Teaching Neuro Images :Crossed cerebellar diaschisis in hemispheric status epilepticus

Abstract

Teaching NeuroImages: Crossed cerebellar diaschisis in hemispheric status epilepticus A 36-year-old woman with Sheehan syndrome was found unresponsive. Evaluation was consistent with Addisonian crisis and myxedema coma. Continuous EEG demonstrated right frontotemporal nonconvulsive status initially refractory to multiple antiepileptic drugs (figure 1). MRI brain revealed restricted diffusion (figure 2) within the cortex of the right hemisphere and left cerebellum, suggestive of focal status epilepticus. There was no associated enhancement on apparent diffusion coefficient (ADC) (figure 2), and near normalization of ADC mapping on follow-up imaging. Although primarily recognized in the stroke literature, crossed cerebellar diaschisis may represent injury caused by excessive neuronal transmission from prolonged excitatory synaptic activity via the cortico-pontine-cerebellar pathways. 1,2

Cerebellar Hypoperfusion in Migraine Attack: Incidence and Significance

“…26 In seizure-related CCD, the outcome is variable, ranging from complete neurologic recovery to permanent disability depending on the duration of prolonged excitatory synaptic activity affecting cortico-ponto-cerebellar pathways. [27][28][29][30][31] While diffusion restriction is a common consequence of perfusion changes and related metabolic depletion in patients with stroke and epilepsy, this should be considered an exceptional phenomenon in migraine. In our cohort, none of the 106 patients had restricted diffusion or preexisting cerebellar infarct-like lesions.…”

Prognostic and Mechanistic Factors Characterizing Seizure-Associated Crossed Cerebellar Diaschisis

“…As compared to CCD in the setting of an acute infarct, this seizure-associated hyperactivation-deafferentation phenomenon is frequently transient, and most case reports describing CCD document clinical and radiographic resolution soon after seizure control is established [7,9,10]. In these patients, the transneuronal depression is akin to Fig.…”

“…The first radiographic description was published in 1980, using positron emission tomography (PET) in acute infarct patients [2]. Subsequent reports have described CCD using magnetic resonance imaging (MRI) and characterized the finding in neoplasms, arteriovenous malformations, hemorrhages, and-in conjunction with continuous electroencephalography (cEEG)-have correlated CCD with seizures [9,10,12,13].…”

“…In the setting of seizures, CCD is thought to arise from excessive excitatory activity along the cortico-pontine-cerebellar pathways, which produces a similar phenomenon to the deafferentation syndrome observed after acute infarct [9,10,12]. Cases documenting seizure-associated CCD vary considerably in terms of outcome, ranging from full neurologic recovery to permanent disability.…”

Crossed Cerebellar Diaschisis: Risk Factors and Prognostic Value in Medically Intractable Epilepsy by 18F-FDG PET/CT

“…We thought that these ndings were closely related to the CPC pathways. Massaro [29] found CCD in patients with status epilepticus by MRI and attributed the nding to excessive neuronal transmission caused by prolonged excitatory synaptic activity from the supratentorial hemisphere to the contralateral cerebellum through the CPC pathway, resulting in increased energy metabolism and cerebral blood ow.…”