Neuralgia del trigémino (TN)

Trigeminal Neuralgia (TN) and Medical Cannabis

Definition

Neuralgia essentially stands for “nerve pain”, and can occur in a nerve in any part of the body. In the case of Trigeminal Neuralgia, it is the trigeminal nerve (the fifth cranial nerve, also known as CN 5), which is the largest cranial nerve, and is responsible for sensation in the face as well as functions such as biting and chewing.

Potential Efficacy / Quality of Evidence (Low, Average, High) of Medical Marijuana for Trigeminal Neuralgia

Average

Cannabinoids, Terpenes/Terpenoids, Strains and Ratios that May Help

THC, CBD, CBG, CBC, THCV, CBDA and beta-caryophyllene may be useful for TN.

Medical Cannabis Pros

Fewer side-effects in comparison to many other medications.

Cannabinoids can be used to improve mood, sleep and appetite, which are all affected severely by the pain of TN.

CBD may act as a neuroprotectant and help slow the degradation of the myelin sheath due to multiple sclerosis or any other neurodegenerative disease.

Cannabinoids “may prove useful in pain modulation by inhibiting neuronal transmission in pain pathways. Considering the pronounced antinociceptive effects produced by cannabinoids, they may be a promising therapeutic approach for the clinical management of trigeminal neuralgia.” Liang YC, Huang CC, Hsu KS. ‘Therapeutic potential of cannabinoids in trigeminal neuralgia‘ Curr Drug Targets CNS Neurol Disord. 2004 Dec;3(6):507-14. doi: 10.2174/1568007043336833. PMID: 15578967.

Medical Cannabis Cons

Too high a dose of THC may increase anxiety and exacerbate pain. Increasing anxiety can increase sensitivity to pain in any condition.

Those suffering from cluster headaches as well may have to be careful with cannabinoids such as THC, as in some it may trigger an attack.

More About the Condition

Trigeminal neuralgia (TN) is a chronic pain disorder, where the trigeminal nerve (responsible for actions such as biting and chewing, as well as many other facial sensations) is damaged. As is to be expected, those who suffer from conditions such as multiple sclerosis, AIDS/HIV and diabetes are more likely to be affected, as the myelin sheath surrounding the TN nerve is damaged. An estimated 1 in 8,000 people a year develop TN, with onset usually beginning after 50 years old.

The pain of TN is extreme and has the unfortunate moniker of being a “suicide disease”, as 25% of sufferers commit suicide. The only condition with similar suicide rates are cluster headaches, and it is possible that the two conditions are linked in some way. The pain of both TN and cluster headaches are said to be so excruciating that it is often ranked alongside or even exceeds the pain of being bitten by a bullet ant, giving birth or even being shot by an actual gun! Burning and/or a persistent hammering or stabbing pain is often associated with TN, as well as “shock”-like pain.

Opioid and opiate-based medications are not recommended for TN, as they are ineffective at treating nerve pain to any significant degree. Serotonin-norepinephrine reuptake inhibitors (SNRIs) are often used, as are anticonvulsants such as gabapentin. Antipsychotics may also be prescribed, as are antiepileptic and anticonvulsant medications. GABA receptor agonists are also often prescribed, but their side-effects can be extremely deleterious and sedative, making doing anything else difficult. It is not unusual for a TN patient to be prescribed a cocktail of drugs, including a low dose of opioids, even if they don’t help with nerve pain directly.

Quotes from Experts

“Cannabis‐based medicines may increase the number of people achieving 50% or greater pain relief compared with placebo (21% versus 17%; risk difference (RD) 0.05 (95% confidence interval (CI) 0.00 to 0.09); NNTB 20 (95% CI 11 to 100); 1001 participants, eight studies, low‐quality evidence). We rated the evidence for improvement in Patient Global Impression of Change (PGIC) with cannabis to be of very low quality (26% versus 21%;RD 0.09 (95% CI 0.01 to 0.17); NNTB 11 (95% CI 6 to 100); 1092 participants, six studies). More participants withdrew from the studies due to adverse events with cannabis‐based medicines (10% of participants) than with placebo (5% of participants) (RD 0.04 (95% CI 0.02 to 0.07); NNTH 25 (95% CI 16 to 50); 1848 participants, 13 studies, moderate‐quality evidence). We did not have enough evidence to determine if cannabis‐based medicines increase the frequency of serious adverse events compared with placebo (RD 0.01 (95% CI ‐0.01 to 0.03); 1876 participants, 13 studies, low‐quality evidence).

Cannabis‐based medicines probably increase the number of people achieving pain relief of 30% or greater compared with placebo (39% versus 33%; RD 0.09 (95% CI 0.03 to 0.15); NNTB 11 (95% CI 7 to 33); 1586 participants, 10 studies, moderate quality evidence). Cannabis‐based medicines may increase nervous system adverse events compared with placebo (61% versus 29%; RD 0.38 (95% CI 0.18 to 0.58); NNTH 3 (95% CI 2 to 6); 1304 participants, nine studies, low‐quality evidence). Psychiatric disorders occurred in 17% of participants using cannabis‐based medicines and in 5% using placebo (RD 0.10 (95% CI 0.06 to 0.15); NNTH 10 (95% CI 7 to 16); 1314 participants, nine studies, low‐quality evidence).” Source: Mücke, Martin et al. ‘Cannabis-based medicines for chronic neuropathic pain in adults‘ The Cochrane database of systematic reviews vol. 3,3 CD012182. 7 Mar. 2018, doi:10.1002/14651858.CD012182.pub2