Nonepileptic seizures (NES) are defined as a conversion disorder manifested by paroxysmal changes in behavior that mimic epileptic seizures but which are not associated with electrographic ictal activity. The term spells is also used, meaning episodic phenomena with or without alteration of awareness. Other descriptives such as “psychogenic seizures” and “psuedoseizures” are also used, implying a conversion disorder causing a seizure; no single term completely encompasses the condition. NES will be used throughout this chapter in reference to this disorder.

Conversion disorders are classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) as one of the somatoform disorders, which also include somatization disorder (previously termed hysteria or Briquet syndrome), undifferentiated somatoform disorder, pain disorder, hypochondriasis, body dysmorphic disorder, and somatoform disorder not otherwise specified. These conditions are all linked by the presence of physical symptoms that are suggestive of medical illness but are not explained by the presence of a medical disorder, effects of a substance, or symptoms of another psychiatric condition, such as loss of energy because of a current episode of major depression. The patient cannot produce them intentionally.

Clinicians who work with epilepsy will undoubtedly encounter patients whose symptoms appear to be non-neurologic in nature. Approximately one third of new patients seen by neurologists have symptoms that are described as “not at all” or only “somewhat” explained by disease; statistics that are similar to the incidence of somatoform disorders in primary and secondary care settings for other medical specialties (de Waal et al.).¹ In neurologic specialty clinics, psychogenic symptoms are common; nonepileptic seizures account for 10% to 20% of cases referred to epileptologists for lack of response to antiepileptic medications and 50% of status epilepticus admissions.

Risk factors for development of NES include female gender, lower socio-economic status, history of previously unexplained medical symptoms, history of other psychiatric conditions (including personality disorders); history or abuse or trauma may also increase risk of NES.²

The public health implications of somatoform or conversion disorders in general are known to be considerable although NES have received little study in particular. These patients use health care resources at high rates, including frequent office visits, demands for expensive evaluations, unneeded surgical interventions, and referrals for numerous consultations and second opinions. Niemark et al. using a conservative estimate that psychogenic symptoms of all types account for 10% of medical costs, calculated that the annual cost of these symptoms to the US health care system is over$100 billion.³ The estimate does not include time spent on disability or compensation received because of psychogenic symptoms. NES have been shown to cause reduction in quality of life comparable to or exceeding that seen in epileptic seizures.

Nonepileptic spells are often dramatic in nature, and can be extremely upsetting to those who witness them. Signs and symptoms, reviewed in Table 8.1, may include, but are not limited to thrashing, violent movements, side-to-side head movement, asynchronous eye movements, unresponsiveness, and episodes mimicking partial seizures.²,⁴ Approximately two thirds of NES consist primarily of motor signs and symptoms. Commonly, the nonepileptic spells last for over 2 minutes; a fluctuating course of illness is often seen. Nonepileptic spells that are not explained by a medical condition such as syncope, migraine, or metabolic disorder may be a somatoform disorder, or may result from factitious disorder or malingering (see Table 8.2 for conditions to consider in evaluation of nonepileptic spells).

NES may occur in up to 50% of patients with epilepsy. NES may be particularly common in patients with treatment refractory epilepsy.

Other psychiatric conditions such as depression and affective disorders are commonly seen in somatoform disorders.¹ Personality disorders and somatization are also seen with high frequency, reflecting the abnormal coping skills these patients have learned in their development. History of abuse or trauma may increase risk of NES; therefore, patients should be queried about dissociative symptoms and post-traumatic stress disorder.

Medical morbidity resulting from NES can be considerable. Patients are exposed to numerous procedures, often repeatedly, in search of a diagnosis. Medications used to treat epileptic seizures may be given erroneously, exposing patients to side effects. Dependence on benzodiazepines may occur in patients who receive large doses over long periods. Polypharmacy is common, again exposing patients to side effects, especially because of medication interactions.

Data on the natural history of NES suggests that in some, but not all individuals, symptoms develop in response to a specific stressor or situation. However, many patients do not have a particular event that triggers onset, but rather develop NES as part of poor general coping skills and to gain attention and support that are otherwise unavailable to them.

Approximately 40% of patients stop having NES once a diagnosis is reached. Most patients continue to have NES and experience considerable disability, including inability to fulfill obligations at work and at home. Up to half of patients who continue to have NES will remain on some form of public assistance for their financial support.

Prognostic features of good outcome include diagnosis of NES soon after symptom onset and acceptance of the NES diagnosis.

Indicators of poor prognosis include the presence of comorbid psychiatric disorders.