Stroke Alert: A Review of Current Clinical Stroke Literature

By Matthew E. Fink, MD, Interim Chair and Neurologist-in-Chief, Director, Division of Stroke & Critical Care Neurology, Weill Cornell Medical College and New York Presbyterian Hospital. Dr. Fink reports no financial relationships relevant to this field of study.

Intermittent fasting may reduce the risk and consequences of stroke in younger, rather than older animals

Arumugam TV, et al. Age and energy intake interact to modify cell stress pathways and stroke outcome. Ann Neurol 2010;67:41–52.

Age and obesity are known to be risk factors for the development of ischemic stroke, but it is unknown how these factors may influence the degree of brain injury or recovery. Epidemiological studies suggest that calorie-restricted diets that result in very low body-mass index may extend life. In a study using a mouse model of stroke, using middle cerebral artery occlusion, these investigators studied the effects of age, by looking at young, middle-aged, and old animals, and the impact of intermitted fasting on the degree of brain injury from stroke. In addition to severity of stroke and outcome, the investigators also measured a variety of inflammatory and pro-aptotic mediators in the fasting and control groups, to determine if fasting influenced the production of mediators that increased cell death.

Mortality from focal ischemic stroke was increased by advancing age, but decreased by fasting. Intermittent fasting reduced brain injury and functional impairment in the younger animals but not in the older ones. The basal and poststroke levels of neurotrophic factors, protein chaperones (heat shock protein 70 and glucose regulated protein 78), and the antioxidant enzyme heme oxygenase-1 were decreased, whereas levels of inflammatory cytokines were increased in the cerebral cortex and striatum of old mice compared with younger mice. Intermittent fasting increased levels of protective proteins and decreased levels of inflammatory cytokines in the younger animals, but not in the older ones.

Modern medical therapy, especially the use of statins, can slow carotid artery atherosclerosis progression and subsequent stroke risk.

Spence JD, et al. Effects of intensive medical therapy on microemboli and cardiovascular risk in asymptomatic carotid stenosis. Arch Neurol 2010;67:180-186.

Asymptomatic carotid artery stenosis (acs) >60% may be treated with endarterectomy or stenting, but the real benefit of these interventions over modern medical therapy is unknown. When the ACS Trial was performed, there were few medical therapies available, and the potent statins were not used in the medical arm. Therefore, there is great interest in determining if modern medical therapy would now compare favorably to surgical intervention, but a new randomized trial is not likely to be initiated.

With this in mind, the investigators studied a cohort of 468 ACS patients, looking at microemboli by TCD, cardiovascular events, rate of carotid atherosclerosis progression, and medical therapies before and after 2003. Microemboli were present in 12.6% before 2003 and 3.7% since 2003. Since 2003, there have been significantly fewer cardiovascular events among patients with ACS: 17.6% had stroke, death, myocardial infarction, or carotid endarterectomy for symptoms before 2003, vs 5.6% since 2003. The rate of carotid plaque progression in the first year of follow-up has declined from 69 mm2 (SD, 96 mm2) to 23 mm2 (SD, 86 mm2). The changes in outcomes coincided with improved control of plasma lipids, and more aggressive management of hypertension. Modern medical management will continue to reduce the risk of stroke in patients with ACS and very few will require a surgical intervention.

Carotid endarterectomy remains the gold-standard in the treatment of symptomatic carotid artery stenosis

International Carotid Stenting Study Investigators. Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): An interim analysis of a randomised controlled trial. Lancet (early online publication) 26 February 2010 doi:10.1016/S0140-6736(10)60239-5.

The icss was a multicenter, randomized trial designed to directly compare the short-term safety and long-term efficacy of carotid artery stenting (CAS) compared to carotid artery endarterectomy (CEA) in patients with symptomatic carotid artery stenosis. The three-year outcome data is still being analyzed; this report gives 120 day safety data for the two groups.

The trial enrolled 1,713 patients (stenting group, n = 855; endarterectomy group, n = 858). Between randomisation and 120 days, there were 34 (4•0%) events of disabling stroke or death in the stenting group compared with 27 (3•2%) events in the endarterectomy group (hazard ratio [HR] 1•28, 95% CI 0•77–2•11). The incidence of stroke, death, or procedural myocardial infarction was 8•5% in the stenting group compared with 5•2% in the endarterectomy group (72 vs 44 events; HR 1•69, 1•16–2•45, p = 0•006). Risks of any stroke (65 vs 35 events; HR 1•92, 1•27–2•89) and all-cause death (19 vs 7 events; HR 2•76, 1•16–6•56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. The initial safety data from this trial shows CEA to be favorable compared to CAS. However, the primary efficacy measure, outcome at three years, has yet to be analyzed and reported.

One day after the ICSS data was reported, the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) primary results were presented at the International Stroke Meeting in Texas (abstract # 197). The overall conclusion of the CREST trial was that CEA and CAS were comparable in terms of safety and efficacy. However, we will await publication of the results before making any further comments.

Obstructive sleep apnea after stroke may be missed

Arzt M, et al. Dissociation of obstructive sleep apnea from hypersomnolence and obesity in patients with stroke. Stroke 2010;DOI: 10.1161/STROKEAHA.109.566463.

Sleep-disordered breathing is a risk factor for stroke and other cardiovascular diseases, and the development of obstructive sleep apnea (OSA) after stroke is a significant risk factor for recurrent stroke and death. However, many stroke patients with this disorder are not recognized, and this study attempted to determine the clinical characteristics that would lead to a correct diagnosis of OSA.

Polysomnography was performed on 96 consecutive stroke patients admitted to a rehabilitation unit, and compared with a large community control group for severity of daytime sleepiness (Epworth Scale), body mass index, and severity of OSA. Compared with the community sample, patients with stroke with OSA had significantly lower Epworth Sleepiness Scale scores and body mass index for mild, moderate, and severe degrees of OSA. Therefore, many stroke patients who have OSA will be missed if they are screened with the usual tools to identify high risk groups. A high index of suspicion should be used when evaluating a stroke patient for sleep-disordered breathing.