Journal name: Substance Abuse and Rehabilitation Article Designation: CASE REPORT Year: 2016 Volume: 7 Substance Abuse and Rehabilitation Dovepress Running head verso: Mancke et al Running head recto: Psychiatric comorbidities and nitrous oxide-induced myelopathy open access to scientific and medical research DOI: http://dx.doi.org/10.2147/SAR.S114404 Open Access Full Text Article CASE REPORT Psychiatric comorbidities in a young man with subacute myelopathy induced by abusive nitrous oxide consumption: a case report 1,2, Falk Mancke * Abstract: Nitrous oxide (N2O), a long-standing anesthetic, is known for its recreational use, Gintare˙ Kaklauskaite˙1,* and its consumption is on the rise. Several case studies have reported neurological and psychi- 3 atric complications of N O use. To date, however, there has not been a study using standardized Jennifer Kollmer 2 1 diagnostic procedures to assess psychiatric comorbidities in a patient consuming N O. Here, Markus Weiler 2 we report about a 35-year-old male with magnetic resonance imaging confirmed subacute 1Department of Neurology, myelopathy induced by N O consumption, who suffered from comorbid cannabinoid and 2Department of General Psychiatry, 2 Center for Psychosocial Medicine, nicotine dependence as well as abuse of amphetamines, cocaine, lysergic acid diethylamide, 3 Department of Neuroradiology, and ketamine. Additionally, there was evidence of a preceding transient psychotic and depres- Heidelberg University Hospital, Heidelberg, Germany sive episode induced by synthetic cannabinoid abuse. In summary, this case raises awareness For personal use only. of an important mechanism of neural toxicity, with which physicians working in the field of *These authors contributed equally to this work substance-related disorders should be familiar. In fact, excluding N2O toxicity in patients with recognized substance-related disorders and new neurological deficits is compulsory, as untreated for months the damage to the nervous system is at risk of becoming irreversible. Keywords: addictive disorders, laughing gas, subacute combined degeneration, substance use disorder, vitamin B12 deficiency Introduction Besides its use in anesthesia, nitrous oxide (N2O) has a long history as a recreational drug. In recent years, an increasing amount of case reports have documented the neu- rological and psychiatric complications of N2O use, and myelopathy has been regarded as the most common manifestation (see for a recent review).1 To date, however, there Substance Abuse and Rehabilitation downloaded from https://www.dovepress.com/ by 54.70.40.11 on 19-Dec-2018 has not been a study using standardized diagnostic procedures to assess psychiatric Correspondence: Falk Mancke Department of General Psychiatry, comorbidities in a patient consuming N2O. Knowing these comorbidities will help to Center for Psychosocial Medicine, further characterize the patient population affected, which, in turn, will raise awareness Heidelberg University Hospital, Voßstraße 2, Heidelberg D-69115, of this mechanism of neural toxicity where it is most relevant. Germany Tel +49 6221 56 35709 Fax +49 6221 56 5374 Case report Email [email protected] A 35-year-old man presented to the department of neurology at Heidelberg University Markus Weiler Hospital reporting a 3-day history of progressive symmetrical numbness in his legs, Department of Neurology, Heidelberg tingling sensations in his legs and hands, imbalance, and difficulty walking. Past medi- University Hospital, Im Neuenheimer cal history was largely inconspicuous for any physical disorder. The patient further Feld 400, Heidelberg D-69120, Germany Tel +49 6221 56 7504 reported a 2-month daily habit of inhaling “laughing gas” of up to 50 whipped-cream Fax +49 6221 56 5461 capsules, each containing 10 mL of 100% N O. He bought these capsules at a super- Email [email protected] 2 heidelberg.de market nearby and used a whipped-cream utensil to inhale their contents. submit your manuscript | www.dovepress.com Substance Abuse and Rehabilitation 2016:7 155–159 155 Dovepress © 2016 Mancke et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms. php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work http://dx.doi.org/10.2147/SAR.S114404 you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). Powered by TCPDF (www.tcpdf.org) 1 / 1 Mancke et al Dovepress Psychiatric assessment using the Structured Clinical (anti-nuclear antibody) or neutrophil cytoplasmic epitopes Interview for Diagnostic and Statistical Manual of Mental (antineutrophil cytoplasmic antibody [ANCA]), double- Disorders, fourth edition, text revision (DSM-IV-TR) and stranded DNA, or cardiolipin were not detectable, and the International Personality Disorder Examination revealed rheumatoid factor was normal. Cerebrospinal fluid test current cannabinoid and nicotine dependence.2,3 Starting in results were normal for cell count, glucose, and lactate, yet his late teenage years, the patient had consumed a variety showed a slight increase of protein concentration at 0.69 g/L of psychotropic substances for approximately 10 years. The (normal, <0.4 g/L). Esophagogastroendoscopy did not reveal following substances met the criteria for substance abuse: any evidence of atrophic gastritis. amphetamines, cocaine, lysergic acid diethylamide, and Except for nonelicitable tibial nerve somatosensory ketamine (Tables 1 and 2). In addition, the patient’s current evoked potentials, neurophysiological test results were all use of N2O fulfilled the DSM-IV-TR criteria of substance normal; in particular, there were no electroneurographic dependence and there was evidence of a transient psychotic signs of peripheral neuropathy. A contrast-enhanced cra- episode lasting for 2 weeks with delusions of persecution nial magnetic resonance imaging (MRI) scan was normal. following the use of synthetic cannabinoids 8 months back However, a spinal MRI showed marked T2W-hyperintense and a cannabinoid-induced depressive disorder lasting for signal alterations confined to the posterior columns of the 4 weeks 5 months back. whole cervical spinal cord without pathological contrast Neurological examination revealed combined ataxic and enhancement (Figure 1), also determined as “inverted V” or pyramidal signs comprising a decreased tactile and vibra- “rabbit ears” sign.4 tory sensation of the legs, a dysmetric heel-to-shin test on The patient was diagnosed with subacute combined both sides, a positive Romberg’s sign, a grossly ataxic gait, degeneration of the spinal cord induced by N2O consump- as well as pathologically brisk tendon reflexes, including tion and treated with daily intramuscular B12 injections bilateral ankle cloni and a slight weakness of the right leg (1 g/d), physiotherapy, and methionine tablets (1 g/d).5 (Medical Research Council [MRC] grade 4+/5). Blood tests Shortly after initiating treatment, partial symptom regres- For personal use only. revealed a hyperchromic nonanemic macrocytosis, increased sion was observed and after 7 days the patient was able to bilirubin and alanine aminotransferase (ALT) levels, low walk without support again. The patient was advised to con- –12 levels of vitamin B12 (B12) at 110×10 mol/L (normal, tinue taking 400 mg B12 and 1 g methionine per day orally 160–670×10–12 mol/L), normal holotranscobalamin, as for the following 6 months. Psychoeducative interventions –6 well as elevated levels of homocysteine at 64.5×10 mol/L regarding the health consequences of N2O consumption – ( normal, <12×10–6 mol/L), and methylmalonic acid at which the patient was totally unaware of – were conducted, 3,560×10–9 mol/L (normal, 50–300×10–9 mol/L). Serum and an addiction-specific outpatient treatment was set in antibodies against parietal cells, intrinsic factor, nuclear motion. Table 1 Fulfilled diagnostic criteria of dependence according toDSM-IV -TR of the individual substances consumed by the patient Substance Tolerance Withdrawal Use Larger/longer Unsuccessful Time to obtain Reduction of social, Substance Abuse and Rehabilitation downloaded from https://www.dovepress.com/ by 54.70.40.11 on 19-Dec-2018 despite use than desire/effort substance or occupational, or harm intended to reduce use recover from effects recreational pursuits Cannabinoid x – x x x x x Nicotine x x x x – – – Nitrous oxide x – x x – x x Note: Diagnostic criteria of dependence according to DSM-IV-TR19 of the individual substances consumed by the patient. An “x” represents fulfillment and “–” absence of the criterion. Table 2 Fulfilled diagnostic criteria of abuse according toDSM-IV -TR of the individual substances consumed by the patient Substance Recurrent Recurrent use Recurrent Continued use despite failure to fulfill when it is physically substance-related recurrent social or obligations hazardous legal problems interpersonal problems Amphetamines x x – – Cocaine – x – – Lysergic acid – – – x diethylamide Ketamine – x – – Note: Diagnostic criteria of abuse according to DSM-IV-TR19 of the individual substances consumed by the patient. An “x” represents fulfillment