Vertical pons hyperintensity and hot cross bun sign in cerebellar-type multiple system atrophy and spinocerebellar ataxia type 3

Table 3 Hot cross bun (HCB) sign on MRI in MSA-C, SCA3, snd controls

	Grade 1 or 2 HCB sign (vertical or cruciform hyper-intensity)	Grade 2 HCB sign (cruciform hyper-intensity)
MSA-C	38/41 (92.7%)	30/41 (73.2%)
SCA3	21/26 (80.8%)	8/26 (30.8%)
Controls	0/22 (0%)	0/22 (0%)
P value for group comparison	< 0.001^a	< 0.001^a
p value for post-hoc group comparisons
MSA-C vs. SCA3	0.141^b	0.001^a
MSA-C vs. Controls	< 0.001^a	< 0.001^a
SCA3 vs. Controls	< 0.001^a	0.004^b
MSA-C within 2 years after onset	22/24 (91.7%)	13/24 (54.2%)
SCA3 within 2 years after onset	2/4 (50.0%)	0/4 (0%)
P value	0.086^b	0.067^b
MSA-C within 3 years after onset	33/36 (91.7%)	24/36 (66.7%)
SCA3 within 3 years after onset	4/8 (50.0%)	0/8 (0%)
P value	0.014^b	0.001^b

^aChi-squared test (post-hoc chi-squared tests adjusted for multiple comparison: P < 0.05/3 = 0.0167)
^bFisher's exact probability test (post-hoc Fisher's exact probability test adjusted for multiple comparison: P < 0.05/3 = 0.0167)

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