Deep Brain Stimulation Battery Longevity: Comparison of Monopolar Versus Bipolar Stimulation Modes.

BACKGROUND: Deep brain stimulation is an effective treatment for movement disorders, but it is relatively complex, invasive, and costly. Little is known about whether stimulation mode alters pulse generator (battery) longevity in routine clinical care. OBJECTIVE: To compare battery longevity during monopolar versus bipolar stimulation in patients who underwent deep brain stimulation for movement disorders. METHODS: We evaluated 2,902 programming adjustments and calculated the average stimulator settings for 393 batteries in 200 unique patients with Parkinson's disease and essential tremor. We classified the pulse generators into different stimulation modes (monopolar, bipolar, tripolar, double monopolar) and compared battery longevity with Kaplan Meier survival analyses using the log rank test. We exclusively implanted the Medtronic 3387 lead with adjacent electrode contacts separated by 1.5 mm. RESULTS: The mean pulse generator longevity was 47.6±1.6 months regardless of diagnosis or stimulation mode. Bipolar stimulation mode was associated with greater longevity than monopolar stimulation (56.1±3.4 versus 44.2±2.1 months, p=0.006). This effect was most pronounced when stimulation parameters were at low to moderate intensity settings. Double monopolar configuration was associated with less pulse generator longevity than conventional stimulation modes (37.8±5.6 versus 49.7±1.9, p=0.014). CONCLUSION: IPGs initially programmed in bipolar mode provided one year of additional battery longevity versus monopolar mode in this large retrospective series of patients with essential tremor and Parkinson's disease. Given satisfactory efficacy for motor symptoms, bipolar stimulation mode is a feasible alternative programming strategy at the initiation of DBS therapy.

Patient Selection for Drip and Ship Thrombolysis in Acute Ischemic Stroke.

OBJECTIVES: The drip and ship model is a method used to deliver thrombolysis to acute stroke patients in facilities lacking onsite neurology coverage. We sought to determine whether our drip and ship population differs from patients treated directly at our stroke center (direct presenters). METHODS: We retrospectively reviewed consecutive patients who received thrombolysis at an outside facility with subsequent transfer to our center between 2009 and 2011. Patients received thrombolysis after telephone consultation with a stroke specialist. We examined demographics, vascular risk factors, laboratory values, and stroke severity in drip and ship patients compared with direct presenters. RESULTS: Ninety-six patients were identified who received thrombolysis by drip and ship compared with 212 direct presenters. The two groups did not differ with respect to sex, ethnicity, vascular risk factors, or admission glucose. The odds ratio (OR) of arriving at our hospital as a drip and ship for someone 80 years or older was 0.31 (95% confidence interval [CI] 0.15-0.61, P < 0.001). Only 21% of drip and ship patients were black versus 38% of direct presenters (OR 0.434, 95% CI 0.25-0.76, P = 0.004). Even after stratifying by age (<80 vs ≥80), a smaller proportion of drip and ship patients were black (OR 0.44, 95% CI 0.24-0.81, P = 0.008). Furthermore, we found that fewer black patients with severe strokes arrived by drip and ship (OR 0.33, 95% CI 0.11-0.98, P = 0.0028). CONCLUSIONS: Our study showed that a smaller proportion of blacks and older adults arrived at our center by the drip and ship model. This may reflect differences in how patients are selected for thrombolysis and transfer to a higher level of care.

Investigating the utility of previously developed prediction scores in acute ischemic stroke patients in the stroke belt.

BACKGROUND: To assess the utility of previously developed scoring systems, we compared SEDAN, named after the components of the score (baseline blood Sugar, Early infarct signs and (hyper) Dense cerebral artery sign on admission computed tomography scan, Age, and National Institutes of Health Stroke Scale on admission), Totaled Health Risks in Vascular Events (THRIVE), Houston Intra-arterial Therapy (HIAT), and HIAT-2 scoring systems among patients receiving systemic (intravenous [IV] tissue plasminogen activator [tPA]) and endovascular (intra-arterial [IA]) treatments. METHODS: We retrospectively reviewed all IV tPA and IA patients presenting to our center from 2008-2011. The scores were assessed in patients who were treated with IV tPA only, IA only, and a combination of IV tPA and IA (IV-IA). We tested the ability of THRIVE to predict discharge modified Rankin scale (mRS) 3-6, HIAT and HIAT-2 discharge mRS 4-6, and SEDAN symptomatic intracerebral hemorrhage (sICH). RESULTS: Of the 366 patients who were included in this study, 243 had IV tPA only, 89 had IA only, and 34 had IV-IA. THRIVE was predictive of mRS 3-6 in the IV-IA (odds ratio [OR], 1.95; 95% confidence interval [CI], 1.30-2.91) and the IV group (OR, 1.71; 95% CI, 1.43-2.04), but not in the IA group. HIAT was predictive of mRS 4-6 in the IA (OR, 3.55; 95% CI, 1.65-7.25), IV (OR, 3.47; 95% CI, 2.26-5.33), and IV-IA group (OR, 6.48; 95% CI, 1.41-29.71). HIAT-2 was predictive of mRS 4-6 in the IA (OR, 1.39; 95% CI, 1.03-1.87) and IV group (OR, 1.36; 95% CI, 1.18-1.57), but not in the IV-IA group. SEDAN was not predictive of sICH in the IA or the IV-IA group, but was predictive in the IV group (OR, 1.54; 95% CI, 1.01-2.36). CONCLUSIONS: Our study demonstrated that although highly predictive of outcome in the original study design treatment groups, prediction scores may not generalize to all patient samples, highlighting the importance of validating prediction scores in diverse samples.

Safety of intravenous tissue plasminogen activator administration with computed tomography evidence of prior infarction.

BACKGROUND: Prior stroke within 3 months excludes patients from thrombolysis; however, patients may have computed tomography (CT) evidence of prior infarct, often of unknown time of origin. We aimed to determine if the presence of a previous infarct on pretreatment CT is a predictor of hemorrhagic complications and functional outcomes after the administration of intravenous (IV) tissue plasminogen activator (tPA). METHODS: We retrospectively analyzed consecutive patients treated with IV tPA at our institution from 2009-2011. Pretreatment CTs were reviewed for evidence of any prior infarct. Further review determined if any hemorrhagic transformation (HT) or symptomatic intracerebral hemorrhage (sICH) were present on repeat CT or magnetic resonance imaging. Outcomes included sICH, any HT, poor functional outcome (modified Rankin Scale score of 4-6), and discharge disposition. RESULTS: Of 212 IV tPA-treated patients, 84 (40%) had evidence of prior infarct on pretreatment CT. Patients with prior infarcts on CT were older (median age, 72 versus 65 years; P=.001) and had higher pretreatment National Institutes of Health Stroke Scale scores (median, 10 versus 7; P=.023). Patients with prior infarcts on CT did not experience more sICH (4% versus 2%; P=.221) or any HT (18% versus 14%; P=.471). These patients did have a higher frequency of poor functional outcome at discharge (82% versus 50%; P<.001) and were less often discharged to home or inpatient rehabilitation center (61% versus 73%; P=.065). CONCLUSIONS: Visualization of prior infarcts on pretreatment CT did not predict an increased risk of sICH in our study and should not be viewed as a reason to withhold systemic tPA treatment after clinically evident strokes within 3 months were excluded.

Shorter pulse generator longevity and more frequent stimulator adjustments with pallidal DBS for dystonia versus other movement disorders.

BACKGROUND: Deep brain stimulation has become a routine therapy for movement disorders, but it is relatively invasive and costly. Although stimulation intensity relates to battery longevity, less is known about how diagnosis and stimulation target contribute to this clinical outcome. Here we evaluate battery longevity in movement disorders patients who were treated at a tertiary referral center. OBJECTIVE: To compare single channel pulse generator longevity in patients with movement disorders. METHODS: With Institutional Review Board approval, we evaluated 470 consecutive Soletra implants for routine care. Battery longevity was estimated with Kaplan-Meier analyses, and group comparisons were performed with the log rank mean test. The frequency of clinic encounters for ongoing care was evaluated across diagnoses with analysis of variance (ANOVA). RESULTS: The mean pulse generator longevity was 44.9 ± 1.4 months. Pallidal DBS for dystonia was associated with shorter battery longevity than subthalamic and thalamic DBS for Parkinson's disease and essential tremor (28.1 ± 2.1 versus 47.1 ± 1.8 and 47.8 ± 2.6 months, respectively, mean ± standard error, P < 0.001), and dystonia patients required more frequent clinic visits for routine care (F = 6.0, P = 0.003). Pallidal DBS for Parkinson's disease and thalamic DBS for cerebellar outflow tremor were associated with shorter battery longevity, as well (35.3 ± 4.6 and 26.4 ± 4.3 months, respectively). CONCLUSIONS: Pallidal DBS for dystonia was associated with shorter battery longevity and more frequent stimulator adjustments versus DBS for Parkinson's disease and essential tremor. Characteristics of the stimulation target and disease pathophysiology both likely contribute to battery longevity in patients with movement disorders.

Predictors of systemic inflammatory response syndrome in ischemic stroke undergoing systemic thrombolysis with intravenous tissue plasminogen activator.

BACKGROUND: Systemic inflammatory response syndrome (SIRS) is an inflammatory process associated with poor outcomes in acute ischemic stroke (AIS) patients. However, no study to date has investigated predictors of SIRS in AIS patients treated with intravenous (IV) tissue plasminogen activator (tPA). METHODS: Consecutive patients were retrospectively reviewed for evidence of SIRS during their acute hospitalization. SIRS was defined as the presence of 2 or more of the following: (1) body temperature less than 36°C or greater than 38°C, (2) heart rate greater than 90, (3) respiratory rate greater than 20, or (4) white blood cell count less than 4000/mm or greater than 12,000/mm or more than 10% bands for more than 24 hours. Those diagnosed with an infection were excluded. A scoring system was created to predict SIRS based on patient characteristics available at the time of admission. Logistic regression was used to evaluate potential predictors of SIRS using a sensitivity cutoff of ≥65% or area under the curve of .6 or more. RESULTS: Of 212 patients, 44 had evidence of SIRS (21%). Patients with SIRS were more likely to be black (61% versus 54%; P = .011), have lower median total cholesterol at baseline (143 versus 167 mg/dL; P = .0207), and have history of previous stroke (51% versus 35%; P = .0810). Ranging from 0 to 6, the SIRS prediction score consists of African American (2 points), history of hypertension (1 point), history of previous stroke (1 point), and admission total cholesterol less than 200 (2 points). Patients with an SIRS score of 4 or more were 3 times as likely to develop SIRS when compared with patients with a score of ≤3 (odds ratio = 2.815, 95% confidence interval 1.43-5.56, P = .0029). CONCLUSIONS: In our sample of IV tPA-treated AIS patients, clinical and laboratory characteristics available on presentation were able to identify patients likely to develop SIRS during their acute hospitalization. Validation is required in other populations. If validated, this score could assist providers in predicting who will develop SIRS after treatment with IV tPA.

Safety of protocol violations in acute stroke tPA administration.

BACKGROUND: Intravenous (IV) tissue plasminogen activator remains the only approved therapy for acute ischemic stroke (AIS) in the United States; however, less than 10% of patients receive treatment. This is partially because of the large number of contraindications, narrow treatment window, and physician reluctance to deviate from these criteria. METHODS: We retrospectively analyzed consecutive patients who received IV thrombolysis at our stroke center for National Institute of Neurological Disorders and Stroke (NINDS) protocol violations and rates of symptomatic intracerebral hemorrhage (sICH). Other outcome variables included systemic hemorrhage, modified Rankin Scale at discharge, and discharge disposition. RESULTS: A total of 212 patients were identified in our stroke registry between 2009 and 2011 and included in the analysis. Protocol violations occurred in 76 patients (36%). The most common violations were thrombolysis beyond 3 hours (26%), aggressive blood pressure management (15%), elevated prothrombin time (PT) or partial thromboplastin time (PTT) (6.6%), minor or resolving deficits (4.2%), unclear time of onset (3.9%), and stroke within 3 months (3%). There were no significant differences in any of the safety outcomes or discharge disposition between patients with or without protocol violations. Controlling for age, National Institutes of Health Stroke Scale on admission, and glucose on admission, there was no significant increase in sICH (odds ratio: 3.8; 95% confidence interval: .37-38.72) in the patients who had protocol violations. CONCLUSIONS: Despite more than one third of patients receiving thrombolysis with protocol violations, overall rates of hemorrhage remained low and did not differ from those who did not have violations. Our data support the need to expand access to thrombolysis in AIS patients.

Systemic inflammatory response syndrome in tissue-type plasminogen activator-treated patients is associated with worse short-term functional outcome.

BACKGROUND AND PURPOSE: Systemic inflammatory response syndrome (SIRS) is a generalized inflammatory state. The primary goal of the study was to determine whether differences exist in outcomes in SIRS and non-SIRS intravenous tissue-type plasminogen activator-treated patients. METHODS: Consecutive patients were retrospectively reviewed for the evidence of SIRS during their admission. SIRS was defined as the presence of ≥2 of the following: body temperature<36°C or >38°C, heart rate>90, respiratory rate>20, and white blood cells<4000/mm or >12 000 mm, or >10% bands. Patients diagnosed with infection (via positive culture) were excluded. RESULTS: Of the 241 patients, 44 had evidence of SIRS (18%). Adjusting for pre-tissue-type plasminogen activator National Institutes of Health Stroke Scale, age, and race, SIRS remained a predictor of poor functional outcome at discharge (odds ratio [OR], 2.58; 95% confidence interval [CI], 1.16-5.73; P=0.0197). CONCLUSIONS: In our sample of tissue-type plasminogen activator-treated (tPA) patients, ~1 in 5 patients developed SIRS. Furthermore, we found the presence of SIRS to be associated with poor short-term functional outcomes and prolonged length of stay.

The Potential Impact of Maintaining a 3-Hour IV Thrombolysis Window: How Many More Patients can we Safely Treat?

BACKGROUND: In 2008, the European Cooperative Acute Stroke Study-3 (ECASS-3) demonstrated that intravenous-tissue plasminogen activator could be safely administered for acute stroke patients presenting between 3 and 4.5 hours from symptom onset. Recently, the Food and Drug Administration rejected expansion of this time window in the United States. We sought to determine how many fewer patients would be treated by maintaining this restricted time window. METHODS: We reviewed charts from patients who received intravenous thrombolysis at the University of Alabama at Birmingham between January 2009 and December 2011. Patients were divided into two groups (treated within 3 hours of onset, treated between 3 and 4.5 hours from onset). Demographics, stroke severity and protocol deviations according to the ECASS-3 trial were collected. Our safety measures were any hemorrhagic transformation, symptomatic intracerebral hemorrhage and systemic hemorrhage. RESULTS: Two hundred and twelve patients were identified, of whom 192 were included in our analysis. A total of 36 patients (19%) were treated between 3 and 4.5 hours. No statistical differences were seen between age (p=0.633), gender (p=0.677), race (p=0.207) or admission stroke severity (p=0.737). Protocol deviations from the ECASS-3 criteria were found in 20 patients (56%). These were primarily age > 80 and aggressive blood pressure management. Despite these deviations, we did not see significant increases in the rates of adverse events in patients treated in the extended time window. CONCLUSIONS: Our data are consistent with previously reported international data that IV thrombolysis can safely be used up to 4.5 hours from symptom onset. Restricting the time window to 3 hours would have resulted in almost one-fifth fewer patients treated at our center.

Hemorrhagic Transformation (HT) and Symptomatic Intracerebral Hemorrhage (sICH) Risk Prediction Models for Postthrombolytic Hemorrhage in the Stroke Belt.

BACKGROUND: Symptomatic intracerebral hemorrhage (sICH) remains the most feared complication of intravenous tissue plasminogen activator (IV tPA) treatment. We aimed to investigate how previously validated scoring methodologies would perform in treated patients in two US Stroke Belt states. METHODS AND RESULTS: We retrospectively reviewed consecutive patients from two centers in two Stroke Belt states who received IV tPA (2008-2011). We assessed the ability of three models to predict sICH. sICH was defined as a type 2 parenchymal hemorrhage with deterioration in National Institutes of Health Stroke Scale (NIHSS) score of ≥4 points or death. Among 457 IV tPA-treated patients, 19 (4.2%) had sICH (mean age 68, 26.3% Black, 63.2% female). The Cucchiara model was most predictive of sICH in the entire cohort (AUC: 0.6528) and most predictive of sICH among Blacks (OR = 6.03, 95% CI 1.07-34.1, P = 0.0422) when patients were dichotomized by score. CONCLUSIONS: In our small sample from the racially heterogeneous US Stroke Belt, the Cucchiara model outperformed the other models at predicting sICH. While predictive models should not be used to justify nontreatment with thrombolytics, those interested in understanding contributors to sICH may choose to use the Cucchiara model until a Stroke Belt model is developed for this region.