A 42-year-old woman comes to the office due to left lower jaw pain for the past 10 days. The patient describes brief attacks of severe, stabbing pain that shoots from near her left ear down along her jawline. The pain often occurs while chewing food and lasts several seconds, and she has had no episodes while asleep. The patient has no prior medical history other than postpartum depression after the birth of her second child 6 years ago. She has had no trauma or recent surgery. Vital signs are within normal limits. The patient has no facial rash or tenderness, but during the examination, she develops another episode of pain when the left cheek is lightly touched. Ear, nose, and oral cavity examination is normal. Which of the following is the most appropriate pharmacotherapy for this patient?

Question

A 42-year-old woman comes to the office due to left lower jaw pain for the past 10 days.  The patient describes brief attacks of severe, stabbing pain that shoots from near her left ear down along her jawline.  The pain often occurs while chewing food and lasts several seconds, and she has had no episodes while asleep.  The patient has no prior medical history other than postpartum depression after the birth of her second child 6 years ago.  She has had no trauma or recent surgery.  Vital signs are within normal limits.  The patient has no facial rash or tenderness, but during the examination, she develops another episode of pain when the left cheek is lightly touched.  Ear, nose, and oral cavity examination is normal.  Which of the following is the most appropriate pharmacotherapy for this patient?

Quizplus · Accepted Answer

11ec25c8_d2d6_7680_bc81_3b9119211bb6_MD0003_00 This patient likely has trigeminal neuralgia (TN), as evidenced by the unilateral, intermittent, stabbing ear pain that radiates down the jaw, lasts several seconds, and is triggered by minor stimuli (eg, chewing, light touch). TN usually causes severe neuropathic (burning, electric shock-like) pain along the V2 (maxillary) and V3 (mandibular) branches of the trigeminal nerve (CN V). trigeminal nerve TN is most often caused by vascular compression of the trigeminal nerve root as it enters the pons. Because of the risks associated with neurosurgical microvascular decompression, control of symptoms with medication is preferred; surgery is reserved for patients who fail medical management. First-line therapy is usually carbamazepine or oxcarbazepine, antiepileptic drugs that inhibit action potentials by modulating sodium channels. Oxcarbazepine is often better tolerated (eg, less nausea/vomiting, less risk for leukopenia), but patients are at risk for hyponatremia due to increased sensitivity to antidiuretic hormone. (Choice A) Acyclovir can treat reactivation of herpes viruses, which can cause neuralgia (eg, zoster) or neuropathy (eg, Bell palsy). Like TN, herpetic neuralgia has a dermatomal distribution and is associated with allodynia (ie, pain from light touch). Pain can precede the vesicular rash by several days. However, seconds-long paroxysms of pain that do not occur at night and are not accompanied by a rash after >1 week are more consistent with TN. Acyclovir would not improve TN, which is caused by nerve compression. (Choice B) Naproxen is used for temporomandibular joint disorders, which can present with severe ear, face, and/or jaw pain aggravated by chewing. Morning headaches (due to night bruxism) are common; examination often shows tenderness of the mastication muscles, tooth wear, and crepitus of the temporomandibular joint with motion, none of which are seen in this patient. Neuropathic pain does not typically respond to NSAIDs. (Choice D) Prednisone is given for clinically suspected giant cell arteritis, which causes a unilateral headache with tenderness to palpation of the temporal artery (vs allodynia in TN). However, most patients are age >50 and have systemic symptoms (eg, fatigue, fever) and jaw claudication (ie, pain or fatigue with chewing, relieved with rest) versus short episodes of neuropathic pain. (Choice E) Sumatriptan is used for cluster headaches, which can cause severe, paroxysmal, unilateral head and facial pain. However, episodes often occur at night, last approximately 90 minutes (vs seconds), predominantly affect the upper face, and are often accompanied by autonomic symptoms (ie, miosis, lacrimation). Educational objective: Trigeminal neuralgia is characterized by short, episodic, severe pain usually along the V2 (maxillary) and V3 (mandibular) branches of the trigeminal nerve (CN V), often triggered by minor stimuli. Oxcarbazepine or carbamazepine is first-line therapy. References: Trigeminal neuralgia-a prospective systematic study of clinical characteristics in 158 patients. (http://www.ncbi.nlm.nih.gov/pubmed/25231219) Increased risk of trigeminal neuralgia after hypertension: a population-based study. (http://www.ncbi.nlm.nih.gov/pubmed/21998318)

A 42-Year-Old Woman Comes to the Office Due to Left