THE CLINICAL SYNDROME

• Face and neck pain can occasionally be brought on by a condition known as reflex sympathetic dystrophy (RSD).

• RSD of the face is a classic situation in which the doctor needs to think about the diagnosis in order to make it. This condition is also known as chronic regional pain syndrome type I.

• Even though the symptom complex of this illness is rather consistent from one patient to the next, and even though the presentation of RSD of the face and neck closely mimics its presentation in an upper or lower extremity, the diagnosis is sometimes missed.

• As a consequence of this, numerous diagnostic and therapeutic procedures could be carried out on the patient in an effort to alleviate the facial discomfort that they are experiencing.

• Trauma is the one factor that is consistent among all patients who are diagnosed with RSD of the face.

• Trauma can manifest itself in a number of different ways, including direct damage to the soft tissues, dentition, or bones of the face; infection; cancer; arthritis; or insults to the central nervous system or cranial nerves. However, the one thing that is constant is that trauma is the cause.

SIGNS AND SYMPTOMS

• Burning pain is one of the most prominent symptoms of RSD of the face.

• The pain does not follow the route of either the cranial or the peripheral nerves, and it is frequently linked with cutaneous or mucosal allodynia.

• RSD frequently causes trigger sites, most notably in the oral mucosa, as well as trophic skin and mucosal alterations in the region that is afflicted by the condition.

• Alterations in sudomotor and vasomotor function may also be observed, but these alterations are typically less noticeable than they are in patients suffering from RSD of the extremities.

• Patients who suffer with RSD of the face frequently show signs of having undergone dental extractions in the past in an attempt to find relief from their facial pain.

• In addition to this, these individuals usually suffer from considerable sleep disturbances as well as depression.

TESTING

• Even though there isn't a test that can definitively diagnose RSD, a presumptive diagnosis can be made if the patient reports significant pain alleviation following a stellate ganglion block that was performed with a local anesthetic.

  • However, due to the different form of the tissue injuries that can produce RSD of the face, the clinician needs to diligently seek for occult diseases that may mimic or coexist with RSD.

• This is necessary because of the range of the tissue injuries that can cause RSD of the face.

• A magnetic resonance imaging (MRI) test of the brain and, if severe occipital or nuchal symptoms are present, an MRI test of the cervical spine should be performed on every patient who has a presumptive diagnosis of RSD of the face.

• To rule out infection or other inflammatory causes of tissue injury that may serve as a nidus for RSD, screening laboratory tests consisting of a complete blood count, erythrocyte sedimentation rate, and automated blood chemistry should be performed.

  • These tests should be performed in order to determine whether or not RSD is present.

DIFFERENTIAL DIAGNOSIS

• The clinical symptoms of RSD of the face can be mistaken for pain originating in the teeth or sinuses, or they can be incorrectly classified as atypical facial pain or trigeminal neuralgia.

• In most cases, the clinician will be able to differentiate between these overlapping pain syndromes by doing careful questioning and physical examination.

• Stellate ganglion block may be helpful in distinguishing RSD from atypical face pain due to the fact that RSD easily responds to sympathetic nerve block, whilst atypical facial pain does not.

• It is possible for tumors of the zygoma and mandible, as well as tumors of the posterior fossa and retropharyngeal tumors, to produce ill-defined pain that is attributed to RSD of the face.

• These potentially life-threatening diseases need to be ruled out in any patient who is experiencing facial pain.

• The pain of jaw claudication, which is associated with temporal arteritis, must also be differentiated from RSD of the face.

TREATMENT

• Successful facial RSD therapy involves two steps.

• First, identify and eliminate any tissue injuries causing sympathetic dysfunction and symptoms.

• Second, stellate ganglion block with local anesthetic must impede facial sympathetic innervation. This may require long-term daily stellate ganglion block.

• Tactile desensitization may also help.

• Nortriptyline, a 25-mg nighttime dose of a tricyclic antidepressant, is optimal for treating depression and sleep disturbance.

• Gabapentin can relieve neuritic pain if begun initially with a 300-mg bedtime dose and gradually increased to 3600 mg per day.

• Pregabalin may be better tolerated than gabapentin. As side effects allow, pregabalin is started at 50 mg three times a day and increased to 100 mg. Patients with renal impairment should reduce pregabalin dosage because the kidneys eliminate it.

• In larger investigations, intravenous mannitol to scavenge free radicals has failed to treat refractory reflex dystrophy.

• Avoid opioids and benzodiazepines to avoid iatrogenic chemical dependence.

COMPLICATIONS AND PITFALLS

• The most significant problems that might arise from RSD of the face are those that are related with its incorrect diagnosis.

• In this particular instance, drug dependency, sadness, and repeated unsuccessful attempts at therapeutic interventions are more the norm than the exception.

• The stellate ganglion block is a method for the management of pain that is both safe and effective, although it is not without the potential for adverse effects and hazards.