Background:

• The human thalami receive vascular supply from numerous perforating arteries with complex and variable distributions.
• The artery of Percheron is a rare anatomical variant supplying the paramedian thalami bilaterally.
• Occlusion of the artery of Percheron can lead to symmetric paramedian thalamic infarction, often causing impaired consciousness and hypersomnia.

Observation:

• A 68-year-old patient with artery of Percheron occlusion presented with severe disruption of sleep-wake schedules.
• EEG monitoring revealed irregular episodes of sleep and wakefulness occurring throughout the day and night.
• The patient experienced recurrent episodes of unresponsiveness, suggesting a link between thalamic function and arousal.

Findings:

• The study details the sleep-wake schedules, sleep structure, and microstructure in a patient with artery of Percheron occlusion.
• EEG data demonstrated a severely disrupted sleep-wake cycle following the infarction.
• Medial thalamic nuclei, crucial for arousal and sleep regulation, are implicated in the observed symptoms.

Implications:

• This case underscores the critical role of the thalamus, particularly medial nuclei, in maintaining normal sleep-wake regulation and arousal.
• Paramedian thalamic infarction should be considered in the differential diagnosis for patients presenting with recurrent unresponsiveness and altered consciousness.
• Understanding rare vascular variants like the artery of Percheron is essential for accurate diagnosis and management of neurological deficits.