History and physical examination of a patient with a newly diagnosed cavernoma should include a thorough review of prior neurologic events, review of any antithrombotic medications, seizure history, detailed neurologic exam and 3-generation family history, particularly concerning vascular malformations.[10]

Cavernomas can be more difficult to diagnose than other vascular malformations because of their low flow state and small size of the abnormal blood vessels. In particular, cerebral angiography is insensitive for detection of these lesions, giving rise to the term "angiographically occult".

On computed tomography (CT) imaging, cavernomas may appear well demarcated with either a homogeneous or heterogeneous high density related to calcification, thrombosis, increased blood volume, and hemosiderin deposition. They may demonstrate some degree of contrast enhancement. Significant edema or mass effect is unusual except in cases with recent hemorrhage.[11] CT lacks both sensitivity and specificity for cavernous malformations. It should not be the primary imaging study performed in these cases due to the high probability of missing or misdiagnosing lesions.

MRI is the diagnostic modality of choice, particularly gradient echo sequences and susceptibility-weighted imaging sequences that show areas of prior hemorrhage. Cavernous malformations can be divided into four groups based on their appearance on MRI.[12] Type I lesions appear hyperintense on both T1- and T2-weighted sequences due to their subacute hemorrhage and hemosiderin core. Type II lesions represent the classic "popcorn" lesions often described. These type II lesions have mixed signal intensity on both T1 and T2 sequences due to multiple loculated hemorrhages of various stages enclosed by gliotic margins. For these lesions, the gliotic peripheral rim demonstrates decreased signal intensity on T2 sequences. Type III lesions demonstrate chronic resolved hemorrhage within an isointense core. Type IV lesions are thought to represent small capillary telangiectasias that can only be seen on gradient resonance echo sequences. Some authors report an increased risk of hemorrhage for Type 1 and type 2 lesions, prompting consideration for more aggressive surgical management for these types.[1],[12] Diffusion tensor sequences and functional MRI (fMRI) can be useful for surgical planning by visualizing white matter tracts and eloquent areas.[3],[1] Presence of an associated developmental venous anomaly on imaging should also be noted due to implications for hemorrhage risk and surgical technique. If several cavernomas surround the periphery of a single developmental venous anomaly, then this is considered part of a single vascular complex consistent with sporadic (versus familial) occurrence.[10]

Conservative management with serial imaging and observation, microsurgical resection, and stereotactic radiosurgery are the 3 main options for management of cerebral cavernomas. When discussing treatment options, the risks of intervention versus the risks of having an untreated cavernous malformation must be weighed carefully. The natural history of cavernous malformations, clinical presentation, lesion location, number of hemorrhagic events, and medical comorbidities help guide this discussion.[13] For small and incidentally discovered lesions, observation is often reasonable.[13]

According to the Cerebral Cavernous Malformations Care Guidelines published in 2017 by the Angioma Alliance, surgical resection is not recommended for asymptomatic cavernous malformations. This is particularly true for multiple lesions or situations in which the lesions are located in deep, eloquent, or brainstem tissue. Surgical resection may be considered for a solitary asymptomatic cavernous malformation if the lesion is in non-eloquent and accessible location. In those cases, the benefits to resection may include prevention of hemorrhage, reduction of time and costs of follow-up, relief of psychological burden, lifestyle or career decisions, or facilitation of future anti-coagulation if needed.[10]

Per those same guidelines, early surgical resection should be considered for medically refractory epilepsy when the epileptogenic focus is related to the cavernoma. Such early intervention may prevent a "kindling" effect and improve the likelihood of seizure freedom. For symptomatic and easily accessible cavernous hemangiomas, it has been suggested that morbidity and mortality associated with surgery are approximately equivalent to the risk of living with a cavernoma for 2 years. For symptomatic and deeply located cavernomas, morbidity and mortality associated with surgical resection may be considered to be approximately equivalent to living with the cavernoma for 5 to 10 years. While surgery is not typically recommended for brainstem cavernomas due to a significant risk of complications, many recommend operating after a second symptomatic bleed due to the concept that those cavernomas may have a more aggressive natural course. Indications for resection of brainstem cavernomas after a single disabling hemorrhage or spinal cavernomas are more controversial.[10]

For cases undergoing surgical resection, steroids may be considered 1 to 2 weeks before surgery to reduce edema and aide with resection. Resection of any associated developmental venous anomalies should be strictly avoided due to potential venous infarction. Complete removal of the lesion is required to prevent recurrent hemorrhages. If the surgery is being performed for seizures, the hemosiderin stained surrounding neural parenchyma and gliosis should also be resected when feasible. After surgery, MRI within 72 hours is recommended to ensure complete resection. Some authors report a 40% risk of rebleeding of cavernoma remnants after partial resection.[3]

Stereotactic radiosurgery has been proposed as an alternative to microsurgery for treatment, although the effect of radiosurgery on reducing risks of re-bleeding remains controversial. Even for proponents of the technique, radiosurgery is thought to have a 2-year latency period before optimal risk reduction of recurrent hemorrhage occurs. While microsurgical resection remains the standard treatment for cavernomas, stereotactic radiosurgery is an option for solitary symptomatic lesions with an unacceptably high surgical risk.[3],[10] In general, it is not recommended for cavernous malformations that are asymptomatic, surgically accessible, or familial due to the risk of de novo cavernoma formation.[10]

For patients with a newly diagnosed cerebral cavernoma and with no history of brain radiation, no positive family history, or multiple cavernous malformations, genetic testing should be considered. If a positive mutation is found, genetic counseling should be offered to the patient and family.[10] First-degree relatives of patients with more than one family member with a cavernoma should also have a screening MRI recommended as well as genetic counseling.

Differential diagnosis may include other cerebral vascular malformations such as arteriovenous malformations, venous angiomas, capillary telangiectasias, dural arterio-venous fistulas, aneurysm, and vein of Galen malformations. MRI is the best study to diagnose cerebral cavernous malformations due to characteristic imaging findings, although angiography for the exclusion of other cerebrovascular pathologies under consideration may be helpful in certain clinical settings (such as spontaneous intracranial hemorrhage).

Neurosurgery consultation is recommended for management of patients with a cerebral or spinal cavernous malformation.

MRI is the standard imaging modality for diagnosis of cavernous malformations. Cerebral angiography is typically not indicated unless exclusion of other cerebrovascular pathology is being considered.

• For an initial seizure thought to be related to a cavernoma, anti-epileptic medication is a reasonable first-line therapy (Class I, Level B). Surgical resection should be considered for medically refractory epilepsy when the epileptogenic focus is related to a cavernoma.[10]
• Genetic counseling should be considered for those with familial or multiple cavernomas (Class I, Level C).[10]
• Neurosurgical consultation is indicated for the management of cavernous malformations. Treatment options include observation with serial imaging, surgical resection, and stereotactic radiosurgery.