Conversion reactions are commonly seen conditions in health care and come in various forms and presentations. Two common conversion reactions seen in the emergency department are conversion coma and psychogenic nonepileptic seizures (PNES). Both mimic life-threatening conditions and require rapid differentiation. Premature anchoring and wrong diagnoses can result in potentially harmful outcomes or expensive and unnecessary procedures, workups, and evaluations.
Conversion disorder, or functional neurological symptom disorder, is categorized under the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, (DSM-5) under the category of "Somatic Symptom and Related Disorders." Conversion disorder is characterized by physical symptoms or deficits affecting voluntary motor or sensory function that resemble those of a nervous system disorder. Common examples of conversion symptoms are blindness, diplopia, paralysis, amnesia, coma, aphonia, seizures, pseudocyesis, and others. These physical signs and symptoms are typically triggered by emotional or mental factors such as conflict or other stressors. Unlike factitious disorders and malingering, the symptoms of somatoform disorders are not intentional or under the patient's conscious control.
Psychogenic Nonepileptic Seizures (PNES)
Patients presenting with PNES may show symptoms that look similar to those of epileptic seizures. They can mimic absence seizures, complex partial seizures, or tonic-clonic seizures. Abnormal brain electrical discharges are not the cause of PNES, however, and this can be confirmed with an EEG.
Many patients with PNES will have a specific traumatic event, such as physical or sexual abuse, incest, divorce, or the death of a loved one. My most recent patient with psychogenic nonepileptic seizures was found "seizing" in the bathroom outside of the intensive care unit where her daughter, the victim of a home invasion and multiple gunshot wounds, was being treated. Characteristics of patients with PNES can include the following:
- Side-to-side shaking of the head
- Bilateral asynchronous movements (e.g., bicycling)
- Limb or truncal movements
- Facial movements with or without movements of the limbs or trunk
- Weeping or stuttering
- Arching of the back
- Preserved awareness
- Eyelid fluttering
- Episodes affected by bystanders (intensified or alleviated)
- Tongue-biting and infrequent incontinence
Patients presenting in a comatose state that is, in reality, a conversion disorder often have characteristic findings. They can be extremely difficult to differentiate from other more serious causes of coma. We typically use nociceptive or noxious stimuli to help differentiate the etiology of the altered mental status, but other history and physical signs and symptoms can be helpful. Conversion coma patients may have the following exam findings:
- May be observed to "slump" to the floor and avoid hitting their heads.
- Often resist examination and make semi-purposeful avoiding movements.
- Have normal pupils, corneal reflexes, plantar reflexes, and sphincters.
- Keep their eyes closed tightly and resist attempts to open them while in organic coma; eye closure is slow and difficult to simulate.
- Have Bell's phenomenon, e.g., eyes roll up when lids are raised while the eyes of patients with true coma remain in a neutral position
- Display geotropic eye movements.
- Their hands will often just miss when dropped toward their faces.
- Respond with purposeful movement to painful stimulation and avoid unpleasant stimuli
Conversion coma is perhaps as difficult to diagnose as psychogenic nonepileptic seizures and should be diagnosed through exclusion. A short list of potential emergency conditions to be ruled out includes intracranial hemorrhage, toxic ingestions, hyperosmolar hyperglycemic nonketotic coma, meningitis, hypoxia or hypercarbia, hepatic encephalopathy, and uremia.
Diagnostic and therapeutic goals for managing these patients are to rule out true medical and surgical emergencies, or to confirm the existence of a conversion disorder using laboratory testing, physical examination findings, and noxious or nociceptive stimuli. Noxious or nociceptive stimuli have been part of the neurologic examination for centuries. In fact, painful stimuli are central to the Glasgow Coma Scale.
Using of pain as a diagnostic tool may seem contrary to the basic tenets of medicine, but it can be a lifesaving maneuver. Painful stimuli can assist with the neurologic examination to demonstrate true paralysis or other evidence of a stroke. It can also confirm a conversion disorder and protect the patient from the administration of unnecessary medications, unneeded clinical and imaging studies, and potentially dangerous procedures and emergency interventions.
The video demonstrates the following noxious and nociceptive tests: the drop arm test, sternal rub, nipple squeeze, nail bed compression, and the Soto saline sign. The Soto saline sign is a new test described by Mario Soto, MD, in which saline is squirted into the eye of a comatose or seizing patient. It has been proven to be surprisingly effective in our shop.
Dr. Mario Soto, Medical College of Georgia at Augusta University, described the new Soto saline sign test to confirm a conversion disorder. Watch a video of a demonstration of this new diagnostic tool.