# Jugular Paraganglioma Presenting As Isolated Hypoglossal Nerve Palsy: An Anatomical Enigma

## TL;DR

A rare case of isolated hypoglossal nerve palsy caused by a jugular paraganglioma highlights the importance of considering this tumor in unusual neurological presentations.

## Contribution

This case report presents a rare anatomical presentation of jugular paraganglioma causing isolated hypoglossal nerve palsy without typical syndromic features.

## Key findings

- MRI confirmed a vascular lesion in the left jugular foramen extending into the hypoglossal canal.
- The absence of cranial nerves IX, X, and XI involvement ruled out Collet-Sicard syndrome.
- Non-invasive management was chosen due to the patient's stability and risks of surgery.

## Abstract

Hypoglossal nerve palsy is most commonly associated with trauma, tumors, or vascular insults affecting the skull base, but isolated palsy due to jugular paraganglioma is extremely rare. We present the case of a woman in her 40s with progressive dysarthria and isolated left hypoglossal nerve palsy. MRI revealed a vascular lesion localized in the left jugular foramen with extension into the hypoglossal canal, sparing the adjacent lower cranial nerves. The absence of involvement of cranial nerves IX, X, and XI ruled out a complete Collet-Sicard syndrome. Imaging characteristics and anatomical correlation were clearly consistent with a jugular paraganglioma. Given the slow progression, high morbidity associated with surgical resection, and the patient's clinical stability, a deep discussion by a multidisciplinary team recommended non-invasive management. Although stereotactic radiosurgery and succinate dehydrogenase (SDH) mutation testing were offered, the patient declined both and opted for clinical surveillance. This case underscores the importance of considering jugular paragangliomas in the differential diagnosis of isolated cranial neuropathies, especially when typical syndromic presentations are absent. The selective involvement of the hypoglossal nerve without apparent and concurrent dysfunction of adjacent lower cranial nerves represents a rare anatomical enigma, likely explained by the spatial relationships and embryological separation between the hypoglossal and jugular foramina. High-resolution imaging and collaborative multidisciplinary decision-making remain essential in tailoring patient-centered treatment strategies for skull base tumors.