Hemodynamic state of periictal hyperperfusion revealed by arterial spin-labeling perfusion MR images with dual postlabeling delay

Abstract

BackgroundMagnetic resonance imaging (MRI), including perfusion MRI with arterial spin labeling (ASL) and diffusion-weighted imaging (DWI), are applied in the periictal detection of circulatory and metabolic consequences associated with epilepsy. Although previous report revealed that prolonged ictal hyperperfusion on ASL can be firstly detected and cortical hyperintensity of cytotoxic edema on DWI secondarily obtained from an epileptically activated cortex, the hemodynamic state of the periictal hyperperfusion has not been fully demonstrated.Methods: study-1We retrospectively analyzed the relationship between seizure manifestations and the development of periictal MRI findings, in Case 1 with symptomatic partial epilepsy, who underwent repeated periictal ASL/DWI examination for three epileptic ictuses (one examination for each ictus). Study-2: We evaluated the hemodynamic state of periictal hyperperfusion with the ASL technique using a dual postlabeling delay (PLD) of 1.5 and 2.5 s in nine patients, according to the presence or absence of the localized epileptogenic lesion (EL) on conventional 3 T-MRI, who were divided into Group EL+ (six patients) and Group EL− (three patients).ResultsStudy-1 confirmed that the stratified representation of the periictal MRI findings depends on the time interval between the ictal cessation and MRI examination in addition to the magnitude and duration of the epileptic activity. In Study-2, two types of periictal hyperperfusion were noted. In all six Group EL+ patients, periictal ASL findings showed “fast flow type”. Markedly increased ASL signals were noted at the epileptically activated cortex, having a tight topographical relationship with EL, on ASL with a PLD of 1.5 s, which is decreased on ASL with a PLD of 2.5 s. In all three Group EL− patients, periictal ASL findings showed “gradual flow type”, which is characterized by gradual signal increase of the epileptically activated cortex on ASL with a PLD of 1.5 and 2.5 s.ConclusionWe confirmed that ASL hyperperfusion is superior to DWI in the periictal detection of epileptic events. ASL with dual PLD offers the ability to document two types of hemodynamics of periictal hyperperfusion.

Definitions and classification of malformations of cortical development: practical guidelines

“…If this still give equivocal results, an ictal SPECT can be performed to help to identify the epileptic zone by showing hyperperfusion. In the peri-ictal stage, perfusion MRI with arterial spin labelling (ASL) is also showing great promise in the identification of regional hyperperfusion secondary to the increased metabolic demands ( Takahara et al , 2018 ).…”

Arterial Spin Labeling technique and clinical applications of the intracranial compartment in stroke and stroke mimics - A case-based review

“…These ictal MRI findings on ASL and DWI are reversible in most cases. 65,67 Takahara et al reported that ASL hyperperfusion is superior to DWI in the periictal detection of epileptic events. 67

Figure 9.Ictal state seizure with Todd’s paralysis.

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“…65,67 Takahara et al reported that ASL hyperperfusion is superior to DWI in the periictal detection of epileptic events. 67

Figure 9.Ictal state seizure with Todd’s paralysis. 56-year-old male with seizure and focal right arm weakness and aphasia.

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“…This ictal hyperperfusion is identified as increased ASL signals in the epileptogenic focus (Figure 9). [65][66][67] When this hyperperfusion is no longer sufficient to supply the metabolic demand of the hyperactive cortical area, pathophysiological changes can lead to cytotoxic edema in epileptic cortical neurons. The affected areas are detected as high signal on DWI and low signal on apparent diffusion coefficient (ADC).…”

Cerebrovascular Disease; A Leading Cause of Epilepsy

“…Initial use of brain magnetic resonance imaging is useful not only to detect cerebrovascular disorders and other neurological conditions but also to evaluate seizure foci and spread of seizures via neural network. Hyperintensity of diffusionweighted imaging especially in the cortex and hyperperfusion of arterial spin labeling can help early diagnosis of nonconvulsive status epilepticus [118,119,121,122].…”