Natural history of spinal cavernous malformations.

Spinal cavernous malformations are intramedullary vascular lesions. They have low pressure and flow, so they may take many years to present with clinical symptoms. Because of their relatively benign nature, surgical intervention is not always indicated. An understanding of the natural history of cavernous malformations helps make decisions about when and if to intervene. In patients who do not have surgery, 88.7% have stable or improved neurologic function, whereas 89.3% have these outcomes in the surgical group. Of note, 51.5% of patients were found to improve in the surgical group, compared to 30.2% in the nonsurgical group. Characteristics that correlated with better neurologic outcome were: resection within 3 months of the onset of symptoms, gross total resection, presentation with motor symptoms, and an acute course. Sensory symptoms correlated with worse outcome. Given the natural history of spinal cavernous malformations, surgery may be considered for symptomatic patients, when general medical health and lesion location permit safe resection. The severity of symptoms must also be considered, as the natural history of the disease can be benign.