Hot cross bun sign and prominent cerebellar peduncle involvement in a patient with oculodentodigital dysplasia

A Review on Radiologic Hot Cross Bun Sign and Related Clinical Conditions

The hot cross bun (HCB) sign is a cruciform-shaped hyperintensity on axial T2 weighted-image magnetic resonance imaging (MRI), mostly reported with multiple system atrophy (MSA). However, several other diagnoses were reported with this radiologic manifestation as well. This review investigates the wide spectrum of disorders in which the HCB sign has been reported as a positive radiologic manifestation. This narrative review was conducted using the PubMed database. Studies reporting the HCB sign in their manuscript are included in this manuscript. 83 studies with available full text met the inclusion criteria for this review. The total number of reported patients with HCB sign is addressed in the manuscript. In addition to MSA, the HCB sign has been reported in various other disorders, including spinocerebellar ataxia, malignancies, infections, autoimmune disorders, and some vascular and ischemic changes. Any disorder involving the pontocerebellar fibers can manifest the HCB sign following the gliosis changes or infarction-mediated damage to the region, whether due to gliosis changes. The range of diseases linked to the HCB sign is broader than previously recognized, as numerous disorders affect the transverse pontocerebellar fibers and cause radiologic HCB manifestation. MSA remains the most common condition; however, clinicians should consider alternate differential diagnoses in patients displaying the HCB sign in whom clinical presentation is not typical of MSA.

Oculo-dento-digital dysplasia: a systematic analysis of published dental literature

INTRODUCTION

Oculo-dento-digital dysplasia (ODDD, OMIM# 164200) is a rare genetic disorder caused by mutation in Gap junction alpha gene that encodes connexin 43 (Cx43) protein. In this paper, the case of a 16-year-old boy is reported who presented with the complaint of toothache. Examination revealed unusual facial features, i.e., long narrow nose, hypertelorism, prominent epicanthal folds along with syndactyly and camptodactyly. We have also compiled available dental literature on ODDD that will help clinicians in early diagnosis and management of this condition.

MATERIALS AND METHODS

A literature search was performed in PubMed NLM, EBSCO Dentistry & Oral Sciences Source, and EBSCO CINAHL Plus.

RESULTS

A total of 309 articles were identified in the literature search. Only 17 articles were included based on the predetermined inclusion and exclusion criteria in the review synthesis. The included articles were case reports (n = 15), a case report and review (n = 1), and an original article (n = 1). Enamel hypoplasia, hypomineralization, microdontia, pulp stones, curved roots, and taurodontism were common dental findings in ODDD.

CONCLUSIONS

After establishing definitive diagnosis, a multidisciplinary team should work in cohesion to improve the quality of life of patients. Immediate treatment should be focused on the correction of current oral condition and symptomatic treatment. In the long term, attention should be diverted to prevent tooth wear and maintaining the occlusal vertical dimension to establish adequate function.

The "Hot Cross Bun Sign" in Spinocerebellar Ataxia Types 2 and 7-Case Reports and Review of Literature

Background

The "hot cross bun" sign is a cruciform hyperintensity is seen on T2 weighted imaging within the pons. The sign is considered to be pathognomic for Multiple system atrophy type C. The clinical and radiological features of Multiple system atrophy type C overlap with the autosomal dominant inherited ataxias. We present a case series of 3 African patients with genetically proven Spinocerebellar Ataxia presenting with the Hot cross bun sign and a scoping review of similar studies.

Cases

We described the phenotypic and radiological presentation of genetically confirmed SCA-2 in two, and SCA-7 in one patient, with the "hot cross bun" sign.

Literature Review

We performed a scoping review on the Hot Cross Bun Sign.A total of 66 articles were retrieved. We describe the diverse aetiologies of the sign and associated phenotypic and radiological features. We review the Spinocerebellar Ataxias described with a Hot cross bun sign and make comparisons to Multiple System Atrophy Type C [Ref. 1,2].

Conclusions

To our knowledge this is the first description of an African cohort presenting with the Hot Cross Bun Sign. We expand the differential diagnosis of the Hot Cross Bun Sign.

The “hot cross bun sign” in patients with autoimmune cerebellar ataxia: A case report and literature review

Objectives

The “hot cross bun sign” (HCBs) on magnetic resonance imaging (MRI) has been initially considered specific for multiple system atrophy with cerebellar features. However, a number of other conditions have since been described, which may be associated with this imaging sign. We herein describe a patient with anti-Ri and paraneoplastic cerebellar ataxia, and review the association of the HCBs on imaging with various neurological autoimmune conditions.

Methods

We report a 40-year-old woman with anti-Ri-associated paraneoplastic neurological syndrome and breast carcinoma, in whom brain MRI revealed the HCBs late in the disease course. We also reviewed similar cases reported in the literature.

Results

The patient presented with cerebellar ataxia, polyneuropathy, and pyramidal signs. Although brain MRI was initially unremarkable, the HCBs and T2-weighted hyperintensity of the bilateral middle cerebellar peduncles were observed at later follow-up. Anti-Ri was detected in the serum and cerebrospinal fluid. Breast adenocarcinoma was confirmed via an axillary lymph node biopsy. Her symptoms partially resolved after the first corticosteroid pulse. However, subsequent immunotherapy and tumor treatments were ineffective. Four autoimmune cerebellar ataxia cases with the HCBs (two paraneoplastic and two non-paraneoplastic) were identified in the literature.

Discussion

The HCBs can be associated with paraneoplastic and non-paraneoplastic cerebellar ataxia, which may reflect neurodegeneration secondary to autoimmune injury. Thus, the HCBs should not be considered a contraindication for autoimmune cerebellar syndrome.