Workflow Optimization for Ischemic Stroke in a Community-Based Stroke Center.

BACKGROUND: We analyzed the effect of specific optimization steps to reduce treatment delays in a nonacademic stroke hospital setting. METHODS: The data from patients with ischemic stroke who had been treated with intravenous tissue plasminogen activator or endovascular therapy, or both, were analyzed. The metrics were divided into 2 periods: preoptimization period (October 1, 2015 to September 30, 2016) and postoptimization period (October 1, 2016 to September 30, 2017). The key interventions were 1) notification by the emergency medical service to the emergency department and stroke team; 2) division of the stroke alert between level 1 (intravenous/intra-arterial candidate) and level 2; 3) direct transportation of level 1 patients to brain computed tomography; 4) limitation of nonessential interventions; 5) stroke orientation; 6) 24-hour, 7-day code stroke response by a vascular neurologist; 7) earlier notification of the interventional radiology team; 8) direct transportation from computed tomography to angiography suite for large vessel occlusion; and 9) multidisciplinary monthly meetings to discuss delayed cases. RESULTS: A total of 279 patients were identified. No significant differences in any of the baseline characteristics were documented. Almost all metrics favored the postoptimization period, with remarkable improvement in the door-to-puncture time (median, 64 minutes; interquartile range, 36-86; vs. 47 minutes; interquartile range, 20-62; P = 0.001). We observed an increased percentage of good clinical outcomes in the postoptimization group (60.1% vs. 54.8%; P = 0.500). We found an 8.4% increase in patients with good clinical outcomes in the postoptimization group compared with our previously reported work. CONCLUSIONS: For acute reperfusion therapies, significant reductions in workflow intervals can be achieved after simple optimization methods in a nonacademic community-based hospital.

The role of ICP monitoring in meningitis.

Intracranial pressure (ICP) monitoring has been widely accepted in the management of traumatic brain injury. However, its use in other pathologies that affect ICP has not been advocated as strongly, especially in CNS infections. Despite the most aggressive and novel antimicrobial therapies for meningitis, the mortality rate associated with this disease is far from satisfactory. Although intracranial hypertension and subsequent death have long been known to complicate meningitis, no specific guidelines targeting ICP monitoring are available. A review of the literature was performed to understand the pathophysiology of elevated ICP in meningitis, diagnostic challenges, and clinical outcomes in the use of ICP monitoring.

Therapeutic intravascular normothermia reduces the burden of metabolic crisis.

BACKGROUND: We aim to investigate whether therapeutic-induced normothermia (TIN) ≤ 37.5 °C, by means of intravascular cooling devices is more efficacious than standard medical therapy (MED) in alleviating metabolic crisis (MC) acutely following traumatic brain injury (TBI). METHODS: We retrospectively analyzed data from 62 patients with severe TBI, GCS ≤ 8. We divided the cohort into two groups. (1) Patients who had temperature controlled via standard medical therapies (n = 52), (2) TIN group (n = 10). For each group, we analyzed the percent time spent in normothermia, and in MC. Furthermore, we focused the investigation on pre-TIN versus post-TIN comparing temp, intracranial pressure (ICP), sedation, and MC before and after intravascular cooling. RESULTS: TIN patients had a better temperature control than MED group (60.72 ± 19.53 vs 69.75 ± 24.98 %, p < 0.001) and spent shorter time in MC (22.60 ± 20.45 vs 32.17 ± 27.25 %, p < 0.001). Temperature control was associated with reduced incidence of MC in TIN (OR 0.51, CI 0.38-0.67, p < 0.001, p < 0.001) but not in MED (OR 0.97, CI 0.87-1.1, p = 0.63). Within TIN group analysis, following TIN both temperature and incidence of MC improved from 37.62 ± 0.34 versus 36.69 ± 0.90 °C (p < 0.005) and 41.95 ± 27.74 % before to 8.35 ± 9.78 % (p = 0.005) after, respectively. ICP was well controlled both before and after intravascular cooling (13.07 vs 15.83 mmHg, p = 0.20). CONCLUSION: Therapeutic normothermia, using intravascular cooling, results in a reduction in the burden of MC. This differential effect occurs despite equivalent control of ICP in both TIN and MED treatments. These results demonstrate proof of concept of normothermia, when applied in a controlled manner, being neuroprotective.

Clinical and radiologic spectrum of corpus callosum infarctions: clues to the etiology.

Infarctions of the corpus callosum are rare. The clinical picture varies from an acute onset to slow evolving symptoms, frequently with poor localizing signs; however, the location of the infarct in the callosum often correlates with a specific etiology. We describe three patients with varying degrees of callosal infarction, each corresponding to a particular etiology.

Endovascular stroke therapy: a single-center retrospective review.

OBJECT: Endovascular treatment of acute ischemic stroke delivers direct therapy at the site of an occluded cerebral artery and can be employed beyond the 3-4.5-hour window limit set for intravenous recombinant tissue plasminogen activator. In this paper, the authors report their experience with various endovascular therapies in acute ischemic stroke. METHODS: The authors conducted a retrospective review of their clinical database for acute ischemic stroke in large-vessel cerebral territories that underwent endovascular treatment between May 2005 and February 2009. Endovascular treatment was defined as pharmacological and/or mechanical intervention, angioplasty, stenting, or a combination of these methods. Admission National Institutes of Health Stroke Scale and the modified Rankin Scale scores were recorded. Thrombolysis in Myocardial Infarction (TIMI) scores of 0, 1, 2A, 2B, and 3 were used to define recanalization. RESULTS: Forty procedures were performed in 39 patients, with 1 patient having sequential bilateral strokes. Nine patients were lost to follow-up after discharge. Strokes in the carotid artery circulation occurred in 82.5% of cases, and those in the vertebral-basilar territory occurred in 17.5%. The Merci device was used in 22 (55%) of 40 procedures, and the Penumbra device in 9 (22.5%) of 40. Angioplasty was performed in 15 (37.5%) of 40 procedures, and intraarterial recombinant tissue plasminogen activator was administered in 23 (57.5%) of 40 procedures. In 23 (57.5%) of 40 cases, multiple recanalization methods were used. The recanalization rate for all methods was 60%. The recanalization rate from TIMI Score 0/1 occlusions was 71.4% (20 of 28). An estimated modified Rankin Scale score of ≤ 2 was obtained in 11 (36.7%) of 30 cases. The overall mortality rate was 26.7% (8 of 30). Intracerebral hemorrhage at 24 hours postprocedure was noted in 17 (42.5%) of 40 cases, 3 (7.5%) of which were symptomatic. CONCLUSIONS: The authors' institution performs endovascular stroke treatment with a safety and efficacy profile comparable to those of other major endovascular stroke therapy studies. Recanalization was associated with an improved clinical outcome. Protocols to maximize efficient triage of patients and better documentation of stroke treatments can assist in further studies.

Relationship of growth to aneurysm rupture in asymptomatic aneurysms ≤ 7 mm: a systematic analysis of the literature.

BACKGROUND: The apparent paradox of natural history data suggesting low rupture risk of small asymptomatic aneurysms and the median size of aneurysm rupture remains unexplained. Aneurysm growth rates and their potential relationship with rupture risk have not been well examined in natural history studies. OBJECTIVE: To examine the question of whether small asymptomatic aneurysms ≤ 7 mm that are followed up over time rupture and to determine the relationship between aneurysm growth and rupture. METHODS: We reviewed all publications on unruptured aneurysms published from 1966 to 2009. We then selected all aneurysms ≤ 7 mm for which measurements were reported for at least 2 time points and for which initial asymptomatic status and ultimate outcome (rupture vs unruptured) were reported. Using the Mann-Whitney U test, we compared absolute diameter annual growth rate. RESULTS: Our search retrieved 64 aneurysms. Thirty aneurysms ruptured during follow-up, of which 27 were enlarged before rupture (90%). Thirty-four aneurysms did not rupture, of which 24 enlarged during follow-up (71%). There was a statistically significant trend toward larger absolute diameter growth for ruptured aneurysms vs unruptured aneurysms (3.89 ± 2.34 vs 1.79 ± 1.02 mm; P < .001), respectively. Annual growth rates for aneurysms for the 2 groups, however, were not statistically different (27.46 ± 18.76 vs 32.00 ± 29.30; P = .92). CONCLUSION: Small aneurysms are prone to growth and rupture. Aneurysm rupture is more likely to occur in aneurysms with larger absolute diameter growth, but rupture can also occur in the absence of growth. The annual growth rate in both groups suggests that rate of growth of aneurysms is highly variable and unpredictable, justifying treatment or close diagnostic follow-up.

Visual field expansion after visual restoration therapy.

OBJECTIVE: To determine whether visual field expansion occurs with visual restoration therapy (VRT), using fundus-controlled microperimetry to assess visual fields. DESIGN: This longitudinal cohort analysis assesses patients' visual fields before and after visual restoration therapy using microperimetry and standard high-resolution perimetry. SUBJECTS: Seven patients with stroke-induced homonymous field cuts were studied. INTERVENTION: Visual restoration therapy is a computerized, home-based treatment aimed at reducing the size of the visual field defect of stroke patients with hemianopia through repetitive stimulation of the visual borderzone adjacent to the blind field. During twice-daily therapy for three months patients maintain central fixation while responding to eccentrically placed stimuli in the visual borderzone. The programme is adjusted monthly to changes in the patient's visual field. Controversy exists as to whether expansion of visual fields measured at home with high-resolution perimetry is due to inadvertent eye movements and therefore would overrepresent the treatment's effect. MAIN MEASURES: Microperimentry uses an infrared camera to track retinal vessels so that any shift or movement between the reference image and the real-time fundus image corrects the stimulus position, thus delivering stimuli to known retinal locations, and allowing accurate assessment of visual fields independent of eye movements. RESULTS: There was an average improvement in stimulus detection rate by microperimetry of 12.5% (range -1.4% to 38.9%, P =0.033). Six of 7 patients had ≥ 3% improvement in stimulus detection by home-based perimetry. CONCLUSION: Our results demonstrate modest but real expansion in visual fields following visual restoration therapy which is not due to eye movements.

Reperfusion normalizes motor activation patterns in large-vessel disease.

OBJECTIVE: Hemodynamic impairment in one hemisphere has been shown to trigger ipsilateral motor activation in the opposite hemisphere on functional imaging. We hypothesized that reversing the hypoperfusion would normalize the motor activation pattern. METHODS: We studied four patients with high-grade stenosis and impaired vasomotor reactivity (VMR) but no stroke. Functional magnetic resonance imaging motor activation pattern before and after VMR normalization was compared with seven healthy control subjects scanned at an interval of 3 months using voxel-wise statistical parametric maps and region of interest analysis. Subjects performed a repetitive hand closure task in synchrony with 1Hz metronome tone. We used repeated-measures analysis of variance to compute the interaction between group (patients/control subjects) and time by obtaining the average blood oxygen level dependent signal of three motor regions of interest in each hemisphere. RESULTS: Two patients normalized their VMR after spontaneous resolution of dissection, and two after revascularization procedures. Both voxel-wise statistical maps and region of interest analysis showed that VMR normalization was associated in each case with a reduction in the atypical activation in the hemisphere opposite to the previously hypoperfused hemisphere (p < 0.001). INTERPRETATION: In the presence of a physiological stressor such as hypoperfusion, the brain is capable of dynamic functional reorganization to the opposite hemisphere that is reversible when normal blood flow is restored. These findings are important to our understanding of the clinical consequences of hemodynamic failure and the role of the ipsilateral hemisphere in maintaining normal neurological function.

Brain activity associated with stimulation therapy of the visual borderzone in hemianopic stroke patients.

BACKGROUND AND OBJECTIVE: Visual restoration therapy is a home-based treatment program intended to expand visual fields of hemianopic patients through repetitive stimulation of the borderzone adjacent to the blind field. We hypothesized that the training itself would induce visual field location-specific changes in the brain's response to stimuli, a phenomenon demonstrated in animal experiments but never in humans with brain injury. METHODS: Six chronic right hemianopic patients underwent functional magnetic resonance imaging (fMRI)--responding to stimuli in the trained visual borderzone versus the nontrained seeing field before and after 1 month of visual restoration therapy. Spatially normalized fMRI time-series data were analyzed in a fixed-effects group analysis comparing blood oxygen level dependent (BOLD) activity in the borderzone versus seeing location at baseline and at 1 month. Percent BOLD change was measured to determine each condition's contribution to the time-by-condition interaction. RESULTS: There was a significant time by condition interaction manifested as increased BOLD activity for borderzone detection relative to seeing detection after the first month of therapy, which correlated with a relative improvement in response times in the borderzone location out-of-scanner. The right inferior and lateral temporal, right dorsolateral frontal, bilateral anterior cingulate, and bilateral basal ganglia showed the greatest response. CONCLUSION: Visual restoration therapy appears to induce an alteration in brain activity associated with a shift of attention from the nontrained seeing field to the trained borderzone. The effect appears to be mediated by the anterior cingulate and dorsolateral frontal cortex in conjunction with other higher order visual areas in the occipitotemporal and middle temporal regions. Demonstration of a visual field-specific training effect on brain activity provides an important starting point for understanding the potential for visual therapy in hemianopia.

Chronic ischemia and neurocognition.

Cognitive impairment from a major stroke as a consequence of carotid disease is an acknowledged clinical outcome; however, cognitive impairment without major stroke is open to discussion. The three recognized mechanisms for cognitive dysfunction from internal carotid artery are microembolization, white-matter disease, and hypoperfusion. The last has been most difficult to characterize physiologically. In this article, the authors review evidence supporting the existence of chronic ischemia in the brain and its direct impact on cognitive functions. By incorporating the pathophysiology of chronic ischemia into the algorithm of the management of carotid artery disease, we may be able to extend the goals of carotid artery revascularization beyond merely preventing stroke to include preventing or reversing cognitive decline.

Cortical reorganization following intradigital tendon transfer.

We distinguish between two models of adult cortical reorganization, adaptive and constant somatotopy, using functional magnetic resonance imaging maps corresponding to individual thumb and fourth-finger digits in a patient with a right-hand fourth digit tendon transfer that salvaged impaired function of the right thumb. Comparison of motor and sensory maps for both digits and both hands was consistent with a model of 'adaptive somatotopy' in which thumb control was taken over by regions adjacent to the fourth finger control cluster rather than at the presurgical lateral region as predicted by a model of 'constant somatotopy'. These findings are the first to demonstrate that rerouting of peripheral input, in the absence of brain injury, is sufficient to drive cortical reorganization resulting in recovery of lost motor function, and further suggest an adaptive mechanism associated with brain tissue engaged in intact motor functions.