Factors behind poor cognitive outcome following a thalamic stroke

Area of Science:

• Neuroscience
• Cognitive Neurology
• Stroke Research

Background:

• Thalamic strokes can cause varied neurological, cognitive, and behavioral symptoms.
• While severe deficits were once assumed, recent evidence suggests milder impairments are common.
• Identifying factors influencing cognitive outcomes after thalamic stroke is crucial.

Purpose of the Study:

• To determine factors influencing cognitive impairment severity in patients with thalamic stroke.
• To differentiate cognitive profiles and identify predictors of poor outcomes.

Main Methods:

• Neuroimaging and neuropsychological assessments were performed on 40 patients with chronic isolated thalamic stroke and 45 healthy controls.
• Cluster and principal component analyses identified cognitive profiles.
• Disconnectome mapping and cortical thickness analysis explored distant effects of thalamic lesions.

Main Results:

• Two distinct cognitive profiles emerged: one with minimal deficits (Cluster 1) and another with severe verbal memory, executive function, and attention deficits (Cluster 2).
• Cluster 1 included healthy subjects and patients with right-sided or no thalamic stroke.
• Cluster 2 comprised patients with bilateral strokes, mammillothalamic tract interruption, or left-sided strokes with specific lesion characteristics (lateral, anterior projection disruption).

Conclusions:

• Contrary to traditional views, many thalamic stroke patients exhibit relatively good cognitive outcomes.
• Specific factors, including lesion laterality, tract involvement, and volume, predict poor cognitive performance.
• Findings aid clinicians in anticipating and managing cognitive deficits post-thalamic stroke.