Hypoglossal nerve palsy after SARS-CoV-2 vaccination - report of two cases

Background SARS-CoV-2 vaccination is associated with an increased risk for Bell's palsy and some other neurological disorders assumed to be of autoimmune origin. While facial nerve palsy is frequent and usually idiopathic, hypoglossal nerve palsy is rare, and a specific cause is almost always found. We firstly report two patients who developed isolated hypoglossal nerve palsy shortly after SARS-CoV-2 vaccination. Case presentation Two otherwise healthy patients, a 49-year-old man and a 39-year-old woman, developed unilateral hypoglossal nerve palsy 10 and 7 days after the second SARS-CoV-2-vaccination (AstraZeneca and BioNTech/Pfizer), respectively. In both subjects, needle electromyography showed denervation and rarefication of motor units. CT, MRI, examination of blood and CSF as well as ENT exam were unremarkable. In both subjects symptoms gradually improved. Conclusion Due to close temporal relationship, the absence of other etiologies, and spontaneous improvement we suspect the vaccination as the cause for hypoglossal nerve palsy in both patients. This is further supported by the rarity of isolated hypoglossal nerve palsies, especially in idiopathic cases. We suggest the addition of hypoglossal nerve palsy to the list of neurological injuries potentially caused by SARS-CoV-2 vaccination.