Dorsolateral Prefrontal Cortex Impairment in Methoxetamine-Induced Psychosis: An 18F-FDG PET/CT Case Study
Lorenzo Moccia, A. Tofani, Marianna Mazza, Marcello Covino, Giovanni Martinotti, Fabrizio Schifano, Luigi Janiri, Marco di Nicola
Journal of Psychoactive Drugs February 9, 2019 DOI: 10.1080/02791072.2019.1578444 via OpenAlex
Summary
A 23-year-old man developed a substance-induced psychotic disorder after intravenously injecting an unspecified amount of methoxetamine (MXE), a ketamine derivative hallucinogen. Clinically, he showed blunted affect, diminished social drive, loss of sense of purpose, and detachment from the environment. Psychometric tests revealed severe dissociation, lack of motivation, and mild impairments in verbal fluency, working memory, and attention. Brain scans using 18F-FDG PET/CT showed significantly reduced tracer uptake in the dorsolateral prefrontal cortex (DLPFC), a region critical for goal-oriented cognition, working memory, and attention. This case indicates that a single acute MXE intoxication can cause severe brain impairment.
Study at a glance
| Characteristics | Case study Case report Peer reviewed |
|---|---|
| Sample size | 1 |
| Population | A 23-year-old man who intravenously injected methoxetamine |
| Intervention | Methoxetamine (MXE) |
| Keywords | Dorsolateral prefrontal cortex Positron emission tomography Verbal fluency test Working memory Neuropsychology |
| Citations | 10 |
| Key finding | A single acute methoxetamine intoxication produced severe bilateral reduction of DLPFC tracer uptake on PET/CT, along with psychotic and cognitive symptoms. |
Abstract
Novel psychoactive substances (NPSs) have currently become a major public health concern because of relatively easy accessibility to these compounds and difficulty in identifying them with routine laboratory techniques. Here, we report the 18F-fluorodeoxyglucose positron emission tomography/computerized tomography (18F-FDG PET/CT) case study of a 23-year-old man who developed a substance-induced psychotic disorder after having intravenously injected himself with an unspecified amount of methoxetamine (MXE), a ketamine derivative hallucinogen. From a clinical perspective, a blunted affective responsiveness with diminished social drive and sense of purpose, along with a profound detachment from the environment, was observed. Psychometric and neuropsychological assessments highlighted severe dissociative symptoms and lack of motivation, along with a mild impairment of verbal fluency, working memory, and attention. Patient’s 18F-FDG PET/CT scans displayed a significant bilateral deficit of tracer uptake within the dorsolateral prefrontal cortex (DLPFC). DLPFC activity is critical to goal-oriented cognitive functions, including working memory and sustained attention. DLPFC is also involved in both the temporal integration across multiple sensory modes and in the volitional control of actions, leading to the possibility to construct logically coherent temporal configurations of thought, speech, and behavior. This report highlights that a single acute MXE intoxication may produce severe brain impairment.