CT perfusion and EEG patterns in patients with acute isolated aphasia in seizure-related stroke mimics

Abstract

Isolated speech impairment is one of the most challenging clinical manifestations of stroke mimic (SM). We aimed to investigate perfusional and EEG pattern of isolated aphasia to better differentiate between vascular and epileptic etiology in emergency settings. Method: We retrospectively analyzed 481 cases with acute focal neurological symptoms admitted to our Stroke Unit. The patients showing isolated aphasia and confirmed ischemic infarction or SM with seizure etiology on follow-up were included for subsequent analysis of clinical, neuroimaging, and EEG data. We investigated differences in CT Perfusion maps between ROI in the anatomical area compatible with clinical presentation, contralateral ROI and EEG in order to evaluate perfusion and brain oscillatory activity abnormalities. Results: 45 patients presented isolated aphasia as principal neurological symptom: 27 cases due to acute ischemic event, 11 due to seizure SM, while 7 were SM due to other etiologies. Out of 11 SM patients with seizure etiology, significant hyperperfusion on CTP maps (MTT AI% < -10%) and sharp EEG waves were observed in 8 patients, while in 3 patients slight hypoperfusion (MTT AI% < 20%) and slow EEG rhythms were detected. 24 out of 27 ischemic stroke patients presented severe hypoperfusion with MTT AI above the stroke threshold (MTT AI > 45%). All ischemic stroke patients presented slower EEG rhythms. Conclusions:The main finding of this study is the identification of different clinical and neuroimaging patterns of isolated aphasia with epileptic or ischemic etiology in emergency settings.

Hyper-acute EEG alterations predict functional and morphological outcomes in thrombolysis-treated ischemic stroke: a wireless EEG study

“…Perfusion neuroimaging, such as MRI and CTP techniques, are crucial in ischemic stroke assessment and patient selection due the identification of ischemic core and salvageable hypoperfused penumbra [ 15 , 16 , 21 , 26 ] However, these techniques are not feasible tools to monitor brain ischemia evolution in the acute phase. Brain oscillatory activity changes occurring in acute ischemic stroke are related to neurophysiological changes (measured by EEG) in the cerebral tissue during hypoperfusion as manifestation of neurovascular coupling [ 29 , 32 ].…”

A physiological perspective of the associations between hydration status and CTP neuroimaging parameters in hyper‐acute ischaemic stroke patients

“…Despite a growing evidence showing the association between hydration status and ischaemic stroke outcomes, few studies tried to investigate what physiological mechanisms may be involved. To the best of the author's knowledge, this is the first study attempting to show any association in hyper‐acute (<4.5 hr) stroke between hydration status and whole‐brain CTP parameters, a neuroimaging technique that gives indications of cerebral perfusion during the hyper‐acute phase of ischaemic stroke (Bivard et al., 2018; Furlanis et al., 2018, 2019; Lin et al., 2009; Manganotti et al., 2019; Shankar et al., 2016). Additionally, this study separately analyses blood and urine biomarkers of hydration status that may differently affect ischaemic lesion.…”

“…CTP image processing (Figure 1) was performed by using Extended Brilliance Workstation v 4.5 (Philips Medical Systems, Best, Netherlands) and a dedicated routine developed in MATLAB (MathWorks Inc., Natick, MA), as previously described (Furlanis et al., 2018; Manganotti et al., 2019; Stragapede et al., 2019). Deconvolution‐based algorithm was used to calculate mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF) perfusion maps.…”

“…Computed tomography perfusion (CTP) imaging is a well‐validated technique used in emergency setting to help identifying in the hyper‐acute phase the irreversible infarct volume (core) and surrounding salvageable hypoperfused tissue (penumbra) (Gonzalez, 2006). Recently, CTP has been characterized by a growing research interest, and its parameters are well associated with clinical presentation and functional outcomes after ischaemic stroke (Albers et al., 2018; Caruso et al., 2018; Campbell et al., 2019; Furlanis et al., 2018, 2020; Haranhalli et al., 2019; Manganotti et al., 2019; Stragapede et al., 2019; Vilela & Rowley, 2017).…”

CT perfusion in hyper-acute ischemic stroke: the acid test for COVID-19 fear

“…Advanced multimodal neuroimaging plays an increasingly relevant role in the management of patients with stroke-related symptoms [ 4 , 6 , 7 , 11 , 12 , 28 , 29 ]. Using CTP to identify irreversible infarct core and the ischemic salvageable penumbra area in a quick and accurate manner allows stroke emergency management based on the tissue-clock approach instead of on the time-clock approach.…”