Depression in complex partial seizures. Electroencephalography and cerebral metabolic correlates

Area of Science:

• Neuroscience
• Clinical Neurology
• Psychiatry

Background:

• Complex partial seizures (CPS) are frequently associated with psychiatric comorbidities, including depression.
• Understanding the neurobiological underpinnings of depression in epilepsy is crucial for effective management.

Purpose of the Study:

• To investigate the association between the laterality of seizure onset and cerebral hypometabolism and the occurrence of depressive disorders in patients with CPS.
• To determine if left-sided versus right-sided ictal onset or temporal lobe hypometabolism influences depression frequency.

Main Methods:

• Fifty-three patients with medically intractable CPS underwent video-electroencephalographic telemetry and fludeoxyglucose F18 positron emission tomographic (FDG-PET) scanning.
• Depressive disorders were assessed using modified Structured Clinical Interview for DSM-III-R criteria, focusing on major depressive episodes (MDEs).
• Outcomes compared depression history based on left vs. right ictal onset and left vs. right temporal lobe hypometabolism.

Main Results:

• 62% of patients had a history of interictal depressive disorders; 30% met criteria for MDEs.
• Left-sided ictal onset was associated with a higher frequency of depression history.
• Left temporal lobe hypometabolism, especially with high-degree changes, showed a strong association with MDEs.
• High-degree hypometabolism in the right temporal lobe was also linked to MDEs.

Conclusions:

• The laterality of ictal onset and the degree of interictal temporal lobe hypometabolism are potential interdependent factors influencing depressive disorder risk in CPS patients.
• These findings suggest specific neuroanatomical correlates for depression in epilepsy, guiding further research and clinical attention.