Cervical lower motor neuron syndrome caused by cervicothoracic dural arteriovenous fistula: illustrative case

BACKGROUND Brachial nerve palsy without sensory impairment is called cervical lower motor neuron syndrome (CLMNS), and differential diagnosis can be difficult. OBSERVATIONS A 50-year-old man presented with left brachial nerve palsy (C7, C8, and T1). Neuroradiological imaging findings showed a dural arteriovenous fistula at the cervicothoracic junction. Symptoms were promptly alleviated by direct shunt occlusion via a microsurgical procedure. LESSONS Cervical spinal venous malformations presenting with CLMNS are very rare. It is essential to perform a differential diagnosis and determine surgical treatment based on an understanding of vascular anatomy. https://thejns.org/doi/10.3171/CASE25353