The correlation between magnetic resonance imaging features of the brainstem and cerebellum and clinical features of spinocerebellar ataxia 3/Machado-Joseph disease.(Original Article)(Report)

Byline: Xiaochun. Liang, Hong. Jiang, Changqing. Chen, Gaofeng. Zhou, Junling. Wang, Shen. Zhang, Liwang. Lei, Xiaoyi. Wang, Beisha. Tang

Background : Brainstem and cerebellar atrophy are the most important features in magnetic resonance imaging (MRI) in spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD). However, the correlation between brainstem and cerebellar atrophy and the clinical features has not been well studied. Aim : To study the correlation between MRI features of the brainstem and cerebellum and predominant clinical features in SCA3/MJD. Design and Setting : University teaching hospital. Patients and Methods : By using the linear measurement method, we assessed 32 patients with SCA3/MJD to study the correlations between the morphometric data of the brainstem and cerebellum and clinical features: Duration of the disease, age of onset, total international cooperative ataxia rating scale (ICARS) score; total scale for the assessment and rating of ataxia (SARA) score; ICARS subscores, and SARA subscores. Statistical Analysis : Pearson correlation test. Results : There was a significant invese correlation between anteroposterior diameter of the midbrain and pons and total ICARS scores, total SARA scores, ICARS and SARA subscores (r= -0.381~-0.57, P < 0.05 or 0.01) and disease duration (r=- 0.42~-0.51, P < 0.05 or 0.01). Additionally, superoinferior diameter of the cerebellum was inversely correlated with total SARA scores and ICARS and SARA subscores except for ataxia of posture and gait in both scales (r=- 0.37~-0.44, P < 0.05). The superoinferior diameter of the fourth ventricle was inversely correlated with age of onset (r=-0.45, P < 0.05). Conclusion : The effect on the cerebellum and brainstem is related to predominant clinical features in SCA3/MJD patients.

Introduction

Spinocerebellar ataxias (SCAs) are a group of inherited neurodegenerative disorders with clinical heterogeneity. [sup][1],[2] Worldwide spinocerebellar ataxia type 3, also known as Machado-Joseph disease (SCA3/MJD), is the most common SCA subtype. In China the reported frequency of SCA3/MJD is about 50% of SCAs. [sup][3] The disease-causing gene MJD1 has been mapped to chromosome 14q32.1.[sup] [4] The molecular basis of SCA3/MJD is an unstable and expanded (CAG) [sub]n trinucleotide repeat within the coding region of the MJD1 gene, ranging from 45 to 86 repeats (normal is less than 47). [sup][5] Clinically, SCA3/MJD is characterized principally by cerebellar ataxia and also nystagmus, dysarthria, pyramidal and extrapyramidal signs and peripheral neuropathy at variable frequency.[sup] [6]

Morphological changes of the brain associated with various neurodegenerative disorders can best be studied in vivo with magnetic resonance imaging (MRI). The most important MRI feature in SCAs is brainstem and/ or cerebellar atrophy.[sup] [7],[8],[9],[10] Previous studies in patients with SCA3/MJD have shown a close correlation between brainstem and cerebellum atrophy and CAG trinucleotide repeat lengths.[sup] [11],[12],[13] Till date there are no studies correlating brainstem and cerebellum atrophy and the clinical features in SCA3/MJD. By using the linear measurement method, we assessed 32 patients with SCA3/MJD to study the correlations between the morphometric data of the brainstem and cerebellum and clinical features.

Patients and Methods

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