Case ReportTransient and permanent magnetic resonance imaging abnormalities after complex partial status epilepticus
Introduction
Magnetic resonance imaging (MRI) is mandatory in the diagnostic workup of patients with epileptic seizures to delineate any structural epileptogenic lesion. In addition, transient signal abnormalities can occur and have been attributed to functional changes due to seizure activity. With EEG-triggered functional MRI (fMRI), signal changes have been demonstrated in areas of interictal spiking [1], and fMRI changes can also be observed after single seizures [2]. Acute postictal cerebral imaging may show reversible abnormalities [3], and postictal diffusion-weighted MRI (DWI) can help to delineate epileptic areas [4]. Status epilepticus with prominent motor symptoms (convulsive status epilepticus, CSE) causes MRI changes after generalized [5] and focal motor seizures [6], [7], [8]. Status epilepticus with no or only minor motor symptoms (nonconvulsive status epilepticus, NCSE) can be broken down into generalized and focal types. MRI changes with generalized NCSE are exceptional [9]. Focal NCSE occurs mostly as complex partial status epilepticus (CPSE). Several articles have reported transient MRI abnormalities after CPSE [10], [11]. Other types of focal NCSE (visual, inhibitory, aphasic) with transient MRI abnormalities are difficult to differentiate from vascular ischemic events.
We report a unique case of repeated episodes of CPSE with marked transient MRI abnormalities followed by localized brain atrophy and discuss the clinical and therapeutic consequences.
Section snippets
Case report
A 43-year-old right-handed man had his first seizure in the second decade of life. Seizures consisted of an aura with epigastric sensations and fear, followed by unresponsiveness and automatisms as well as ictally preserved, grammatically correct speech. He was seen at our institution for the first time at the age of 22 after he had two episodes of nonconvulsive seizure activity with altered consciousness characterized by a twilight state, disturbed reactivity, embarrassment, repeated automatic
MRI abnormalities
MRI examinations 7 months prior to admission revealed normal volume and signal behavior of the right temporal lobe, including the hippocampus (Fig. 1). On admission, serial MRI scans (1.5-T Sonata, Siemens, Erlangen, Germany) were obtained. After repeated episodes of NCSE, diffusion-weighted images and T2-weighted images (Fig. 2) exhibited abnormal hyperintense signal in the right frontal, temporal, insular, and bilateral cingulated cortices. The abnormalities appeared more extensive on
Discussion
Epileptic seizures are characterized by neuronal release of massive amounts of excitatory neurotransmitters such as glutamate. How the cellular changes of the excitatory cascade become MRI-detectable is not yet established [12]. Postictal DWI studies in animal experiments concentrate on studies after induction of status epilepticus. Seizures may lead to localized cell swelling and fluctuations in the extracellular water reflected by an increase in the T2-weighted signal intensity [13] and
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