CASE 11654 Published on 07.04.2014

Cavernoma-related epilepsy

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Bagetakos I, Gurer O.

Department of Radiology,
Hôpitaux Universitaires de Genève,
Geneva, Switzerland;
Email: Ilias.Bagetakos@hcuge.ch
Patient

49 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique CT, MR, MR-Angiography
Clinical History
A 49-year-old man with no significant past medical history presented in the emergency department for a head trauma after a fall due to an epileptic seizure, with loss of consciousness. No neurological deficit or headaches at admission.
Imaging Findings
An initial brain CT without contrast enhancement was performed demonstrating a bilobate lesion with a hypodense centre and hyperdense contours, situated in the right insular cortex of the brain. Neither haemorrhage nor other similar lesions were found.
On the contrast-enhanced brain CT, this lesion presented a discreet contrast enhancement.
Contrast-enhanced MRI shows the above described lesion, which has its origin at the anterior part of the right insular cortex up to the area of the primary auditory cortex (Heschl's gyrus) in the superior temporal lobe. It appears hypointense on T2-weighted images with a hyperintensity in its centre and a nodular “popcorn-like” pattern, hyperintense on T1-weighted images, with susceptibility artefacts on T2 *-weighted images and discreet contrast uptake. No other abnormality was noted on this MRI, especially no micro-bleeds on T2 *-weighted images.
Discussion
Cerebral cavernous malformations are also referred to as cavernous angiomas, cavernous haemangiomas, or cavernomas and are composed of a "mulberry-like" cluster of dilated thin-walled capillaries, with surrounding haemosiderin and without intervening brain parenchyma [1]. They may occur as either single or multiple lesions, sporadically or in a familial pattern with autosomal dominant transmission and their incidence is thought to range between 0.4% and 0.8%. Multiple cavernomas are more frequent in familial forms. They can occur in all parts of the central nervous system but most commonly in the cerebral hemispheres, mainly in the rolandic and temporal area [2].

Cavernomas can remain asymptomatic throughout life and be found incidentally. If symptomatic, the average age of onset is 30 to 40 years, and they usually present with seizures (epilepsy), headaches, or neurological deficits due to haemorrhage or focal mass effect [3].

MRI has a key role in the diagnosis of cavernous malformation demonstrating characteristic findings on T-1 and T-2 weighted images such as "popcorn" or "berry" appearance lesions containing blood products of various ages and therefore various signal intensities on T1- and T2-weighted imaging. A rim of signal loss due to haemosiderin, which is best seen on T2 or gradient echo sequences at the periphery of the lesion, is suggestive of remote haemorrhage. The development of susceptibility weighted imaging (SWI) sequences has further increased sensitivity for the detection of CCMs. There is no or only mild contrast enhancement [4]. Contrast enhanced images should be obtained in order to delineate any potential associated DVAs that may alter the surgical approach [5].

CT with or without contrast administration detects only 30-50% of lesions. Cavernomas usually manifest as a nonspecific, irregular, hyperdense mass, sometimes with internal calcifications. Mild or no enhancement is observed following intravenous contrast administration. Mass effect is not common unless the lesion is associated with recent haemorrhage [6].

In this case, the origin of the epileptic seizure was attributed, according to the MRI, to a small lesion in the right insulary cortex of the brain, identified as a cerebral cavernous malformation. Most lesions discovered incidentally require no therapy. Occasionally, these lesions cannot be differentiated from tumours, and a biopsy is indicated. Cavernomas associated with epilepsy are normally managed with conservative medical treatment of antiepileptic drugs. Surgical resection can be attempted when seizures cannot be controlled with pharmacological treatment or the adverse effects of the drugs are too serious [6].
Differential Diagnosis List
Cavernous malformation of the brain.
Haemorrhagic metastases
Diffuse axonal injury
Developmental venous anomalies (DVAs)
Capillary teleangiectasias
Arteriovenous malformations (AVMs)
Leptomeningeal angiomatosis (Sturge-Weber syndrome)
Cerebral amyloid angiopathy
Final Diagnosis
Cavernous malformation of the brain.
Case information
URL: https://www.eurorad.org/case/11654
DOI: 10.1594/EURORAD/CASE.11654
ISSN: 1563-4086