I was taking a deep dive into different types of pain this week (for an article I'm working on) and I thought this list of terms was especially susinct and might be useful to you. It is from an article by the wonderful Dr. Clare Rusbridge (https://doi.org/10.1177/1098612X241246518) from the Journal of Feline Medicine and Surgery (2024). I strongly recommend reading the entire article entitled Neuropathic pain in cats: mechanisms and multimodal management for more detailed information. I have abridged the list from the article so if you would like the entire list please check out the article!
Nociceptive pain - pain that arises from activation of nociceptors during actual or threatened damage to non-neural tissue and transmitted by normal functioning nerves to the central nervous system. The pain is localized to the area of damage and removal of the insult results in resolution of pain. This term is used with a normally functioning nervous system.
Nociplastic pain – pain that arises from altered nociception, despite no clear evidence of (i) actual or threatened tissue damage causing the activation of the peripheral nociceptors or (ii) disease or a lesion affecting the somatosensory system. It is possible to have both nociceptive and nociplastic pain.
Neuropathic pain – pain due to abnormal somatosensory processing in the PNS or CNS. This term must accompany another diagnosis (e.g. sciatic nerve damage with neuropathic pain) and is not used to describe the feeling of pain.
Hyperalgesia – increased pain reaction/behavior from a stimulus that normally provokes pain.
Allodynia – pain from a stimulus that does not normally provoke pain. (e.g. light touch perceived as burning.)
Analgesia – inability to feel pain
Hypoaesthesia – decreased sensitivity to stimuli, excluding special senses (sight, hearing, smell, taste)
Are you looking for some pain control medications now? Read further to see a few of the treatment options discussed in the article.
Anti-NGF monoclonal antibody – chronic painful stimuli increase NGF, a neurotrophins that binds to TKA. When the NGF-TKA complex is translocated to the DRG it results in overexpression of substance P and calcitonin gene-related peptide leading to peripheral sensitization and neurogenic inflammation. Think of frunevetmab (Solensia).
Glucocorticoids – block transcription of inflammatory genes, upregulate anti-inflammatory genes and have excitatory and inhibitory effects of lots of neuronal systems. They can be applied locally (epidural methylprednisolone) or orally (prednisolone).
NSAIDs – prostaglandins contribute to the development of neuropathic pain.
Local anesthetics – injectable lidocaine can be considered for cats undergoing dental procedures to reduce the likelihood that the procedure will stimulate central sensitization (causing FOPS??). Topical lidocaine has been useful for humans but is less so for veterinary species.
Topiramate – an antiepileptic drug useful for neuropathic pain and self-mutilation. It is often called a voltage-dependent sodium channel blocker which results in a reduction of ectopic firing in PNS and DRG however there are central mechanisms as well. The central mechanisms may include potentiation of GABA neurotransmission, inhibition of the excitatory neurotransmitter glutamate and inhibition of voltage-activated calcium channels.
Carbamazepine/oxcarbazepine – a voltage-sensitive sodium channel antagonism which reduced high frequency repetitive neuronal firing and glutamate release. This could be useful for FOPS but is the most common treatment for human trigeminal neuralgia.
Gabapentin/ pregabalin – prevent the release of glutamate, among other things. Pregabalin is 5x more potent than gabapentin and the ½ life is longer therefore q12h dosing is appropriate. Transdermal route is unpredictable so stick with oral dosing for now (2025).
Amantadine – NMDA receptor antagonist and possibly potentiate dopaminergic neurotransmission and has anticholinergic activity. There is not much data published in cats!
Phenobarbital – reverses hyperalgesia via GABA actions and reduction of glutamate release, among other channels. This medication is not just for your seizure patients anymore!
If you are looking for drug doses, please see the referenced article. The article is also the place to look for references related to these drug treatments if you want to see the originally published data (always a good idea in my opinion). Spoiler alert - multimodal pain control does a better job for cats than single mode therapy. Prednisolone + phenobarbital or topiramate, NSAIDS + pregablin, or acupuncture + local anesthetics... you get the picture.
Thanks for reading! Please reach out with any questions or check the article for dosing recommendations. Have a great week and thanks for reading!