Palsy of the hypoglossal nerve is frequently associated with other cranial nerve palsies and can be related to vascular, neoplastic, infectious or traumatic conditions. Isolated hypoglossal nerve palsy is quite rare and very few cases have been reported in the literature to date 1).
Intracranial juxtafacet (ganglion and synovial) cysts compressing the hypoglossal nerve should be considered in the differential diagnosis with other lesions of this region 2).
Isolated paralysis of the hypoglossal nerve due to atlanto-occipital joint cysts 3).
A isolated left hypoglossal nerve palsy secondary to compression from a prominent degenerative osteophyte from the left atlanto-occipital joint 4)
A 54-year-old woman with a 5-month history of headache and weakness of the tongue with deviation to the left side who had a rare extraneural intradural bilobate ganglion cyst of the atlanto-occipital joint compressing the hypoglossal nerve. An MRI showed a bilobate cystic lesion in the premedullary cistern on the left side at the level of the hypoglossal canal. This lesion was removed using a lateral suboccipital approach in the semi-sitting position with removal of the C1 hemiarch. The lesion proved to be a ganglion cyst on histopathology 5).
Atlanto-occipital joint cyst revealed by hypoglossal nerve palsy in a 75-year-old woman. Due to the paucity of neurological signs and the patient's advanced age, she was managed conservatively; 8 months later the cyst resolved completely. They discuss the potential factors involved in the pathogenesis and the therapeutic options for this uncommon cervical entity. We advise conservative treatment as a first therapeutic option for SC without signs of spinal cord compression 6).