Background and Purpose

Beta-propeller protein-associated neurodegeneration (BPAN) is one subtype of neurodegeneration with brain iron accumulation. It is difficult to diagnose BPAN due to the non-specificity of their clinical findings and neuroimaging in early childhood. We experienced four pediatric patients with serial brain MRI and evaluated the alteration of the findings through their course.

Methods

We retrospectively reviewed the clinical findings and 21 MRI findings of the four patients with genetically confirmed pediatric BPAN. We also performed a quantitative MR assessment using the quantitative susceptibility mapping (QSM) values of the globus pallidus (GP), substantia nigra (SN), and deep cerebellar nuclei (DCN) compared to 10 age-matched disease controls.

Results

Only one patient was suspected of BPAN based on imaging findings before the genetic diagnosis was made. The other three patients could not be suspected until their Whole-exome sequencings (WES) done. In all four cases, no abnormal signals were noted in the GP and SN at the initial brain MRI, but hypointensities were observed after the ages of 4–7 years on T2-weighted images and after the ages of 2–7 years on susceptibility-weighted images. In three patients, T2 hyperintensity in the bilateral DCN was persistently observed throughout the observational period. Three patients showed transient T2 hyperintensity and swelling in the GP, SN and/or DCN during the episodes of pyrexia and seizures. The other findings included cerebral and cerebellar atrophy, thinning of the corpus callosum, and delayed myelination. The QSM values of the GP and SN were significantly higher in the patients compared to the controls (P = 0.005, respectively), but that of the DCN did not differ significantly (P = 0.16).

Conclusion

Brain MRI is a useful method to establish the early diagnosis of BPAN.

中文翻译：

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β-螺旋桨蛋白相关神经变性 (BPAN) 儿科患者的连续 MRI 改变

背景和目的

β 螺旋桨蛋白相关神经变性 (BPAN) 是一种具有脑铁积累的神经变性亚型。由于 BPAN 的临床表现和儿童早期神经影像学的非特异性，因此很难诊断出 BPAN。我们经历了四名连续脑部 MRI 的儿科患者，并评估了他们整个过程中发现的变化。

方法

我们回顾性审查了 4 名经基因证实的小儿 BPAN 患者的临床发现和 21 项 MRI 发现。我们还使用苍白球 (GP)、黑质 (SN) 和小脑深部核 (DCN) 的定量磁敏度图 (QSM) 值与 10 个年龄匹配的疾病对照进行了定量 MR 评估。

结果

在进行基因诊断之前，只有一名患者根据影像学发现怀疑患有 BPAN。在完成全外显子组测序（WES）之前，无法怀疑其他三名患者。在所有四个病例中，初始脑部 MRI 的 GP 和 SN 均未发现异常信号，但在 T2 加权图像上 4-7 岁后和在磁敏度上 2-7 岁后观察到低信号 -加权图像。在三名患者中，在整个观察期内持续观察到双侧 DCN 的 T2 高信号。三名患者在发热和癫痫发作期间表现出一过性 T2 高信号和 GP、SN 和/或 DCN 肿胀。其他发现包括大脑和小脑萎缩、胼胝体变薄和髓鞘形成延迟。  分别为P = 0.005），但 DCN 的差异不显着（P  =  0.16）。

结论

脑部 MRI 是建立 BPAN 早期诊断的有用方法。