PSYCHOGENIC SEIZURES

PSYCHOGENIC (NON-EPILEPTIC) SEIZURES

Non-epileptic seizures (NES) are quite common and we encounter them in OPD as well the ER. It is important to make a correct diagnosis of NES in order to start them on appropriate psychiatric treatment and avoid unnecessary anti-epileptic medicines. If we adopt a systematic approach, it would be fairly easy to make a diagnosis of NES. I would classify the diagnostic clues into three headings- history, examination and investigations.

Points in history that point towards a diagnosis of non-epileptic seizures

1. Non-epileptic seizures usually occur only in front of others. NES usually do not occur or occur at a lower frequency, when patients are alone. This is because most patients with NES have attention-seeking behaviour. 

2. Non-epileptic seizures usually occur at a much higher frequency- in some cases, upto 20-30 or even more number of times per day. Multiple seizures per day are uncommon in patients with true seizures. 

3. Immediate return to normal sensorium. After a "true" generalised seizure stops, patients are often drowsy, stuporous or unconscious for several minutes. However, after single or multiple episodes of non-epileptic seizures, patients return to normal sensorium almost immediately. 

4. After a true seizure, patients may sustain injury due to tongue bite or falling. Injuries usually do not occur after a non-epileptic seizure. In a true seizure, tongue bite usually occurs on the sides of tongue; on the other hand, tongue bite (rarely present) in patients with NES usually occur at the tip of tongue. 

5. Urinary incontinence, if present, usually suggests a diagnosis of true seizure. 

(Please note- I remember seeing a young boy with non-epileptic seizure, who would intentionally bite his tongue and pass urine during seizure episodes.)

6. Psychogenic or non-epileptic seizures may not follow a well known seizure semiology. Bizarre movements such as pelvic thrusting usually suggest a diagnosis of NES. 

7. The most common people affected with NES are young women. 

8. History of stress or psychological conflicts can usually be elicited in patients with NES.

9. Seizures not adequately controlled despite being on good doses of multiple anti-epileptic drugs, may point to a NES. 

Clues during clinical examination that aid in the diagnosis of non-epileptic seizures

1. During or after a true generalised seizure, plantar response is extensor. After a non-epileptic seizure, plantar response is flexor or withdrawal.

2. During a true seizure, pupils may be dilated. Heart rate and BP may be high. These findings are unusual during a non-epileptic seizure. 

3. Tongue bite: usually absent in NES. If present, it is on tip of tongue. In true seizures, tongue bites are more common and occur on the sides.

4. Presence of post ictal state characterised by drowsiness, confusion, etc are more common after a true seizure. Patients with NES are usually not confused or drowsy after a seizure attack. 

5. A non-epileptic seizure can be induced by the suggestion of a doctor. This can be done by simply applying a vibrating tuning fork to the forehead or sometimes by starting an IV infusion, and suggesting to the patient that by doing so, a seizure would occur.

6. A psychogenic seizure can be stopped by a placebo injection (such as saline or water for injection) or sometimes just by suggestion. This is unlikely in a case of true seizure.

Investigations helpful in differentiating true and psychogenic seizure

1. Long term EEG recording- would show epileptiform discharges in patients with true seizures and would be normal in patients with NES.

2. Serum prolactin may be elevated after a generalised true seizure, if the blood sample can be collected within 30 minutes of a seizure. 

3. An EEG can be recorded while inducing a seizure. Obviously, the EEG recording during an induced seizure would be normal, as it is likely to be non-epileptic in nature. 

The above points would be valuable in differentiating a psychogenic non-epileptic seizure from a true seizure. The correct diagnosis of NES would ensure a referral to the psychiatrist for the appropriate treatment. Moreover, unnecessary anti-epileptic medications can be avoided or withdrawn from a patient with NES. 

We should note that some of the patients have a combination of true and psychogenic seizures. AEDs need to be continued in them, in addition to psychiatry treatment.


Dr Sudhir Kumar MD DM (Neurology)
Senior Consultant Neurologist
Apollo Hospitals, Hyderabad
04023607777/60601066
drsudhirkumar@yahoo.com