Literature
Clinical Pearls & Morning Reports
Published March 13, 2024
How are cerebral cavernous malformations managed?
Cerebral cavernous malformations (CCMs) are compact clusters of spongelike vascular spaces without intervening neural parenchyma that occur in the brain or spinal cord. The vessels lack normal smooth muscle and elastic tissue, making their thin walls prone to distortion and rupture. Read the NEJM Review Article here.
Clinical Pearls
Q: What is the most common type of CCM?
A: The majority of CCMs (approximately 85%) are single, sporadic lesions due to somatic variants, whereas multiple CCMs are typically associated with pathogenic germline variants (often in CCM1, CCM2, or CCM3) or prior cranial irradiation. Radiation-induced CCMs typically develop in the brain approximately 10 years after cranial radiation therapy and have been reported in approximately 8% of previously irradiated patients, with risk factors including treatment at less than 10 years of age and a radiation dose of more than 3000 cGy.
Q: How do symptomatic CCMs typically present?
A: Symptoms of CCMs are typically due to the accruing hemorrhage within and surrounding a lesion and to growth of the underlying malformation. The common presentations are focal seizures (in approximately 50% of cases) and focal neurologic deficits (in approximately 25%). Sporadic CCMs are found in the cerebral hemispheres (in approximately 66% of cases), brain stem (in approximately 20%), cerebellum (in 6%), and basal ganglia or deep nuclei (in approximately 8%). Twenty to fifty percent of CCMs are asymptomatic and are incidental findings on imaging performed for various reasons such as headache.
Morning Report Questions
Q: What is the greatest risk factor for cerebral hemorrhage from a CCM?
A: The risk of intracranial bleeding from nonfamilial CCMs is approximately 0.1 to 1% annually for patients with incidentally found lesions. The risk of subsequent hemorrhage in the first 1 to 5 years after an initial single hemorrhage is approximately 14 to 56%. Thus, the greatest risk factor for cerebral hemorrhage is a previous hemorrhage. Overall, the bleeding rate among patients with familial lesions is approximately 4% per year, with approximately 60% of patients having symptomatic hemorrhage and approximately 32 to 60% having seizures. These data suggest that patients who present with a hemorrhage and those with familial CCMs warrant close follow-up.
Q: How are CCMs managed?
A: Surgical resection is usually recommended by multidisciplinary working groups as first-line therapy for most symptomatic CCMs. Primary indications for the treatment of CCMs typically include symptomatic or progressive growth or hemorrhage and seizures that are considered, on the basis of clinical findings or special studies, to originate in the region of a CCM. Some case series have shown seizure control in 80% of patients after resection, with lesion recurrence among approximately 1%, although this benefit comes with an approximately 4% risk of long-term neurologic deficits from surgery. CCMs that have not bled, are asymptomatic, or are located in high-risk areas for surgery, such as the brain stem or thalamus, require individualized risk–benefit assessments but are usually observed rather than surgically excised. Stereotactic radiation therapy is also useful for treating CCMs and has particular value for surgically inaccessible lesions such as those in the brain stem or in symptomatic patients with sporadic lesions who are poor candidates for surgery.