Kleindorfer et al2021 Guideline for the Secondary Prevention of Ischemic Stroke AdherenceA key component of secondary stroke prevention is assessing and addressing barriers to adherence to medications and a healthy lifestyle. If a patient has a recurrent stroke while on secondary stroke prevention medications, it is vital to assess whether they were taking the medications that they were prescribed and, if possible, to explore and address factors that contributed to nonadherence before assuming that the medications were ineffective. Antithrombotic DosingUnless stated otherwise in the recommendations herein, the international normalized ratio (INR) goal for warfarin is 2.0 to 3.0 and the dose of aspirin is 81 to 325 mg. Application Across PopulationsUnless otherwise indicated, the recommendations in this guideline apply across race/ethnicity, sex, and age groups. Special considerations to address health equity are delineated in section 6.3, Health Equity. DIAGNOSTIC EVALUATION FOR SECONDARY STROKE PREVENTION Recommendations for Diagnostic EvaluationReferenced studies that support recommendations are summarized in online Data Supplements 1 and 2. CORLOE Recommendations 1 B-R Recommendations for Diagnostic Evaluation (Continued) COR LOE Recommendations

The anatomy of the arterial system supplying blood to the brain can influence the development of arterial disease such as aneurysms, dolichoectasia and atherosclerosis. As the arteries supplying blood to the brain develop during embryogenesis, variation in their anatomy may occur and this variation may influence the development of arterial disease. Angiogenesis, which occurs mainly by sprouting of parent arteries, is the first stage at which variations can occur. At day 24 of embryological life, the internal carotid artery is the first artery to form and it provides all the blood required by the primitive brain. As the occipital region, brain stem and cerebellum enlarge; the internal carotid supply becomes insufficient, triggering the development of the posterior circulation. At this stage, the posterior circulation consists of a primitive mesh of arterial networks that originate from projection of penetrators from the distal carotid artery and more proximally from carotid-vertebrobasilar anastomoses. These anastomoses regress when the basilar artery and the vertebral arteries become independent from the internal carotid artery, but their persistence is not uncommon in adults (e.g., persistent trigeminal artery). Other common remnants of embryological development include fenestration or duplication (most commonly of the basilar artery), hypoplasia (typically of the posterior communicating artery) or agenesis (typically of the anterior communicating artery). Learning more about the hemodynamic consequence that these variants may have on the brain territories they supply may help understand better the underlying physiopathology of cerebral arterial remodeling and stroke in patients with these variants.

ILInterleukin CD Cluster of differentiation INF Interferon SSPE Subacute sclerosing panencephalitis Subacute sclerosing panencephalitis (SSPE) is a chronic encephalitis occurring after infection with measles virus. The prevalence of the disease varies depending on uptake of measles vaccination, with the virus disproportionally affecting regions with low vaccination rates. The physiopathology of the disease is not fully understood; however, there is evidence that it involves factors that favour humoral over cellular immune response against the virus. As a result, the virus is able to infect the neurons and to survive in a latent form for years. The clinical manifestations occur, on average, 6 years after measles virus infection. The onset of SSPE is insidious, and psychiatric manifestations are prominent. Subsequently, myoclonic seizures usually lead to a final stage of akinetic mutism. The diagnosis is clinical, supported by periodic complexes on electroencephalography, brain imaging suggestive of demyelination, and immunological evidence of measles infection. Management of the disease includes seizure control and avoidance of secondary complications associated with the progressive disability. Trials of treatment with interferon, ribavirin, and isoprinosine using different methodologies have reported beneficial results. However, the disease shows relentless progression; only 5% of individuals with SSPE undergo spontaneous remission, with the remaining 95% dying within 5 years of diagnosis.

Dolichoectasia is an arterial disease that causes dilatation and/or tortuosity of the affected vessel. The prevalence of dolichoectasia increases with age, and this disease is also associated with other traditional cardiovascular risk factors. Multiple pathophysiological processes might lead to the development of dolichoectatic vessels, and activation of metalloproteinases and irregular turbulent blood flow seem to cause irreversible disruption of the internal elastic lamina. Intracranial dolichoectasia commonly presents with ischemic or hemorrhagic stroke, and/or cranial neuropathies. The posterior circulation is more frequently affected by the dolichoectatic process than the anterior circulation. A positive diagnosis of dolichoectasia requires visual assessment of vessel shape and, if the posterior circulation is affected, application of Smoker's criteria. Reproducible criteria that aid diagnosis of dolichoectasia in the anterior circulation are lacking. No specific treatment for dolichoectasia exists, and the surgical and medical therapies that have been used to treat this condition have not been systematically evaluated. More evidence is needed to better understand the underlying dilatatory artheriopathy that causes this disease, and to determine whether patients with dolichoectasia might benefit from early diagnosis. In this article, we provide a comprehensive review of current knowledge regarding dolichoectasia, and highlight gaps in our knowledge to aid future research.

Background and Purpose Silent brain infarction (SBI) on magnetic resonance imaging (MRI) has been proposed as a subclinical risk marker for future symptomatic stroke. We performed a systematic review and meta-analysis to summarize the association between MRI-defined SBI and future stroke risk. Methods We searched the medical literature to identify cohort studies involving adults with MRI detection of SBI who were subsequently followed for incident clinically-defined stroke. Study data and quality assessment were recorded in duplicate with disagreements in data extraction resolved by a third reader. Strength association between MRI detected SBI and future symptomatic stroke measured by a hazard ratio (HR). Results The meta-analysis included 13 studies (14,764 subjects) with a mean follow-up ranging from 25.7 to 174 months. SBI predicted the occurrence of stroke with a random effects crude relative risk of 2.94 (95% CI 2.24–3.86, P<0.001; Q=39.65, P<0.001). In the eight studies of 10,427 subjects providing HR adjusted for cardiovascular risk factors, SBI was an independent predictor of incident stroke (HR 2.08 [95% CI 1.69–2.56, P<0.001]; Q=8.99, P=0.25). In a subgroup analysis pooling 9,483 stroke-free individuals from large population-based studies, SBI was present in ~18% of participants and remained a strong predictor of future stroke (HR 2.06 [95% CI 1.64–2.59], p<0.01). Conclusions SBI is present in approximately one in five stroke-free older adults and is associated with a 2-fold increased risk of future stroke. Future studies of in-depth stroke risk evaluations and intensive prevention measures are warranted in patients with clinically unrecognized radiologically evident brain infarctions.