|Year : 2019 | Volume
| Issue : 1 | Page : 131-133
Differential diagnosis of hot cross bun sign
Jamir Pitton Rissardo, Ana Letícia Fornari Caprara
Department of Medicine, Federal University of Santa Maria, Santa Maria, RS, Brazil
|Date of Web Publication||12-Jun-2019|
Mr. Jamir Pitton Rissardo
Department of Medicine, Federal University of Santa Maria, Santa Maria, RS
Source of Support: None, Conflict of Interest: None
Multiple system atrophy (MSA) is a term that represents a group of neurodegenerative diseases characterized by different levels of autonomic, cerebellar, parkinsonism, and pyramidal features. Hereinafter, we report a case of an elderly male who presented to our hospital with progressive gait instability and slurred speech. On examination, an orthostatic decrease of blood pressure of standing was observed. The neurological examination showed cerebellar signs and symptoms. A brain magnetic resonance imaging showed radiologic findings of MSA. The diagnosis of probable MSA with predominant cerebellar ataxia was made.
Keywords: Hot cross bun, magnetic resonance imaging, multiple system atrophy
|How to cite this article:|
Rissardo JP, Fornari Caprara AL. Differential diagnosis of hot cross bun sign. Arch Med Health Sci 2019;7:131-3
A 59-year-old male presented to our hospital with progressive gait instability and slurred speech. The subject stated that he had gone to another clinic 2-year ago because he had experienced postural faintness recurrently. The physical examination at that time was normal. Laboratory tests and echocardiogram were within normal limits. The diagnosis of orthostatic hypotension due to dehydration was made.
On admission, he reported that faintness remained; also, he mentioned the motor symptoms and urinary incontinence with more than 1 year of onset. He was previously healthy and his family history was unremarkable. The neuropsychological assessment was normal. On examination, an orthostatic decrease of blood pressure of standing was observed. The neurological examination showed ataxic gait, slurred speech, nystagmus, and dysdiadochokinesia. In addition, he also manifested mild bradykinesia and resting tremor bilaterally. Laboratory tests and cerebrospinal fluid were within normal limits. A cranial computed tomography scan was normal. A brain magnetic resonance imaging [Figure 1] showed radiologic findings of multiple system atrophy (MSA). Levodopa was started. However, the subject had a poor response to therapy, and levodopa was stopped. The diagnosis of probable MSA with predominant cerebellar ataxia was made. Symptomatic treatment was instituted with partial improvement of the symptoms.
|Figure 1: Neuroimages showing radiographic features of multiple system atrophy. Axial Gd T1-weighted (a), axial T2-weighted (c), axial FLAIR (e), and axial merged fast field echo (h) revealing the classic “hot cross bun” sign in the pons. Sagittal Gd T1-weighted (b) and FLAIR (d) disclosing pontine and cerebellar atrophy. Axial FLAIR (f) exhibit abnormally high linear rim surrounding the putamen (putaminal rim sign). Axial apparent diffusion coefficient (g) depicting higher values in the putamen. Hot cross bun figure (i). FLAIR: Fluid-attenuation inversion recovery, Gd: Gadolinium-enhanced|
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| Discussion|| |
MSA is a term that represents a group of neurodegenerative diseases characterized by different levels of autonomic, cerebellar, Parkinsonism More Details, and pyramidal features. In this context, there are three clinical syndromes: MSA with predominant cerebellar ataxia, MSA with predominant parkinsonism (MSA-P), and MSA with predominant autonomic signs and symptoms. However, these clinical subtypes share common histopathological changes, characterized by neuronal loss, gliosis, and the presence of glial cytoplasmic inclusions with alpha-synuclein. Therefore, the diagnosis of MSA is based on clinical features with the radiological features such as the hot cross bun (HCB) and middle cerebellar peduncle signs being supportive for the diagnosis of this entity. Moreover, it is worthy to mention that the characteristic findings on routine magnetic resonance imaging (MRI) can contribute to the differentiation among the akinetic-rigid syndromes.
HCB sign refers to the cruciform-shaped of the pons on MRI. The name of the sign derives from a spiced sweet bun, marked with a cross at the top, and traditionally eaten on Good Friday. The HCB sign probably occurs due to selective loss of transverse pontocerebellar fibers and neurons in the pontine raphe without pontine tegmentum and corticospinal tracts being affected., Although first described in MSA individuals and be more commonly related with the predominant cerebellar ataxia form, it is not pathognomonic of this disease. HCB sign has already been described in individuals with other diseases [Table 1].,,,,,, Furthermore, we agree with the statement of Way et al. that probably any cause of pontocerebellar degeneration would result in the HCB sign.
Other MRI signs present in some neurological diseases almost look alike the HCB sign. First, the “Mercedes-Benz” or “trident” sign that is associated with Wilson's disease and central pontine myelinolysis. This finding represents the central pontine myelinolysis trisected with preferential involvement of transverse pontine fibers. Second, the inverse trident sign reported secondary to neurosarcoidosis at the level of upper pons. Third, the reverse HCB sign, which is a cruciform hypointensity quadrisecting the pontine hyperintensities, related to Wilson's disease.,
The putaminal rim sign, also known as the putaminal slit sign, was other MRI feature of the present case. This signal demonstrates the appearance of a linear region of high signal surrounding the lateral aspect of the putamen at MRI on T2-weighted or apparent diffusion coefficient. Nevertheless, it is more associated with MSA-P could be found in the others MSA clinical syndromes.,
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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