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Trigeminal Neuropathy F003

Last amended 
6 July 2015
Current RMA Instruments:
Reasonable Hypothesis SOP
79 of 2015
Balance of Probabilities SOP 80 of 2015
Changes from Previous Instruments:

SOP Bulletin 184

ICD Coding

  • ICD-9-CM Codes: 350.8
  • ICD-10-AM Codes: G50.8
Brief description:

There are two SOPs concerning the trigeminal (5th cranial) nerve, being trigeminal neuralgia and trigeminal neuropathy. The trigeminal nerve provides sensation to the face, the top of the head, gums and anterior tongue, and motor function to the muscles of mastication (chewing).

Trigeminal neuropathy is a disease or injury of the trigeminal nerve or ganglion which involves loss of function of the trigeminal nerve, with objective signs as well as symptoms.

Trigeminal neuralgia is a paroxysmal facial pain disorder in the trigeminal nerve sensory distribution which is precipitated by various innocuous stimuli and the paroxysms are of short duration and are separated in time by asymptomatic intervals.

There are other facial pain syndromes that are not covered by either SOP.

Confirming the diagnosis:

To confirm the diagnosis a report from a specialist neurologist is required.

Additional diagnoses covered by these SOPs
  • Peripheral painful post-traumatic trigeminal neuropathy
  • Postherpetic neuralgia – if in the trigeminal nerve distribution and there are sensory or motor signs.
  • Trigeminal neuropathy occurring as part of a wider neuropathy is technically covered by this SOP but would be better dealt with as a manifestation of the wider disease using the relevant SOP, e.g. cerebrovascular accident, multiple sclerosis.
Conditions not covered by these SOPs   
  • Classical trigeminal neuralgia*    (trigeminal neuralgia)
  • Cluster headache*
  • Glossopharyngeal neuralgia#
  • Herpetic neuralgia# - That is pain at the time of the infection   (Herpes Zoster)
  • Migraine*  
  • Neuropathy in other cranial nerves not being in the trigeminal nerve distribution# 
  • Peripheral neuropathy*
  • Persistent idiopathic facial pain – if not in the trigeminal nerve distribution
  • Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) #
  • Symptomatic (secondary) trigeminal neuralgia*    (trigeminal neuralgia)
  • Tic Douloureux*    (trigeminal neuralgia)
  • Trigeminal neuralgia*

* another SOP applies  - the SOP has the same name unless otherwise specified

Clinical onset

The clinical onset is the earliest time prior to the confirmation of the disease, that the pathognomonic set of symptoms could be documented. 

Clinical worsening

The natural history of trigeminal neuropathy depends on the cause of the pathology. If the cause is an injury, and the injury agent has ceased, the trigeminal neuropathy should not worsen over time but be fixed. If the neuropathy is part of a progressive neurological disease (malignancy, diabetes mellitus, multiple sclerosis), the natural history of the neuropathy will generally track that of the underlying disease.

If it is thought that there is a clinical worsening, it is recommended that an expert opinion be sought from a neurologist to evaluate whether the clinical worsening was out of keeping with the natural history of the underlying pathology.