Psychogenic nonepileptic seizures: diagnosis, aetiology, treatment and prognosis

Abstract

Psychogenic nonepileptic seizures (PNES) are episodes of altered movement, sensation or experience resembling epileptic seizures, but associated with pathopsychological processes and not with ictal electrical discharges in the brain. The prevalence of psychogenic nonepileptic seizures is equivalent to about 4% of that of epilepsy. The early recognition of psychogenic nonepileptic seizures is important if delays in the treatment of underlying or associated psychopathology and iatrogenic harm due to inappropriate treatment of seizures with antiepileptic drugs are to be avoided. The most helpful pointers to a diagnosis of psychogenic nonepileptic seizures rather than epileptic events are perhaps seizures which occur in stressful situations (for instance seizures in front of a doctor), seizures of long duration (especially if they cause recurrent admissions to hospital), prolonged atonic seizures and closed eyes during tonic-clonic-like seizures. If the diagnosis of psychogenic nonepileptic seizures is suspected or the diagnosis of epilepsy is in doubt, the recording of a typical event with video-EEG should be considered. Seizure provocation techniques can be helpful in making a firm diagnosis in patients with infrequent seizures in whom no spontaneous event could be recorded with video-EEG monitoring. There is no single pathway to psychogenic nonepileptic seizures. A range of predisposing, precipitating or perpetuating factors can be identified. Childhood trauma (especially sexual abuse), stressful life events, a dysfunctional home and social environment, psychiatric comorbidity, personality pathology, epilepsy, learning disability and other organic brain disorders and abnormalities can all play an aetiological role. Different factors may interact with each other. Precipitating factors may allow patients to accept that there is a link between their emotions or thoughts and seizures. This can help clinicians to engage them in a therapeutic relationship. Perpetuating factors are often the main focus of treatment. Ongoing abuse, unresolvable dilemmas, poor coping strategies and communication, psychiatric comorbidity, low IQ and social status as well as financial and social illness gain commonly perpetuate psychogenic nonepileptic seizures. In view of the diversity of possible aetiological factors, treatment has to be tailored to individual patients. It should, however, share some common elements: the non-confrontational, sympathetic communication of the diagnosis and an offer of psychological treatment or case management for more intractable patients. There is no information about which form of psychological treatment is best at present. In the wider field of the psychological treatment of medically unexplained symptoms the evidence is strongest for variants of cognitive behavioural therapy, but psychoanalytical approaches have also been used. Medication has a limited (and usually purely supportive) role. Antidepressants can be used to modify emotional dysregulation and low-dose neuroleptics can be useful in some patients with distressing dissociative symptoms. At present, social and seizure outcome are poor. Over two thirds of patients continue to have seizures 12 years after manifestation and over half receive social benefits. The fact that many patients with psychogenic nonepileptic seizures continue to be treated with antiepileptic drugs by nonepilepsy specialists after a clear diagnosis of psychogenic nonepileptic seizures has been made suggests that specialist follow-up should be offered more widely to facilitate regular critical review and (if appropriate) retention of the diagnosis. It is hoped that earlier identification, improved communication of the diagnosis and the offer of appropriate psychological treatment to more patients will improve the outcome in the future.