Cognitive impairment in isolated subtentorial stroke.

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Subtentorial lesions in the brainstem or cerebellum are increasingly recognized as affecting neurocognitive circuitry.
• Understanding the cognitive impact of these specific stroke locations is crucial for comprehensive patient care.

Purpose of the Study:

• To investigate cognitive impairment in patients with isolated brainstem stroke (IBSS) and isolated cerebellar stroke (ICS).
• To compare the frequency and nature of cognitive deficits in IBSS and ICS to those with cerebral hemispheric lesions.

Main Methods:

• Utilized a hospital-based stroke registry for patient accrual (n=1360).
• Employed bedside cognitive screening and formal neuropsychological assessments to evaluate higher cortical functions.
• Defined cognitive impairment as scores at or below -1.5 standard deviations, adjusted for age and education.

Main Results:

• Isolated brainstem infarcts occurred in 38% and isolated cerebellar infarcts in 46.8% of relevant stroke cases.
• Cognitive impairment frequency in IBSS (53%) and ICS (35.1%) was comparable to cerebral infarcts (58% and 44.4%, respectively).
• Frontal/executive functions were most affected (47% impairment), followed by delayed recall (40%), while immediate memory and visuospatial skills were relatively spared.

Conclusions:

• Cognitive impairment is a common outcome of isolated subtentorial strokes.
• The prevalence of cognitive deficits is similar for isolated brainstem or cerebellar infarcts and comparable to cerebral lesions.
• Frontal networks and metacognitive functions represent the most frequently impaired cognitive domains.