Autonomic Dysfunction in Neuroacanthocytosis and Causes of Sudden Death: Analysis of a Case of Chorea-Acanthocytosis with Dysautonomia

We reported a 25-year-old woman with chorea-acanthocytosis (ChAc), with typical features of lip- and tongue-biting, choreiform movements and increased levels of serum creatine phosphokinase. She presented with orthostatic hypotension, and on evaluation had a moderately decreased heart rate response to deep breathing and mildly abnormal QSART in the lower extremities. These results indicated that autonomic dysfunction in our patient was mainly due to a postganglionic lesion. Although a few previous reports have described autonomic dysfunction associated with ChAc and have indicated that impairments are primarily sympathetic, our case study suggests that there is also parasympathetic dysfunction. We hypothesize that ChAc, and possibly other neuroacanthocytosis syndromes, have post-ganglionic sympathetic neuropathy in the early stages, which results in denervation hypersensitivity to norepinephrine in heart muscle. This denervation hypersensitivity results in an increase in norepinephrine receptor density and affinity on cardiac muscle and these abnormalities may induce fatal arrhythmia.