2007 Trigeminal Neuralgia- For One Nerve a Multitude of Treatments

Review 10.1586/14737175.7.11.1565 © 2007 Future Drugs Ltd ISSN 1473-7175 1565 www.future-drugs.com Trigeminal neuralgia: for one nerve a multitude of treatments William P Cheshire Jr Department of Neurology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA Tel.: +1 904 953 7229 Fax: +1 904 953 0757 [email protected] KEYWORDS: facial pain, multiple sclerosis, trigeminal autonomic cephalalgias, trigeminal neuralgia, trigeminal neuropathy Trigeminal neuralgia (TN) is reputed to be one of the most painful conditions in human experience. Thus, many treatments, both medical and surgical, have been developed for this relapsing and remitting, paroxysmal stabbing or electrical, facial pain syndrome. The likely etiology in many cases is vascular compression of the trigeminal nerve root entry zone, leading to focal demyelination and aberrant neural discharges. MRI may disclose neurovascular contact, although not with sufficient sensitivity or specificity to substitute for careful clinical diagnosis. In treating TN, antiepileptic drugs are superior to traditional analgesics. Carbamazepine is the first choice drug. Additional drugs for which there is evidence of efficacy include oxcarbazepine, baclofen, gabapentin, lamotrigine and phenytoin. Many patients eventually experience tachyphylaxis or may not tolerate effective doses. Surgical options include: microvascular decompression; balloon compression; radiofrequency thermocoagulation or glycerol rhizotomies; and subcutaneous alcohol branch blockade. Stereotactic gamma knife radiosurgery is a further option. Motor cortex stimulation and transcranial magnetic stimulation, although having shown initial promise for trigeminal neuropathic pain, seem to be ineffective for classical TN. The choice of drug, whether or when to operate, and which procedure to choose should be individualized to the particular needs and conditions of the patient. Expert Rev. Neurotherapeutics 7(11), 1565–1579 (2007) Pain arising from the trigeminal nerve com- mands more attention than pain from any other nerve, so sensitive and vital is facial sen- sation. Trigeminal neuralgia (TN) is defined by the International Association for the Study of Pain as “a sudden, usually unilateral, severe, brief, stabbing, recurrent pain in the distribu- tion of one or more branches of the fifth cranial nerve” [1]. Its excruciating intensity as well as its facial location, sharp or electrical quality, phasic temporal profile, and particular drug responsiveness distinguish TN from other types of cranial pain (BOX 1). Epidemiology Onset is typically after the fifth decade and is increasingly frequent with advancing age, although it can occur at any age. In a 40-year Rochester (MN, USA) population study, the annual age-adjusted incidence of TN per 100,000 was 4.3 for both sexes combined, 5.9 for women and 3.4 for men [2]. In addition to female gender, a history of hypertension or multiple sclerosis (MS) was associated with an elevated relative risk [2]. A higher rate was found in a prospective community-based UK epidemiologic study, which reported an age- and sex-adjusted annual incidence of eight per 100,000, as well as a lifetime prevalence of 0.7 per 1000 for patients in the London area [3]. Disease burden The pain resulting from TN imposes a sub- stantial burden on patients. During severe attacks, affected patients may be unable to speak or eat. Even between attacks, some patients are gripped by an overwhelming fear that the pain could suddenly return at any time [4]. TN is associated with impairment in daily function and reduced quality of life. A European patient survey found that pain severity correlated with reduced measures of daily functioning, quality of life, wellbeing, sleep, mood and overall health status [5]. TN CONTENTS Epidemiology Disease burden Clinical diagnosis Pathogenesis Differential diagnosis Neuroimaging Pharmacologic treatment Surgical treatment Radiosurgical treatment Motor cortex stimulation Transcranial magnetic stimulation Treatment of neuralgia in multiple sclerosis Expert commentary Five-year view Key issues Financial & competing interests disclosure References Affiliation For reprint orders, please contact [email protected]

2007 Trigeminal Neuralgia- For One Nerve a Multitude of Treatments

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