Beyond video-EEG: identifying functional/dissociative seizures through clinical assessment

Area of Science:

• Neurology
• Clinical Neuroscience
• Psychiatry

Background:

• Distinguishing functional/dissociative seizures (FDS) from epileptic seizures is crucial for effective treatment.
• Clinical semiology is a key factor in early identification, but overlap exists between seizure types.

Purpose of the Study:

• To compare the clinical features of functional/dissociative seizures (FDS) and epileptic seizures.
• To identify specific semiological indicators for early and accurate diagnosis of FDS.

Main Methods:

• Retrospective analysis of seizure semiology in 51 FDS patients and 51 age/sex-matched epilepsy patients.
• Video-electroencephalogram (video-EEG) confirmed all diagnoses.
• Evaluated features included eye closure, head/body movements, pelvic thrusting, opisthotonus, grimacing, course fluctuation, tremors, vocalization, awareness, and duration.

Main Results:

• FDS patients more frequently showed sustained eye closure (90.2%), pelvic thrusting (43.1%), opisthotonus (27.5%), fluctuating course (66.7%), and limb tremors (76.5%) (p < 0.001).
• FDS episodes were significantly longer (median 180s vs. 66s, p < 0.001).
• Independent predictors for FDS included sustained eye closure (OR: 56.9), pelvic thrusting (OR: 8.1), and seizure duration (OR: 1.011 per second).

Conclusions:

• Sustained eye closure, pelvic thrusting, and prolonged seizure duration are key indicators of FDS.
• Improved diagnostic accuracy, especially when video-EEG is unavailable.
• Prevention of unnecessary anti-seizure medication and timely initiation of psychological care.