Psychosis Between Seizures Is Often Misdiagnosed

What was studied

This paper was a review of published literature on interictal psychosis in people with epilepsy, with eligible articles sorted into case reports and non-case reports. Interictal psychosis is described as a neuropsychiatric condition secondary to epilepsy, but without a chronological relationship to seizures.

The authors searched PubMed and included additional studies from other sources. In the case reports they summarized, 69 patients were studied. The average age was 34.7 years.

What they found

The review describes interictal psychosis as differing from schizophrenia in some ways: negative symptoms were less prominent, and deterioration of personality was uncommon. On average, interictal psychosis appeared 13.8 years after epilepsy.

More than half of the patients had neuropsychiatric comorbidities. Psychoses and head trauma were among the most commonly reported. About 20% were mistakenly diagnosed with primary psychosis.

Among patients with available testing information, many had abnormal EEGs, and some had episodes of forced normalization. Some patients had a left hemisphere focus, most often in the temporal lobe. In the subgroup with neuroimaging available, the largest single subgroup had no reported abnormalities.

Limits of the evidence

This review included case reports, and the abstract does not provide the same level of detail for every patient or every test. Not all patients had complete testing information, and the total number of patients in the case reports was 69.

Because the review was based on published literature, the findings may not represent all people with interictal psychosis. The abstract also gives limited detail about treatment outcomes, although it notes that treatment relies on balancing antipsychotics and antiseizure medications and that surgery remains controversial.

For families and caregivers

For families, this review suggests that psychosis in a person with epilepsy may sometimes be considered part of the epilepsy-related condition rather than a primary psychotic disorder. The abstract also notes that some patients were mistakenly diagnosed with primary psychosis.

The review highlights that treatment can be complicated, including episodes of forced normalization. This means careful evaluation may be important when epilepsy and psychotic symptoms occur together.

What to watch next

The authors state that it is urgent to implement guidelines for diagnosis, theragnosis, and prognosis of interictal psychosis.

Terms in this summary

interictal psychosis

A psychotic condition described in people with epilepsy that occurs without a chronological relationship to seizures.

psychosis

A mental state that can include symptoms such as hallucinations or delusions.

negative symptoms

Symptoms such as reduced emotional expression, motivation, speech, or social engagement.

forced normalization

An antagonistic relationship between seizures and psychosis that may be observed in some patients.

EEG

A test that records the brain's electrical activity.

temporal lobe

A region of the brain where seizure focus was commonly reported in this review.

neuroimaging

Brain imaging tests used to look for abnormalities.

primary psychosis

A psychotic disorder diagnosed as primary rather than related to another condition such as epilepsy.