Neurologic Symptoms

Nitrous oxide has become an increasingly popular recreational drug amongst young people, particularly at festivals, nightclubs and parties. Considering the drug is not illegal to possess, has low cost in the form of 'whippets' and can be easily purchased online, it has become the second most commonly used recreational drug amongst people aged 16-24 in the UK. However, nitrous oxide is known to irreversibly inactivate the functioning of vitamin B12, a vitamin required for the maintenance and proper functioning of nerves in the spinal cord. Neurological symptoms in this population have been reported in around 3.4% of nitrous oxide users, although the true incidence is expected to be higher as the cases being reported by UK hospitals continues to rise. Patients may present with adverse neurological symptoms like tingling, weakness, coordination and mobility problems. Currently, studies reviewing the functional recovery of these patients have been limited by a retrospective study design, short follow up duration and being limited to small cohort sizes. This is in part linked to patient non-compliance and non-attendance at follow-up appointments. The investigators will therefore prospectively recruit all patients presenting with these symptoms and continue to collect data relating to their neurological recovery for 12 months. Data collection will be remote to ensure it is of low burden to the participants. This will allow the investigating team and others to fully appraise the severity of these toxic neuropathies and understand how best to manage their follow up.

Cerebral lesions are responsible for two thirds of deaths in patients admitted to intensive care following cardiac arrest. Patients with neurological lesions should be the priority target for neuroprotective interventions, which are the cornerstone of post-cardiac arrest care (allowing a reduction in the burden of care for patients without this type of lesion). Furthermore, these interventions must be based on a precise assessment of the severity of these brain lesions: carrying out neuro-protective interventions in patients without brain lesions exposes these patients to unnecessary treatment potentially associated with adverse effects without any possible benefit. However, the early assessment of neurological prognosis, particularly on admission to intensive care, is an area where there is little research and where it is not possible to obtain a precise and reproducible assessment. Several tools can be used to assess this prognosis at an early stage: anamnesis and characteristics of the cardiac arrest and the patient's comorbidities, imaging, electrophysiology and biomarkers. To assess the predictive value of early biomarker testing in patients resuscitated after cardiac arrest, whatever the cause, the investigators plan to conduct a prospective observational multicentre trial. It is important to bear in mind that the aim of this study is not to assess the long-term prognosis of patients suffering cardiac arrest in order to take measures to limit or discontinue active therapies, but simply to provide a reliable tool, simple and quick to use, in order to be able to identify a sub-population of patients who should be the subject of preferential neuro-protection measures, and conversely to simplify management (moderate temperature control, early cessation of sedation, early extubation) for patients with no neurological lesions.