High Resolution MRI of Vestibulocochlear Nerve Involvement by a Posterior Fossa Ganglioglioma: Case Report and Review of Literature

Excerpt

White matter tracts from brainstem cranial nerve (CN) nuclei are organized within the brainstem in axonal bundles before emerging from the brainstem as individual CN. The CN transitional zone (TZ) is the segment of the CN where transition from the myelinated axons of oligodendrocytes to the more robust fascicular organization of the peripheral nervous system myelinated by Schwann cells occurs [1, 2]. In rare cases, brainstem glial tumors have been observed to involve the TZ manifesting as asymmetric thickening and enhancement on magnetic resonance imaging (MRI). We present a case of brainstem ganglioglioma with involvement of the proximal cisternal segment of the vestibulocochlear nerve. To the best of our knowledge, this is the first reported case of a posterior fossa ganglioglioma with CN involvement. The unique combination of MRI findings and clinical data provide insights into the pathophysiologic mechanism of CN involvement by glioma. …