Multifocal periodic lateralized epileptiform discharges (PLEDs): EEG features and clinical correlations

Area of Science:

• Neurology
• Clinical Neurophysiology
• Epileptology

Background:

• Periodic lateralized epileptiform discharges (PLEDs) are EEG patterns associated with acute brain injury.
• Multifocal PLEDs, involving three or more distinct EEG foci, represent a more complex cerebral disturbance.

Purpose of the Study:

• To investigate the clinical characteristics and electroencephalographic (EEG) findings in patients presenting with multifocal PLEDs.
• To determine the underlying etiologies and outcomes associated with multifocal PLEDs.

Main Methods:

• Retrospective review of EEG recordings from 35 patients diagnosed with multifocal PLEDs (≥3 foci).
• Analysis of patient demographics, clinical diagnoses, and mortality data.
• Utilized Laplacian montages to enhance visualization of PLEDs' spatiotemporal distribution.

Main Results:

• Common etiologies included vascular lesions (9), CNS infections (7), metabolic/toxic disorders (6), and seizure disorder exacerbation (6).
• Other causes identified were hypoxic ischemic insults (3), fat embolism, paraneoplastic encephalitis, cerebral metastasis, and multiple sclerosis (1 each).
• A significant mortality rate of 57% (20 out of 35 patients) was observed.

Conclusions:

• Multifocal PLEDs are indicative of diffuse or multifocal cerebral dysfunction.
• The presence of multifocal PLEDs signifies a severe disturbance in brain function.
• Multifocal PLEDs are associated with a high mortality rate, underscoring their prognostic significance.