Brain Arteriovenous Malformations Located in Premotor Cortex: Surgical Outcomes and Risk Factors for Postoperative Neurologic Deficits

OBJECTIVE: The premotor cortex (PMC) is known to have a dual role in movement and language processing. Nevertheless, surgical outcomes of brain arteriovenous malformations located in PMC (PMC-BAVMs) have not been well defined. The aim of this study was to determine surgical outcomes and risk factors for neurologic deficits (NDs) after surgery in patients with PMC-BAVMs. METHODS: We retrospectively reviewed patients with PMC-BAVMs who underwent surgical resection of the nidus. All patients had undergone preoperative functional magnetic resonance imaging, diffusion tensor imaging, magnetic resonance imaging, three-dimensional time-offlight magnetic resonance angiography, and digital subtraction angiography. Functional and angioarchitectural factors were analyzed with respect to postoperative NDs. Function-related fiber tracts, corticospinal tract, and dominant arcuate fasciculus were tracked. Lesion-to-fiber distance was measured. RESULTS: We identified 36 patients with PMC-BAVMs. Radical resection was achieved in all patients. Four patients (11.1%) presented with limb-kinetic apraxia and bradykinesia. Short-term NDs developed in 12 (33.3%) patients, among which 6 developed aphasias and 7 developed muscle weakness. A shorter lesion-to-eloquent fiber distance (P = 0.012) and larger nidus size (P = 0.048) were significantly associated with short-term NDs. Long-term NDs occurred in 5 patients. Larger nidus size was significantly associated (P = 0.015) with long-term NDs. CONCLUSIONS: Varying degrees of motor and language deficits can be induced immediately after resection of PMC-BAVMs. Permanent and long-term severe motor or language deficits are rare. Shorter lesion-to-eloquent fiber distance is a risk factor for short-term NDs. Larger nidus size is a risk factor for short-term and long-term NDs.