Evolution of a channelopathy, CACNA1 mutation in a young man

We report a 17-year-old young man, who presented again to our neuropediatric clinic after 16 years. In infancy, he had been diagnosed with severe muscular hypotonia and a benign paroxysmal tonic upgaze in childhood (PTUC), which had subsided and vanished during childhood as expected. Secondary findings were a questionable jactatio capitis at the age of 5 years, which also was described as a tic disorder. As a school child, he had shown mild mental retardation but was able to attend a regular school. At the age of 16 years, he presented a paroxysmal postural vertigo for the first time, leading to nausea and considerable ataxic gait pattern, combined with a distinctly slurred speech, which was interpreted as ataxic dysarthria as well. The symptoms lasted for a few hours and subsided without any treatment. Since then, he suffered from 1 to 2 attacks every month. The neurologic examination revealed hypermetric saccadic eye movements and only mild ataxic gait and stand. Otherwise, his examination was normal. A diagnosis of episodic ataxia type II (EAII) was suspected from history (paroxysmal ataxia, PTUC) and clinical observations (mild ataxia) and was confirmed by mutation analysis of CACNA1. The combination of paroxysmal ataxia and PTUC is pathognomic for EAII and shows the evolution of a channelopathy from infancy to adulthood. Epidemiologic evidences concerning the role of CACNA1 in PTUC are still lacking.