Psychogenic non epileptic seizures
General information
- Psycogenic non-epileptic seizures (PNES) have an estimated incidence of 4.9/100,000/year.
- ~50% of patients with PNES also have epilepsy.
- Differentiating a particular episode as psychogenic or epileptic may be very challenging.
- Some patients with complex partial seizures may have normal ictal EEGs.
- Partial seizures involving the supplemental motor area may present with bilateral motor activity despite preserved consciousness.
- A normal prolactin level does not rule out non-generalized seizures.
- Prolactin may be markedly elevated in patients after syncope and may be moderately elevated following a non-epileptic seizure.
- Intravenous benzodiazepines treat epileptic as well as psychogenic seizures.
- Evaluation at an epilepsy unit with video-EEG is the best diagnostic strategy in indeterminate cases.
| Feature | PNES | Epileptic seizures |
|---|---|---|
Debut age <10 years old | Unusual | Common |
| Seizures in the presence of doctors | Common | Unusual |
| Psychiatric treatment | Common | Rare |
| Recurrent “status epilepticus” | Common | Rare |
| History of multiple invasive tests or operations | Common | Rare |
| History of physical or sexual abuse | Common | Rare |
| Multiple unexplained symptoms | Common | Rare |
| Self injury | Occasional | Occasional |
| Situational onset | Occasional | Rare |
| Gradual onset | Common | Rare |
| Precipitated by stimuli (eg. light) | Occasional | Rare |
| Purposeful movements | Occasional | Very rare |
| Tongue bite | Usually the tip | Usually the side |
| Prolongued ictal atonia | Occasional | Very rare |
| Ictal vocalizations | Occasional | Very rare |
| Ictal hyperventilation | Common | Very rare |
| Ictal incontinence | Occasional | Occasional |
| Ictal crying | Occasional | Very rare |
| Undulating motor activity | Common | Very rare |
| Asynchronous limb movements | Common | Rare |
| Side-to-side head shaking | Common | Rare |
| Closed mouth in tonic phase | Occasional | Very rare |
| Closed eyelids | Very common | Rare |
| Resisted eyelid opening | Common | Very rare |
Convulsion >2 min | Common | Very rare |
| Reactivity during “unconsciousness” | Occasional | Very rare |
| Rapid postictal reorientation | Common | Unusual |
| Postictal sertourous breathing | Rare | Occasional |
| Postictal rapid shallow breathing | Occasional | Very rare |
| Preserved pupillary reflex | Very common | Rare |
| Cyanosis | Rare | Common |
References
- Epidemiology of psychogenic nonepileptic seizures. Epilepsy Behav. 2015;46:60–65 doi: 10.1016/j.yebeh.2015.03.015
- Differentiating between nonepileptic and epileptic seizures. Nature Reviews Neurology. 2011;7:210–220 doi: 10.1038/nrneurol.2011.24
- Newly presenting psychogenic nonepileptic seizures: incidence, population characteristics, and early outcome from a prospective audit of a first seizure clinic. Epilepsy Behav. 2011;20:308–311 doi: 10.1016/j.yebeh.2010.10.022