Technetium-99m-HMPAO SPECT in partial status epilepticus

In this paper we correlate the findings on ^99mTc-HMPAO brain SPECT with the results of clinical examinations and electroencephalography to determine the utility of SPECT in the evaluation of patients with suspected status epilepticus. Methods: Thirteen patients with suspected status epilepticus underwent serial neurologic examinations, serial electroencephalograms, CT/MRI scanning and ^99mTc-HMPAO SPECT. Seven patients were diagnosed with status epilepticus and six patients received other neurological diagnoses. Results: All patients with status epilepticus at the time of the brain SPECT scan demonstrated focal hyperperfusion on SPECT in an area concordant with that suggested by EEG. One patient with status epilepticus demonstrated a persistent area of hyperperfusion on SPECT 24 hr after the cessation of status with no evidence of breakdown in the blood-brain barrier demonstrated by ^99mTc-HMPAO SPECT. No patient in this study without a diagnosis of status epilepticus had focal areas of hyperperfusion on SPECT. Conclusion: We suggest that a ^99mTc-HMPAO SPECT scan demonstrating focal hyperperfusion in a patient being evaluated for partial status epilepticus is nonspecific. Even in the absence of a structural lesion causing local breakdown in the blood-brain barrier, it may indicate either ongoing status epilepticus or recently terminated status. However, a SPECT scan demonstrating no area of focal hyperperfusion argues against the diagnosis of partial status.