Pontine hot cross bun sign in spinocerebellar ataxia type 2

“Sinal da cruz” na ponte na ataxia espinocerebelar tipo 2

A 27-year-old man presenting with 11 years of progressive gait ataxia, imbalance, hand dexterity impairment, dysarthria, and urinary frequency.

Examination showed slow saccades, dysarthria, head and upper extremities tremor, dysmetria, and gait ataxia.

Brain MRI (Figure 1) showed severe pontocerebellar atrophy with hot cross bun sign.

Figure 1.
(A) Brain MRI showing severe pontocerebellar atrophy in sagittal T1-weighted imaging; (B and C) cruciform hyperintensity in the pons, the hot cross bun sign, in axial T2 FLAIR imaging reflecting selective degeneration of pontocerebellar tracts.

A genetic study revealed a heterozygous 43 CAG repeat expansion of the ATXN2 gene compatible with spinocerebellar ataxia type 2 (SCA2).

The hot cross bun sign was classically regarded as a typical neuroimaging finding of the cerebellar variant of multiple system atrophy. However, it is not pathognomonic, having been described in other degenerative disorders manifesting ataxia^1,2,3.

References

• ¹
  Lee YC, Liu CS, Wu HM, Wang PS, Chang MH, Soong BW. The ’hot cross bun’ sign in the patients with spinocerebellar ataxia. Eur J Neurol. 2009 Apr;16(4):513-6. https://doi.org/10.1111/j.1468-1331.2008.02524.x
  » https://doi.org/https://doi.org/10.1111/j.1468-1331.2008.02524.x
• ²
  Gooneratne IK, Caldera MC, Perera SP, Gamage R. Hot cross bun sign in a patient with cerebellar ataxia. Ann Indian Acad Neurol. 2013;16(3):406. https://doi.org/10.4103/0972-2327.116973
  » https://doi.org/https://doi.org/10.4103/0972-2327.116973
• ³
  Meira AT, Arruda WO, Ono SE, Carvalho Neto A, Raskin S, Camargo CH, et al. Neuroradiological findings in the spinocerebellar ataxias. Tremor Other Hyperkinet Mov (NY). 2019 Sep;9:10.7916/tohm.v0.682. https://doi.org/10.7916/tohm.v0.682
  » https://doi.org/https://doi.org/10.7916/tohm.v0.682

Publication Dates

• Publication in this collection
  26 Oct 2020
• Date of issue
  Oct 2020

History

• Reviewed
  16 Apr 2020
• Received
  06 May 2020
• Accepted
  25 May 2020