Case Studies in Neuroscience: Transcranial Doppler assessment of increased cerebral blood flow during iterative seizures.

This case study aimed at monitoring ictal vasodilation in a clinical setting to confirm the experimental data on enhanced cerebral perfusion during epileptic seizures. Clinical observation of a patient presenting relapsing seizures in the intensive care unit. Transcranial Doppler (TCD) was used to monitor both blood velocities and the arterial caliber in the B-flow mode as a proxy of blood flow of the middle cerebral artery (MCA). A 35-yr-old woman experienced partial epileptic seizures lasting for 1 min that recurred every 5 min. Seizures were monitored with continuous EEG and TCD. During the seizure, the MCA caliber increased whereas velocities remained stable, which doubled the MCA blood flow. Immediately after the seizure, the artery caliber returned to its initial value, and the velocities increased by one-third of the initial value. After intensification of antiepileptic treatment, clinical seizures ceased, and TCD findings returned to normal MCA caliber and velocities. Autoimmune encephalitis was identified by brain biopsy and the patient recovered with corticosteroids treatment. This is the first description of ictal vasodilatation assessed by TCD. Our current understanding holds that cerebral blood flow increases during a seizure, but our report demonstrates that arterial dilation preceded the acceleration of velocities. This case study in a clinical setting confirms the impact of seizures on cerebral blood flow. NEW & NOTEWORTHY The case study is a clinical demonstration of ictal vasodilation. By assessing arterial caliber and blood velocities with transcranial Doppler, we dissected the impact of seizures on blood flow of the middle cerebral artery in the following sequence: 1) vasodilation occurred, concomitant to the epileptic activity, whereas the blood velocities remained stable and 2) immediately after the seizure, the velocities increased and the artery caliber returned to its initial value. As per author, there was no protocol, but one patient gave consent to use data from her medical file.

Reducing the time to successful intravenous cannulation in anaesthetised children with poor vein visibility using a near-infrared device: A randomised multicentre trial.

BACKGROUND: During inhalational induction of anaesthesia for children, severe respiratory events can occur but can be rapidly treated once intravenous access is in place. Reducing the time to successful cannulation during inhalational induction for children with poor vein visibility would improve safety. OBJECTIVE: To study the effectiveness of a near-infrared (NIR) vascular imaging device (Veinviewer) to facilitate intravenous cannulation. DESIGN: A prospective, multicentre, randomised, open clinical trial. SETTING: The operating rooms of three paediatric hospitals in Paris, France, from 1 October 2012 to 31 March 2016. PATIENTS: Children up to the age of 7 years, with poor vein visibility requiring general anaesthesia. INTERVENTION: Inhalational anaesthesia was initiated and intravenous cannulation was performed with the standard approach or with the Veinviewer Vision. MAIN OUTCOME MEASURES: The primary outcome was the time to successful intravenous cannulation. A secondary outcome was the proportion of successful first attempts. RESULTS: The mean time to successful intravenous cannulation was 200 (95% CI, 143 to 295) seconds in the Veinviewer and 252 (95% CI, 194 to 328) seconds for the control group: hazard ratio 1.28 (1.02 to 1.60) (P = 0.03). The adjusted hazard ratio for known predictive factors was 1.25 (0.99 to 1.56) (P = 0.06). Success at the first attempt was 64.6% (102/158) in the 'Veinviewer' group vs. 55.6% (85/153) in the 'control' group (P = 0.10). CONCLUSION: The Veinviewer has limited value in reducing the time to successful intravenous cannulation during inhalational anaesthesia for young children with poor vein visibility. However, there is a strong trend to reducing the delay in some cases and, given its absence of side effects, it could be part of a rescue option for a difficult venous-access strategy. CLINICAL TRIAL REGISTRATION: NCT01685866 (http://www.clinicaltrials.gov).

Correction to: COVID-19-associated acute cerebral venous thrombosis: clinical, CT, MRI and EEG features.

An amendment to this paper has been published and can be accessed via the original article.