Isolated hypoglossal nerve palsy

We describe a case of isolated idiopathic hypoglossal nerve palsy in a young male patient and discuss several of the aetiopathogenic mechanisms which may cause this entity. Our patient was a 36-year-old man with no relevant medical history who attended the emergency department with a tongue motility disorder, which caused difficulty chewing food. A week before, he developed a right-sided hemicranial headache, reported to be of moderate-high intensity, starting in the cervical region and radiating to the occipital region; he did not present nausea, vomiting, photophobia, or phonophobia. The previous day, he had experienced discomfort in the right pharyngeal region, which he described as an oppressive and inflammatory sensation. The neurological examination revealed right-sided deviation of the tongue; the patient had difficulty moving it further to the right (Fig. 1). An examination of the remaining cranial nerves, motor function, sensitivity, static coordination, and gait revealed no abnormal findings. The general physical examination obtained normal results, with no palpable pathological peripheral adenopathies. We performed an analytical study including a complete blood count, urea, creatinine, uric acid, electrolytes, transaminases, alkaline phosphatase, LDH, total and direct bilirubin, creatin kinase, C reactive protein (CRP), rheumatoid factor, and angiotensin-converting enzyme (ACE). As part of the autoimmunity study, we requested anti-nuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA) tests, as well as serology tests for HIV, EBV, HSV, and VZV. A lumbar puncture was performed; CSF samples were sent for cytobiochemical study, Tibbling index, oligoclonal band testing, microbiological studies, and serology tests. All these parameters were normal or negative. A chest radiography showed no pathological findings. A head magnetic resonance imaging (MRI) scan only revealed a cyst of the septum pellucidum. MRI angiography of the