Thrombotic thrombocytopenic purpura (TTP) can produce fluctuating neurologic deficits with variable EEG findings.A 40-year-old man presented with waxing/waning expressive aphasia and altered mental status, with systemic features of microangiopathy and laboratory evidence of hemolysis and thrombocytopenia.MRI demonstrated asymmetric leptomeningeal enhancement with left hemispheric FLAIR hyperintensity (Figure 1).Continuous EEG recorded medium to high-amplitude 2-3-Hz lateralized rhythmic delta activity (LRDA) in the left temporal region, which became nearly continuous during aphasic episodes, without meeting criteria for electrographic seizures (Figure 2).Levetiracetam did not improve clinical or electrographic findings.A PLASMIC score of 7 prompted empiric treatment with IV steroids and plasma exchange; ADAMTS13 activity <5% confirmed autoimmune TTP. 1 After treatment, LRDA markedly decreased, aphasia resolved, and MRI showed resolution of leptomeningeal enhancement.This case highlights that temporal LRDA can be an electrographic correlate of transient aphasia in TTP, possibly reflecting dynamic microvascular cerebral dysfunction/ischemia that improves with disease-directed therapy. 2Figure 1 MRI With Leptomeningeal Enhancement Axial fluid attenuated inversion recovery (FLAIR) images showing asymmetric leptomeningeal enhancement and postcontrast FLAIR hyperintensity (red and white arrows) in several left frontal, parietal, and temporal sulci.
Wolkiewicz et al. (Fri,) studied this question.