Cavernoma

Cavernomas, also known as cavernous malformations, are vascular malformations in a sinusoidal formation lined only by endothelium, which has an irregularly thick wall. Cavernomas do not have large feeding arteries or large draining veins. In most cases, cavernomas have a diameter of 1–5 cm and may calcify, thrombose, or hemorrhage[^1].

Epidemiology

The average age at which cavernomas are diagnosed is approximately 30 years, and they are diagnosed with equal frequency in women and men[^2]. Cavernomas account for approximately 5–13 % of all vascular pathologies in the central nervous system and develop in approximately 0.02–0.16 % of the population[^1]. 48–86 % of cavernomas are located supratentorial, 4–35 % in the brainstem, and approximately 5–10% in the basal ganglia[^3]. In 23 %[^4] to 50 %[^5] of cases, multiple cavernomas are present at diagnosis. In very rare cases, cavernomas may also occur in the spinal cord. Cavernomas may also occur with familial clustering, for which various genetic loci have been identified: CCM1, CCM2, CCM3. The PIK3CA genetic locus has been identified for sporadic cavernomas[^9].

Symptoms

Cavernomas become symptomatic in 50 % of cases through epileptic seizures or symptoms of acute hemorrhage from the cavernoma. Patients frequently present with acute-onset headaches or new neurological deficits corresponding to the location of the cavernoma. A first hemorrhage from a cavernoma is rarely fatal. The risk of epileptic seizures is particularly high with supratentorial cavernomas.

Imaging

The gold standard for diagnosing cavernomas is MRI imaging.

Risk of hemorrhage

The risk of acute hemorrhage depends on the location of the cavernoma. Cavernomas located deep or in the brainstem have an annual hemorrhage risk of approximately 4–5 % per lesion per year. Superficially located supratentorial cavernomas have an annual hemorrhage risk of <1 %[^6].

Location

Spinal intramedullary cavernomas

Intramedullary cavernomas may clinically and radiologically mimic demyelinating or neoplastic processes[^8]. Approximately 27 % of patients also have cranial cavernomas. Spinal cavernomas may manifest clinically in different ways. In approximately 30 % of cases, there is stepwise worsening; in approximately 41 %, progressive worsening; and in approximately 26 %, acute neurological deterioration[^7].

Diagnosis

Cavernomas are usually diagnosed with MRI imaging, with the T2 and SWI sequence being particularly helpful. On MRI, cavernomas typically show a “popcorn-like” or “mulberry-like” appearance. Classification is often based on the Zabramski classification. digital subtraction angiography does not visualize cavernomas, but it may play a role in the diagnostic workup to exclude other vascular pathologies in unclear cases[^1].

Prognosis

After complete surgical removal, the risk of regrowth or hemorrhage is generally eliminated entirely[^1]. However, symptoms may recur after partial removal or even after presumed complete removal[^1]. Postoperatively, cavernomas—particularly those located in the brainstem—may frequently be associated with postoperative deterioration, which is generally transient but may persist for months[^1].