History

Fact Explanation
Introduction Trigeminal neuralgia is a facial pain that can be excruciating and debilitating. [1] It is an episodic, severe, brief, stabbing recurrent pain in the distribution along the branch(es) of the fifth cranial nerve. [1,4] Although theaetiopathogenesis of the condition is unknown, [3] The lifetime prevalence is estimated as 107.5/1,000,000 for men and 200.2/1,000,000 for women, and has a female preponderance . [4] This can be stereotyped in an individual patient. [4] There are two types of trigeminal neuralgia according to the International Headache Society (IHS) description: classical type with no identifiable aetiology and symptomatic type with with demonstrated vascular or other aetiology as evident by investigations or posterior fossa exploration. [4] Vascular compression and de-myelination are the most frequently identified pathological findings. [4]
Facial pain There is usually a sharp, deep, electric like, stabbing type unilateral facial pain, [1] which is most often on the right side of the face, commonly localised to the line dividing the mandibular and maxillary nerves or the line dividing the mandibular and ophthalmic divisions of the nerve and therefore felt over the parietal and temporal regions of the head, and the lateral face including the cheek, mandible, and mouth Some describes it as formication (bugs crawling on the skin). [4] There are two subtypes of TN as type 1 and 2. Type 1 is defined as >50% episodic onset of pain and type 2 defined by >50% constant pain. [5]
Frequency and duration of pain The frequency of attacks may vary from none to 12 or more attacks per hour and up to hundreds per day. Only 5% are having bilateral pain. [2] Pain will last only few seconds lasting less than 10 seconds to minutes [4] and person is free of pain inbetween attacks. This is described as paroxysmal type of pain. [2]
Triggering factors for the pain Talking or smiling, chewing, drinking cold or hot fluids, shaving, brushing teeth, blowing the nose or even touching etc may aggravate the facial pain making that activities difficult. [2] But sometimes the pain may be spontaneous in origin. [2] Abnormal movements of the head Once the patient gets an attack , patient may di certain movements like grimace, wince, or make an aversive head movement, as to over come the pain and is therefore is called "tic douloureux". [2]
Features of multiple sclerosis Patients can have associated multiple sclerosis. [3] Sensory disturbances like paresthesias (numbness and tingling), dysesthesias (burning and “pins and needles”) which will resolve or lead to chronic neuropathic pain, diplopia, ataxia, vertigo, optic neuritis causing visual problems and bladder disturbances. [6]
Suicidal attempts This causes a severe agonizing pain which may sometimes leading to suicidal attempts. [1]
References
  1. ONG KS, KENG SB. Evaluation of surgical procedures for trigeminal neuralgia. Anesth Prog [online] 2003, 50(4):181-188 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2007453
  2. PENMAN J. The Differential Diagnosis and Treatment of Tic Douloureux Postgrad Med J [online] 1950 Dec, 26(302):627-636 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2530375
  3. BROGGI G, FERROLI P, FRANZINI A, SERVELLO D, DONES I. Microvascular decompression for trigeminal neuralgia: comments on a series of 250 cases, including 10 patients with multiple sclerosis J Neurol Neurosurg Psychiatry [online] 2000 Jan, 68(1):59-64 [viewed 02 October 2014] Available from: doi:10.1136/jnnp.68.1.59
  4. RODINE RJ, AKER P. Trigeminal neuralgia and chiropractic care: a case report J Can Chiropr Assoc [online] 2010 Sep, 54(3):177-186 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921783
  5. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  6. GOLDENBERG MM. Multiple Sclerosis Review P T [online] 2012 Mar, 37(3):175-184 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351877

Examination

Fact Explanation
Unshaven area in the face Males tend to avoid shaving of the affected area either due to actual triggering of the pain or fear of triggering pain by shaving. [1]
Facial tenderness There are trigger zones in the area of trigeminal nerve distribution. Light touch will be provoking the pain over these small areas is a characteristic finding in trigeminal neuralgia. [2] The temperomandibular joint (TMJ), masseter, pterygoid and temporalis muscles are tender to palpation. [4] Sensory function Usually trigeminal nerve gives the sensory supply to the face by ophthalmic, mandibular and maxillary divisions. In classic trigeminal neuralgia there is no associated sensory loss. [3]
Motor function Masseter musbulk and strength shpuld be normal in trigeminal neuralgia. Rest of the neurological motor examination of the upper extremity, including motor power, deep tendon reflexes are found be normal. [4]
Corneal reflex Sensory trigeminal root is the afferent limb of the reflex , goes through the pons and efferent is the facial nerve. [5] This usually normal in classic trigeminal neuralgia.
Jaw jerk Jaw-jerk response is elicited by tapping on the chin in a downward direction causing closing of the jaw, and is done to assess the integrity of the trigeminal musculature. [6] This has to be normal in classical trigeminal neuralgia.
Cranial nerve screening Rest of the cranial nerve examination is normal. [4]
Cervical axial compression testing with and without rotation This is positive with no dorsal or arm pain. [4]
Focal neurological signs, visual problems Patients under the age of 40 years are commonly associated with multiple sclerosis or a tumor as a causative lesion. [3]
References
  1. ONG KS, KENG SB. Evaluation of surgical procedures for trigeminal neuralgia. Anesth Prog [online] 2003, 50(4):181-188 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2007453
  2. PENMAN J. The Differential Diagnosis and Treatment of Tic Douloureux Postgrad Med J [online] 1950 Dec, 26(302):627-636 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2530375
  3. BROGGI G, FERROLI P, FRANZINI A, SERVELLO D, DONES I. Microvascular decompression for trigeminal neuralgia: comments on a series of 250 cases, including 10 patients with multiple sclerosis J Neurol Neurosurg Psychiatry [online] 2000 Jan, 68(1):59-64 [viewed 02 October 2014] Available from: doi:10.1136/jnnp.68.1.59
  4. RODINE RJ, AKER P. Trigeminal neuralgia and chiropractic care: a case report J Can Chiropr Assoc [online] 2010 Sep, 54(3):177-186 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921783
  5. SANDERS EA, ONGERBOER DE VISSER BW, BARENDSWAARD EC, ARTS RJ. Jaw, blink and corneal reflex latencies in multiple sclerosis. J Neurol Neurosurg Psychiatry [online] 1985 Dec, 48(12):1284-1289 [viewed 02 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1028615
  6. LEWIS GR, PILCHER R, YEMM R. The effect of stimulus strength on the jaw-jerk response in man. J Neurol Neurosurg Psychiatry [online] 1980 Aug, 43(8):699-704 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC490641

Differential Diagnoses

Fact Explanation
Dental pain/sinus pain This may be severe type of pain, but it is different from the trigeminal neuralgia as this is a continuous type of pain with no clear precipitants. [1] Sinusitis may be associated with rhinorrhoea, headache, nasal congestion andsneezing like symptoms. Dental carries will be evident on examination of the oral cavity.
Atypical neuralgia Aching, burning, type of pain and is exacerbated by cold, fatigue, excitement which are not the precipitants for trigeminal neuralgia. [1] Also this is a bilateral continuous type of pain and may involve the neck that makes it different from the trigeminal neuralgia which is mostly unilateral. [1] Reddening of the skin and lacrimation may also associated.
Post hepatic trigeminal neuralgia Herpes zoster, commonly called shingles, is caused by reactivation of varicella zoster virus (VZV). [4] There is a history of shingles with a blistering skin eruption in a dermatomal distribution, [4] pain may be shooting and associated areas of anaesthesia may present. Scaring may present and true precipitants may be absent as in trigeminal neuralgia. [1]
Migranous neuralgia Patient may have a history of migraine, and these attacks will more longer lasting nearly 10 minutes to hours, which will be few seconds in trigeminal neuralgia (TN). [1] Conjunctival flushing and lacrimation are prominent in cilliary neuralgia. [1] Attacks are not suddenly precipitated as in trigeminal neuralgia and no clear precipitants identified.
Glossopharyngeal neuralgia Glossopharyngeal neuralgia may be due to the cerebellopontine angle tumors, an elongated styloid process, vascular compression or a calcified stylohyoid ligament, but most of these cases are of 'idiopathic' in origin. It is characterized by paroxysms of burning pain in the oropharynx. [2] This is precipitated by actions like swallowing, coughing and tongue movements. [1] Pain may be located in areas that are different from trigeminal neuralgia, eg:- pharynx, soft palate, back of the tongue and tonsils. Electromyography can be performed to confirm the diagnosis [2].
Multiple sclerosis (MS) is a chronic autoimmune, inflammatory neurological disease of the central nervous system (CNS). Multiple sclerosis is a chronic autoimmune, relapsing–remitting inflammatory disease in the central nervous system causing destruction of the myelin and the axons to varying degrees. [3] Presentation would be sensory disturbances,like paresthesias (numbness and tingling), dysesthesias (burning and “pins and needles”) which will resolve or lead to chronic neuropathic pain, diplopia, ataxia, vertigo, optic neuritisand bladder disturbances. Trigeminal neuralgia also seen in these patients. [3]
References
  1. PENMAN J. The Differential Diagnosis and Treatment of Tic Douloureux Postgrad Med J [online] 1950 Dec, 26(302):627-636 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2530375
  2. ISBIR CA. Treatment of a Patient with Glossopharyngeal Neuralgia by the Anterior Tonsillar Pillar Method Case Rep Neurol [online] , 3(1):27-31 [viewed 03 October 2014] Available from: doi:10.1159/000324093
  3. GOLDENBERG MM. Multiple Sclerosis Review P T [online] 2012 Mar, 37(3):175-184 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351877
  4. SAMPATHKUMAR P, DRAGE LA, MARTIN DP. Herpes Zoster (Shingles) and Postherpetic Neuralgia Mayo Clin Proc [online] 2009 Mar, 84(3):274-280 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664599

Investigations - for Diagnosis

Fact Explanation
Magnetic Resonance Imaging MRI can differentiate secondary causes of trigeminal neuralgia from the idiopathic causes. Most commonly identified structural causes include cerebello-pontine angle tumours and multiple sclerosis plaques. [1] MRI can visualize the trigeminal nerve compression at its exit from the brainstem by an aberrant loop of artery or vein. [2] Gadolinium enhanced three dimensional magnetic resonance angiography is also used to detect vascular compression. [2]
CElectrophysiological examination Neurophysiology testing with a blink reflex may be helpful to see a lesion of the trigeminus. Electrophysiological studies are able to differentiate between classic and symptomatic trigeminal neuralgia. [1]
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. BENNETTO L, PATEL NK, FULLER G. Trigeminal neuralgia and its management BMJ [online] 2007 Jan 27, 334(7586):201-205 [viewed 03 October 2014] Available from: doi:10.1136/bmj.39085.614792.BE

Investigations - Fitness for Management

Fact Explanation
Three-dimensional reconstructed high-resolution balanced fast-field echo (BFFE) and images, Magnetic resonance angiography These are done as pre-surgical assessment studies to evaluate any nerve, vascular conflicts. [1] Eg:- posteroinferior cerebellar artery compresses the trigeminal root. [1,2]
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. BENNETTO L, PATEL NK, FULLER G. Trigeminal neuralgia and its management BMJ [online] 2007 Jan 27, 334(7586):201-205 [viewed 03 October 2014] Available from: doi:10.1136/bmj.39085.614792.BE

Investigations - Followup

Fact Explanation
Complete blood count Myelosuppression and aplastic anaemia causing low blood cell counts and reduction in the level of haemoglobin is seen with carbamazepine. [1]
Serum electrolytes Hyponatremia is a complication of medical therapy. [1]
Liver function tests Elevation of transaminasescan and hepatotoxicity occur due to carbamazepine and other drugs. [1]
Prothrombin time and International normalized ratio To detect any bleeding diathesis before surgery. [2]
Electrocardiogram and electrocardiogram Indicated prior to surgery particularly in patients who have a high risk for the cardiovascular morbidities. [2]
Serum electrolytes and Creatinine These are particularly important in patients with co-morbities like diabetes mellitus or hypertension. [2]
Random blood sugar If patient is diabetic, blood sugar should be repeated on the day of surgery. [2]
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. ZAMBOURI A. Preoperative evaluation and preparation for anesthesia and surgery Hippokratia [online] 2007, 11(1):13-21 [viewed 30 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2464262

Investigations - Screening/Staging

Fact Explanation
Three-dimensional reconstructed high-resolution balanced fast-field echo (BFFE) and images, Magnetic resonance angiography Symptomatic trigeminal neuralgia is associated with an underlying aetiology. Evaluation of any nerve, vascular conflicts can be done using these investigations. [1] Eg:- posteroinferior cerebellar artery compresse
Spinal tap and cerebrospinal fluid examination Examination of cerebrospinal fluid for oligoclonal bands is needed in suspicious patients with multiple sclerosis. [2]
Dental x rays Daking dental x rays may be helpful to exclude the other causes of facial pain like dental pain. [3]
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. GOLDENBERG MM. Multiple Sclerosis Review P T [online] 2012 Mar, 37(3):175-184 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351877
  3. BENNETTO L, PATEL NK, FULLER G. Trigeminal neuralgia and its management BMJ [online] 2007 Jan 27, 334(7586):201-205 [viewed 03 October 2014] Available from: doi:10.1136/bmj.39085.614792.BE

Management - General Measures

Fact Explanation
Patient education Educating the patient about the nature of the disease, [3] particularly about the idiopathic nature, [2] complications, treatment options and their side effects are important to ensure the compliance. Particularly carbamazepine induces serious adverse effects including the allergic rash, myelosuppression, hepatotoxicity, systemic lupus erythematosus, Stevens–Johnson syndrome and aplastic anaemia and warning signs have to be informed. [1]
Acute neuralgia attack treatment Studies have shown the use of phenytoin as a loading dose of 14 mg/kg intravenously and subcutaneous sumatriptan 3 mg to relieve the pain for 1–2 days, Intranasal lidocaine 8% is a temporarily method of relieving neuralgic pain. [1]
Follow up Pain improvement with the treatment, recurrrance, potential side effects of therapy, eg:- Carbamazepine : drowsiness, nausea, dizziness, diplopia, ataxia, elevation of transaminases and hyponatremia, allergic rash, myelosuppression, hepatotoxicity, lymphadenopathy, systemic lupus erythematosus, Stevens–Johnson syndrome and aplastic anaemia need to be monitored during follow up. [1]
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. SIQUEIRA SR, TEIXEIRA MJ, SIQUEIRA JT. Clinical Characteristics of Patients with Trigeminal Neuralgia Referred to Neurosurgery Eur J Dent [online] 2009 Jul, 3(3):207-212 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2741192
  3. BENNETTO L, PATEL NK, FULLER G. Trigeminal neuralgia and its management BMJ [online] 2007 Jan 27, 334(7586):201-205 [viewed 03 October 2014] Available from: doi:10.1136/bmj.39085.614792.BE

Management - Specific Treatments

Fact Explanation
Medical management of classical trigeminal neuralgia First-line therapy medical therapy is carbamazepine (200–1200 mg/day) [3] and oxcarbazepine (OXC; 600–1800 mg/day). [4] Typical maintenance doses are ranging from 300 to 800 mg/day in two to three divided doses. [1] The mechanism of providing analgesia may be related to the blockade of voltage-sensitive sodium channels that stabilizes the hyperexcited neural membranes and inhibition of repetitive firing or reduction of propagation of synaptic impulses. Second-line treatment options include amotrigine (400 mg/day), baclofen (40–80 mg/day) or pimozide (4–12 mg/day). [1] Other antiepileptic drugs such as phenytoin, clonazepam, gabapentin, pregabalin, topiramate, levetiracetam and valproate as well as tocainide are suggeste as alternative treatment options. Analgesic effect of botulinum neurotoxin type A (BoNT-A) is known to benefit in these patients by means of local release of anti-nociceptive neuropeptides such as substance P, glutamate and calcitonin-gene related peptide (CGRP) inhibiting central and possibly peripheral sensitization. [1]
Surgical management of classical trigeminal neuralgia If the pain does not responding to adequate doses of at least three drugs including carbamazepine. The type of the required procedure will depend on clinical presentation. [1] Surgery may be either destructive (ablative), that is intentionally destroyed the trigeminal nerve sensory function, or non-destructive, decompressing the nerve preserving its normal function. [1]
Percutaneous techniques Gasserian ganglion percutaneous techniques such as radiofrequency thermocoagulation, balloon compression and percutaneous glycerol rhizolysis causes destructive to the nerve. [1] Alcohol injection of the nerve root may also gives the good outcome. [3]
Gamma knife surgery This is a type of focused beam of radiation targeting the trigeminal root in the posterior fossa. It is an expensive procedure and causes sensory complications. Suits for patients who cannot undergo open surgery or receiving warfarin. [1]
Microvascular decompression This is the method that gives most sustained pain relief in most patients. [2] Disadvantages of the procedure are, a major surgical procedure that entails craniotomy to reach the trigeminal nerve in the posterior fossa, associated average mortality nearly 0.2% to 0.5%, complications like aseptic meningitis, sensory loss, hearing loss. [1,5]
Management of symptomatic trigeminal neuralgia Underlying cause has to be treated with adition of medical management with drugs like gabapentin, lamotrigine and topiramate. [1]
Repetitive transcranial magnetic stimulation This is an emerging technology to assess the response of trigeminal neuropathic pain to direct epidural cortical stimulation. [1]
Management of trigeminal neuralgia in patients with multiple sclerosis Microvascular decompression gives a more favourable response in majority of patients. [1] Surgery is planned relatively at an early stage for these patients.
References
  1. OBERMANN M. Treatment options in trigeminal neuralgia Ther Adv Neurol Disord [online] 2010 Mar, 3(2):107-115 [viewed 03 October 2014] Available from: doi:10.1177/1756285609359317
  2. ADAMS CB, KAYE AH, TEDDY PJ. The treatment of trigeminal neuralgia by posterior fossa microsurgery. J Neurol Neurosurg Psychiatry [online] 1982 Nov, 45(11):1020-1026 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC491639
  3. FREEMONT AJ, MILLAC P. The place of peripheral neurectomy in the management of trigeminal neuralgia. Postgrad Med J [online] 1981 Feb, 57(664):75-76 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC24248
  4. STAJCIC Z, TODOROVIC L. Is carbamazepine less effective in the treatment of trigeminal neuralgia when prescribed by oral and maxillofacial surgeons? Anesth Prog [online] 1997, 44(2):55-58 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2148835
  5. WILSON CB, YORKE C, PRIOLEAU G. Microsurgical Vascular Decompression for Trigeminal Neuralgia and Hemifacial Spasm West J Med [online] 1980 Jun, 132(6):481-484 [viewed 03 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1272139