Neuropathy of the phrenic nerve associated with antiganglioside antibodies.

BACKGROUND AND PURPOSE: Antiganglioside antibodies have been implicated in several autoimmune-mediated neuropathies, and binding of these antibodies can result in inflammatory changes of the nerves. Diaphragmatic paralysis is a rare condition, mostly arising from diseases affecting the phrenic nerve, neuromuscular junction, or skeletal muscle. OBJECTIVES: In this case series, we identified five patients with diaphragmatic paralysis due to unilateral or bilateral neuropathy of the phrenic nerve associated with the presence of antiganglioside antibodies (immunoglobulin G anti-GT1a antibodies and immunoglobulin M anti-GM1 antibodies). DISCUSSION: The combination of an isolated phrenic nerve palsy with anti-GM1 antibodies has only once been described. On the other hand, the association of anti-GT1a antibodies with phrenic nerve palsy has never been reported before. CONCLUSIONS: We report an association between phrenic nerve palsy and the presence of antiganglioside antibodies, but it remains unclear if there is a causal relationship. Further studies are needed to explore this matter.

Paraneoplastic tumefactive demyelination in a 47-year-old man with underlying seminoma.

BACKGROUND: Tumefactive demyelination presents as an aggressive, fast progressive focal demyelinating lesion in the central nervous system, with often devastating clinical outcome if not acutely treated. Correct and early treatment is threatened by its real diagnostic challenge. CASE REPORT: We describe a 47-year-old man with tumefactive demyelination and testicular seminoma. He presented with aphasia, cognitive impairment and right sided weakness of the arm and lower face. MRI revealed a lesion characteristic of tumefactive demyelination. Cerebral biopsy confirmed this diagnosis. In addition, a testicular seminoma was diagnosed. Temporal association of demyelination and malignancy was highly suggestive for a paraneoplastic syndrome. He responded well to corticosteroid therapy plus orchiectomy, but a behavioral disturbance remained. DISCUSSION: A good knowledge of specific imaging characteristics of tumefactive demyelination can help in early diagnosis. Multiple underlying causes should be considered, including, but not limited to multiple sclerosis. A paraneoplastic syndrome should not be overlooked. This is the fifth case in which seminoma is associated with a paraneoplastic tumefactive demyelination lesion.