Alternating and postictal psychoses: review and a unifying hypothesis

Area of Science:

• Neuroscience
• Psychiatry
• Epileptology

Background:

• Postictal psychosis (PIP) and brief interictal or alternating psychosis (BIAP) are distinct syndromes in epilepsy.
• Understanding their shared pathophysiological features is crucial for diagnosis and management.

Purpose of the Study:

• To compare clinical and pathophysiological features of PIP and BIAP.
• To investigate if the underlying mechanisms of these two psychotic syndromes are distinct.

Main Methods:

• A selective review of published English literature on epilepsy and brief psychosis.
• Analysis of clinical and pathophysiological data from existing studies.

Main Results:

• PIP and BIAP exhibit significant similarities despite being considered separate syndromes.
• Common underlying pathomechanisms are proposed, involving the brain's inhibitory responses to seizures.
• These mechanisms include electrophysiological, cerebral blood flow, and neurotransmitter changes, particularly involving Gamma-aminobutyric acid (GABA).

Conclusions:

• Prolonged inhibition in limbic circuits is likely implicated in both syndromes.
• Further seizures can modulate psychosis through disinhibition or enhanced inhibition.
• Understanding these shared mechanisms aids in managing epilepsy-associated psychosis and schizophrenia-like episodes.