Pontine Atrophy in Spinocerebellar Ataxia Type 6

Abstract

To investigate the clinical range of spinocerebellar ataxia type 6 (SCA6), we screened CAG repeat expansion in the voltage-dependent alpha 1A calcium channel gene (CACNL1A4) in 71 ataxic patients in 60 families; 54 patients in 43 families with hereditary ataxia and 17 sporadic patients. Thirteen patients with SCA6 were detected to have elongated CAG in CACNL1A4. Of these, 7 patients had been diagnosed as having hereditary cerebellar cortical atrophy, and 6 patients had been found to have sporadic occurrence. One patient showed distinct pontine atrophy with prominent horizontal or oblique gaze nystagmus which is an unusual feature in sporadic olivopontocerebellar atrophy. For the efficient screening of SCA6, we would propose testing CAG repeat expansion in CACNL1A4, in patients with one of two markers: (1) horizontal or oblique gaze nystagmus without other eye movement disorders, (2) pure cerebellar atrophy, even if occurrence is sporadic. We should note that the pontine atrophy could also be caused by CAG repeat expansion in CACNL1A4.

Pontine atrophy precedes cerebellar degeneration in spinocerebellar ataxia 7: MRI-based volumetric analysis

“…In this study, we observed severe pontine atrophy in the patients with SCA7; this was much more prominent than in other types of SCA (SCA3 and SCA6) and was consistently found in patients with varying degrees of cerebellar atrophy and severity of illness. Pontine atrophy has been reported in other SCAs, even in SCA6, 18 although it is quite unexpected for such patients to have pontine atrophy with their cerebellum spared, which we found in our patients with SCA7. All patients with SCA7 may not have the neuroradiological characteristics observed in this study, yet pontine atrophy was a prominent finding in our patients with SCA7.…”

Clinical and Neuroradiological Features of Patients With Spinocerebellar Ataxias From Korean Kindreds

“…Therefore, MRI results may enable physicians to conjecture the underlying mutations and to direct gene testing for these mutations. Pontine atrophy has been reported in other types of SCA, including SCA6 35,36 ; however, it is exceptional for such patients to have pontine atrophy with their cerebellum spared, which was observed in our patients with SCA7.…”

Biochemical changes in the brain of hemiplegic migraine patients measured with 7 tesla 1H-MRS

“…Interestingly, the CACNA1A gene is also implicated in two other disorders, namely episodic ataxia type 2 (EA2) and chronic spinocerebellar ataxia type 6 (SCA6) (17,18). Both phenotypes also involve progressive cerebellar ataxia and atrophy (19–21). In a small MRS study no differences were found in cerebellar tNAA/tCre ratios between EA2 patients and controls possibly because of lack of power (22), whereas MRS studies focusing on SCA6 showed a lower cerebellar tNAA/tCre ratio (23,24).…”