Although most pain of carotid or vertebral artery dissection is localized to the site of injury in the anterior or posterior neck, Arnold and colleagues have emphasized the frequency with which ipsilateral headache, and not neck pain, was the sole feature. Some had a paroxysmal (“thunderclap”) onset but most had throbbing and progressive pain over days, sometimes bilaterally. The combination of focal neck pain and localized headache over an eye is particularly suggestive of carotid dissection and, of course, if there are corresponding symptoms of fluctuating or static regional brain ischemia, Horner syndrome, or lower cranial nerve palsies, the diagnosis is likely.
This is a form of craniofacial pain from dysfunction of one temporomandibular joint. Malocclusion because of ill-fitting dentures or loss of molar teeth on one side with alteration of the normal bite may lead to distortion of and ultimately degenerative changes in the joint and to pain in front of the ear, with radiation to the temple and over the face (see Guralnick et al). Most patients, according to Scrivani and colleagues report deviation of the mandible to the affected side on jaw opening and clicking noises emanating from the joint. Locking of the jaw in either the open or closed position is another feature. The diagnosis is supported by the findings of tenderness over the joint, crepitus on opening the mouth, and limitation of jaw opening. The favored diagnostic maneuver involves palpating the joint from its posterior aspect by placing a finger in the external auditory meatus and pressing forward. The diagnosis can be made with some confidence only if this entirely reproduces the patient’s pain. CT and plain films are rarely helpful, but effusions have been shown in the joints by MRI. Management consists of careful adjustment of the bite by a dental specialist. Small doses of amitriptyline at bedtime may be helpful. In our experience, most of the putative diagnoses of Costen syndrome that reach the neurologist have been uncertain, and the number of headaches and facial pains that are attributed to “temporomandibular joint dysfunction” is probably excessive, especially if judged by the response to treatment. The temporomandibular joint may also be the source of pain when involved with rheumatoid arthritis and other connective tissue diseases.
Facial Pain of Dental or Sinus Origin
Maxillary and mandibular discomfort is a common effect of nerve irritation from deep caries, abscess, dental pulp degeneration, or periodontal disease. The pain of dental nerve origin is usually most severe at night, slightly pulsating, and often associated with local tenderness at the root of the tooth in response to heat, cold, or pressure.
The diagnosis can be confirmed by infiltrating the base of the tooth with lidocaine, and the pain is eradicated by proper dental management.
Trigeminal neuritis following dental extractions or oral surgery is another vexing problem. There may be sensory loss in the tongue or lower lip and weakness of the masseter or pterygoid muscle.
Sometimes the onset of “atypical facial pain” (see below) can be dated to a dental procedure such as tooth extraction, and, as usually happens, neither the dentist nor the neurologist is able to find a source for the pain or any malfunction of the trigeminal nerve. Roberts and coworkers, as well as Ratner and associates, have pointed out that residual microabscesses and subacute bone infection account for some of these cases. They isolated the affected region by using local anesthetic blocks, curetted the bone, and administered antibiotics, following which the pain resolved. The removed bone fragments showed vascular and inflammatory changes and infection with oral bacterial flora, but there was no control material.
Facial Pain of Uncertain Origin (Idiopathic, “Atypical” Facial Pain)