Author Affiliations: Neuroscience Institute, Advocate Christ Medical Center, Oak Lawn (Dr Kapur); and Section of Parkinson Disease and Movement Disorders, Department of Neurological Sciences, Rush University Medical Center, Chicago (Dr Goldman), Illinois.
We appreciate this report of a second patient who carries genetic mutations for both spinocerebellar ataxia types 2 (SCA2) and 10 (SCA10). These 2 unusual cases exhibit a gradually progressive cerebellar ataxia syndrome plus features specifically associated with SCA2 (ie, slowed saccades) and SCA10 (ie, seizures). Our case also had mild cognitive deficits, sensory neuropathy, and muscle cramps, which are more typical of SCA2. Neither case exhibited parkinsonism, which has been reported in SCA2 cases.1 Hyperkinetic movement disorders have not been associated with SCA2 or SCA10 but may occur in other SCAs (eg, in SCA3, SCA6, SCA7, SCA14, SCA15, and SCA17), particularly as chorea, dystonia, myoclonus, or tremor.2 However, tics, which are often included in the differential diagnosis for hyperkinetic movement disorders, are unusual in SCAs, reported in 1 patient with SCA25.3 Therefore, in our view, the motor and phonic tics reported in the case by Baizabal-Carvallo and Jankovic are most likely coincidental. However, additional information regarding a family history of tics or comorbidities associated with tic disorders may help elucidate the relationship of his tics and SCAs.
Kapur SS, Goldman JG. Spinocerebellar Ataxia Types 2 and 10: More Than a Coincidental Association?—Reply. Arch Neurol. 2012;69(11):1524–1525. doi:10.1001/archneurol.2012.2771