First episode of generalised seizure and posterior headache

Clinical History

A previously healthy 44-year-old man was referred to our hospital due to one episode of generalised seizure. It was his first episode. The patient could not remember it.
Headache was present after the episode.

Imaging Findings

Figure 1. Basal (A) and contrast enhanced (B) axial computed tomography show a hyperattenuated, heterogeneous, nodular lesion with discrete calcification areas at the right temporo-occipital region. There is no significant contrast enhancement or mass effect.
Figure 2. Basal (A) and gadolinium enhanced (B) T1 weighted coronal images show a discrete hyperintense nodular lesion at the right temporo-occipital region. There is no significant contrast enhancement.
Figure 3. T2-weighted axial image (A) shows a heterogeneous hyperintense nodular lesion. T2*-weighted gradient-echo axial image (B) shows a markedly hypointense halo surrounding the core.

Discussion

Cavernomas, also called cavernous angiomas, are congenital cerebrovascular hamartomas which occur sporadic or familial (10-30%), assembled of a thin endothelin-lined wall of sinusoids separated by fibrous collagenous bands. Total absence of intervening neural tissue is its most defining characteristic. They may be multiple or single. Cavernomas may present calcifications, gliosis, haemorrhage and blood degradation products at various stages of evolution. In a macroscopic examination, cavernomas are small (usually less than 3 centimetres in size), raspberry-like lesions, usually encapsulated and sometimes calcified. This kind of vascular malformation can be found throughout the central nervous system, including every region of the brain, brain stem, spinal cord, ventricles and cranial nerves.
The prevalence in the general population is not known. Estimates have been made using autopsy studies and cohort studies. Represent 5 to 13% of all vascular lesions. They may be found in an estimated 0.4 to 0.6% of the population, with male and female patients equally affected in all ages [1].
Clinical presentation is variable. The range goes from an incidental asymptomatic finding to an autopsy discovered haemorrhage. The most common symptom is seizure (all types) followed by focal neurological deficits, acute haemorrhage, and headache. Haemorrhage is not always symptomatic. Symptoms usually start at 20-40 years but may be present at any age of life. Haemorrhagic and neurological disability risks are related to multiple factors: lesion location, age, gender, pregnancy and previous haemorrhage. The annual bleeding risk is 1-2% per person/year and there is a 1.5% risk of developing epilepsy [1].
Computed tomography (CT) shows a hyperattenuated, well-defined nodular lesion with no significant mass effect. Multiple discrete calcification areas and venous malformations may be visible.
Cavernous malformations usually cause small, asymptomatic haemorrhages confined to the location of the lesion but clinically significant bleeding is not common. Magnetic resonance (MRI) is the best diagnostic imaging procedure, because haemoglobin degradation products such as haemosiderin, methaemoglobin and ferritin present after haemorrhage in the location of the lesion change the local magnetic environment allowing magnetic resonance detection. T2 weighted images may show a hyperintense and irregular lesion surrounded by a hypointense halo. T2*-weighted gradient-echo images are highly specific detecting old haemorrhage as a markedly hypointense rim.
Magnetic resonance imaging findings may be classified into four categories:
I) Sub-acute haemorrhage, II) Loculated areas of haemorrhage surrounded by gliosis and haemosiderin stained brain, III) Chronic resolved haemorrhage with haemosiderin staining within the lesion, IV) Minute cavernous malformation similar in appearance to telangiectases [1].

Differential Diagnosis List

Final Diagnosis

Cavernous angioma in right temporo-occipital region.

URL:	https://www.eurorad.org/case/9493
DOI:	10.1594/EURORAD/CASE.9493
ISSN:	1563-4086