Cognitive Impairment in Young Stroke Survivors: An Epidemiological Study from Eastern India

Stroke has traditionally been characterized as a disease of aging; however, emerging epidemiological evidence demonstrates a rising incidence in younger adults, particularly those under 50 years of age.¹ While stroke mortality and major disability rates have declined due to advances in thrombolysis and rehabilitation, cognitive impairment—a frequent but under-recognized sequela—significantly impacts quality of life, vocational rehabilitation, and long-term functional independence in this productive population.

The World Health Organization defines stroke as a rapidly developing focal or global disturbance of cerebral function with symptoms lasting ≥24 hours without apparent non-vascular cause 2 Young stroke, defined in the Indian context as stroke occurring before age 50, comprises approximately 10–18.6% of all stroke cases, with increasing prevalence over the past two decades. Unlike elderly stroke populations, where physical recovery dominates clinical discourse, young stroke survivors face prolonged societal engagement, career progression, and family responsibilities that are substantially disrupted by cognitive sequelae.

Post-stroke cognitive impairment (PSCI) represents one of the most disabling consequences, affecting 30–70% of stroke survivors depending on assessment timing, methodology, and cohort characteristics.3 Earlier studies documented that 60% of patients develop cognitive impairment within 4–12 months post-stroke, with impairment persisting in 35% even at 11-year follow-up. More recent longitudinal analyses indicate that cognitive improvement predominantly occurs within the first six months, with minimal recovery thereafter—a finding suggesting that the critical three-month evaluation window captures early recovery dynamics and provides predictive value for long-term trajectories.4

Contrary to robust physical recovery documented in many young stroke patients, cognitive domains, including attention, executive function, processing speed, and memory, demonstrate inconsistent and often incomplete recovery patterns.5 This dissociation between physical and cognitive recovery has critical implications for return-to-work, academic pursuits, and social reintegration.6

A notable gap exists between cognitive assessment approaches in clinical practice versus research settings. Brief screening instruments (Mini-Mental State Examination, Montreal Cognitive Assessment) are more frequently employed in acute stroke settings than comprehensive neuropsychological batteries, potentially underestimating domain-specific impairments.7,8 Comprehensive cognitive assessment remains underutilized in young stroke cohorts, particularly in resource-limited settings.

This prospective observational study aimed to: (1) characterize the prevalence of cognitive impairment in young stroke survivors (aged 18–50 years) at three months post-stroke using MoCA (2) correlate cognitive outcomes with stroke risk factors and stroke characteristics (type, location, severity). This investigation addresses a significant gap in the Indian literature regarding structured cognitive assessment in young stroke survivors during the critical early recovery period.

The study cohort comprised 98 young stroke patients with a mean age of 42.9 ± 6.7 years (range 21–50), demonstrating a male predominance (62.2%). Slightly more than half of the participants were from rural areas (53.1%). The majority had educational attainment up to matriculation (75.5%), while 16.3% were graduates and 8.2% had post-graduate education, indicating a predominantly moderate educational background within the cohort (Table 1).

Table 1. Baseline Cohort Characteristics (n = 98)

Table 2. Stroke Characteristics in the study cohort:

Table 3. Detailed Cognitive Test Performance

Ischemic stroke constituted the majority of cases (85.7%), with hemorrhagic stroke accounting for 14.3%. Among ischemic subtypes, large-vessel disease was most common (42.9%), followed by lacunar infarction (21.4%) and cardioembolic stroke (12.2%). The middle cerebral artery territory was most frequently involved (49.0%), and hemiparesis was the predominant presenting symptom (76.5%). The mean admission GCS was 10.6 ± 1.2, while at three months patients demonstrated relatively favorable functional outcomes (mean mRS 1.9 ± 0.7) but reduced global cognitive performance (mean MoCA 20.3 ± 4.0) (Table 2).

At the three-month follow-up, a detailed neuropsychological assessment demonstrated uniform cognitive performance across domains. Mean TMT-A and TMT-B completion times were 68.1 ± 9.8 seconds and 171.4 ± 20.1 seconds, respectively. Verbal fluency, memory, language, visuospatial, and executive function scores—including Ten-Word List recall, TNI-93, Philadelphia Naming Test, and Taylor Complex Figure—were consistently within the 25th–50th percentile range relative to normative data. Territory-specific analysis revealed no significant domain-specific deficits attributable to stroke location, indicating mild but globally distributed cognitive impairment (Table 3).

Presence or absence of hypertension, diabetes mellitus, smoking, obesity, dyslipidemia, and cardiac abnormalities did not significantly influence MoCA scores or domain-specific cognitive test performance (all p>0.05). This finding suggests that in young stroke populations, vascular risk factor burden does not substantially modulate cognitive outcomes at the three-month assessment window.

This prospective assessment of 98 young stroke survivors at three months post-stroke using comprehensive neuropsychological testing demonstrated globally uniform cognitive performance across all assessed domains, without marked domain-specific deficits despite neuroimaging evidence of acute ischemia or hemorrhage. Several mechanisms may account for this pattern. First, cognitive reserve- the capacity of the brain to tolerate pathological insult through flexible cognitive processing- is substantially greater in younger cohorts compared to elderly populations¹⁸. Younger individuals exhibit enhanced neural plasticity, greater social and occupational cognitive engagement, and relatively higher educational attainment (75.5% completed matriculation or higher), potentially conferring protection against overt cognitive decline during early recovery. Second, timing of assessment is critical. The three-month interval represents a phase of maximal neuroplasticity and spontaneous recovery, characterized by cortical reorganization and restoration of penumbral tissue viability¹⁹. Longitudinal studies indicate that cognitive improvement often plateaus after six months, suggesting that persistent deficits may emerge later. Third, methodological considerations are relevant. Brief screening tools such as the MoCA, which demonstrate lower specificity, may report higher impairment prevalence (50-70% across populations) compared to detailed domain-specific batteries²⁰.

The findings differ from literature reporting post-stroke cognitive impairment (PSCI) prevalence of 30-70% at three months. Such variation may reflect methodological heterogeneity and differences in study populations. International studies frequently include older cohorts (mean age 65-75 years) with greater baseline cognitive vulnerability and vascular burden³. In contrast, the present young cohort (mean age 42.9 years) likely represents a biologically distinct phenotype characterized by greater cognitive reserve. Longitudinal analyses by Pendlebury and Rothwell² and data from the Stroke and Cognition Consortium demonstrate that cognitive decline often accelerates between one and three years post-stroke rather than within the initial three-month period. This temporal pattern supports preserved early cognitive performance with potential for delayed deterioration in younger survivors.

Several implications for clinical practice and research emerge. Comprehensive neuropsychological evaluation is essential, as brief screening measures may underestimate subtle but functionally relevant deficits in young stroke survivors²¹. Extended longitudinal follow-up at 6, 12, and 24 months is necessary to delineate cognitive trajectories and identify individuals at risk for progressive impairment⁴˒²². Interventions aimed at enhancing cognitive reserve-including structured cognitive rehabilitation, physical activity, occupational engagement, and continued education-may be particularly beneficial in younger populations where neuroplasticity remains robust²³. Given the central role of cognition in vocational functioning, detailed neuropsychological assessment should inform occupational rehabilitation planning, especially for individuals engaged in cognitively demanding professions⁶.

Several limitations warrant consideration. The absence of an age-matched control group limits determination of whether observed performance reflects preserved cognition or subtle impairment relative to stroke-free peers. The cross-sectional assessment at a single three-month time point restricts inference regarding cognitive trajectories, while the modest sample size may reduce power to detect subtle clinicocognitive associations. Minor variability in assessment timing (±2 weeks) and potential selection bias, particularly if more cognitively impaired individuals were unable to participate, may have influenced results. Educational heterogeneity may further limit applicability of normative comparisons. Future longitudinal studies incorporating assessments at 3, 6, 12, and 24 months⁴˒²⁴, inclusion of age-matched controls, larger sample sizes, advanced neuroimaging correlates such as diffusion tensor imaging and perfusion metrics²⁵˒²⁶, occupational outcome evaluation, and biomarker profiling including inflammatory markers²⁶˒²⁷ are necessary to better delineate cognitive trajectories and predictors of outcome.

This three-month neuropsychological evaluation of 98 young stroke survivors (18–50 years) demonstrated globally uniform cognitive performance across attention, executive, memory, language, and visuospatial domains, possibly reflecting greater cognitive reserve and neuroplasticity during early recovery or limitations of available assessment tools in detecting subtle deficits. Although these findings suggest relatively preserved early cognitive outcomes, interpretation requires caution due to the cross-sectional design, single timepoint assessment, and absence of control comparisons. Longitudinal prospective studies are necessary to delineate cognitive recovery trajectories, identify individuals at risk for delayed impairment, and refine targeted rehabilitation strategies in this economically productive population.