Arteriovenous malformation of the trigeminal nerve root presented with venous congestive edema of the medulla oblongata and upper cervical cord: illustrative case

Abstract

BACKGROUND Arteriovenous malformation (AVM) of the trigeminal nerve root (TNR) is a rare subtype of the lateral pontine AVM. Most of them are diagnosed when they bleed or exert trigeminal neuralgia. Venous congestive edema is a rare phenomenon caused by TNR AVMs. OBSERVATIONS An 82-year-old man was admitted with progressive limb weakness and dysphasia. Magnetic resonance imaging (MRI) revealed extensive edema of the medulla oblongata and the upper cervical cord with signal flow void at the C3 anterior spinal cord. Vertebral angiography revealed a small nidus fed mainly by the pontine perforating arteries (PPAs). The anterior pontomesencephalic vein (AMPV) was dilated, functioning as the main drainage route. This suggests that venous hypertension triggered the brainstem and upper cervical cord edema. MRI with gadolinium enhancement showed that the nidus was located around the right TNR. Because the nidus sat extrinsically on the pial surface of the right TNR’s base, microsurgical obliteration with minimum parenchymal injury was achieved. Postoperative MRI showed disappearance of the brainstem and cervical cord edema with improved clinical symptoms. LESSONS TNR AVM is rarely associated with brainstem and upper cervical cord edema caused by venous hypertension of the congestive drainage system.

Case report: A choroidal fissure pial arteriovenous malformation inducing venous congestive edema of the medulla oblongata and cervicothoracic spinal cord presented with proximal arm predominant weakness

“…Here, we present a rare case of a choroidal fissure pial arteriovenous malformation (AVM) with exclusive spinal venous drainage that induced venous congestive edema of the medulla oblongata and the cervicothoracic spinal cord. To the best of our knowledge, only one case of infratentorial trigeminal nerve root pial AVM-associated myelopathy has been reported, whereas no cases of supratentorial pial AVM-causing myelopathy have been described ( 7 ). In contrast to the intracranial DAVF, in which patients mainly present with ascending myelopathy ( 1 – 5 ), our patient presented with pronounced arm weakness with minimal leg involvement 2 months after the onset of symptoms.…”