Diagnosis and Treatment of Patients with Trigeminal Neuralgia

Diagnosis and Treatment of Patients with Trigeminal Neuralgia

Reference: Bagheeri, Farhidvash, Perciaccante, JADA, Vol. 135, December 2004, pages 1713 to 1717.

1) Description

a) Neuralgia: unexplained peripheral nerve pain

b) Mean Incidence: 4 per 100,000

c) Mean Age: 50

d) Female gender preference of 1:2 to 2:3

2) History

a) 1677: John Locke described encounter with a patient

b) 1756: Nicolaus Andre coined the term “tic doloreaux”

c) 1773: John Fothergill gave full description before the Medical Society of London

3) Characteristics

a) Paroxysmal pain restricted to the trigeminal nerve

b) Usually unilateral

c) More commonly right side

d) More often the mandibular or maxillary branch of the trigeminal nerve

e) Pain attacks

i) Spontaneously

ii) Triggered by sensory stimulus

(1) Skin

(2) Oral mucosa

(3) Tongue

iii) Length of attack is seconds

iv) Intervals between attacks short

v) Exacerbations and remissions

vi) Rare during sleep

4) Differential Diagnosis

a) Trigeminal Neuropathy

i) Loss of sensation

ii) Slight pain

b) Post Herpetic Neuralgia

i) Occurs after chicken pox

ii) Older people

iii) Predilection for ophthalmic branch of trigeminal nerve

c) Multiple Sclerosis

i) Trigeminal Neuralgia is secondary to demyelination of the trigeminal root entry zone

d) NICO

i) Neuralgia-Inducing Cavitational Ostemyelitis

ii) Originates from the jaw bone

iii) Controversial, several authors challenge it’s existence

5) Inheritance

a) Not established

i) 4.1% of patients with unilateral TN

ii) 17% of patients with bilateral TN

6) Pathogenesis is uncertain

a) Traumatic compression of the nerve

i) Vascular anomalies: most popular explanation

(1) TN caused by a vascular loop

(2) Compresses nerve a few millimeters proximal to the pons

(i) Area known as nerve root entry zone

(ii) Area of transition from central to peripheral myelin

ii) Neoplastic (mass, tumor)

b) Infectious agents (herpes simplex virus, etc.)

c) Demylinating conditions (multiple sclerosis)

d) Dental problems (microabscesses)

7) Treatment

a) Oral Medication

i) First choice: Carbamazepine

ii) Other: baclofen,clonazepam, phenytoin, pimozide, valproic acid

b) Surgical Procedures

i) Destructive (damages nerve fibers) in trigeminal ganglion

(a) Radiofrequency thermal rhizotomy

(b) Glycerol rhizotomy

(d) Gamma knife (not mentioned in this article)

ii) Non-destructive

(a) MVD (microvascular decompression)

(i) Supports the hypothesis that TN is caused by vascular compression

8) Management algorithm (not everyone agrees)

a) Requirements for diagnosis

i) Pain

(1) Paroxysmal

(2) Unilateral

(3) Restricted to the trigeminal nerve

(4) No sensory deficit

(5) Identifiable trigger zones

b) Workup

i) MRI

(1) Why do it?

(i) Reveal lesions (tumor, mass)

(ii) Demyelinating lesions (MS)

(iii) Vascular anomalies

(2) Abnormal MRI: neurological consultation

(3) Normal MRI

(i) Oral medication

(ii) Surgery (if oral medication fails)

Conclusion: TN is the most common form of neuralgia, and patients often visit several clinicians with complaints of pain. Clinicians must recognize this condition and diagnose it correctly for patients to receive a proper referral and therapy for this relatively treatable condition. The authors identified more than 50 articles on the topic. Generally, there was concordance regarding the diagnosis of this condition; however, some questions and controversy exist regarding the pathogenesis and treatment modality of choice. The authors relied on the most representative and complete articles for this review article.

Reviewed by Wm. Pat Marshall, M.D.

TN Patient and member of the TNA Board of Directors

Updated 3-10-05