Cervical radiculopathy secondary to vertebral artery dissection: clinical features and outcomes

PURPOSE

Cervical radiculopathy due to various mechanical causes is commonly seen, however, cervical vertebral artery dissection (cVAD)-related radiculopathy is very rare with poorly characterized clinical outcomes. Thus, we conducted a systematic review of published literature and reported an institutional case to provide a better illustration of this rare entity.

METHODS

We systematically reviewed the PubMed literature and queried the clinical database at our center for cVAD-related radiculopathy. We described the baseline characteristics of patients with cVAD-related radiculopathy, the involved segment, diagnostic approach and treatment options.

RESULT

14 previously published studies met the inclusion criteria and along with the case we identified in our center, our study included 17 patients total (median age: 35 years, 9 females). C5 was the most commonly affected root and ipsilateral shoulder/arm pain along with shoulder abduction weakness was most common presentation. Antiplatelet or anticoagulant therapy was the treatment of choice. Most cases managed conservatively (82%). Majority of the cases (92%) had either complete or partial resolution of their symptoms.

CONCLUSION

Despite its limitations, this study show that cVAD related radiculopathy is a relatively benign entity with excellent clinical outcomes when managed medically.

Epidemiology of Spontaneous Cervical Artery Dissection: Population-Based Study

BACKGROUND

Cervical artery dissection (CeAD) represents up to 15% to 25% of ischemic strokes in people under the age of 50 years. Noninvasive vessel imaging is increasingly used in clinical practice, but the impact on the frequency of detection of CeAD is unknown. In 2006, the yearly incidence rate of CeAD was estimated at 2.6 per 100 000 person-years, but the current incidence is unknown.

METHODS

In this population-based retrospective observational cohort study, we utilized the resources of the Rochester Epidemiology Project to ascertain all adult residents of Olmsted County, MN, diagnosed with internal carotid artery dissection and common carotid artery dissection or vertebral artery dissection from 2002 to 2020. Patients with only intracranial involvement or CeAD following major trauma were excluded. Age-adjusted sex-specific and age- and sex-adjusted incidence rates were estimated using the US White 2010 decennial census, with rates expressed per 100 000 person-years. We assessed longitudinal trends by dividing the data into 5-year time intervals, with the last being a 4-year interval.

RESULTS

We identified 123 patients with a diagnosis of CeAD. There were 63 patients with internal carotid artery dissection, 54 with vertebral artery dissection, 2 with concurrent internal carotid artery dissection and vertebral artery dissection, and 4 with common carotid artery dissection. There were 63 (51.2%) female patients and 60 (48.8%) male patients. The average age at diagnosis was 50.2 years (SD, 15.1 [95% CI, 20.1-90.5] years). The incidence rate of spontaneous CeAD encompassing all locations was 4.69 per 100 000 person-years (2.43 for internal carotid artery dissection and 2.01 for vertebral artery dissection). The incidence rate increased from 2.30 per 100 000 person-years from 2002 to 2006 to 8.93 per 100 000 person-years from 2017 to 2020 (P<0.0001). The incidence rate for female patients rose from 0.81 per 100 000 person-years from 2002 to 2006 to 10.17 per 100 000 person-years from 2017 to 2020.

CONCLUSIONS

The incidence rate of spontaneous CeAD increased nearly 4-fold over a 19-year period from 2002 to 2020. The incidence rate in women rose over 12-fold. The increase in incidence rates likely reflects the increased use of noninvasive vascular imaging.

Coronavirus Disease 2019 Infection in Cervical Artery Dissections

OBJECTIVE

Most cervical artery dissection (CeAD) cases are spontaneous or due to minor traumas, and preceding viral infections have been suggested to be a triggering event for CeAD in some. Herein, we analyze the prevalence of coronavirus disease 2019 (COVID-19) in hospitalized patients with CeAD using a national database.

METHODS

The National Inpatient Sample was queried from April 2020 to December 2020 for patients with a diagnosis of CeAD using International Classification of Diseases, 10th edition-Clinical Modification codes. Among these, patients with COVID-19 were identified. Multivariable logistic regression was conducted to assess the patient profile of those with COVID-19, in-patient mortality, and home discharge among patients with CeAD.

RESULTS

There were 360 (2.32%) hospitalizations involving COVID-19 among 15,500 with CeAD. Concomitant acute ischemic stroke constituted 43.06% of those with a COVID-19 diagnosis, whereas it was 43.73% among those without a COVID-19 diagnosis ( P = 0.902). Home discharges were less common in patients with COVID-19 and CeAD compared to CeAD alone (34.85% vs. 48.63%; P = 0.03), but this was likely due to other factors as multivariate regression analysis did not show an association between COVID-19 and home discharges (odds ratio: 0.69; 95% CI: 0.39 to 1.25; P = 0.22). COVID-19 diagnosis had similar odds of inpatient mortality (odds ratio: 1.11; 95% CI: 0.43 to 2.84; P = 0.84).

CONCLUSION

The prevalence of COVID-19 among hospitalized patients with CeAD is low with 2.32% of all CeAD cases. Concomitant COVID infection did not lead to an increased risk of stroke in CeAD. However, potentially worse functional outcomes (fewer home discharges) without an increase in mortality were seen in patients with COVID and CeAD.

Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection: The STOP-CAD Study

Background: Small, randomized trials of cervical artery dissection (CAD) patients showed conflicting results regarding optimal stroke prevention strategies. We aimed to compare outcomes in patients with CAD treated with antiplatelets versus anticoagulation. Methods: This is a multi-center observational retrospective international study (16 countries, 63 sites) that included CAD patients without major trauma. The exposure was antithrombotic treatment type (anticoagulation vs. antiplatelets) and outcomes were subsequent ischemic stroke and major hemorrhage (intracranial or extracranial hemorrhage). We used adjusted Cox regression with Inverse Probability of Treatment Weighting (IPTW) to determine associations between anticoagulation and study outcomes within 30 and 180 days. The main analysis used an "as treated" cross-over approach and only included outcomes occurring on the above treatments. Results: The study included 3,636 patients [402 (11.1%) received exclusively anticoagulation and 2,453 (67.5%) received exclusively antiplatelets]. By day 180, there were 162 new ischemic strokes (4.4%) and 28 major hemorrhages (0.8%); 87.0% of ischemic strokes occurred by day 30. In adjusted Cox regression with IPTW, compared to antiplatelet therapy, anticoagulation was associated with a non-significantly lower risk of subsequent ischemic stroke by day 30 (adjusted HR 0.71 95% CI 0.45-1.12, p=0.145) and by day 180 (adjusted HR 0.80 95% CI 0.28-2.24, p=0.670). Anticoagulation therapy was not associated with a higher risk of major hemorrhage by day 30 (adjusted HR 1.39 95% CI 0.35-5.45, p=0.637) but was by day 180 (adjusted HR 5.56 95% CI 1.53-20.13, p=0.009). In interaction analyses, patients with occlusive dissection had significantly lower ischemic stroke risk with anticoagulation (adjusted HR 0.40 95% CI 0.18-0.88) (Pinteraction=0.009). Conclusions: Our study does not rule out a benefit of anticoagulation in reducing ischemic stroke risk, particularly in patients with occlusive dissection. If anticoagulation is chosen, it seems reasonable to switch to antiplatelet therapy before 180 days to lower the risk of major bleeding. Large prospective studies are needed to validate our findings.

Endovascular treatments of intracranial vertebral and internal carotid arteries dissections: An interactive systematic review and meta-analysis

INTRODUCTION

Management of intracranial artery dissection (IAD) remains elusive in medical practice. Intracranially, vertebral artery dissection (VAD) is more commonly encountered than internal carotid artery dissection (ICAD). Deconstructive (EVT-d) and reconstructive (EVT-r) endovascular techniques have been utilized to treat VAD and ICAD. This meta-analysis investigates the safety and efficacy of EVT-r and EVT-d in the management of VAD and ICAD.

METHODS

The literature was searched for all studies with consecutive patient series evaluating EVT-d or EVT-r for VAD or ICAD management. Baseline characteristics and outcomes were compared between EVT-r and EVT-d groups using the random-effect model and meta-regression approaches.

RESULTS

Overall, 1095 cases pooled from 56 studies were included. There was no statistically significant difference in baseline characteristics between VAD and ICAD. EVT-r was applied in 647 cases (59.1%) and EVT-d in the rest There was no statistical difference in the rate of procedural complications between EVT-r and EVT-d. Although EVT-d was significantly associated with higher rates of complete aneurysm occlusion (86.4%), lower rates of good clinical outcomes (72.1%) and higher mortality (15.1%) were achieved compared to EVT-r (70.2%, 83.3%, and 9.5%; respectively). The mortality rate was higher, and good clinical outcomes were less common in ruptured aneurysms. Ischemic presentation was statistically associated with poor outcomes (mRS 3-5) but low mortality. ICAD often tended to grow following treatment and resulted in poor neurological outcomes.

CONCLUSIONS

IAD has favorable outcomes when treated appropriately. Novel reconstructive endovascular techniques are promising and should be integrated well in endovascular practice. Further studies are warranted.

Moving From Alteplase to Tenecteplase for Acute Ischemic Stroke: Mayo Clinic Experience

OBJECTIVES

Tenecteplase is a fibrin-specific plasminogen activator that has shown promising results in the treatment of acute ischemic stroke. Tenecteplase has been suggested to reduce door-to-needle time and to increase the rate of spontaneous recanalization. In February 2021, Mayo Clinic Health System switched to Tenecteplase as the standard thrombolytic therapy for acute ischemic stroke.

METHODS

In this center-based observational cohort study, we present clinical characteristics and outcomes of patients with acute ischemic stroke treated with tenecteplase between February 2021 and May 2022 compared with alteplase treatment between September 2019 and February 2021. We used descriptive and comparative statistics.

RESULTS

Baseline characteristics were comparable between the groups. The incidence of symptomatic intracerebral hemorrhage was significantly less among the tenecteplase group (0.65% vs. 5%, P =0.027). Both groups had a similar door-to-needle time [55 (IQR 30.5) vs. 57 (IQR 38) in the tissue plasminogen activator group, P =0.395]. Spontaneous partial or complete recanalization was more commonly observed in the tenecteplase group (10.4% vs. 1.4%, P =0.038). Mechanical thrombectomy for large vessel occlusion was deferred due to marked clinical improvement more commonly in tenecteplase (6.3% vs. 1.4%); however, this difference was not statistically significant. Ninety-day modified Rankin Scale did not show a significant difference between the groups.

CONCLUSION

Tenecteplase use as the thrombolytic agent in acute ischemic stroke was associated with lower rates of symptomatic intracranial hemorrhage, higher rates of spontaneous recanalization, but similar door-to-needle time and 90-day modified Rankin Scale as compared with tissue plasminogen activator.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Neuromodulation for Post-Stroke Motor Recovery: a Narrative Review of Invasive and Non‑Invasive Tools

PURPOSE OF REVIEW

Stroke remains a leading disabling condition, and many survivors have permanent disability despite acute stroke treatment and subsequent standard-of-care rehabilitation therapies. Adjunctive neuromodulation is an emerging frontier in the field of stroke recovery. In this narrative review, we aim to highlight and summarize various neuromodulation techniques currently being investigated to enhance recovery and reduce impairment in patients with stroke.

RECENT FINDINGS

For motor recovery, repetitive transcranial magnetic simulation (rTMS) and direct current stimulation (tDCS) have shown promising results in many smaller-scale trials. Still, their efficacy has yet to be proven in large-scale pivotal trials. A promising large-scale study investigating higher dose tDCS combined with constraint movement therapy to enhance motor recovery is currently underway. MRI-guided tDCS studies in subacute and chronic post-stroke aphasia showed promising benefits for picture-naming recovery. rTMS, particularly inhibitory stimulation over the contralesional homolog, could represent a pathway forward in post-stroke motor recovery in the setting of a well-designed and adequately powered clinical trial. Recently evidenced-based guideline actually supported Level A (definite efficacy) for the use of low-frequency rTMS of the primary motor cortex for hand motor recovery in the post-acute stage of stroke based on the meta-analysis result. Adjunctive vagal nerve stimulation has recently received FDA approval to enhance upper limb motor recovery in chronic ischemic stroke with moderate impairment, and progress has been made to implement it in real-world practice. Despite a few small and large-scale studies in epidural stimulation (EDS), further research on the utilization of EDS in post-stroke recovery is needed. Deep brain stimulation or stent-based neuromodulation has yet to be further tested regarding safety and efficacy. Adjunctive neuromodulation to rehabilitation therapy is a promising avenue for promoting post-stroke recovery and decreasing the overall burden of disability. The pipeline for neuromodulation technology remains strong as they span from the preclinical stage to the post-market stage. We are optimistic to see that more neuromodulation tools will be available to stroke survivors in the not-to-distant future.

Advances in Stroke Neurorehabilitation

Stroke is one of the leading causes of disability worldwide despite recent advances in hyperacute interventions to lessen the initial impact of stroke. Stroke recovery therapies are crucial in reducing the long-term disability burden after stroke. Stroke recovery treatment options have rapidly expanded within the last decade, and we are in the dawn of an exciting era of multimodal therapeutic approaches to improve post-stroke recovery. In this narrative review, we highlighted various promising advances in treatment and technologies targeting stroke rehabilitation, including activity-based therapies, non-invasive and minimally invasive brain stimulation techniques, robotics-assisted therapies, brain-computer interfaces, pharmacological treatments, and cognitive therapies. These new therapies are targeted to enhance neural plasticity as well as provide an adequate dose of rehabilitation and improve adherence and participation. Novel activity-based therapies and telerehabilitation are promising tools to improve accessibility and provide adequate dosing. Multidisciplinary treatment models are crucial for post-stroke neurorehabilitation, and further adjuvant treatments with brain stimulation techniques and pharmacological agents should be considered to maximize the recovery. Among many challenges in the field, the heterogeneity of patients included in the study and the mixed methodologies and results across small-scale studies are the cardinal ones. Biomarker-driven individualized approaches will move the field forward, and so will large-scale clinical trials with a well-targeted patient population.

Spontaneous cervical artery dissection: is it really a connective tissue disease? A comprehensive review

Background

Spontaneous cervical artery dissection (sCeAD) is an important cause of stroke in young adults. The underlying pathophysiology remains unclear, without validated biomarkers to identify subjects at risk. Previous studies suggested the role of abnormalities in the connective component of the arterial wall.

Purpose

To assess dermal ultrastructural aberrations of connective tissue by skin biopsy and genetic variations in sCeAD patients.

Method

We searched the PubMed and Scopus databases until August 2023 with PRISMA guidelines. Original articles assessing skin biopsy in sCeAD patients were included. Two reviewers independently conducted the screening.

Findings

We included 16 studies compromising 459 patients. Thirteen studies assessed ultrastructural changes and found aberrations of collagen and elastic fibers, described as irregular contours and calibers of collagen fibrils, composite flower-like fibrils, fragmented moth-eaten elastin, and microcalcifications, cumulatively in 50.5% of patients. Seven studies showed no causative mutations in collagen type I, III, V, or elastin genes. One study showed linkage between connective tissue alterations and mutation on chromosomes 15q2 and 10q26 using genome-wide linkage analysis, while another study found significant copy number variant enrichments in genes involved in extracellular matrix (COL5A2/COL3A1/SNTA1) and collagen fibril organizations (COL5A2/COL3A1). Finally, differential expression of extracellular proteins was linked to connective tissue disorder in patients with recurrent sCeAD using a quantitative proteomics approach.

Conclusion

Current literature supports the hypothesis that an underlying, subclinical connective tissue disorder, likely genetically determined, may predispose to arterial wall weakness and sCeAD. Further studies with larger sample sizes and robust methodology are needed to better define the role of connective tissue in sCeAD pathogenesis.

Identifying the white matter pathways involved in multiple sclerosis-related tremor using diffusion tensor imaging

Background

Tremor affects up to 45% of patients with Multiple Sclerosis (PwMS). Current understanding is based on insights from other neurological disorders, thus, not fully addressing the distinctive aspects of MS pathology.

Objective

To characterize the brain white matter (WM) correlates of MS-related tremor using diffusion tensor imaging (DTI).

Methods

In a prospective case-control study, PwMS with tremor were assessed for tremor severity and underwent MRI scans including DTI. PwMS without tremor served as matched controls. After tract selection and segmentation, the resulting diffusivity measures were used to calculate group differences and correlations with tremor severity.

Results

This study included 72 PwMS. The tremor group (n = 36) exhibited significant changes in several pathways, notably in the right inferior longitudinal fasciculus (Cohen's d = 1.53, q < 0.001) and left corticospinal tract (d = 1.32, q < 0.001), compared to controls (n = 36). Furthermore, specific tracts showed a significant correlation with tremor severity, notably in the left medial lemniscus (Spearman's coefficient [rsp] = -0.56, p < 0.001), and forceps minor of corpus callosum (rsp = -0.45, p < 0.01).

Conclusion

MS-related tremor is associated with widespread diffusivity changes in WM pathways and its severity correlates with commissural and sensory projection pathways, which suggests a role for proprioception or involvement of the dentato-rubro-olivary circuit.

Risk Profile of Patients with Spontaneous Cervical Artery Dissection

OBJECTIVE

Epidemiological data to characterize the individual risk profile of patients with spontaneous cervical artery dissection (sCeAD) are rather inconsistent.

METHODS AND RESULTS

In the setting of the Italian Project on Stroke in Young Adults Cervical Artery Dissection (IPSYS CeAD), we compared the characteristics of 1,468 patients with sCeAD (mean age = 47.3 ± 11.3 years, men = 56.7%) prospectively recruited at 39 Italian centers with those of 2 control groups, composed of (1) patients whose ischemic stroke was caused by mechanisms other than dissection (non-CeAD IS) selected from the prospective IPSYS registry and Brescia Stroke Registry and (2) stroke-free individuals selected from the staff members of participating hospitals, matched 1:1:1 by sex, age, and race. Compared to stroke-free subjects, patients with sCeAD were more likely to be hypertensive (odds ratio [OR] = 1.65, 95% confidence interval [CI] = 1.37-1.98), to have personal history of migraine with aura (OR = 2.45, 95% CI = 1.74-3.34), without aura (OR = 2.67, 95% CI = 2.15-3.32), and family history of vascular disease in first-degree relatives (OR = 1.69, 95% CI = 1.39-2.05), and less likely to be diabetic (OR = 0.65, 95% CI = 0.47-0.91), hypercholesterolemic (OR = 0.75, 95% CI = 0.62-0.91), and obese (OR = 0.41, 95% CI = 0.31-0.54). Migraine without aura was also associated with sCeAD (OR = 1.81, 95% CI = 1.47-2.22) in comparison with patients with non-CeAD IS. In the subgroup of patients with migraine, patients with sCeAD had higher frequency of migraine attacks and were less likely to take anti-migraine preventive medications, especially beta-blockers, compared with the other groups.

INTERPRETATION

The risk of sCeAD is influenced by migraine, especially migraine without aura, more than by other factors, increases with increasing frequency of attacks, and seems to be reduced by migraine preventive medications, namely beta-blockers. ANN NEUROL 2023;94:585-595.

Safety of intravenous thrombolysis for ischemic stroke in patients with hematologic malignancies: A single institution experience

BACKGROUND

Data on safety of thrombolysis for acute ischemic stroke (AIS) in patients with hematologic malignancy is not well established. We report our single institution experience with thrombolysis in this patient population.

METHODS

We identified patients with pathology-confirmed hematologic malignancy from 2000-2022. Primary exposure was presence of AIS and receipt of intravenous (IV) thrombolysis. Primary outcome was safety of IV thrombolysis in this patient population. Safety was measured through imaging review for hemorrhagic transformation, post-stroke mortality, and modified Rankin Scale (mRS) at 90 days.

RESULTS

Among 45,894 patients with hematologic malignancy, 1,099 (2.4%) were identified as having a suspected AIS. Twenty (1.8%) received IV tissue plasminogen activator (tPA) for AIS, three underwent endovascular intervention, and 17 had AIS confirmed on MRI. Two patients with confirmed AIS experienced hemorrhagic transformation, one of which was symptomatic. Most patients (n=10, 59%) were functionally independent (mRS 0-2) at 90 days post-stroke, including all patients with active hematologic malignancy at the time of stroke (n=3). Four patients died within 90 days of AIS. None of these deaths were patients with active hematologic malignancy at the time of stroke.

CONCLUSIONS

Without other contraindications, IV alteplase should be considered for management of AIS in patients with hematologic malignancy. The safety profile of tPA administration in this patient population may be similar to the general population, whether underlying hematologic malignancy is active or in remission.

Corticocerebellar White Matter Integrity Is Related to Naming Outcome in Post-Stroke Aphasia

Studies have shown that the integrity of white matter tracts connecting different regions in the left cerebral hemisphere is important for aphasia recovery after stroke. However, the impact of the underlying structural connection between the cortex and the cerebellum in post-stroke aphasia is poorly understood. We studied the microstructural integrity of the cerebellum and the corticocerebellar connections and their role in picture naming. Fifty-six patients with left cerebral infarcts (sparing the cerebellum) underwent diffusion tensor imaging (DTI) and Boston Naming Test. We compared the fractional anisotropy (FA) and mean diffusivity (MD) values of the right and the left cerebellum (lobular gray and white matter structures) and cerebellocortical connections. Recursive feature elimination and Spearman correlation analyses were performed to evaluate the relationship between naming performance and the corticocerebellar connections. We found that the right, relative to left, cerebellar structures and their connections with the left cerebrum showed lower FA and higher MD values, both reflecting lower microstructural integrity. This trend was not observed in the healthy controls. Higher MD values of the right major cerebellar outflow tract were associated with poorer picture naming performance. Our study provides the first DTI data demonstrating the critical importance of ascending and descending corticocerebellar connections for naming outcomes after stroke.

Supporting Post-Stroke Language and Cognition with Pharmacotherapy: Tools for Each Phase of Care

PURPOSE OF REVIEW

There is enormous enthusiasm for the possibility of pharmacotherapies to treat language deficits that can arise after stroke. Speech language therapy remains the most frequently utilized and most strongly evidenced treatment, but the numerous barriers to patients receiving the therapy necessary to recover have motivated the creation of a relatively modest, yet highly cited, body of evidence to support the use of pharmacotherapy to treat post-stroke aphasia directly or to augment traditional post-stroke aphasia treatment. In this review, we survey the use of pharmacotherapy to preserve and support language and cognition in the context of stroke across phases of care, discuss key ongoing clinical trials, and identify targets that may become emerging interventions in the future.

RECENT FINDINGS

Recent trials have shifted focus from short periods of drug therapy supporting therapy in the chronic phase to longer terms approaching pharmacological maintenance beginning more acutely. Recent innovations in hyperacute stroke care, such as tenecteplase, and acute initiation of neuroprotective agents and serotonin reuptake inhibitors are important areas of ongoing research that complement the ongoing search for effective adjuvants to later therapy. Currently there are no drugs approved in the United States for the treatment of aphasia. Nevertheless, pharmacological intervention may provide a benefit to all phases of stroke care.

Supervised, Self-Administered Tablet-Based Cognitive Assessment in Neurodegenerative Disorders and Stroke

INTRODUCTION

As the population ages, the prevalence of cognitive impairment is expanding. Given the recent pandemic, there is a need for remote testing modalities to assess cognitive deficits in individuals with neurological disorders. Self-administered, remote, tablet-based cognitive assessments would be clinically valuable if they can detect and classify cognitive deficits as effectively as traditional in-person neuropsychological testing.

METHODS

We tested whether the Miro application, a tablet-based neurocognitive platform, measured the same cognitive domains as traditional pencil-and-paper neuropsychological tests. Seventy-nine patients were recruited and then randomized to either undergo pencil-and-paper or tablet testing first. Twenty-nine age-matched healthy controls completed the tablet-based assessments. We identified Pearson correlations between Miro tablet-based modules and corresponding neuropsychological tests in patients and compared scores of patients with neurological disorders with those of healthy controls using t tests.

RESULTS

Statistically significant Pearson correlations between the neuropsychological tests and their tablet equivalents were found for all domains with moderate (r > 0.3) or strong (r > 0.7) correlations in 16 of 17 tests (p < 0.05). All tablet-based subtests differentiated healthy controls from neurologically impaired patients by t tests except for the spatial span forward and finger tapping modules. Participants reported enjoyment of the tablet-based testing, denied that it provoked anxiety, and noted no preference between modalities.

CONCLUSIONS

This tablet-based application was found to be widely acceptable to participants. This study supports the validity of these tablet-based assessments in the differentiation of healthy controls from patients with neurocognitive deficits in a variety of cognitive domains and across multiple neurological disease etiologies.

Traumatic posterior cerebral artery dissection and dissecting aneurysms: A systematic review with an illustrative case report

BACKGROUND

Traumatic posterior cerebral artery (tPCA) dissection and dissecting aneurysms are rare and constitute a challenging clinical entity.

OBJECTIVE

We analyze existing literature on tPCA dissection and present our institutional experience.

METHODS

We retrospectively queried our database for tPCA isolated dissection or dissecting aneurysms from 2008 until now and conducted a systematic literature review of published cases. We analyzed the clinical and radiographic characteristics and treatment outcomes of tPCA dissection.

RESULTS

Including our case, a total of 11 cases with either isolated dissection (n = 2) or dissecting aneurysms (n = 9) were included. The median age was 27 years, and 45% were females. The median interval between trauma and tPCA dissection diagnosis was nine days. Mental status declined in four (36%) patients. Half of the patients demonstrated tentorial subdural hematoma on head CT. Ischemic stroke was detected in three (43%) patients. Four (36%) patients were conservatively managed, one (9.1%) patient was treated with surgical clipping of the proximal PCA, and six patients underwent endovascular treatments. The complication rate was 20%. Immediate total occlusion was demonstrated in five patients (100%), and the conservatively managed case showed immediate, spontaneous thrombosis of the aneurysm. Glasgow Coma Scale scores were 15 in eight (89%) and 14 in one (11%) patients at the last clinical follow-up with a median of six months. The mortality and retreatment rates were null.

CONCLUSIONS

tPCA dissection is diagnosed late and commonly affects the young population. The clinical outcome for this condition is typically favorable. Current endovascular techniques showed considerable efficacy and safety.

Abstract WP139: Current Practice Trends In The Management Of Cervical Artery Dissection - Preliminary Results

Introduction: Cervical artery dissection (CAD) is a well-recognized cause of acute ischemic stroke, especially in young adults, accounting for up to 20-25% of all cases. Several studies reported an incidence between 2.5-5 per 100,000 in the general population. However, the actual incidence may be higher as many patients remain asymptomatic. Even though CAD is one of the leading causes of ischemic stroke, there is a lack of consensus in management. Our study surveyed practicing clinicians involved in the management of CAD to characterize current practice trends and provide a foundation for future research.

Methods: An online case-based questionnaire with 11 questions regarding the management of cervical artery dissection was developed and piloted internally with 12 Mayo Clinic cerebrovascular neurologist/neurosurgeons. The survey was finalized, and initially sent to the STOP-CAD study group. We then sent the survey to practicing vascular neurologists across different academic institutions. Surveys were sent to 126 unique individuals.

Results: A total of 42 clinicians completed the questionnaires. The response rate was 33% (42/126). Aspirin antiplatelet monotherapy was seen as the most appropriate therapy for asymptomatic CAD (81% [34/42]). Anticoagulation was the treatment of choice for cases with CAD and concomitant intraluminal thrombus (74% [31/42]). Most (74% [31/42]) of the participants recommended repeat imaging at three months. However, no consistent response regarding the type of antithrombotic agent for symptomatic CAD without intramural thrombus or cases with pseudoaneurysm. There was marked variability regarding the duration of antithrombotic therapy, ranging from three months to life-long treatment.

Conclusion: Marked variability was seen in the management of CAD, especially regarding the choice of antithrombotic agent in symptomatic and complicated (stenosis or pseudoaneurysm) cases and the duration of such therapy, which reflects the lack of definitive clinical trial data. Ongoing research is needed to better guide the optimal management of these patients.

Abstract WP135: Trends In The Incidence Of Spontaneous Cervical Artery Dissection

Background: Arterial dissection represents a rare but significant cause of ischemic stroke. We hypothesized that the detection rate of arterial dissections has increased in recent decades.

Objective: To determine the incidence of cervical artery dissection in a defined population.

Methods: We identified Olmsted County, Minnesota residents diagnosed with carotid artery or vertebral artery dissection between 2002 and 2020 using the Rochester Epidemiology Project database. Patients who had suffered major trauma, were under 18 years of age or had intracranial artery dissections were excluded. Virtually all Olmsted County residents receive their medical care within the participating health systems, leading to a high likelihood of complete case ascertainment. We assessed longitudinal trends by dividing the data into 5-year time windows, with the last being a 4-year interval. Incidence rates were adjusted for age and sex.

Results: In a 19-year period from 2002 through 2020, 127 patients with a diagnosis of cervical artery dissection were identified. There were 64 females (50.4%) and 63 males (49.6%). The average age at diagnosis was 51.2 years (SD 15.7). There were 63 internal carotid artery dissections (ICAD), 60 vertebral artery dissections (VAD), and three common carotid artery dissections (CCAD) identified. One patient had ICAD and VAD at diagnosis. The overall incidence rate of detection for cervical artery dissection, adjusted for age and sex, was 4.9 per 100,000 person-years (py) (95% CI, 4.0 to 5.7). The incidence rate of ICAD was 2.5 per 100,000 py (95% CI, 1.8 to 3.1). The incidence rate of VAD was 2.3 per 100,000 py (95% CI, 1.7 to 2.9). The incidence rate of CAD gradually increased over time from 2.3 per 100,000 py (95% CI, 1.1 to 3.5) in 2002-2006 to 9.4 per 100,000 py (95% CI, 6.9 to 11.8) in 2017-2020, a 4.2-fold increase.

Conclusion: The incidence of detection rate of cervical artery dissection increased over four-fold in the last 19 years. This can potentially be attributed to increased usage of non-invasive angiographic imaging.

High-resolution MRI to noninvasively characterize drainage around the carotid artery into the cervical lymph nodes

BACKGROUND AND PURPOSE

Previous studies have proposed multiple parallel channels for waste clearance from the brain, though many gaps remain in our understanding of these systems. In this study, we examined periarterial fluid drainage around intracranial and extracranial segments of the internal carotid arteries (ICAs) from the brain into the cervical lymph nodes using a noninvasive and clinical-based method.

METHODS

Eighty-one subjects (45 females, aged 15-80 years old) with nonlesioned epilepsy underwent high-resolution 3-dimensional T2-weighted fluid-attenuated inversion recovery (FLAIR) MRI. We utilized a noninvasive and clinical-based method with a manual semiautomated approach to characterize the periarterial lymphatic system's maximum thickness and signal intensities along the ICAs using high-resolution 3-dimensional FLAIR imaging. We conducted group comparisons and correlation analyses to investigate sex- and age-based trends. Results were corrected with Bonferroni's test for multiple comparisons, and we performed power analysis for sample size calculations.

RESULTS

Using high-resolution FLAIR images, we show evidence that fluid drainage emerges around the ICA petrous segment and joins lymphatic flow from cranial nerves in the upper neck, with this flow ultimately draining into the cervical lymph nodes bilaterally. Lymphatic signal at the petrous segment level was significantly thinner in females compared to males bilaterally (w = 413, p = .0001 on the right, w = 356, p < .0001 on the left). Lymphatic drainage around the petrous segments of the ICAs bilaterally was thicker with age in males but not in females.

CONCLUSIONS

We describe the in vivo high-resolution imaging characteristics of periarterial fluid drainage along the vessel walls of ICAs. This represents a potentially major channel for brain waste clearance. We also report interesting sex- and age-based trends in these structures within our cohort.

Ischemic Stroke in Patients With Malignancy

Approximately one-quarter to one-third of patients with ischemic stroke have an embolic stroke of undetermined source (ESUS). An estimated 5% to 10% of patients with ESUS have an active cancer diagnosis. Presence of cancer potentially increases the risk of acute ischemic stroke through various mechanisms such as cancer-related hypercoagulability, intracranial tumors leading to an arterial compression, or intracardiac tumors leading to cardioembolism. Certain cancer therapeutics can also contribute to risk of ischemic stroke. Multiple vascular lesions involving bilateral anterior and posterior circulations, high plasma D-dimer levels, and elevated inflammatory markers might suggest cancer-related ischemic stroke. Patients with ischemic stroke related to malignancy are also at higher risk of stroke recurrence, early neurologic deterioration, and mortality. Cancer screening in acute ischemic stroke patients can be considered when no other etiology for stroke can be established and clinical history such as tobacco use, unexplained constitutional symptoms such as fever or night sweats, or unexplained weight loss suggests an underlying malignancy. Selection of antithrombotics for secondary stroke prevention remains controversial as clinical trial data for use of antiplatelet therapy vs anticoagulation in ESUS and cancer patients is limited. Future clinical trials should specifically focus on patients with ischemic stroke related to malignancy are needed to guide appropriate therapeutic agent selection.

Cervical Artery Dissections: Etiopathogenesis and Management

Cervical Artery Dissection (CeAD) is a frequent stroke etiology for patients younger than 50 years old. The most common immediate complications related to CeAD are headache and neck pain (65–95%), TIA/ischemic stroke (>50%), and partial Horner’s syndrome (25%). The prevailing hypothesis regarding the pathogenesis of sCeAD is that the underlying constitutional vessel wall weakness of patients with sCeAD is genetically determined and that environmental factors could act as triggers. The stroke prevention treatment of CeAD remains controversial, involving anticoagulation or antiplatelet therapy and potentially emergent stenting and/or thrombectomy or angioplasty for selected cases of carotid artery dissection with occlusion. The treatment of headache associated with CeAD depends on the headache phenotype and comorbidities. Radiographically, more than 75% of CeAD cases present with occlusion or non-occlusive stenosis. Many patients demonstrate partial and complete healing, more commonly in the carotid arteries. One-fifth of the patients develop dissecting pseudoaneurysm, but this is a benign clinical entity with an extremely low rupture and stroke recurrence risk. Good recovery is achieved in many CeAD cases, and mortality remains low. Family history of CeAD, connective tissue disorders like Ehlers-Danlos syndrome type IV, and fibromuscular dysplasia are risk factors for recurrent CeAD, which can occur in 3–9% of the cases. This review serves as a comprehensive, updated overview of CeAD, emphasizing etiopathogenesis and management.

Vitamin K antagonist versus novel oral anticoagulants for management of cervical artery dissection: Interactive systematic review and meta-analysis

Purpose:

Cervical artery dissection (CAD) represents a unique clinical entity with a high risk of ischemic stroke. Vitamin K antagonists (VKA) showed good efficacy in CAD management but are cumbersome to use with potentially higher bleeding rates. Novel oral anticoagulants (NOAC) are easier to use and may have similar effects but lower hemorrhagic risk. In this systematic review, we compare the efficacy of NOAC to VKA as a potential alternative treatment.

Methods:

The literature was searched on Pubmed, PMC, and Embase via API through the Nested Knowledge AutoLit software in February 2022 for studies evaluating both NOAC and VKA. Baseline characteristics, clinical and radiographic outcomes, and hemorrhagic and ischemic complications were collected for single and double-arm studies and analyzed using random-effect subgroup meta-analysis.

Findings:

Overall, 11 studies were included with 699 patients treated with VKA and 53 treated with NOAC (from three studies; two were head-to-head comparative studies). There was no statistical difference in the baseline characteristics of VKA and NOAC patients. The rates of TIA/stroke in VKA and NOAC groups were 12.3% (95% CI; 0%, 28.6%) and 5.7% (95% CI; 0%, 12.2%), respectively. Major bleeding or intracranial bleeding were comparable between groups. Lesions treated with VKA showed angiographic recanalization with a rate of 51.4% (95% CI; 35.6%, 67.1%) and for those treated with NOAC was 58.4% (95% CI; 23.9%, 93.9%). The rates of good clinical outcomes were 79.9% (95% CI; 67.6%, 92.2%) in the VKA group and 91.4% (95% CI; 78.1%, 100%) in NOAC. No statistical difference was noted among any of the outcomes between the two treatment groups.

Discussion and conclusion:

We highlighted comparable efficacy and safety of NOAC to VKA for stroke prevention in CAD. Further head-to-head studies are warranted to validate these results.

No evidence of impediment by three common classes of prescription drugs to post-stroke aphasia recovery in a retrospective longitudinal sample

A number of pharmaceuticals have been identified as potential adjuvants to speech language therapy following stroke, but it is also important to consider which pharmaceuticals may result in a less robust recovery. Here we examine whether post-stroke language recovery was meaningfully impeded by cholinergic, GABAergic, or dopaminergic medications patients received. Eighty participants with left hemisphere stroke were examined retrospectively to see whether the use of one of these three classes of medication prior to admission for acute stroke, during their inpatient stay, or at discharge was associated with differences in recovery on three common measures of language. While prescription of any of the candidate drugs was relatively uncommon, groups were very well matched for many common factors that impact performance. When age, education, and acute lesion volume were controlled, there were no significant differences in performance among those taking cholinergic, GABAergic, or dopaminergic medications and those who were not. Those who experienced a "good recovery" of language (≥10% improvement on any one language measure over time) had similar exposure to these drugs to those with a poor recovery. This work represents a first look at these drug classes with regard to their effects on the recovery of language after stroke and should not be interpreted as resolving all potential for concern, but these results do offer modest reassurance that these common classes of pharmacotherapy, when given for short periods in this population, do not appear to have marked deleterious effects on post-stroke recovery of language.

Craniocervical Artery Dissections: A Concise Review for Clinicians

Craniocervical artery dissection (CAD), although uncommon, can affect the young and lead to devastating complications, including stroke and subarachnoid hemorrhage. It starts with a tear in the intima of a vessel with subsequent formation of an intramural hematoma. Most CAD occurs spontaneously or after minor trauma. Patients with CAD may exhibit isolated symptoms of an underlying subclinical connective tissue disorder or have a clinically diagnosed connective tissue disorder. Emergent evaluation and computed tomography angiography or magnetic resonance imaging/angiography of the head and neck are required to screen for and to diagnose CAD. Carotid ultrasound is not recommended as an initial test because of limited anatomic windows; diagnostic catheter-based angiography is reserved for atypical cases or acutely if severe neurologic deficits are present. Patients with CAD can present with focal neurologic deficits due to ischemia (thromboembolism or arterial occlusion) or subarachnoid hemorrhage (pseudoaneurysm formation and rupture). Also common are local symptoms, such as head and neck pain, pulsatile tinnitus, Horner syndrome, and cranial neuropathy, or cervical radiculopathy from mass effect. Acute management of transient ischemic attack/stroke in CAD is not different from the management of ischemic stroke of other causes. Patients with CAD need long-term antithrombotic therapy for secondary stroke prevention. Anticoagulation or dual antiplatelet therapy followed by single antiplatelet therapy is recommended for extracranial CAD and antiplatelet therapy for intracranial CAD. Recurrent ischemic events and dissections are rare and typically occur early. Patients with CAD should avoid deep neck massage or chiropractic neck manipulation involving sudden excessive, forced neck movements.

Electroencephalogram (EEG) With or Without Transcranial Magnetic Stimulation (TMS) as Biomarkers for Post-stroke Recovery: A Narrative Review

Stroke is one of the leading causes of death and disability. Despite the high prevalence of stroke, characterizing the acute neural recovery patterns that follow stroke and predicting long-term recovery remains challenging. Objective methods to quantify and characterize neural injury are still lacking. Since neuroimaging methods have a poor temporal resolution, EEG has been used as a method for characterizing post-stroke recovery mechanisms for various deficits including motor, language, and cognition as well as predicting treatment response to experimental therapies. In addition, transcranial magnetic stimulation (TMS), a form of non-invasive brain stimulation, has been used in conjunction with EEG (TMS-EEG) to evaluate neurophysiology for a variety of indications. TMS-EEG has significant potential for exploring brain connectivity using focal TMS-evoked potentials and oscillations, which may allow for the system-specific delineation of recovery patterns after stroke. In this review, we summarize the use of EEG alone or in combination with TMS in post-stroke motor, language, cognition, and functional/global recovery. Overall, stroke leads to a reduction in higher frequency activity (≥8 Hz) and intra-hemispheric connectivity in the lesioned hemisphere, which creates an activity imbalance between non-lesioned and lesioned hemispheres. Compensatory activity in the non-lesioned hemisphere leads mostly to unfavorable outcomes and further aggravated interhemispheric imbalance. Balanced interhemispheric activity with increased intrahemispheric coherence in the lesioned networks correlates with improved post-stroke recovery. TMS-EEG studies reveal the clinical importance of cortical reactivity and functional connectivity within the sensorimotor cortex for motor recovery after stroke. Although post-stroke motor studies support the prognostic value of TMS-EEG, more studies are needed to determine its utility as a biomarker for recovery across domains including language, cognition, and hemispatial neglect. As a complement to MRI-based technologies, EEG-based technologies are accessible and valuable non-invasive clinical tools in stroke neurology.

Concussion in Women's Flat-Track Roller Derby

Concussions are common among flat-track roller derby players, a unique and under-studied sport, but little has been done to assess how common they are or what players can do to manage injury risk. The purpose of this study is to provide an epidemiological investigation of concussion incidence and experience in a large international sampling of roller derby players. Six hundred sixty-five roller derby players from 25 countries responded to a comprehensive online survey about injury and sport participation. Participants also responded to a battery of psychometric assessment tools targeting risk-factors for poor injury recovery (negative bias, social support, mental toughness) and players' thoughts and feelings in response to injury. Per 1,000 athletes, 790.98 concussions were reported. Current players reported an average of 2.2 concussions, while former players reported 3.1 concussions. However, groups were matched when these figures were corrected for differences in years of play (approximately one concussion every 2 years). Other frequent injuries included fractures in extremities and upper limbs, torn knee ligaments, and sprained ankles. We found no evidence that players' position, full-contact scrimmages, or flooring impacted number of concussions. However, neurological history and uncorrected vision were more influential predictors of an individual's number of concussions during roller derby than years of participation or age, though all four contributed significantly. These findings should assist athletes in making informed decisions about participation in roller derby, though more work is needed to understand the nature of risk.

Abstract TP78: Team-based Resident Training For Stroke Code Simulations Decreases Variations In Thrombolytic Door To Needle Times

Introduction: Stroke code simulation training is effective at reducing door to needle times (DTNT) for tPA administration. We aimed to evaluate the effect on DTNT from simulation training specifically for Neurology residents.

Method: Stroke code simulation was implemented at our comprehensive stroke center in July 2017, targeting PGY2 adult neurology residents and PGY3 pediatric neurology residents who were first responders at stroke codes during off-hours. Training was completed at the beginning of the residents’ respective training years. An interrupted time series analysis of DTNT for tPA before and after the implementation of simulation training from July 2016 to July 2019 was performed. Demographics, tPA metrics, and safety and hospital metrics were compared pre and post intervention among the residents. No other quality improvement projects targeting DTNT were implemented during this time.

Results: Between July 2016 and July 2019, 305 patients received thrombolysis from a resident first responder - 118 (39%) of whom were treated pre-simulation and 187 (61.3%) treated during the simulation period. There was no significant difference in patient baseline characteristics between the two groups (Table 1). Median DTNT was 49.5 (IQR 40-71) min during the pre-simulation period and 48 (IQR 37-60) min during the post-simulation period (p= 0.04). Compared to pre-simulation, there were no months in which the median DTNT exceeded 60 min post-simulation. IQR for the DTNT appeared both clinically and statistically different. Pre and post simulation, there was no difference in incidence of symptomatic intracranial hemorrhage nor in 90-day outcomes.

Conclusion: In our analysis of the effect of stroke code simulation training among neurology residents, improvement in DTNT after simulation training appears more driven by improvement in the variation in times rather than a clinically significant decrease in median times.

Disruptions of the Human Connectome Associated With Hemispatial Neglect

BACKGROUND AND OBJECTIVES

Hemispatial neglect is a heterogeneous and complex disorder that can be classified by frame of reference for "left" vs "right," including viewer-centered neglect (VCN, affecting the contralesional side of the view), stimulus-centered neglect (SCN, affecting the contralesional side of the stimulus, irrespective of its location with respect to the viewer), or both. We investigated the effect of acute stroke lesions on the connectivity of neural networks that underlie VCN or SCN.

METHODS

A total of 174 patients within 48 hours of acute right hemispheric infarct underwent a detailed hemispatial neglect assessment that included oral reading, scene copy, line cancellation, gap detection, horizontal line bisection tests, and MRI. Each patient's connectivity map was generated. We performed a linear association analysis between network connectivity strength and continuous measures of neglect to identify lesion-induced disconnections associated with the presence or severity of VCN and SCN. Results were corrected for multiple comparisons.

RESULTS

About 42% of the participants with right hemisphere stroke had at least one type of neglect. The presence of any type of neglect was associated with lesions to tracts connecting the right inferior parietal cortex, orbitofrontal cortex, and right thalamus to other right-hemispheric structures. VCN only was strongly associated with tracts connecting the right putamen to other brain regions and tracts connecting right frontal regions with other brain regions. The presence of both types of neglect was most strongly associated with tracts connecting the right inferior and superior parietal cortex to other brain regions and those connecting left or right mesial temporal cortex to other brain regions.

DISCUSSION

Our study provides new evidence for the specific white matter tracts where disruption can cause hemispatial neglect in a relatively large number of participants and homogeneous time after onset. We obtained MRI and behavioral testing acutely, before the opportunity for rehabilitation or substantial recovery.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that damage to specific white matter tracts identified on MRI are associated with the presence of neglect following right hemispheric stroke.

Clinical and neuroimaging characteristics of primary progressive aphasia

The chapter covers the clinical syndrome of a primary progressive aphasia (PPA), the demographics of this rare neurodegenerative disease, defining clinical and neuroanatomic characteristics of each PPA variant, disease progression, and behavioral features. The chapter begins with a brief introduction that includes references to seminal papers that defined this clinical syndrome and its three variants. The classic PPA subtypes discussed in the chapter are semantic variant PPA (svPPA), nonfluent/agrammatic PPA (nfaPPA), and logopenic variant PPA (lvPPA). The key language and cognitive characteristics, and language tasks that can elicit these language impairments, are detailed. Overlap in the clinical profiles of the PPA variants, which make differential diagnosis challenging, are explained. Disease progression is described, revealing that the PPA variants become more similar over time. Although PPA is language-predominant dementia, there are behavioral manifestations, particularly in svPPA. Changes in behavior in this variant are addressed as well as behavioral changes in nfaPPA and lvPPA that are less well recognized. The patterns of atrophy in the left temporal, parietal, and/or frontal cortices unique to each PPA variant are described. The underlying neuropathologies of the PPA variants are discussed, specifically tauopathies and non-tauopathies associated with svPPA and nfaPPA and Alzheimer's disease pathology in lvPPA.

Diffusion Tensor Imaging Correlates of Concussion Related Cognitive Impairment

Introduction: Cognitive impairment after concussion has been widely reported, but there is no reliable imaging biomarker that predicts the severity of cognitive decline post-concussion. This study tests the hypothesis that patients with a history of concussion and persistent cognitive impairment have fractional anisotropy (FA) and mean diffusivity (MD) values from diffusion tensor imaging (DTI) that are specifically associated with poor performance on the Montreal Cognitive Assessment (MoCA). Methods: Fifty-three subjects (19 females) with concussions and persistent cognitive symptoms had MR imaging and the MoCA. Imaging was analyzed by atlas-based, whole-brain DTI segmentation and FLAIR lesion segmentation. Then, we conducted a random forest-based recursive feature elimination (RFE) with 10-fold cross-validation on the entire dataset, and with partial correlation adjustment for age and lesion load. Results: RFE showed that 11 DTI variables were found to be important predictors of MoCA scores. Partial correlation analyses, corrected for age and lesion load, showed significant correlations between MoCA scores and right fronto-temporal regions: inferior temporal gyrus MD (r = -0.62, p = 0.00001), middle temporal gyrus MD (r = -0.54, p = 0.0001), angular gyrus MD (r = -0.48, p = 0.0008), and inferior frontal gyrus FA (r = 0.44, p = 0.002). Discussion: This is the first study to demonstrate a correlation between MoCA scores and DTI variables in patients with a history of concussion and persistent cognitive impairment. This kind of research will significantly increase our understanding of why certain persons have persistent cognitive changes after concussion which, in turn, may allow us to predict persistent impairment after concussion and suggest new interventions.

Thalamic Nuclei and Thalamocortical Pathways After Left Hemispheric Stroke and Their Association with Picture Naming

Background: Previous studies utilized lesion-centric approaches to study the role of the thalamus in language. In this study, we tested the hypotheses that non-lesioned dorsomedial and ventral anterior nuclei (DMVAC) and pulvinar lateral posterior nuclei complexes (PLC) of the thalamus and their projections to the left hemisphere show secondary effects of the strokes, and that their microstructural integrity is closely related to language-related functions. Methods: Subjects with language impairments after a left-hemispheric cortical and/or subcortical, early stroke (n = 31, ≤6 months) or late stroke (n = 30, ≥12 months) sparing thalamus underwent the Boston Naming Test (BNT) and diffusion tensor imaging (DTI). The tissue integrity of DMVAC, PLC, and their cortical projections was quantified with DTI. The right-left asymmetry profiles of these structures were evaluated in relation to the time since stroke. The association between microstructural integrity and BNT score was investigated in relation to stroke chronicity with partial correlation analyses adjusted for confounds. Results: In both early stroke and late stroke groups, left-sided tracts showed significantly higher mean diffusivities (MDs), which were likely due to Wallerian degeneration. Higher MD values of the cortical projections from the left PLC (r = -0.5, p = 0.005) and DMVAC (r = -0.53, p = 0.002) were correlated with lower BNT score in the late stroke but not early stroke group. Conclusion: Nonlesioned thalamic nuclei and thalamocortical pathways show rightward lateralization of the microstructural integrity after a left hemispheric stroke, and this pattern is associated with poorer naming.

Neural activity modulations and motor recovery following brain-exoskeleton interface mediated stroke rehabilitation

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Motor intention based arm training targets activity-dependent neuroplasticity.

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80% of stroke participants recovered clinically relevant functional movements.

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Ipsi-lesional, delta-band EEG activity was highly correlated with motor recovery.

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Results suggest higher activation of ipsi-lesional hemisphere post-intervention.

Brain-machine interfaces (BMI) based on scalp EEG have the potential to promote cortical plasticity following stroke, which has been shown to improve motor recovery outcomes. However, the efficacy of BMI enabled robotic training for upper-limb recovery is seldom quantified using clinical, EEG-based, and kinematics-based metrics. Further, a movement related neural correlate that can predict the extent of motor recovery still remains elusive, which impedes the clinical translation of BMI-based stroke rehabilitation.

To address above knowledge gaps, 10 chronic stroke individuals with stable baseline clinical scores were recruited to participate in 12 therapy sessions involving a BMI enabled powered exoskeleton for elbow training. On average, 132 ± 22 repetitions were performed per participant, per session. BMI accuracy across all sessions and subjects was 79 ± 18% with a false positives rate of 23 ± 20%.

Post-training clinical assessments found that FMA for upper extremity and ARAT scores significantly improved over baseline by 3.92 ± 3.73 and 5.35 ± 4.62 points, respectively. Also, 80% participants (7 with moderate-mild impairment, 1 with severe impairment) achieved minimal clinically important difference (MCID: FMA-UE >5.2 or ARAT >5.7) during the course of the study. Kinematic measures indicate that, on average, participants’ movements became faster and smoother. Moreover, modulations in movement related cortical potentials, an EEG-based neural correlate measured contralateral to the impaired arm, were significantly correlated with ARAT scores (ρ = 0.72, p < 0.05) and marginally correlated with FMA-UE (ρ = 0.63, p = 0.051). This suggests higher activation of ipsi-lesional hemisphere post-intervention or inhibition of competing contra-lesional hemisphere, which may be evidence of neuroplasticity and cortical reorganization following BMI mediated rehabilitation therapy.

The role of microstructural integrity of major language pathways in narrative speech in the first year after stroke

BACKGROUND AND PURPOSE

Left hemisphere stroke often results in a variety of language deficits due to varying patterns of damage to language networks. The Cookie Theft picture description task, a classic, quick bedside assessment, has been shown to quantify narrative speech reliably. In this study, we utilized diffusion tensor imaging (DTI) to assess language network white matter tract correlates of lexical-semantic and syntactic impairments longitudinally.

METHODS

Twenty-eight patients with mild to severe language impairments after left hemispheric lobar and/or subcortical ischemic stroke underwent the Cookie Theft picture description test and DTI up to three different time points: within the first three months, six months and twelve months after stroke. Dorsal and ventral stream language pathways were segmented to obtain DTI integrity metrics of both hemispheres. Multivariable regression models and partial correlation analyses adjusted for age, education, and lesion load were conducted to evaluate the temporal DTI profile of the white matter microstructural integrity of the language tracts as neural correlates of narrative speech within the first year after stroke.

RESULTS

Among all the major language white matter pathways, the integrity of the left arcuate (AF), inferior fronto-occipital, and inferior longitudinal fasciculi (ILF) were related to picture description performance. After FDR correction, left ILF fractional anisotropy correlated with syntactic cohesiveness (r=0.85,p=0.00087) within the first three months after stroke, whereas at one year post-stroke, the strongest correlations were found between lexical-semantic performance and left AF radial diffusivity (r = -0.71, p = 0.00065).

CONCLUSION

Our study provides a temporal profile of associations between the integrity of the main language pathways and lexical semantics and syntactic impairments in left hemispheric strokes.

Frontal aslant tracts as correlates of lexical retrieval in MS

INTRODUCTION

Previous studies reveal that a newly described white matter pathway, the frontal aslant tract (FAT), connecting inferior and superior frontal gyri has a role in speech and language functions. We explored the role of this tract in a phonemic and semantic fluency tasks in a cohort of multiple sclerosis patients diagnosed with cognitive impairment.

METHODS

Thirty-five MS patients with varying degrees of cognitive impairment underwent diffusion tensor imaging and the Controlled Associated Word Test. Fractional anisotropy (FA) of FAT and arcuate fasciculus (AF) were obtained through a supervised, atlas-based tissue segmentation and parcellation method. Phonemic and semantic fluency scores were obtained from COWAT. We ran a multivariate regression model, and partial correlation analyses adjusted for age, education, and lesion load, and corrected for multiple comparisons. False discovery rate (FDR) was used for the correction of multiple comparisons.

RESULTS

Bilateral FAT FA showed significant association with phonemic verbal fluency task (Left; r = 0.46, p = 0.0058 and right; r = 0.46, p = 0.0059) but not semantic fluency task and this relation remained significant after FDR correction (p = 0.02 bilaterally). Although left AF showed some significant association with phonemic fluency task, this relation was insignificant after FDR correction.

CONCLUSION

We show that bilateral FAT are correlates of phonemic verbal fluency task but not semantic in an MS cohort with cognitive impairment. This finding suggests that FAT is more specialized in lexical retrieval function as semantic fluency test encompasses all the functions except the lexical retrieval.

Racial disparities in post-stroke functional outcomes in young patients with ischemic stroke

BACKGROUND AND PURPOSE

Recent studies show rising incidence of stroke in the young, for which risk factors are not well characterized. There is evidence of increased risk in certain racial and ethnic groups. We assessed racial differences in risk factors, stroke etiology, and outcomes among young stroke patients.

METHODS

Using data from our inpatient registry for ischemic stroke, we reviewed patients aged 18-50 who were admitted 01/2013 to 04/2018. Race/ethnicity were characterized as non-Hispanic White (NHW), non-Hispanic Black (NHB), Hispanic (HIS). For univariate comparisons Chi-square and Kruskal-Wallis tests were performed as appropriate. Multivariable logistic regression was used to assess impact of race on day seven modified Rankin score (mRS).

RESULTS

Among 810 patients with race and outcome data who were admitted in the study period, median age was 43, 57.1% were male, and 36.5% NHW, 43.2% NHB, 20.2% HIS. History of hypertension (HTN), type II diabetes (DM II), smoking, heart failure (CHF), prior stroke, and end-stage renal disease varied significantly by race. Compared to NHW, NHB had higher odds of HTN (OR 2.28, 1.65-3.15), CHF (OR 2.17, 1.06-4.46), and DM II 1.92 (1.25-2.94) while HIS had higher odds of DM II (OR 2.52, 1.55-4.10) and lower odds of smoking (OR 0.56, 0.35-0.90). Arrival NIHSS was higher in NHB, but etiology and rates of tpA treatment and thrombectomy did not vary by race. Compared to NHW patients, NHB (OR 0.50 CI (0.31-0.78)) and HIS (OR 0.37 CI (0.21-0.67)) were less likely to have good functional outcome (mRS <2) at day 7 in adjusted analyses.

CONCLUSIONS

In this study, there was a higher prevalence of several modifiable risk factors in NHB and HIS young stroke patients and early functional outcome was worse in these groups. Our study suggests a need for targeted prevention efforts for younger populations at highest risk for stroke.

A direct visuosensory cortical connectivity of the human limbic system. Dissecting the trajectory of the parieto-occipito-hypothalamic tract in the human brain using diffusion weighted tractography

The human hypothalamus is at the center of the human limbic system anatomically and physiologically. The hypothalamus plays pivotal roles in controlling autonomic responses and instinctive behaviors such as regulating fear, aggression, learning, feeding behavior, circadian rhythm, and reproductive activities. The detailed anatomy of the pathways responsible for mediating these responses, however, is yet to be determined. The inhibitory effect of the cerebral cortex on the hypothalamus in many autonomic responses, suggests the presence of direct connection between the cortex and hypothalamic nuclei. While, there is ample information to support the cortico-hypothalamic association between the prefrontal cortex and hypothalamic nuclei, the information regarding a direct posterior cortico-hypothalamic alliance is scant. The visuosensory information may be crucial for the limbic system to regulate some of the important limbic functions. Multiple dissection animal studies revealed direct posterior cortical connectivity with the hypothalamic nuclei. However, a direct cortico-hypothalamic connectivity from the parieto-occipital cortices has not been revealed in the human brain yet. Diffusion weighted imaging (DWI) may be helpful in better visualizing the anatomy of this direct posterior cortico-limbic connectivity noninvasively in the human brain. We studied 30 healthy human subjects. Using a high-spatial and high angular resolution diffusion weighted tractography technique, for the first time, we were able to delineate and reconstruct the trajectory of the parieto-occipito-hypothalamic tract.

Call to Action: SARS-CoV-2 and CerebrovAscular DisordErs (CASCADE)

Background and purpose

The novel severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), now named coronavirus disease 2019 (COVID-19), may change the risk of stroke through an enhanced systemic inflammatory response, hypercoagulable state, and endothelial damage in the cerebrovascular system. Moreover, due to the current pandemic, some countries have prioritized health resources towards COVID-19 management, making it more challenging to appropriately care for other potentially disabling and fatal diseases such as stroke. The aim of this study is to identify and describe changes in stroke epidemiological trends before, during, and after the COVID-19 pandemic.

Methods

This is an international, multicenter, hospital-based study on stroke incidence and outcomes during the COVID-19 pandemic. We will describe patterns in stroke management, stroke hospitalization rate, and stroke severity, subtype (ischemic/hemorrhagic), and outcomes (including in-hospital mortality) in 2020 during COVID-19 pandemic, comparing them with the corresponding data from 2018 and 2019, and subsequently 2021. We will also use an interrupted time series (ITS) analysis to assess the change in stroke hospitalization rates before, during, and after COVID-19, in each participating center.

Conclusion

The proposed study will potentially enable us to better understand the changes in stroke care protocols, differential hospitalization rate, and severity of stroke, as it pertains to the COVID-19 pandemic. Ultimately, this will help guide clinical-based policies surrounding COVID-19 and other similar global pandemics to ensure that management of cerebrovascular comorbidity is appropriately prioritized during the global crisis. It will also guide public health guidelines for at-risk populations to reduce risks of complications from such comorbidities.

The role of residents in medical students' neurology education: current status and future perspectives

BACKGROUND

Neurophobia, a well-described fear of neurology, affects medical students worldwide and may be one of the factors contributing to a shortage of neurologists in the United States. Residents spend a considerable amount of time with medical students; therefore, we sought to understand better the impact neurology residents have on medical students during their neurology clerkship and their subsequent interest in neurology. We aimed to identify and implement strategies to decrease neurophobia and increase the number of students pursuing neurology as a career.

METHODS

Third-year medical students (n = 234) of UTHealth's McGovern Medical School rotating through their neurology core clerkship completed two surveys regarding their rotation experiences. Surveys were completed anonymously before and after the clerkship to measure their interest and confidence in neurology and the impact of their interactions with the neurology residents during the clerkship. In parallel, residents participated in a teaching workshop focused on small group teaching to improve their teaching effectiveness. Non-parametrical comparison and ordinal regression analyses were utilized for data analyses.

RESULTS

Medical students reported a statistically significant increase in their confidence in managing neurological conditions and interest in pursuing a neurology residency after their clerkship. There was a significant association between the medical students' overall rotation experience and the residents' teaching effectiveness. The overall clerkship experience correlated with the medical students' interest and confidence in neurology. There was a trend towards an increase in residents' teaching effectiveness and students' rotation experience after a resident teaching workshop. Additionally, of note, students who rotated on both and outpatient and inpatient sites during their clerkship reported an increased interest in neurology.

CONCLUSION

Our study supports that resident-led teaching efforts are important in improving medical students' neurologic education and their interest in neurology. Our data also supports that the interest in neurology increased for medical students after their neurology clerkship. We examined future strategies to implement "near-peer" teaching activities to enhance the medical students' neurologic educational experience. These strategies could potentially mitigate neurophobia and ultimately lead to a much-needed increase in future neurologists.

Right Hemispheric Homologous Language Pathways Negatively Predicts Poststroke Naming Recovery

Background and Purpose- Stroke is the leading cause of disability in United States, and aphasia is a common sequela after a left hemisphere stroke. Functional imaging and brain stimulation studies show that right hemisphere structures are detrimental to aphasia recovery but evidence from diffusion tensor imaging is lacking. We investigated the role of homologous language pathways in naming recovery after left hemispheric stroke. Methods- Patients with aphasia after a left hemispheric stroke underwent naming assessment using the Boston Naming Test and diffusion tensor imaging at the acute and chronic time points. We analyzed diffusion tensor imaging of right arcuate fasciculus and frontal aslant tracts. We used Wilcoxon rank-sum test to evaluate structural lateralization patterns and partial Spearman correlation/multivariate generalized linear model to determine the role of right arcuate fasciculus and frontal aslant tracts in naming recovery after controlling for confounders. Results were corrected for multiple comparisons. Results- On average, the structural integrity of left language pathways deteriorated more than their right homologs, such that there was rightward lateralization in the chronic stage. Regression/correlation analyses showed that greater preservation of tract integrity of right arcuate fasciculus was associated with poorer naming recovery. Conclusions- Our study provides preliminary evidence that preservation of right homologs of language pathways is associated with poor recovery of naming after a left hemispheric stroke, consistent with previous evidence that maintaining greater reliance on left hemisphere structures is associated with better language recovery.

Abstract TP205: Higher Vascular Risk and Poorer Outcomes in Young Black and Hispanic Stroke Patients

Introduction: Recent studies show rising incidence of stroke in the young, for which risk factors are not well characterized. There is evidence of increased risk in certain race and ethnic groups. We sought to assess racial differences in risk factors, stroke etiology, and outcomes among young stroke patients.

Methods: Using data from our inpatient registry for ischemic stroke, we reviewed patients aged 18-50 who were admitted 01/2013 to 04/2018. Race/ethnicity were characterized as non-Hispanic White (NHW), non-Hispanic Black(NHB), Hispanic(HIS) and other groups were excluded given small numbers (<6%). For univariate comparisons chi-square, ANOVA and Kruskal-Wallis tests were performed as appropriate. Multivariate logistic regression was used to assess impact of race on day 7 modified Rankin score (mRS) .

Results: Among 862 patients admitted in the study period, mean age was 40.9 (SD 7.8), 57.3% were male, and 36.4% NHW, 42.8% NHB, 20.8% HIS. History of hypertension (HTN), type II diabetes (DM II), smoking, heart failure (CHF), prior stroke, end stage renal disease, and triglycerides varied significantly by race (Table 1). Compared to NHW, NHB had higher odds of HTN (OR 2.2, CI 1.6-3.0), CHF (OR 2.3, CI 1.1-4.6), and DMII (OR 1.81, CI 1.2-2.7) while HIS had higher odds of DMII (OR 2.26, CI 1.4-3.6) and lower odds of smoking (OR 0.5, 0.3-0.8). Arrival NIHSS was higher in NHB, but etiology and rates of tpA treatment and thrombectomy did not vary by race. Compared to NHW patients, NHB (OR 0.5, CI 0.3-0.9 ) and HIS (OR 0.4 CI 0.2-0.9) were less likely to have good functional outcome (mRS <2) at day 7 in adjusted analyses.

Conclusions: In this study, there was a higher prevalence of several modifiable risk factors in NHB and HIS young stroke patients and early functional outcome was worse in these groups. This suggests a need for targeted prevention efforts for younger populations at highest risk. The findings regarding outcomes deserve further study.

Yakovlev's Basolateral Limbic Circuit in Multiple Sclerosis Related Cognitive Impairment

BACKGROUND AND PURPOSE

In 1948, Paul Yakovlev described an additional limbic circuit located basolateral to James Papez's circuit (1937) and included orbitofrontal cortex, amygdala, and dorsomedial nucleus of thalamus. This circuit is shown to be an important component of subcortical cognitive abilities. We aimed to demonstrate this circuit in a multiple sclerosis (MS) cohort using diffusion tensor imaging (DTI) and evaluate its role in MS-related cognitive impairment (CI).

METHODS

We enrolled cognitively intact (n = 10) and impaired (n = 36) MS patients who underwent a comprehensive cognitive assessment; the minimal assessment of cognitive function in MS (MACFIMS) and structural magnetic resonance imaging. Correlation analyses between volumetric and DTI-derived values of the orbitofrontothalamic (OFT), amygdalothalamic tracts (ATTs), and dorsomedial nucleus of thalamus and CI index derived from MACFIMS were computed after adjustment for age, education, and lesion load.

RESULTS

We observed a consistent trend between CI index and bilateral dorsomedial nucleus' mean diffusivity (MD) (r = .316; P = .02), left OFT Fractional anisotropy (FA) (r = -.302; P = .02), MD (r = .380; .006), and radial diffusivities (RDs) (r = .432; P = .002), also with right ATT FA (r = -.475; P = .0006) and left ATT FA ( = -.487; P = .0005). After Bonferroni correction, correlations of left OFT RD and right and left ATT FA with CI were found to be significant.

CONCLUSIONS

Our study provides in vivo DTI delineation of Yakovlev's historical basolateral limbic circuit and establishes a role in MS-related CI. These findings may potentially pave the way for future clinical studies using targeted invasive and noninvasive neurostimulation modalities for CI in MS.

Mapping the trajectory of the amygdalothalamic tract in the human brain

Although the thalamus is not considered primarily as a limbic structure, abundant evidence indicates the essential role of the thalamus as a modulator of limbic functions indirectly through the amygdala. The amygdala is a central component of the limbic system and serves an essential role in modulating the core processes including the memory, decision-making, and emotional reactions. The amygdalothalamic pathway is the largest direct amygdalo-diencephalic connection in the primates including the human brain. Given the crucial role of the amygdalothalamic tract (ATT) in memory function and diencephalic amnesia in stroke patients, diffusion tensor imaging may be helpful in better visualizing the surgical anatomy of this pathway noninvasively. To date, few diffusion-weighted studies have focused on the amygdala, yet the fine neuronal connection of the amygdala and thalamus known as the ATT has yet to be elucidated. This study aimed to investigate the utility of high spatial resolution diffusion tensor tractography for mapping the trajectory of the ATT in the human brain. We studied 15 healthy right-handed human subjects (12 men and 3 women with age range of 24-37 years old). Using a high-resolution diffusion tensor tractography technique, for the first time, we were able to reconstruct and measure the trajectory of the ATT. We further revealed the close relationship of the ATT with the temporopontine tract and the fornix bilaterally in 15 healthy adult human brains.