Felis ISSN 2398-2950

Feline orofacial pain syndrome (FOPS)

Contributor(s): Danielle Gunn-Moore, Clare Rusbridge, Mark Lowrie

Introduction

  • Feline orofacial pain syndrome (FOPS) describes a disorder of pain with episodic behavioral signs of oral discomfort and tongue mutilation.
  • It can occur in any breed but Burmese cats are most commonly recognized to suffer from this condition.
  • Mutilation of the face and/or tongue is seen. In many patients, discomfort is triggered by movements of the mouth such as eating, drinking, or grooming.
  • Affected cats are most commonly presented with exaggerated licking and chewing movements and pawing at the mouth.
  • More severe cases develop self-mutilation of tongue, lips and buccal mucosa.
  • Oral lesions and environmental stress can precipitate the condition.
  • The disease is most likely a neuropathic pain disorder similar to trigeminal neuralgia.

Pathogenesis

Etiology

  • FOPS has similarities to trigeminal neuralgia in humans and is considered to be a neuropathic pain disorder (ie pain due to abnormal nervous system processing of pain messages).
  • Thought to be a dysfunction in the processing of sensory trigeminal information within the brain in combination with damage/sensitization of the ending of the trigeminal nerves, eg by an oral lesion. 

Predisposing factors

General

  • Oral lesions - of the tongue, lips or buccal mucosa.
  • External environmental factors, eg stress:
    • Stress is often triggered by interactions with other cats, eg in multi-cat households or when other cats invade the territory of an affected cat, but can also occur following visits to the veterinary practice, cattery or cat show.

Specific

  • Genetic predisposition.
  • Oral lesions:
  • Environmental stress:
    • Social variables (territorial invasion of other cats), housing (multi-cat households), and other stress factors (eg visiting a veterinary practice, cattery or cat show).

Pathophysiology

  • It is hypothesized that FOPS is an orofacial pain disorder similar to trigeminal neuralgia in people.
  • The trigeminal neuraliga is characterized by severe pain in the distribution of the trigeminal nerve, usually the mandibles and/or maxilla. Typically this results in severe, episodic pain often lasting only seconds but then occur relatively frequently over a longer period of time. Mild stimulation (eg touch, facial movement such as eating or drinking and draughts of wind) of the region innervated by the trigeminal nerve can provoke attacks (so-called allodynia). It is often shown to be caused by demyelination of the trigeminal sensory fibers within the nerve root or brainstem, often due to compression by an overlying artery or vein.
  • A more unusual human facial pain syndrome, part of the spectrum of trigeminal neuralgia, is glossodynia (burning mouth syndrome). This is described as a burning or prickling sensation of the oral mucosa, most commonly at the front of the tongue. The cause in people is unknown with many cases being termed 'idiopathic'. There been mention of a link with anxiety although it is uncertain if this is more the result of the problem rather than the cause. In many of the affected cats, tongue discomfort seems to be the primary problem and so FOPS may be a feline form of glossodynia.
  • It is proposed that affected cats have an underlying, possibly familial, disorder of sensory trigeminal information so that when trigeminal nerve endings are sensitized, eg by dental disease, the consequence is a neuropathic pain disorder.
  • Conditions of neuropathic pain can be greatly influenced by many internal and external factors, eg individuals with poor social coping strategies may be more vulnerable.

Timecourse

  • Acute onset.
  • Clinical signs can be episodic or continuous:
    • Episodic FOPS (80%):
      • Distress often triggered by mouth movement, eg eating or grooming.
      • Episodes lasts between several minutes to several hours.
      • Episodes often preceeding by a short period of behavior suggesting anxiety.
    • Continuous FOPS (20%):
      • Appear to be in discomfort all the time and signs increase in intensity when excited, stressed or following mouth movement.
      • Can severely mutilate oral cavity or face.

Epidemiology

  • Predilection to the Burmese cats (all colors) and their crosses suggests a hereditary susceptibility for some cases.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Rusbridge C, Heath S, Gunn-Moore D A, Knowler S P, Johnston N, McFadyen A K (2010) Feline orofacial pain syndrome (FOPS): a retrospective study of 113 cases. J Feline Med Surg 12(6), 498-508 PubMed.
  • Gilron I & Flatters S J (2006) Gabapentin and pregabalin for the treatment of neuropathic pain: A review of laboratory and clinical evidence. Pain Research & Management 11 (Suppl A), 16A-29A Hindawi.
  • Wood J N, Boorman, J P, Okuse K et al (2004) Voltage-gated sodium channels and pain pathways. Journal of Neurobiology 61 (1), 55-71 PubMed.
  • Vissers K, De Jongh R, Hoffmann V et al (2003) Internal and external factors affecting the development of neuropathic pain in rodents. Is it all about pain? Pain Pract (4), 326-342 PubMed.
  • Fleetwood I G, Innes A M, Hansen S R et al (2001) Familial trigeminal neuralgia. Case report and review of the literature. Journal of Neurosurgery 95 (3), 513-517 PubMed.
  • Kiguchi S, Ichikawa K, Kojima M (2001) Suppressive effects of oxcarbazepine on tooth pulp-evoked potentials recorded at the trigeminal spinal tract nucleus in cats. Clin Exp Pharmacol Physiol 28 (3), 169-175 PubMed.
  • Marbach J J (1999) Medically unexplained chronic orofacial pain. Temporomandibular pain and dysfunction syndrome, orofacial phantom pain, burning mouth syndrome and trigeminal neuralgia. The Medical Clinics of North America 83 (3), 691-710 PubMed.
  • Muzyka B C & De Rossi S S (1999) A review of burning mouth syndrome. Cutis 64 (1), 29-35 PubMed.
  • Roche G M (1994) Irritation from erupting teeth. Vet Rec 134 (14), 360 PubMed.
  • Lee K H (1993) Facial Pain: trigeminal neuralgia. Ann Acad Med Singapore 22 (2), 193-196 PubMed.
  • Kirkpatirck D B (1989) Familial trigeminal neuralgia: case report. Neurosurgery 24 (5), 758-761 PubMed.
  • Braga F M, Bonatelli Ade P, Suriano I et al (1986) Familial Trigeminal neuralgia. Surgical Neurology 26 (4), 405-408 PubMed.


ADDED