Understanding and Reporting Pseudoseizures - R56.9

What Exactly is a Pseudoseizure?

Pseudoseizures are a form of non-epileptic seizure. These are difficult to diagnose and oftentimes extremely difficult for the patient to comprehend. The term “pseudoseizures” is an older term that is still used today to describe psychogenic nonepileptic seizures (PNES). One physician during this research had stated that this term should be regarded as jargon, but as coders, we still see “pseudoseizures” documented by physicians daily. These PNES appear to be epileptic seizures and a clear diagnosis is necessary for appropriate treatment.

Common Causes of Pseudoseizures/PNES

  • Conversion disorder (medical condition where the brain and body’s nerves are not able to send and receive signals properly)
  • History of sexual or physical abuse (PTSD)
  • Depression
  • Anxiety disorders/panic attacks
  • History of trauma or witnessing trauma (PTSD)
  • Drug abuse
  • Attention deficit hyperactivity disorder (ADHD)
  • Anger repression or anger management issues
  • Emotional disturbances
  • Ongoing family conflicts
  • Obsessive-compulsive disorder (OCD)

With the causes listed above, treating the patient’s underlying condition is the key to getting control of the attacks.

How is Pseudoseizure or PNES Diagnosed Over Epileptic Seizures?

OBSERVATION seems to be the best way to diagnose pseudoseizures in addition to video EEG monitoring. An EEG alone is helpful, but can often be normal in people with proven epilepsy. With the video EEG the physician is able to view the video of the activity as well as the brain during the actual attacks/seizure activity. There are many differences in the presence of epileptic vs. non-epileptic seizure activity. Below are just a few differences between the two. Keep in mind these are not present in every case.


Pseudoseizure/Psychogenic nonepileptic seizure activity

Epileptic seizure activity

Closed eyes during episode Open eyes during episode
Wild thrashing, side to side head movements and yelling during these episodes This would represent diffuse cortical involvement and the patient would not be able to communicate during an epileptic episode involving all four extremities
Mouth clenched Mouth is usually open during epileptic seizure
Being distracted by loud noise or stimulus during episode During epileptic convulsion the patient should not startle or respond during an event
Normal activity after episode Epileptic seizure typically leaves patient somnolent or confused for a period of time
Postictal normal breathing Postictal deep, noisy breathing
No increase in heart rate during episode Increase of heart rate up to 30% during episode


With video EEG, the physician is able to view all of the symptoms that are associated with the attack/seizure to help determine the diagnosis.

Is the Treatment the Same?

NO! The treatment will be different if the patient isn’t suffering from epileptic seizures. Treating someone with pseudoseizures as if they have epileptic seizures can be very dangerous. When presenting with seizure activity, if treated as having epileptic seizure, the patient may be administered massive doses of antiepileptic drugs trying to calm the seizure activity. This can result in impaired consciousness and/or respiratory failure. There are also many other adverse effects that can be caused by the use of antiepileptic medications.

Treatment for non-epileptic seizures/pseudoseizures, will require the treatment of the underlying mental condition as well as physician monitoring (usually multiple physicians) and therapies.

Most patients respond to the news of pseudoseizure/PNES diagnosis with disbelief, denial, confusion, anger, doubt, sadness, or relief. Patients feel that this diagnosis labels them as crazy or insane, but that is absolutely not the case. There are only about 10% of the patients diagnosed with this feigning illness. Per Dr. Benbadis, this is a real condition that arises as a response to real stressors and the seizures are not consciously being produced and are not the patient’s fault.

Coding the Diagnosis of Pseudoseizure in ICD-10-CM

A diagnosis of pseudoseizure without mention of conversion disorder is coded to R56.9, Unspecified convulsions. If a patient has a history of seizures and a current admission with diagnosis of pseudoseizures, the physician should be queried to clarify if this represents recurrent seizure vs. pseudoseizure.

Interesting Statistics for PNES/Pseudoseizure Diagnosis

  • 5% to 20% of patients diagnosed with PNES/pseudoseizures may also have epileptic seizures
  • 30% to 50% of patients with PNES/pseudoseizures have been incorrectly diagnosed and admitted to an ICU
  • 20% to 50% of patients stop having PNES/pseudoseizures once the diagnosis is reached and without any specific or new treatment
  • Around 20% to 40% of the patients that attend epilepsy centers for EEG monitoring are having PNES/pseudoseizures rather than epileptic seizures
  • At least 25% of people who have a previous diagnosis of epilepsy and are not responding to drug therapy are found to have been misdiagnosed

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

ICD-10-CM/PCS Coding Clinic,  First Quarter ICD-10 2021 Page: 3

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The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.

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