Recreational nitrous oxide misuse is resulting in serious neurological impairment and persistent disability among users

2021 ◽  
Author(s):  
Simon Mosalski ◽  
Anne Tanner ◽  
Christine T Shiner
Keyword(s):  
Nitrous Oxide ◽  
Neurological Impairment ◽  
Persistent Disability

scholarly journals Tissue folates in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced vitamin B12deficiency and neurological impairment

1987 ◽  
Vol 58 (3) ◽  
pp. 485-491 ◽  
Author(s):  
Justin Van Der Westhuyzen ◽  
Richard E. Davis ◽  
Graham C. Icke ◽  
Jack Metz
Keyword(s):  
Nitrous Oxide ◽  
Subcellular Distribution ◽  
Neurological Impairment ◽  
Fruit Bats ◽  
Fruit Bat

1. Long-term exposure of the fruit bat Rousettus aegyptiacus to nitrous oxide, which inactivates methylco balamin, leads to neurological impairment and ataxia.2. In N2, O-exposed animals, liver concentrations of total folates and methyl folates decreased to less than one fifth that of control animals. Pediococcus cerevisiue-active folates were also reduced.3. In brain, there were no changes in total or methyl folates, but P.cerevisiae-active folates were lower in N2, O-exposed animals.4. Supplementation with methionine retarded the development of neurological impairment and the fall in liver total and methyl folates, but not that in P. cerevisiae-active folates.5. Supplementation with serine failed to retard the development of neurological impairment or fall in hepatic folates.6. The present results suggest that the N2O-induced neurological impairment in the bat is not related to depletion of cerebral folates, but do not exclude changes in the subcellular distribution of folates.

Severe Neurological Impairment in an Infant after Nitrous Oxide Anesthesia

2000 ◽  
Vol 93 (6) ◽  
pp. 1549-1550 ◽  
Author(s):  
James K. McNeely ◽  
Bogdan Buczulinski ◽  
Diane R. Rosner
Keyword(s):  
Nitrous Oxide ◽  
Neurological Impairment ◽  
Severe Neurological Impairment ◽  
Oxide Anesthesia

scholarly journals Plasma amino acids and tissue methionine levels in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced vitamin B12 deficiency

1985 ◽  
Vol 53 (3) ◽  
pp. 657-662 ◽  
Author(s):  
Justin Van Der Westhuyzen ◽  
Suasn V. Van Tonder ◽  
Jayne E. Gibson ◽  
Terence A. Kilroe-smith ◽  
Jack Metz
Keyword(s):  
Nitrous Oxide ◽  
Vitamin B12 Deficiency ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Neurological Impairment ◽  
Vitamin B ◽  
Muscular Weakness ◽  
Fruit Bats ◽  
B12 Deficiency ◽  
Methionine Synthesis

1. The effect of methylcobalamin inactivation by the gas nitrous oxide on plasma amino acid and tissue methionine levels in fruit bats (Rousettus aegyptiacus) was examined.2. Animals exposed to N2O-oxygen (1:1, v/v) for 90 min daily received a fruit diet with or without methionine or betaine supplements. Exposure and diets were continued for up to 17 weeks or until neurological impairment and muscular weakness was established.3. All the groups exposed to N2O had significantly lower liver, brain and plasma methionine concentrations except the methionine-supplemented animals which showed significantly raised levels. Plasma homocysteine, which was absent in controls, was present in all the N2O-exposed groups.4. Betaine supplementation resulted in reduced accumulation of homocysteine in plasma. However, plasma and liver methionine levels were only slightly increased compared with animals on the basal diet, and brain methionine levels were the lowest of all the groups studied.5. These results support the hypothesis that reduced methionine synthesis is an important contributor to the development of neurological impairment in this species and suggest that dietary supplementation with the methionine precursor betaine cannot replace the loss of vitamin B12-dependent methionine synthesis.

Central Nerve System Impairment, AMA Guides, Sixth Edition: An Overview

2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Neurological Impairment ◽  
Sixth Edition ◽  
Central Nerve System ◽  
The Central Nervous System ◽  
The One ◽  
Nerve System ◽  
The Brain

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.

Impairment Tutorial: Neurological Impairment Evaluation: Overview of Sixth Edition Approaches

2008 ◽  
Vol 13 (2) ◽  
pp. 6-8
Author(s):  
Lorne Direnfeld ◽  
Christopher R. Brigham ◽  
Elizabeth Genovese
Keyword(s):  
Spinal Cord ◽  
Neurological Impairment ◽  
Diagnostic Techniques ◽  
Neurological Deficits ◽  
Sixth Edition ◽  
Pain Disability ◽  
Whole Person ◽  
Disability Questionnaire ◽  
Cervical Plating

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), does not provide a Diagnosis-based estimate of impairment due to syringomyelia, a disorder in which a cyst (syrinx), develops within the central spinal cord and destroys neural tissue as it expands. The AMA Guides, however, does provide an approach to rating a syringomyelia based on objective findings of neurological deficits identified during a neurological examination and demonstrated by standard diagnostic techniques. Syringomelia may occur after spinal cord trauma, including a contusion of the cord. A case study illustrates the rating process: The case patient is a 46-year-old male who fell backwards, landing on his upper back and head; over a five-year period he received a T5-6 laminectomy and later partial corpectomies of C5, C6, and C7, cervical discectomy C5-6 and C6-7; iliac crest strut graft fusion of C5-6 and C6-7; and anterior cervical plating of C5 to C7 for treatment of myelopathy; postoperatively, the patient developed dysphagia. The evaluating physician should determine which conditions are ratable, rate each of these components, and combine the resulting whole person impairments without omission or duplication of a ratable impairment. The article includes a pain disability questionnaire that can be used in conjunction with evaluations conducted according to Chapter 3, Pain, and Chapter 17, The Spine.

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