Hypersomnia following paramedian thalamic stroke: A report of 12 patients

Abstract

Paramedian thalamic stroke (PTS) is a cause of organic hypersomnia, which in the absence of systematic sleep-wake studies has been attributed to disruption of ascending activating impulses and considered a "dearoused" state. However, an increasing mount of data suggests a role of the thalamus in sleep regulation and raises the possibility that a sleep disturbance contributes to hypersomnia in PTS. We evaluated 12 patients with magnetic resonance imaging-proven isolated PTS and hypersomnia with 10 to >20 hours of sleep behavior per day. Nocturnal polysomnographic findings paralleled the severity of hypersomnia. All subjects had increased stage 1 NREM sleep, reduced stage 2 NREM sleep, and reduced numbers of sleep spindles. In patients with severe hypersomnia, slow-wave (stages 3-4) NREM sleep was often reduced, but there were no major REM sleep alterations. Daytime sleep behavior was associated mostly with stage 1 sleep by electroencephalogram; there was no correlation between hypersomnia and results of nap tests. We conclude that hypersomnia following PTS is accompanied by deficient arousal during the day and insufficient spindling and slow-wave sleep production at night. These observations support the hypothesis of a dual role of the paramedian thalamus as "final common pathway' for both maintenance of wakefulness and promotion of NREM sleep.

Sleep Spindles – As a Biomarker of Brain Function and Plasticity

“…Bassetti et al (1996), reported in 12 patients showed nocturnal polysomnographic findings paralleled the severity of hypersomnia [128]. Hypersomnia following PTS is accompanied by deficient arousal during the day and insufficient spindling and slow wave production at night, The center of the ischemic lesion was the inferior region of dorsomedial nucleus(DM) and the medial anterior part of the CM(centromedian neucles), confirming the autopsy study of Castaine et al [131].…”

Evolution of Neurological, Neuropsychological and Sleep-Wake Disturbances After Paramedian Thalamic Stroke

“…[1][2][3][4] Patients typically also exhibit neurological symptoms such as vertical gaze palsy and other oculomotor deficits, Horner's syndrome, dysarthria, gait ataxia, and mild sensorimotor deficits. 3,[5][6][7][8][9][10] With the improvement of consciousness, neuropsychological problems such as executive, learning, and memory deficits become more evident.…”

Development of hypersomnia after bilateral paramedian thalamic stroke: case report

“…Paramedian talamik inme sonrası gelişen talamik hipersomninin patogenezinde ise, beyin sapı retiküler formasyondan talamusa uzanan noradrenerjik ve dopaminerjik aktive edici uyarıların oluşmaması vardır (4,5,7,8,9). Bassetti ve ark.…”

“…Talamusun vasküler sendromları üzerine yapılan çalışmalarda, özellikle paramedian arter infarktlarında uyanıklığın belirgin bir şekilde azaldığı belirtilmiştir (2). Hipersomni denilen bu durumun tedavisinde, aralarında levodopa'nın da bulunduğu bazı ilaçların faydalı olduğu bildirilmiştir (3)(4)(5). Burada, bilateral paramedian talamik infarkt sonrası hipersomni gelişen bir olgu ve uygulanan levodopa tedavisine verdiği olumlu yanıt sunulmaktadır.…”