The Tip of the Iceberg: Cerebellar Stroke in a Young Patient with Dyspnoea

Although ischemic stroke has traditionally been considered a disease of older patients with vascular risk factors, approximately 1 in 10 adults with ischemic stroke is younger than 50 years old, with a greater incidence in females specially in pregnant and post-partum women with a 3 times bigger risk.¹

About 10–20% of strokes in the young are the result of a large vessel occlusion yet secondary to atrial fibrillation or due to other pathologies including patent foramen ovale, endocarditis, cardiac tumors, or cardiomyopathies resulting in intracardiac thrombus. On the other hand, different causes from a cardiac origin may be, in order of frequency, vasculopathies such as cerebral artery dissection (25%) and reversible cerebral vasoconstriction syndrome (RCVS) (< 5%), genetic disorders, systemic cancer or infectious diseases.¹

Since cerebellar functions are broadly known for participating in balance, coordination and gait, motor abnormalities caused by the diseased cerebellum are mainly ataxia and dysmetria, just like the patient in our case.

Regarding cerebellar infarcts, it has been described that due to the smaller caliber of arteries supplying the cerebellum, embolism is less common than in the cerebral hemisphere. Bland cerebellar infarctions cause cystic necrosis of the tissue, and the lesion is restricted to the supply territory of the involved artery. Necrosis affects the entire thickness of the cerebellar cortex though Golgi epithelial cells and their processes, the Bergmann glia, show some resistance to the necrotic process. ²

When a stroke is suspected based on impaired consciousness or neurologic findings, beyond the initial evaluation at emergency consisting of brain and vascular imaging, electrocardiogram, and basic blood tests including coagulation status, during inpatient management serology, echocardiography, ultrasound, and other studies should be completed to identify a possible etiology according to the TOAST classification system.^1,3

Anyway young adults with stroke, even when matched for vascular risk factors, have a higher long-term risk of mortality, stroke, and myocardial infarction, than others their age^1, and also risk of malignant ventricular arrhythmias is increased after a stroke and is associated with sudden cardiac death (SCD).⁴

Therefore, it is necessary to determine whether there is a causal relationship between the abnormal ECGs, arrhythmias, and acute stroke, or whether they are simply coincidences⁵. In our patient, the diagnosis of heart failure was made in a different way than usual, with the first noticeable sign being an electrical complication resulting from severely damaged myocardium.

Advanced heart failure is defined as a chronic and irreversible disease in which severely reduced contractile function is unable to maintain the body's economy, resulting in multiple compensatory mechanisms and systemic hypoperfusion due to low cardiac output. Diagnostic criteria can be review on Table 1^6,7,8,9. In this scenario, patients become refractory to traditional therapies, but even if there is still some degree of response, some specialized interventions and treatments should be considered individually for each patient.⁶

As mentioned, patients with heart failure and reduced ejection fraction (LVEF < 35%) are at an increased risk of sudden cardiac death due to ventricular arrhythmias. Trial as SCD-HEFT and DANISH study have shown benefit in reducing SCD risk in patients with non-ischaemic cardiomyopathy who have a LVEF ≤35% with NYHA functional classe II-III, even when compared against amiodarone as in the SCD-HFT⁷. Hence, implantable cardioverter defibrillators (ICDs) represent the only available option proven to prevent arrhythmic SCD, with a greatest risk in those who already suffered from previous ventricular arrhythmic events. According to ESC and AHA guidelines, in these patients an ICD is recommended with a class IA indication when a survival >1 year is expected^7,8. But also, imaging findings and markers of increased arrhythmia risk can potentially be incorporated in the ICD decision making process such as genetic testing, circulating biomarkers, non-invasive electrophysiological testing between others.⁹