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Synonyms: non-epileptic attack disorder, NEAD (the use of the terms 'hysterical seizures' or 'pseudoseizures' is now considered to be inappropriate)
Non-epileptic seizures (NES) is a descriptive term for a diverse group of disorders which refers to paroxysmal events that can be mistaken for epilepsy but are not due to an epileptic disorder. There are two subcategories of NES:
- Physiological: includes a broad spectrum of disorders - eg, syncope, paroxysms of acute neurological insults, paroxysmal toxic phenomena, non-toxic organic hallucinosis, non-epileptic myoclonus, sleep disorders, paroxysmal movement disorders, paroxysmal endocrine disturbances and transient ischaemic attacks (TIAs).
- Psychogenic seizures include different types:
- Dissociative seizures are involuntary and happen unconsciously. This is the most common type of NES and the person has no control over the seizures.
- Associated with psychiatric conditions that cause seizures - eg, panic attacks.
- Factitious seizures - eg, Münchhausen's syndrome, fabricated or induced illness by carers.
- The true prevalence is unknown.
- Up to one fifth of patients who present with seizures to specialist clinics do not have epilepsy. The majority of such patients suffer from psychologically mediated episodes (dissociative seizures).
- Up to one patient in five with apparently intractable epilepsy referred to specialist centres is found to have no organic cause for their seizures.
- Adult studies have shown a 4:1 female:male ratio for psychogenic NES.
- One study found that the psychological factors relevant to the development and maintenance of NES included anxiety or stress, physical abuse, significant bereavement, family dysfunctioning, relationship problems, depression and sexual abuse.
- It can be difficult to differentiate NES from epilepsy, especially as the two disorders co-exist in up to 30% of patients.
- Epileptic and non-epileptic seizures can look the same and have the same features:
- They can happen suddenly and without warning.
- They can include a loss of awareness or the person becoming unresponsive, making strange or repeated movements, or convulsing.
- They can both cause injury and urinary incontinence.
- They can both happen when awake and during sleep.
- It is essential to make a thorough assessment and ensure no further harm is caused by inappropriate diagnosis and treatment.
- Features suggesting NES include: duration over two minutes, gradual onset, fluctuating course, violent thrashing movements, side-to-side head movement, asynchronous movements, eyes closed and recall for period of unresponsiveness.
- Features suggesting epilepsy include automatisms, incontinence and biting the tongue.
Differential diagnosis of epilepsy
- Medical causes of transient neurological dysfunction (with or without loss of consciousness).
- Psychiatric disorders.
- Psychiatric disorders that may be mistaken for epilepsy: panic disorder, psychosis, attention deficit hyperactivity disorder, depersonalisation disorder.
- Dissociative seizures.
- Factitious disorder.
Video-electroencephalogram (VEG) is widely considered to be the gold standard for diagnosing NES.
- Investigations will depend on the specific presentation of each patient. Investigations include:
- A full assessment for the presence of any underlying physical cause for epilepsy - eg, electroencephalograph (EEG), MRI brain scan.
- EEG: provocation by suggestion may be used in the evaluation of non-epileptic attack disorder but its role is limited and may lead to false positive results in some people.
- Investigations for physical causes of NES - eg, fasting glucose, electrolytes, ECG, echocardiogram.
- A full psychiatric assessment.
- Serum prolactin rises in over 90% of patients after a tonic-clonic seizure and 60% of patients after a complex focal seizure (previously called a complex partial seizure). However, an increased postictal prolactin is nonspecific.
A significant number of patients (estimated at up to 30%) having mixed epileptic and non-epileptic seizure disorders.
Where NES are suspected, suitable referral should be made to psychological or psychiatric services for further investigation and treatment.
- Management is directed at treatment of the underlying cause.
- Various treatments have been tried with variable success for psychogenic NES. Treatment regimes for NES include non-psychological (eg, anti-anxiety and antidepressant medication) and psychological therapies (including cognitive behavioural therapy, hypnotherapy and paradoxical injunction therapy). With paradoxical injunction therapy, the therapist imposes a directive that places the client in a therapeutic double bind that promotes change regardless of the client's compliance with the directive.
- There is currently no reliable evidence to support the use of any treatment, including hypnosis or paradoxical injunction therapy, in the treatment of NES.
- A recent review found that, after a mean follow-up of three years, about two thirds of patients continued to have dissociative seizures and more than half remained dependent on social security.
- Receiving psychiatric treatment has been associated with a positive outcome in some studies but not in others.
- A poor prognosis is predicted by a long delay in diagnosis and the presence of psychiatric comorbidity, including personality disorder.
Further reading & references
- Transient loss of consciousness ('blackouts') management in adults and young people; NICE Clinical Guideline (August 2010)
- Epilepsy; NICE CKS, June 2009
- Epilepsy Action
- Epilepsy Society
- Epilepsy Scotland
- Epilepsy Wales
- Non-epileptic seizures, Epilepsy Society
- Mellers JD; The approach to patients with "non-epileptic seizures". Postgrad Med J. 2005 Aug;81(958):498-504.
- Moore PM, Baker GA; Non-epileptic attack disorder: a psychological perspective. Seizure. 1997 Dec;6(6):429-34.
- Mayor R, Smith PE, Reuber M; Management of patients with nonepileptic attack disorder in the United Kingdom: a Epilepsy Behav. 2011 Aug;21(4):402-6. Epub 2011 Jul 12.
- Bodde NM, Brooks JL, Baker GA, et al; Psychogenic non-epileptic seizures--diagnostic issues: a critical review. Clin Neurol Neurosurg. 2009 Jan;111(1):1-9. Epub 2008 Nov 18.
- The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care; NICE Clinical Guideline (January 2012)
- Baker G, Brooks J, Goodfellow L, et al; Treatments for non-epileptic attack disorder. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD006370.
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Dr Colin Tidy
Dr Colin Tidy
Dr John Cox