Continuous EEG monitoring in comatose intensive care patients

Introduction: It is unclear whether patients or subpopulations of patients might benefit from EEG monitoring. Methods: We conducted a prospective trial of continuous electroencephalogram monitoring (CEEG; 48 hours). Results: Eleven of 55 (20%) patients who underwent CEEG monitoring recorded seizures. Of patients with acute structural brain lesions (ASBLs), 10 of 31 (32%) patients experiences recorded seizures, whereas only 24 (4%) patients with metabolic encephalopathies experienced recorded seizures (p<0.01). Six patients with ASBLs (11%) and one patient with metabolic encephalopathy (4%) had spikes/interictal epileptiform discharges (p=0.087). Conclusion: Our study suggests that CEEG monitoring may be more valuable for detection of seizures in patients with ASBLs than in patients with metabolic encephalopathies.     

Prolonged deficits after focal inhibitory seizures

Introduction: Seizures are most commonly associated with positive phenomena such as tonic, clonic or myoclonic movements, automatisms, paresthesias and hallucinations. Negative phenomena, however, are not an uncommon manifestation of seizure activity. Examples of negative seizure phenomena include speech arrest, aphasia, amaurosis, amnesia, numbness, deafness, neglect and atonic seizures. Less commonly described in the literature are focal inhibitory motor seizures. Methods and Results: Two patients presenting with rapidly progressive, prolonged hemiparesis, sensory neglect and hemi-visual field obscuration are described. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain did not reveal progression of known structural lesions or new lesions. The superficial cortex of the hemisphere contralateral to the hemiparesis and sensory neglect enhanced diffusely with gadolinium on T1-weighted MRI images. Electroencephalography demonstrated periodic lateralized epileptiform discharges (PLEDs) in one patient and lateralized suppression and slowing in the other patient. Single photon emission computed tomography (SPECT) revealed hyperperfusion in the hemisphere contralateral to the hemiparesis and sensory neglect. The changes seen on MRI and SPECT resolved with resolution of the symptoms. Conclusion: Taken together with the clinical history, the results from these investigations suggest focal inhibitory seizure as the underlying etiology. A review of the literature and investigations helpful in making this difficult diagnosis are provided.     

A critique of ancillary tests for brain death

The acceptance of brain death by society has allowed for the discontinuation of “life support” and the transplantation of organs. The standard clinical criteria for brain death, when rigorously applied, ensure that the brainstem is destroyed. Because more rostral structures are more vulnerable than the brainstem, these are almost invariably devastated when brainstem function is irreversibly lost as a result of whole brain insults. Then, clinical criteria for “brainstem death” ensure that “whole-brain death” is present. However, if the brainstem is selectively damaged or if brainstem function cannot be adequately assessed clinically, ancillary tests are needed to confirm whole-brain death with certainty. Ancillary tests are also required in very young children. In addition, some societies require their use as a matter of principle. Only tests of whole-brain perfusion adequately serve these purposes.     

Botulinum-A Toxin Treatment of the Lower Eyelid Improves Infraorbital Rhytides and Widens the Eye

Botulinum-A exotoxin (BTX-A) can be used cosmetically to improve rhytides, particularly of the upper one-third of the face. In this study, fifteen women had BTX-A (BOTOX, Allergan, Inc.) injected into the orbicularis oculi muscle. One lower eyelid received two units just subdermally in the midpupillary line three millimeters below the ciliary margin. The opposite periocular area received two units BTX-A in the lower eyelid with 12 units BTX-A injected into the lateral orbital ("crow's foot") area. Three injections of four units each were placed 1.5 cm from the lateral canthus, each 1 cm apart. Patients and physicians independently evaluated the degree of improvement (grade 0 = no improvement, grade 1 = mild improvement, grade 2 = moderate improvement, and grade 3 = dramatic improvement). An independent photographic analysis was performed. Patients reported a grade of 0.73 when two units were injected alone into the lower lid, and a grade of 1.9 when the lower eyelid and the lateral orbital areas were injected. Physician assessment was grade 0.7 with injection of the eyelid alone and grade 1.8 with injection of the lower eyelid and lateral orbital area. Single investigator photographic analysis demonstrated that 40% of the subjects who had injection of the lower eyelid alone had an increased palpebral aperture (IPA), while 86% of the subjects who had injection of the lower eyelid and lateral orbital area had an IPA. Subjects receiving two units alone had an average 0.5 mm IPA and a mean 1.3 mm IPA at full smile. Concomitant treatment of the lateral orbital area produced a mean 1.8 mm IPA at rest and a mean 2.9 mm IPA at full smile. The results were more notable in the Asian eye. Two units of BTX-A injected into the lower eyelid orbicularis oculi muscle improves infraorbital wrinkles, particularly when used in combination with BTX-A treatment of the lateral orbital area.     

Central sleep apnea and hypoventilation syndrome

Opinion statement Central sleep apnea hypopnea syndrome (CSAHS) and sleep hypoventilation syndrome (SHVS) are two distinct clinical syndromes with clearly defined diagnostic criteria. It is important to distinguish between normo/hypocapnic and hypercapnic CSAHS prior to treatment. Nasal continuous positive airway pressure is currently considered the primary treatment of choice for normo/hypocapnic CSAHS. The initial management of hypercapnic CSAHS and SHVS should include identification of any treatable causes and discontinuation of any sedative medications. Medroxyprogesterone may be effective in the long term management of these patients. If pharmacologic therapy fails, assisted ventilation should be considered. Assisted ventilation during the night is usually sufficient to improve hypercapnia and hypoxemia both at night and during the day. Assisted ventilation is usually best administered through a tight fitting nasal mask.     

Neuroimaging and behavior: Probing brain behavior relationships in the 21st century

Functional neuroimaging over the past decade has provided a new way to examine brain behavior relationships. Current noninvasive neuroimaging techniques, which can examine structure and function, have begun to clarify the networks involved in cognitive processes and how these are affected in aging and disease. Functional magnetic resonance imaging (fMRI) has demonstrated the interaction between medial temporal and prefrontal regions in episodic memory. The anatomical correlates of various components of spatial attention and working memory have emerged from elegant event-related fMRI designs. Distinct neural networks for different emotions are being mapped out, and the role of the anterior cingulate in depressed mood has been documented. This review highlights key recent studies that have illuminated the neural substrates of these important cognitive and affective processes.     

Musculoskeletal Sonopathology and Ultrasound-Guided Regional Anesthesia

The use of real-time ultrasound guidance has revolutionized the practice of regional anesthesia. Ultrasound is rapidly becoming the technique of choice for nerve blockade due to increased success rates, faster onset, and potentially improved safety. In the course of ultrasound-guided regional anesthesia, unexpected pathology may be encountered. Such anomalous or pathological findings may alter the choice of nerve block and occasionally affect surgical management. This case series presents a variety of musculoskeletal conditions that may be encountered during ultrasound-guided regional anesthesia practice.     

The effects of droperidol and ondansetron on dispersion of myocardial repolarization in children

Objectives: To compare the effects of droperidol and ondansetron on electrocardiographic indices of myocardial repolarization in children. Aim: To refine understanding of the torsadogenic risk to children exposed to anti‐emetic prophylaxis in the perioperative period. Background: QT interval prolongation is associated with torsades des pointes (TdP), but is a poor predictor of drug torsadogenicity. Susceptibility to TdP arises from increased transmural dispersion of repolarization (TDR) across the myocardial wall, rather than QT interval prolongation per se. TDR can be measured on the electrocardiogram as the time interval between the peak and end of the T wave (Tp‐e). Tp‐e may therefore provide a readily available, noninvasive assay of drug torsadogenicity. The perioperative period is one of high risk for TdP in children with or at risk of long QT syndromes. Droperidol and ondansetron are two drugs commonly administered perioperatively, for prophylaxis of nausea and vomiting, which can prolong the QT interval. This study investigated their effects on myocardial repolarization. Methods: One hundred and eight ASA1‐2 children undergoing elective day‐case surgery were randomized to receive droperidol, ondansetron, both or neither. Pre‐ and post‐administration 12‐lead electrocardiogram (ECGs) were recorded. QT and Tp‐e intervals were measured and compared within and between groups, for the primary endpoint of a 25 ms change in Tp‐e. Results: Eighty children completed the study. There were no demographic or baseline ECG differences between groups. QT intervals lengthened by 10–17 ms after allocated treatments, with no between‐group differences. Values remained within normal limits for all groups. Tp‐e intervals increased by 0–7 ms, with no between‐group differences. There were no instances of dysrhythmia. Conclusions: Droperidol and ondansetron, in therapeutic anti‐emetic doses, produce equivalent, clinically insignificant QT prolongation and negligible Tp‐e prolongation, suggesting that neither is torsadogenic in healthy children at these doses.