A Retrospective Study of Neurological Impairment in a Young Population Exposed to Recreational Nitrous Oxide
Trial Snapshot
- Phase
- Not Applicable
- Status
- Terminated
- Sponsor
- Enrollment
- 20
- Locations
- 2
- Primary Endpoint
- electroneuromyogram
Study Overview
Brief Summary
Nitrous oxide (N2O) is a colorless, flammable, analgesic gas used in surgery and dentistry. The consumption of N2O has increased among young French people aiming to relax because of its short-lived neuropsychological effect (euphoria, depersonalization, analgesia) and its wide availability on the market.
It can be responsible in case of prolonged use and overdose of a vitamin B12 deficiency with possible neuropsychiatric complications: sensitivomotor neuropathy, myelopathy, behavioral and cognitive disorders of acute or sub-acute installation.
N2O inhibits the activitý of methionine synthase, decreases the activitý of methylmalonyl-CoA mutase leading to vitamin B12 deficiency but in addition to the interference with vitamin B12 metabolism there seems to be a direct toxicity of N20.
Myelin alteration was the typical electromyography finding but new axonal profiles were also described. Since myelopathy affects both the posterior and lateral cords, combined spinal cord sclerosis is the most common location of injury associated with N2O intoxication.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Retrospective
Eligibility Criteria
- Ages
- 15 Years to — (Child, Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •patients presenting to the CHU of Nîmes with an acute or sub-acute neurological picture after having consumed N2O
Exclusion Criteria
- Not provided
Arms & Interventions
Patients
patients presenting to the CHU of Nîmes for an acute or subacute neurological picture after having consumed N2O.
Intervention: None, pure observationnal study (Other)
Outcomes
Primary Outcomes
electroneuromyogram
Time Frame: baseline
Normal Yes/No
INCAT Sensory Sum score (ISS)
Time Frame: Baseline
grades from 0 (no involvement) to 20 (severe involvement)
ONLS - Overall Neuropathy Limitations Scale
Time Frame: Baseline
Overall Neuropathy Limitation Scale = arm scale (range 0 to 5) + leg scale (range 0 to 7); (range: 0 (no disability) to 12 (maximum disability)
vitamin B12 level
Time Frame: baseline
vitamin B12 level in µmom/L
MRC score
Time Frame: baseline
MRCss - Medical Research Council sum score : This score assigns a rating to each muscle group: "0" = absence of visible contraction visible contractions, " 1 " = visible contractions without movement of limbs, " 2 " = insufficient 2" = insufficient movements to overcome weightlessness, "3" = movements to overcome weightlessness, "4" = movements against weightlessness and resistance, "5" = normal muscle strength.
Pan-medullary MRI
Time Frame: baseline
lesions yes/No
Romberg score
Time Frame: Baseline
A positive Romberg test means the presence of sensory ataxia
Rankin score
Time Frame: Baseline
disability measurement score from 0 (none) to 6 (death)
Cerebral MRI
Time Frame: baseline
lesions yes/No
methyl malonic acid level
Time Frame: baseline
methyl-malonic acid level
Secondary Outcomes
No secondary outcomes reported