Mental Fatigue Linked to Sensory Hypersensitivity in Stroke Survivors

The Hidden Burden of Sensory and Fatigue Symptoms After Stroke

Post-stroke recovery is frequently hindered by subjective symptoms that impair quality of life and limit rehabilitation efficacy. While clinicians often prioritize motor and cognitive deficits, fatigue remains a prevalent long-term sequela, with similar exhaustion patterns observed in 58% of patients following viral infections such as COVID-19 [1]. Despite its clinical impact, pharmacological interventions often fail to provide comprehensive relief; for instance, a meta-analysis of 1,001 patients found that modafinil only improved mental fatigue (mean difference -2.51; p = 0.0005) without significantly affecting physical or general fatigue [2]. Furthermore, the lack of standardized assessment tools complicates management, as many existing instruments like the Fatigue Severity Scale primarily measure physical dimensions rather than a patient's total lived experience [3]. Emerging evidence suggests that sensory processing issues, which involve how the brain organizes and responds to environmental stimuli, may be an overlooked factor in symptom persistence [4]. A new study investigates the intersection of sensory hypersensitivity and fatigue to clarify how these symptoms interact in the stroke population.

Quantifying the Co-occurrence of Post-Stroke Symptoms

To investigate the relationship between post-stroke fatigue and sensory hypersensitivity (an increased sensitivity to environmental stimuli), researchers conducted a cross-sectional study involving three distinct cohorts. The primary study population consisted of 139 people with stroke, whose outcomes were compared against two control groups: 91 people with orthopedic injury and 109 healthy adults. By including orthopedic patients, the authors aimed to differentiate symptoms specific to neurological injury from those associated with general physical trauma. Participants across all three groups were evaluated using two standardized instruments: the Fatigue in Daily Life Evaluation and the Multi-Modal Evaluation of Sensory Sensitivity. These tools allowed the researchers to capture the multidimensional nature of exhaustion and sensory processing across different clinical populations.

The data revealed a high prevalence of symptom overlap within the stroke cohort. Specifically, 41% of stroke participants reported both fatigue and sensory hypersensitivity, suggesting that these two conditions frequently manifest as a comorbid cluster. In contrast, 28% of the stroke group reported fatigue alone, while only 8% reported hypersensitivity alone. These findings indicate that while sensory sensitivity can occur in isolation, it is far more likely to present alongside fatigue in the post-stroke period. For the practicing physician, this means that any patient presenting with sensory complaints should be immediately screened for concurrent exhaustion. The researchers utilized structural equation modeling (a statistical method used to identify complex relationships between observed and unobserved variables) to further characterize these links, finding that sensory sensitivity was most strongly associated with mental fatigue rather than physical fatigue across all study groups.

The Specific Link Between Sensory Overload and Mental Fatigue

To clarify the underlying architecture of post-stroke symptoms, the researchers used structural equation modeling (a statistical technique that maps complex relationships between multiple variables) to characterize the exact link between fatigue and sensory sensitivity. This analysis revealed that the relationship is not uniform across all types of exhaustion. Across the 139 stroke patients, 91 orthopedic controls, and 109 healthy adults, sensory sensitivity showed a strong association with mental fatigue, suggesting that the cognitive effort required to process environmental stimuli may be a primary driver of exhaustion. In contrast, physical fatigue emerged as a more distinct concept from sensory sensitivity across all groups, indicating that the tiredness associated with bodily exertion operates through different physiological pathways than the fatigue triggered by sensory input.

The findings indicate that post-stroke fatigue and sensory hypersensitivity are interrelated but distinct symptoms, rather than redundant clinical markers. While they often co-occur, the data showed that mental fatigue had the strongest link to sensory sensitivity, providing a specific target for clinical assessment. This distinction is clinically relevant because stroke participants who presented with both symptoms reported significantly more severe fatigue than those experiencing fatigue alone, as confirmed by a Dunn test (a non-parametric statistical method for pairwise comparisons) with a holm-adjusted P value of less than 0.01. For the practicing physician, these results suggest that patients reporting sensory overload are at a higher risk for profound mental exhaustion, necessitating a multidimensional diagnostic approach that separates cognitive and physical fatigue components to better tailor rehabilitation strategies.

Clinical Implications for Patient Assessment and Rehabilitation

The researchers observed that the co-occurrence of fatigue and sensory hypersensitivity was not associated with demographic variables, medical history, stroke characteristics, or cognition. This lack of correlation indicates that traditional clinical markers, such as the patient's age, the specific vascular territory of the stroke, or the presence of comorbid medical conditions, cannot be used to predict which individuals will experience this dual burden. Furthermore, the absence of a link to cognitive performance suggests that even patients who score well on standard neuropsychological tests may still struggle with significant sensory-driven exhaustion. For the practicing physician, these findings emphasize that sensory and fatigue symptoms are largely independent of the primary neurological insult and require dedicated screening regardless of the stroke's severity or location.

Clinical management must account for the cumulative impact of these symptoms on patient well-being and recovery trajectories. The study demonstrated that stroke participants with both symptoms reported more severe fatigue than those with fatigue alone, a difference that reached statistical significance using a Dunn test (a non-parametric pairwise comparison) with a holm-adjusted P value of less than 0.01. This finding suggests that sensory hypersensitivity acts as a constant drain on a patient's limited energy reserves, leading to a more profound state of exhaustion. Consequently, rehabilitation strategies should move beyond a focus on motor recovery to include multidimensional assessments and individualized rehabilitation approaches that address the sensory environment. By implementing sensory management techniques and environmental modifications, such as reducing auditory or visual overstimulation, clinicians may be able to alleviate the mental fatigue that frequently hinders a patient's participation in therapy and daily activities.

References

1. López‐León S, Wegman-Ostrosky T, Perelman C, et al. More than 50 long-term effects of COVID-19: a systematic review and meta-analysis. Scientific Reports. 2021. doi:10.1038/s41598-021-95565-8

2. Petry INS, Tudella GCN, Maximiano MLDB, et al. Efficacy and safety of modafinil in post-stroke fatigue: a systematic review and meta-analysis.. Neurological research. 2026. doi:10.1080/01616412.2026.2631155

3. Wu L, Jin H. A systematic review of post-stroke fatigue measurement scale based on COSMIN guidelines.. Frontiers in neurology. 2024. doi:10.3389/fneur.2024.1411472

4. Patel K, Sutherland H, Henshaw J, et al. Effects of neurofeedback in the management of chronic pain: A systematic review and meta‐analysis of clinical trials. European Journal of Pain. 2020. doi:10.1002/ejp.1612