Effects of low‐dose ketamine on neuropathic pain: An electroencephalogram–electrooculogram/behavioral study
OGA Kentaro, Takuya Kojima, Masato Matsuura, Masanori Nagashima, Jitsu Kato, Shigeru Saeki, Setsuro Ogawa
Psychiatry and Clinical Neurosciences August 1, 2002 DOI: 10.1046/j.1440-1819.2002.01023.x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Single-blind, placebo-controlled study Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | In-patients with chronic neuropathic pain |
| Interventions | Ketamine HCl Saline solution (placebo) |
| Dose | three bolus injections of 5 mg ketamine HCl at 5 min intervals |
| Measures | numerical rating scale for pain, Brief Psychiatric Rating Scale (BPRS), electroencephalograms (EEG), electrooculograms (EOG) |
| Topics | Esketamine Ketamine |
| Citations | 21 |
| Key points | Ketamine reduced pain in chronic neuropathic pain patients, and this reduction was significantly correlated with ketamine-induced changes in hallucinatory behavior and excitement on the BPRS. Ketamine significantly decreased EEG alpha amplitude without reducing EEG frequency, and right central alpha amplitude reduction was significantly related to subjective pain relief. The authors propose that ketamine-induced failure of neural integration between cortical-subcortical regions underlies both psychotic symptoms and altered pain perception. |
Abstract
The aim of the present study was to clarify the neurophysiological changes associated with analgesic and behavioral effects of low-dose ketamine HCl in patients suffering from chronic neuropathic pain. Ten in-patients with neuropathic pain participated in this single-blind, placebo-controlled study after giving written informed consent. Following intravenous injections of a saline solution (placebo), three bolus injections of 5 mg ketamine HCl were administered at 5 min intervals. Changes in pain perception were assessed using a numerical rating scale for pain. Behavioral changes, including psychotomimetic effects, were assessed using the Brief Psychiatric Rating Scale (BPRS). Electroencephalograms (EEG) and electrooculograms (EOG) were recorded continuously throughout the testing period. One minute EEG and closed-eye eye movements were quantified. The effects of ketamine were evaluated by comparing the neurophysiological and behavioral parameters obtained from the placebo and ketamine trials. Pain reduction was significantly correlated with ketamine-induced changes in hallucinatory behavior and excitement as measured by the BPRS. Ketamine injections caused a significant decrease in the EEGalpha amplitude without an accompanying reduction in EEG frequency. The EEGalpha amplitude reduction at the right central electrode was significantly related to subjective pain relief. Subanesthetic doses of ketamine significantly decreased rapid eye movements, but did not initiate slow eye movements. In conclusion, the present EEG-EOG/behavioral results indicate that ketamine-induced failure of neural integration between cortical-subcortical regions induces psychotic symptoms and alters pain perception on neuropathic pain.
Comparable studies
Other randomized controlled trials on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Healthy human subjects recruited from the community | 1994 | Randomized controlled trial | n = 19 |
| Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode | 2013 | Randomized controlled trial | n = 73 |
| Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Patients undergoing major abdominal surgery | 2005 | Randomized controlled trial | n = 75 |
| Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures | 2014 | Randomized controlled trial | n = 41 |
| Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Healthy volunteers | 2000 | Single-blind placebo-controlled study | n = 20 |
Citations in the library
Cited by 2
Cites 4
- Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Archives of General Psychiatry December 1, 2000
- Dissociation of ketamine effects on rule acquisition and rule implementation: possible relevance to NMDA receptor contributions to executive cognitive functions. Biological Psychiatry January 15, 2000
- NMDA receptor function and human cognition: the effects of ketamine in healthy volunteers. Neuropsychopharmacology May 1996
- Effects of ketamine on sensory perception: evidence for a role of N-methyl-D-aspartate receptors. Journal of Pharmacology and Experimental Therapeutics March 1, 1992