Isolated Hypoglossal nerve palsy due to amyloid cervical arthropathy in long term hemodialysis

Sirs: Isolated peripheral hypoglossal nerve palsy is rare and it is caused by primary or secondary tumors of the skull base, leptomeningeal metastases, trauma, carotid artery dissection, surgery or aneurysms of the carotid artery, dural arteriovenous fistula, Chiari malformation, otorhinolaryngological and anesthesiological procedures, radiation, infectious diseases (borreliosis, mononucleosis) and rarely an anomalous vertebral artery course [1,2]. To our knowledge we report the first case of XIIth nerve palsy due to compression by uremic arthropathy. A 69 year-old woman was admitted for a subacute onset of a continuous stabbing pain of the right cervical and occipital regions, associated with difficulty in moving her tongue and in articulating words. Neurological examination showed only mild dysarthria and right hypoglossal nerve palsy, with right hemiatrophy of the tongue (Fig. 1). The patient had required of hemodialytic treatment beginning 14 years ago because of end-stage renal disease secondary to non-steroidal antinflammatory drugs abuse for migraine, and, since then, she had undergone four surgical interventions for total hip arthroplasty and also for bilateral carpal tunnel syndrome. Brain CT was normal. Doppler ultrasound and MR angiography of supraortic vessels excluded the presence of carotid artery dissection. Neoplastic, autoimmune, rheumatological, and infectious diseases were excluded with appropriate tests. Brain and cervical MRI showed the presence of periodontoid soft tissue, hypointense in T1 and T2weighted images, without gadolinium enhancement, extending from the C2 dens, mainly on the right, and reaching the foramen magnum and the medial surface of occipital condyle (Figure 2). This tissue involved the hypoglossal nerve before it entered the hypoglossal canal and occupied the medullary cistern without compressing the medulla. The picture was consistent with synovial hypertrophy. Skull base CT showed small erosions of the dens with well-defined lytic areas (geodes), without atlanto-axial dislocation. Disc herniation, narrowing of the intervertebral space, bone erosion, geodes and mild ankylosis were also detected at the cervical level by CT and MRI. The picture was consistent with destructive spondyloarthropathy (DSA) due to chronic uremia.