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Christopher Lewandowski

Publications and source records attributed to Christopher Lewandowski.

5 recordsLinked to original sources
PubMed2025

Brain dynamics reflecting an intra-network brain state is associated with increased posttraumatic stress symptoms in the early aftermath of trauma.

Post-traumatic stress (PTS) encompasses a range of psychological responses following trauma, which may lead to more severe outcomes such as post-traumatic stress disorder (PTSD). Identifying early neuroimaging biomarkers that link brain function to PTS outcomes is critical for understanding PTSD risk. This longitudinal study examines the association between brain dynamic functional network connectivity (dFNC) and current/future PTS symptom severity, and the impact of sex on this relationship. By analyzing 275 participants' dFNC data obtained ~2 weeks after trauma exposure, we noted that brain dynamics of an inter-network brain state link negatively with current (r=-0.197, p corrected = 0.0079) and future (r=-0.176, p corrected = 0.0176) PTS symptom severity. Also, dynamics of an intra-network brain state correlated with future symptom intensity (r = 0.205, p corrected = 0.0079). We additionally observed that the association between the network dynamics of the inter-network and intra-network brain state with symptom severity is more pronounced in female group. Our findings highlight a potential link between brain network dynamics in the aftermath of trauma with current and future PTSD outcomes, with a stronger effect in female group, underscoring the importance of sex differences.

Journal Article↗
PubMed2005

The impact of imbalances in baseline stroke severity on outcome in the National Institute of Neurological Disorders and Stroke Recombinant Tissue Plasminogen Activator Stroke Study.

STUDY OBJECTIVE: The National Institute of Neurological Disorders and Stroke (NINDS) Recombinant Tissue Plasminogen Activator (rtPA) Stroke Study demonstrated a clinically meaningful and statistically significant benefit of tissue plasminogen activator (tPA). Adjusting for the baseline National Institutes of Health (NIH) Stroke Scale, the benefit of tPA remained. However, other authors suggest that an imbalance in baseline stroke severity between the tPA and placebo groups confounded the results. Another issue that has been raised concerns a possible increase in early mortality for individuals given tPA. In post hoc subgroup analysis, we describe the effect of tPA across a spectrum of time from stroke onset to treatment and stroke severity subgroups. Stroke severity was based on the NIH Stroke Scale. We also compare early mortality (2-week and 30-day) in the tPA and placebo groups. METHODS: Using combined data from the 2 NINDS rtPA Stroke Study trials, we performed post hoc subgroup analyses of 3-month favorable outcome (defined by the NIH Stroke Scale, Barthel, Rankin, and Glasgow Outcome Scales). We categorized patients from the trials into onset to treatment (0 to 90 minutes, 91 to 180 minutes) by NIH Stroke Scale (< or =5, 6 to 20, >20) subgroups. Analyses were adjusted for all variables previously shown to be associated with favorable outcome at 3 months. We also compared early mortality within onset-to-treatment subgroups. RESULTS: For all the 12 specified onset-to-treatment-NIH Stroke Scale subgroups, the adjusted odds ratio for a favorable 3-month outcome was greater than 1.0 and favored tPA. We detected no difference in mortality between patients treated with rtPA and those treated with placebo by 2 weeks posttreatment (rtPA=9%, placebo=13%; P =.49) or by 30 days (rtPA=11%, placebo=16%; P =.30). CONCLUSION: These are descriptive post hoc subgroup analyses. Using cut points defined in previous critiques of the NINDS trials, these analyses give results consistent with previous NINDS Study Group reports. Baseline NIH Stroke Scale imbalance does not account for the better outcome of rtPA-treated patients.

Brain Ischemia↗
PubMed2003

Treatment of acute stroke with recombinant tissue plasminogen activator and abciximab.

OBJECTIVES: Preclinical data suggest that treatment of acute ischemic stroke (AIS) with the combination of recombinant tissue plasminogen activator (rt-PA) and abciximab may increase efficacy and decrease the rate of symptomatic intracranial hemorrhage (sICH). The authors report pilot data of five AIS patients with half-dose rt-PA and abciximab as part of an ongoing phase I safety trial with sICH as the primary outcome. METHODS: Five patients with AIS were treated with the combination of half-dose rt-PA (0.45 mg/kg) and abciximab (0.25 mg/kg bolus followed by a 0.125 microg/kg/min infusion over 12 hours). Head computed tomographic scan was obtained after 24 hours of treatment onset. RESULTS: Four patients received the combination of half-dose abciximab and rt-PA without major complications. One patient experienced a parenchymal hematoma type-1 ICH without significant decline of his neurological status. The average National Institutes of Health Stroke Scale change at discharge in comparison with pretreatment was -5.4 +/- 7.0, and the median change was 6 points with a range of 4 points (worsening) to -13 points (improvement) (p=0.07) based on a one-sided t-test. CONCLUSIONS: Administration of rt-PA and abciximab to AIS patients was completed without difficulty. No sICH were observed; however, 20% (1 out of 5) experienced an asymptomatic ICH. Based on our observation of five patients, there was a trend of treatment efficacy; however, these results need to be confirmed in a larger-scale placebo-controlled clinical trial.

Abciximab↗
PubMed2002

Infrequent causes of stroke.

Infrequent causes of stroke are likely to be encountered by emergency physicians. Infrequent causes of stroke can be recalled using the ABC-IT mnemonic. Of the many infrequent causes, the five conditions more likely to be encountered are sickle cell anemia, migrainous stroke, antiphospholipid antibody syndrome, arterial dissection, and cocaine-related stroke. Consideration of the use of thrombolytic therapy in a patient with stroke from any cause lies at the forefront of treatment strategy in the emergency department.

Anemia, Sickle Cell↗