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Natural course of untreated spinal cord cavernous malformations: a follow-up study within the initial 5 years after diagnosis.

OBJECTIVE
Cavernous spinal cord malformations (SCMs) are believed to have a high rate of bleeding. The risk of intramedullary hemorrhage (IMH) or recurrent IMH and the neurological impact of bleeding events are important for clinical decision-making and could impact current treatment strategies.


METHODS
The authors screened their institutional database for patients with cavernous SCM treated between 2003 and 2020. Patients with complete MRI data sets and clinical baseline characteristics were included. Surgically treated patients were censored after cavernous SCM removal. Neurological functional status was obtained using the modified McCormick (MMcC) scale at diagnosis, first IMH, and second IMH. Kaplan-Meier and Cox regression analyses were performed to determine the cumulative 5-year risk for hemorrhage or rehemorrhage.


RESULTS
Seventy-one patients with cavernous SCM were analyzed. Cox regression analysis identified previous IMH (hazard ratio 7.86, 95% confidence interval 1.01-61.47, p = 0.049) as an independent predictor for rehemorrhage during the 5-year follow-up. The cumulative 5-year risk of bleeding or rebleeding was 41.3% for cavernous SCM. The MMcC score significantly deteriorated in 75% of patients after recurrent hemorrhage (p = 0.012).


CONCLUSIONS
During untreated 5-year follow-up, a considerably increased risk for hemorrhage or rehemorrhage was found in cavernous malformations of the spinal cord compared to cerebral cavernous malformations. Neurological function significantly deteriorates after the second bleeding. The probability of recurrent IMH increased significantly after initial presentation with hemorrhage.