Stroke Impact: Colon Problems And Severe Strokes

A severe stroke can cause colon problems, including constipation and fecal incontinence. The post-stroke constipation prevalence rate in stroke patients is 30-60%. Inactivity, lethargy, insufficient water or nutrition intake, depression, lack of exercise capabilities, cognitive impairment, reduced consciousness, and drug intake can all contribute to post-stroke constipation. In addition, stroke can cause intestinal microbiota changes, severe bowel obstruction, and inflammation.

Bowel function in acute stroke patients

Bowel dysfunction is a common complication following a stroke, with constipation being the most frequent bowel issue. A stroke can cause nerve damage and weak muscles, which can make it difficult to control your bowels. In addition, reduced physical activity and changes in diet after a stroke can also contribute to constipation.

A study on bowel function in acute stroke patients found that 51 stroke patients (29 males, mean age 63.4, onset 13.4 days) were divided into two groups: constipation (n=25) and non-constipation (n=26). The constipation group showed significantly prolonged colon transit time (CTT) in the ascending, descending, and entire colon, as well as more severe swallowing problems. The results also indicated that bowel function in acute stroke patients was associated with functional status and swallowing function. This highlights the need for intensive functional training for post-stroke constipation patients to improve their quality of life and enhance their rehabilitation treatment.

Another study assessed the prevalence of bowel dysfunctions in 98 hospitalized patients admitted for rehabilitation after a stroke. The results showed that the prevalence of bowel dysfunctions increased significantly after a stroke, with constipation being the most frequently reported issue. The chances of developing bowel dysfunctions increased sevenfold after a stroke. This study also found that the use of laxatives after a stroke was not statistically significant in improving bowel function.

The impact of a stroke on bowel function can vary depending on the location and extent of the brain damage. However, overall, stroke patients often experience bowel dysfunction, particularly constipation, which can affect their quality of life and rehabilitation process.

Stroke-induced intestinal paralysis

The activation of the SNS/HPA axis and the release of DAMPs after a stroke trigger microbiota dysbiosis and paralytic ileus, further promoting inflammation. The resulting immune response can lead to an overshooting systemic reaction that fuels ongoing inflammation in the degenerating brain and slows recovery.

The risk of stroke-induced intestinal paralysis is higher in patients with existing gastrointestinal disorders such as dysbiosis, hypertension, diabetes mellitus, and intestinal infections. The usage of laxatives has also been linked to an increased risk of stroke in patients with constipation.

The condition can be treated with a combination of different antibiotics, although this may not always lead to significant improvements in functional outcomes. Other potential therapies include healthy microbiota transplantation, prebiotics, probiotics, and dietary interventions.

Bowel dysfunction in patients admitted for rehabilitation

Bowel dysfunction is a common complication of stroke, and it can significantly impact a patient's quality of life and their rehabilitation treatment. The prevalence of bowel dysfunctions after a stroke is high, with studies reporting rates of up to 55%. The most frequent dysfunction is constipation, with incomplete evacuation and reduced bowel movement frequency also being common. These issues can be caused by various factors, including reduced physical activity, difficulty swallowing, changes in diet, and the use of certain medications.

In addition to constipation, fecal incontinence is another issue that can arise after a stroke. This is less common than constipation but can be very distressing for patients.

There are several strategies that can be employed to manage bowel dysfunction in patients admitted for rehabilitation:

• Dietary changes: Increasing fluid intake and consuming high-fiber foods such as vegetables, fruits, beans, and whole grains can help improve bowel function.
• Physical activity: Encouraging patients to stay active can help keep things moving in the colon.
• Bowel retraining: Scheduling bowel movements at the same time each day and avoiding straining can help retrain the bowel.
• Medication adjustments: Certain medications can cause constipation, so reviewing and adjusting medications may be necessary.
• Laxatives and enemas: In some cases, laxatives or enemas may be recommended to help ease constipation.

Further studies are needed to better understand and characterize bowel dysfunction after a stroke, as this area is currently underrepresented in the literature.

Stroke as a first manifestation of colon cancer

It is rare for occult cancer to present with frequent ischemic stroke as its sole manifestation. However, there is a reported case of a 46-year-old man who experienced frequent strokes in different vascular areas as the initial presentation of occult colon cancer. The patient had no prior systemic disease but had identified risk factors of diabetes and hypercholesterolemia.

The patient was first admitted after experiencing acute bi-ocular diplopia with right internuclear ophthalmoplegia. A survey for stroke risk factors revealed diabetes and hypercholesterolemia. The patient was discharged with aspirin, oral anti-diabetic medication, and a cholesterol-lowering agent. However, 14 days later, the patient experienced another episode of left tonic-gazing, Broca's aphasia, and right hemiparesis. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed acute infarcts in the left cerebellar hemisphere, left superior division of the middle cerebral artery, and watershed infarcts of the right parietal and occipital lobes. During hospitalization, normocytic anemia and occult blood in the stool were recorded.

Due to suspected cardiogenic embolus, another trans-thoracic cardiac echogram was arranged, but the results were unremarkable. As an alternative examination, multi-detector computed tomography (MDCT) was performed, which showed a thrombus in the posterior-lateral aspect of the left atrium. The results indicated non-bacterial thrombotic endocarditis (NBTE), which motivated the search for occult cancer. The level of carcinoembryonic antigen (CEA) was elevated, and adenocarcinoma of the ascending colon was confirmed through colonoscopy pathology.

The patient experienced another episode of consciousness disturbance with left hemiparesis and, unfortunately, died due to intractable intracranial hypertension and septic shock. This rare case highlights the importance of evaluating the possibility of occult cancer in patients with frequent strokes refractory to therapy, regardless of whether risk factors are identified. MDCT can be a valuable tool in detecting cardiogenic embolic sources in such patients.

Stroke-induced immunosuppression

Causes of SIIS

Firstly, a stroke triggers a powerful inflammatory cascade in the brain. This inflammation can lead to a decrease in the number of lymphocytes (a type of white blood cell that helps fight infection) and NK cells (a type of immune cell that helps destroy infected or cancerous cells) in the blood and spleen. This reduction in immune cells impairs the body's ability to defend itself against harmful pathogens.

Secondly, there is a shift from a lymphocyte phenotype T-helper (Th) 1 to a Th2 phenotype. This shift in lymphocyte phenotype alters the balance of immune responses, favouring an anti-inflammatory response over a pro-inflammatory one.

Lastly, the defence mechanisms of neutrophils and monocytes (types of white blood cells that help fight infection) are impaired, further weakening the body's ability to defend against pathogens.

Clinical Consequences of SIIS

The direct consequence of SIIS is an increased susceptibility to infections, particularly stroke-associated pneumonia (SAP). SAP is the most common infection following a stroke and has a significant impact on stroke outcome. Currently, there are no effective treatments or biomarkers to predict SAP, making it a significant challenge in stroke management.

Potential Therapies for SIIS

Some potential therapies for SIIS and post-stroke infections include:

• Local immunomodulation: This approach aims to modify the immune response in the lungs to prevent or treat SAP.
• Pharmacological blockade of the sympathetic pathway or HPA (hypothalamic-pituitary-adrenal) axis: This approach involves using β-blockers or glucocorticoid receptor antagonists to reduce stroke-induced immune dysfunction and improve functional outcome. However, the clinical relevance of this approach is still unclear.
• Boosting peripheral immunity: This strategy involves adoptive transfer of T or NK cells or injection of specific cytokines to reduce the rate of pneumonia and improve outcomes.

In conclusion, stroke-induced immunosuppression is a significant complication of stroke that increases the risk of infections, particularly SAP. Further research and clinical trials are needed to develop effective preventive and treatment strategies for SIIS and post-stroke infections.

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