Teaching Case

An 8-year-old boy with no medical history was received in our emergency department with a consciousness impairment (GCS at 12), fever (38°C) and an episode of seizure. Two weeks prior to that, he had a flu which has been treated with no complications.

During his stay, an initial head CT examination performed before the lumbar puncture showed no sign of encephalitis but multiple spontaneously high density intra-cerebral lesions with mild enhancement. (Fig. 1).
An MRI was performed and showed multiple lesions in low signal in T2w imaging which were more highlighted in T2*w (GE) imaging. There was no significant enhancement (Fig. 2).

Cerebral cavernous malformations or cavernomas are rare vascular malformations characterised by enlarged capillary cavities without intervening brain parenchyma.

The prevalence is now estimated from 0.3 to 0.7% in the general population and 25% are paediatric [1, 2, 3]. Two types of the disease are described: sporadic (70-80%) and familial autosomic type, characterised by multiple and active lesions. [1, 2, 3, 4]. It is often associated with other vascular malformations such as developmental venous anomaly (DVA) in almost 10% of cases.

The outcome is more aggravating in familial types. « De novo » cases are now well known, both in familial or sporadic types and after radiotherapy.

Most of the lesions are non-symptomatic. The haemorrhagic risk is evaluated from 0.5 to 3% each year. The epileptic risk is more frequent for temporal and frontal lesions, evaluated from 4.5 to 11% each year, but these data are controversial [2].

A viral meningitis was the reason our patient was admitted to the ER. The cavernomas were a fortuitous discovery. It was a mix of type 3 and 4 of Zabramsky's classification, known for their better prognosis.

Imaging findings in cerebral cavernomas depend on the type of blood degradation product present in the lesion. MRI is the better imaging technique, whereas a CT examination can be very practical if there is recent bleeding. Angiography can be useful to diagnose associated lesions (e.g. developmental venous anomaly) and for the differentials (e.g. bleeding of a tumour or a capillary telangiectasia) [3].

Zabramsky described 4 types of cavernomas [5]. The rebleeding risk is higher in type 1/2, thus carrying the worst prognosis among all types.

Type 1 : Acute or sub-acute bleeding

Type 2 : Lesions containing bleeding and thrombosis of different ages

Type 3 : Old and chronic bleeding with haemosiderin depositions inside the lesion and its peripheral areas

Type 4 :Tiny cavernoma

Depending on the importance of the symptoms, abstention, drugs or even surgery in some cases can be used to control the disease. Genetic counselling and MRI screening are used in the familial types.

The boy recovered well shortly after the management of the viral meningitis.

The particularity of this case comes from the fact that there was an association of two conditions which could be responsible for the symptoms of our patient, and we managed to dissociate them with accurate analysis of the brain‘s MRI findings which show that the multiple cavernous malformations are chronic lesions with no recent bleeding.