Incidence of Poststroke Depression in Patients With Poststroke Dysphagia.

PURPOSE: Poststroke dysphagia and poststroke depression (PSD) can have devastating effects on stroke survivors, including increased burden of care, higher health care costs, poor quality of life, and greater mortality; however, there is a dearth of research examining depression in patients diagnosed with dysphagia after stroke. Thus, we aimed to study the incidence of PSD in patients with poststroke dysphagia to provide foundational knowledge about this patient population. METHOD: We conducted a retrospective, cross-sectional study of individuals with a primary diagnosis of acute ischemic stroke (AIS) and secondary diagnoses of dysphagia and/or depression using administrative claims data from the 2017 Medicare 5% Limited Data Set. RESULTS: The proportion of depression diagnosis in patients with poststroke dysphagia was significantly higher than the proportion of depression diagnosis in those without poststroke dysphagia during acute hospitalization: 12.01% versus 9.52%, respectively (p = .003). CONCLUSIONS: Our results demonstrated that persons with poststroke dysphagia were as, or slightly more, likely to have PSD compared to the general stroke population, and to our knowledge, they establish the first reported incidence of PSD in Medicare patients with dysphagia after AIS. Future research is warranted to further explore the effects of PSD on poststroke dysphagia.

Commentary: Addressing Racial Disparities in Stroke: The Wide Spectrum Investigation of Stroke Outcome Disparities on Multiple Levels (WISSDOM).

Racial-ethnic disparities in stroke recovery are well-established in the United States but the underlying causes are not well-understood. The typical assumption that racial-ethnic disparities in stroke recovery are explained by health care access inequities may be simplistic as access to stroke-related rehabilitation, for example, does not adequately explain the observed disparities. To approach the problem in a more comprehensive fashion, the Wide Spectrum Investigation of Stroke Outcome Disparities on Multiple Levels (WISSDOM) was developed to bring together scientists from Regenerative Medicine, Neurology, Rehabilitation, and Nursing to examine disparities in stroke "recovery." As a result, three related projects (basic science, clinical science and population science) were designed utilizing animal modeling, mapping of brain connections, and community-based interventions. In this article we describe: 1) the goals and objectives of the individual projects; and 2) how these projects could provide critical evidence to explain why racial-ethnic minorities traditionally experience recovery trajectories that are worse than Whites.

Marginal decision-making in the treatment of refractory epilepsy.

OBJECTIVE: Epilepsy surgery is one of the most effective treatments in modern medicine. Yet, it remains largely under-utilized, in spite of its proven efficacy. The referrals for epilepsy surgery are often delayed until it is too late to prevent the detrimental psychosocial effects of refractory seizures. The reluctance towards epilepsy surgery is influenced by the perceived risks of the procedure by practitioners and patients. This review discusses how, in general decision-making processes, one faces a natural tendency towards emphasizing the risks of the most immediate and operational decision (surgery), at times without contrasting these risks with the alternative (uncontrolled epilepsy). METHODS: In the field of economics, this bias is well recognized and can be overcome through marginal analysis, formally defined as focusing on incremental changes as opposed to absolute levels. RESULTS: Regarding epilepsy surgery, the risks and benefits of surgery are considered separately from the risks of uncontrolled epilepsy. For instance, even though surgery carries an ∼0.1-0.5% risk of perioperative mortality, the chance of sudden unexpected death with refractory epilepsy can be as high as 0.6-0.9% per year. It is suggested that the inadequate way of phrasing clinical questions can be a crucial contributing factor for the under-utilization of epilepsy surgery. SIGNIFICANCE: It is proposed that examining decision-making for epilepsy surgery in the context of marginal analysis may enable providers and patients to make more accurate informed decisions.

Stroke assessment with diffusional kurtosis imaging.

BACKGROUND AND PURPOSE: Despite being the gold standard technique for stroke assessment, conventional diffusion MRI provides only partial information about tissue microstructure. Diffusional kurtosis imaging is an advanced diffusion MRI method that yields, in addition to conventional diffusion information, the diffusional kurtosis, which may help improve characterization of tissue microstructure. In particular, this additional information permits the description of white matter (WM) in terms of WM-specific diffusion metrics. The goal of this study is to elucidate possible biophysical mechanisms underlying ischemia using these new WM metrics. METHODS: We performed a retrospective review of clinical and diffusional kurtosis imaging data of 44 patients with acute/subacute ischemic stroke. Patients with a history of brain neoplasm or intracranial hemorrhages were excluded from this study. Region of interest analysis was performed to measure percent change of diffusion metrics in ischemic WM lesions compared with the contralateral hemisphere. RESULTS: Kurtosis maps exhibit distinct ischemic lesion heterogeneity that is not apparent on apparent diffusion coefficient maps. Kurtosis metrics also have significantly higher absolute percent change than complementary conventional diffusion metrics. Our WM metrics reveal an increase in axonal density and a larger decrease in the intra-axonal (Da) compared with extra-axonal diffusion microenvironment of the ischemic WM lesion. CONCLUSIONS: The well-known decrease in the apparent diffusion coefficient of WM after ischemia is found to be mainly driven by a significant drop in the intra-axonal diffusion microenvironment. Our results suggest that ischemia preferentially alters intra-axonal environment, consistent with a proposed mechanism of focal enlargement of axons known as axonal swelling or beading.

Improving lesion-symptom mapping.

Measures of brain activation (e.g., changes in scalp electrical potentials) have become the most popular method for inferring brain function. However, examining brain disruption (e.g., examining behavior after brain injury) can complement activation studies. Activation techniques identify regions involved with a task, whereas disruption techniques are able to discover which regions are crucial for a task. Voxel-based lesion mapping can be used to determine relationships between behavioral measures and the location of brain injury, revealing the function of brain regions. Lesion mapping can also correlate the effectiveness of neurosurgery with the location of brain resection, identifying optimal surgical targets. Traditionally, voxel-based lesion mapping has employed the chi-square test when the clinical measure is binomial and the Student's t test when measures are continuous. Here we suggest that the Liebermeister approach for binomial data is more sensitive than the chi-square test. We also suggest that a test described by Brunner and Munzel is more appropriate than the t test for nonbinomial data because clinical and neuropsychological data often violate the assumptions of the t test. We test our hypotheses comparing statistical tests using both simulated data and data obtained from a sample of stroke patients with disturbed spatial perception. We also developed software to implement these tests (MRIcron), made freely available to the scientific community.