Neurological and Medical Factors
This chapter addresses the neurological and medical factors associated with psychogenic nonepileptic seizures (PNES). PNES can occur concurrently with epilepsy in 5 to 20% of patients. Traumatic brain injury (TBI) is a major cause of epilepsy, but it is also commonly cited by patients with PNES as the primary cause of their seizures. PNES are also overrepresented in patients with intellectual and learning disabilities. Patients with PNES usually have additional subjective neurological and medical complaints. Pain complaints are overrepresented in patients with PNES and are a major contributor to health care use. Cognitive complaints are also common, with a patient’s mood playing a larger role than objective cognitive dysfunction. Medically unexplained symptoms such as fibromyalgia and chronic fatigue syndrome are overrepresented in patients with PNES. Their occurrence increases the likelihood of diagnosing PNES over epilepsy. These observations reveal a complex pattern of susceptibility to the development of PNES. PNES are thus best viewed as only one symptom of a heterogeneous disorder characterized by multiple physical symptoms used to express psychological distress.