“Hot cross bun” sign resembling multiple system atrophy in a patient with Machado-Joseph disease

“Sinal da cruz” mimetizando atrofia de múltiplos sistemas em um paciente com doença de Machado-Joseph

Figure. 1
Axial T2* weighted brain MRI (A and B) showing the “hot cross bun” sign in the pons and cerebellar and brainstem atrophy. Wallerian degeneration was also observed, characterized by marked hyperintensity in the pontocerebellar fibers (arrow). Axial fluid-attenuated inversion recovery (FLAIR) (C) and sagittal T1 (D) reinforce olivopontocerebellar atrophy, but no hyperintensity was observed in the pontocerebellar fibers. Supratentorial images showed no atrophy or abnormal sign in the basal ganglia.

A 59-year-old woman presented with a 9-year history of progressive gait instability. She also had rapid-eye movement (REM) sleep behavior disorder and urinary incontinency. Neurological examination revealed ataxia and nystagmus. Brain magnetic resonance imaging showed the “hot cross bun” sign in the pons, as well as cerebellar and brainstem atrophy. Multiple system atrophy (MSA) was suspected, but family history was remarkable for an autosomal inherited ataxia. Genetic testing was positive for Machado-Joseph disease (MJD), which is the most common autosomal dominant spinocerebellar ataxia.

MJD may present with REM sleep behavior disorder and dysautonomia, similar to MSA, but to a lesser extent¹–³. The “hot cross bun” sign is rarely found in MJD patients (1.3%), but it is a frequent brain imaging feature in MSA⁴. In this case, a detailed familial investigation was crucial to guide the diagnosis, as MJD is an autosomal dominant inherited ataxia, and MSA is sporadic.

References

• ¹
  Pedroso JL, Braga-Neto P, Felício AC, et al. Sleep disorders in cerebellar ataxias. Arq Neuropsiquiatr 2011;69:253-257.
• ²
  Pedroso JL, Braga-Neto P, Felício AC, et al. Sleep disorders in Machado-Joseph disease: frequency, discriminative thresholds, predictive values, and correlation with ataxia-related motor and non-motor features. Cerebellum 2011;10:291-295.
• ³
  França MC Jr, D’Abreu A, Nucci A, Lopes-Cendes I. Clinical correlates of autonomic dysfunction in patients with Machado-Joseph disease. Acta Neurol Scand 2010;121:422-425.
• ⁴
  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;16:513-516.

Publication Dates

• Publication in this collection
  Oct 2013

History

• Received
  14 Oct 2012
• Reviewed
  14 May 2013
• Accepted
  21 May 2013