Functional neuroimaging in nonepileptiform electroencephalographic patterns in status epilepticus

Area of Science:

• Neurology
• Neuroimaging
• Epilepsy Diagnostics

Background:

• Diagnosing nonconvulsive status epilepticus (NCSE) is challenging, particularly with nonepileptiform electroencephalogram (EEG) patterns.
• Accurate NCSE diagnosis is critical for timely and appropriate patient management.

Purpose of the Study:

• To assess the diagnostic utility of single photon emission computerized tomography (SPECT) and its quantitative analysis (QtSPECT) for NCSE.
• To determine if SPECT findings correlate with NCSE diagnosis in patients with ambiguous EEG results.

Main Methods:

• Retrospective review of patients with suspected NCSE and non-epileptiform EEG patterns who underwent HMPAO-SPECT.
• Classification of patients into confirmed NCSE and non-NCSE groups based on clinical evolution and diagnostic workup.
• Comparison of EEG and SPECT findings between the NCSE and non-NCSE groups.

Main Results:

• Lateralized rhythmic delta activity (LRDA) was more frequent in the NCSE group (45.4%).
• Patients with NCSE exhibited significant hyperperfusion compared to non-NCSE patients (p=0.026).
• Quantitative SPECT (QtSPECT) achieved 91% accuracy for NCSE and 75% for non-NCSE classification (p=0.006).

Conclusions:

• Regional cerebral blood flow, measured by SPECT, can aid NCSE diagnosis.
• SPECT is particularly useful in conjunction with lateralized slow EEG activity and strong clinical suspicion.
• Quantitative SPECT analysis improves diagnostic accuracy for NCSE.