Predictors of neurological deficit after endovascular treatment of cerebral arteriovenous malformations and functional repercussions in prospective follow-up.

Endovascular therapy is a well-established approach to the treatment of cerebral arteriovenous malformations (AVMs). The objective of this study was to determine the predictive factors of neurological deficit following endovascular procedures. Seventy-one patients with cerebral AVMs who underwent 147 embolization sessions from 2006 to 2011 were followed up prospectively (average 31.1 ± 17.5 months). Functional neurological condition was documented by means of the modified Rankin scale. Factors found to be predictors of neurological deficit were the partial obstruction of drainage veins (OR = 197.6; IC = 2.76 -1416.0; P = 0.015), a positive result in the Propofol test (OR = 50.2; IC = 6.18 - 566.5; P = 0.000), AVM diameter under 3 cm (OR = 21.3; IC: 1.71 - 265.6; P = 0.018), the presence of intranidal aneurysms (OR = 11.2; IC = 1.09 - 114.2; P = 0.042), the absence of post-procedure hypotension (OR = 10.2; IC = 1.35 - 77.7; P = 0.003), deep venous drainage (OR = 7.14; IC = 1.15 - 44.4; P = 0.035), and devascularization in excess of 40% per session (OR = 3.3; IC = 1.11 - 16.8; P = 0.056). Fifty-six patients (78.9%) did not experience changes in their neurological condition after the treatment and 13 patients (18.3%) showed a new neurological deficit related to the treatment; 95.8 % of the patients did not show significant long-term incapacity. Partial obstruction of drainage veins, small AVMs, intranidal aneurysms, faulty hemodynamic control and extensive devascularization were found to be predictors of neurological deficit. A significant number of patients with neurological deficit improved in the long term.