Joon Y. Kang

Association between hyperoxia and mortality after stroke: a multicenter cohort study.

Objective:To test the hypothesis that hyperoxia was associated with higher in-hospital mortality in ventilated stroke patients admitted to the ICU. Design:Retrospective multicenter cohort study. Setting:Primary admissions of ventilated stroke patients with acute ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage who had arterial blood gases within 24 hours of admission to the ICU at 84 U.S. ICUs between 2003 and 2008. Patients were divided into three exposure groups: hyperoxia was defined as PaO2 ≥300 mm Hg (39.99 kPa), hypoxia as any PaO2<60 mm Hg (7.99 kPa) or PaO2/FiO2 ratio ⩽300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Participants:Two thousand eight hundred ninety-four patients. Methods:Patients were divided into three exposure groups: hyperoxia was defined as PaO2 more than or equal to 300 mm Hg (39.99 kPa), hypoxia as any PaO2 less than 60 mm Hg (7.99 kPa) or PaO2/FIO2 ratio less than or equal to 300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Interventions:Exposure to hyperoxia. Results:Over the 5-year period, we identified 554 ventilated patients with acute ischemic stroke (19%), 936 ventilated patients with subarachnoid hemorrhage (32%), and 1,404 ventilated patients with intracerebral hemorrhage (49%) of whom 1,084 (38%) were normoxic, 1,316 (46%) were hypoxic, and 450 (16%) were hyperoxic. Mortality was higher in the hyperoxia group as compared with normoxia (crude odds ratio 1.7 [95% CI 1.3-2.1]; p < 0.0001) and hypoxia groups (crude odds ratio, 1.3 [95% CI, 1.1–1.7]; p < 0.01). In a multivariable analysis adjusted for admission diagnosis, other potential confounders, the probability of being exposed to hyperoxia, and hospital-specific effects, exposure to hyperoxia was independently associated with in-hospital mortality (adjusted odds ratio, 1.2 [95% CI, 1.04–1.5]). Conclusion:In ventilated stroke patients admitted to the ICU, arterial hyperoxia was independently associated with in-hospital death as compared with either normoxia or hypoxia. These data underscore the need for studies of controlled reoxygenation in ventilated critically ill stroke populations. In the absence of results from clinical trials, unnecessary oxygen delivery should be avoided in ventilated stroke patients.

Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy

To describe mesial temporal lobe ablated volumes, verbal memory, and surgical outcomes in patients with medically intractable mesial temporal lobe epilepsy (mTLE) treated with magnetic resonance imaging (MRI)–guided stereotactic laser interstitial thermal therapy (LiTT).

Significance of arterial hyperoxia and relationship with case fatality in traumatic brain injury: a multicentre cohort study

Objective In this retrospective multi-centre cohort study, we tested the hypothesis that hyperoxia was not associated with higher in-hospital case fatality in ventilated traumatic brain injury (TBI) patients admitted to the intensive care unit (ICU). Methods Admissions of ventilated TBI patients who had arterial blood gases within 24 h of admission to the ICU at 61 US hospitals between 2003 and 2008 were identified. Hyperoxia was defined as PaO2 ≥300 mm Hg (39.99 kPa), hypoxia as any PaO2 <60 mm Hg (7.99 kPa) or PaO2/FiO2 ratio ≤300 and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital case fatality. Results Over the 5-year period, we identified 1212 ventilated TBI patients, of whom 403 (33%) were normoxic, 553 (46%) were hypoxic and 256 (21%) were hyperoxic. The case-fatality was higher in the hypoxia group (224/553 [41%], crude OR 2.3, 95% CI 1.7-3.0, p<.0001) followed by hyperoxia (80/256 [32%], crude OR 1.5, 95% CI 1.1-2.5, p=.01) as compared to normoxia (87/403 [23%]). In a multivariate analysis adjusted for other potential confounders, the probability of being exposed to hyperoxia and hospital-specific characteristics, exposure to hyperoxia was independently associated with higher in-hospital case fatality adjusted OR 1.5, 95% CI 1.02-2.4, p=0.04. Conclusions In ventilated TBI patients admitted to the ICU, arterial hyperoxia was independently associated with higher in-hospital case fatality. In the absence of results from clinical trials, unnecessary oxygen delivery should be avoided in critically ill ventilated TBI patients.

Equivocal significance of post-ictal generalized EEG suppression as a marker of SUDEP risk

PURPOSE Our objective was to determine the significance of PGES as a possible EEG marker of increased risk for SUDEP and explore factors that influence PGES. METHODS We identified 17 patients who died due to definite or probable SUDEP and 52 living control patients with drug resistant focal epilepsy who underwent EEG monitoring and least one seizure recorded on EEG. We reviewed 305 seizures on EEG and when available, on video, for presence or absence of PGES, the duration of PGES immediately after seizure end, seizure type, state seizure occurred (sleep vs. wake), tonic duration and time from seizure onset to initial nursing intervention. We noted that majority (93% in SUDEP group and 83% living controls) with PGES had additional brief bursts of suppression. We measured the time from the end of seizure to end of last brief suppression to determine the time to final PGES. RESULTS SUDEP patients had statistically significant shorter PGES duration compared to living controls (unadjusted: -32.8s, 95%CI[-54.5, -11.2], adjusted: -39.5s, 95% CI[-59.4, -19.6]). SUDEP status was associated with longer time to final PGES compare to living controls, but this was not statistically significant. Earlier nursing intervention was associated with shorter seizure duration. PGES occurred only after GCS. Time to nursing intervention, tonic duration or state did not have a statistically significant effect on PGES. CONCLUSIONS PGES is an equivocal marker of increased SUDEP risk. Earlier nursing intervention is associated with shorter seizure duration and may play a role in reducing risk of SUDEP.

Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy for Treatment of Drug-Resistant Epilepsy.

Surgery is the most effective treatment for drug-resistant epilepsy. Long-term studies demonstrate that about 60% to 80% of patients become seizure-free after anterior temporal lobectomy and a majority of patients (about 95%) report significant seizure reduction after surgery. In the last few years, there has been significant advances in minimally invasive surgical techniques to treat drug-resistant epilepsy. These minimally invasive procedures have significant advantages over open surgery in that they produce less immediate discomfort and disability, while allowing for greater preservation of functional tissue. Laser interstitial thermal therapy (LiTT) is an example of such a procedure. Recent advances in imaging, surgical navigation, and real-time thermal monitoring have made LiTT safer and easier to implement, offering an effective and powerful neurosurgical tool for drug-resistant epilepsy. This article will review the technical considerations, uses, and potential future directions for LiTT in drug-resistant epilepsy.

Epileptologist's view: Laser interstitial thermal ablation for treatment of temporal lobe epilepsy

A procedure called laser interstitial thermal ablation has been utilized to treat drug resistant epilepsy. With this technique, a probe is stereotactically inserted into a target structure responsible for seizures, such as mesial temporal lobe, hypothalamic hamartoma, or a small malformation of cortical development, and the tip is then heated by application of laser energy to ablate structures adjacent to the probe tip. This procedure has the advantage of selectively targeting small lesions responsible for seizures, and is far less invasive than open surgery with shorter hospitalization, less pain, and rapid return to normal activities. Initial results in mesial temporal lobe epilepsy are promising, with perhaps half of patients becoming free of seizures after the procedure. Neuropsychological deficits appear to be reduced because of the smaller volume of ablated cortex in contrast to large resections. More research must be done to establish optimal targeting of structures for ablation and selection of candidates for surgery, and more patients must be studied to better establish efficacy and adverse effect rates.

Driving and Epilepsy: a Review of Important Issues

Driving restrictions in people with epilepsy (PWE) is a highly contentious topic. The fundamental difficulty lies in achieving a balance between safety and practicality. The aim of this review is to provide an overview, history, and rationale behind current laws regarding driving restriction in PWE. We also discuss recent findings that may be helpful to practitioners during individual discussions with PWE including seizure recurrence risk after first seizure, recurrent seizure, and anticonvulsant with drawl and driving restrictions in patients with psychogenic non-epileptic seizures (PNES).

Strategies for non-EEG seizure detection and timing for alerting and interventions with tonic-clonic seizures

Sudden unexpected death in epilepsy (SUDEP) is a common cause of death in epilepsy and frequently occurs following generalized tonic–clonic seizures (GTCS). Non–electroencephalography (EEG) seizure detection systems using mobile sensor devices permit caregivers to assist patients during seizures and may reduce risks for complications of seizures such as injuries and SUDEP. We review changes in accelerometry, electrodermal activity, and heart rate associated with tonic–clonic seizures and their use in detection systems, including multimodal detectors. We reviewed current and past publications reporting data on linkage between GTCS, post‐ictal generalized EEG suppression (PGES), and ventilatory dysfunction. The timing and duration of postictal immobility and respiratory dysfunction associated with convulsions help identify which patients might benefit the most from seizure monitoring and from benchmarks for the timing of seizure detection, caregiver alerting, and interventions.