Transcranial Sonography in Mitochondrial Membrane Protein-Associated Neurodegeneration

Marta Skowronska,Tomasz Kmiec,Iwona Kurkowska-Jastrzębska,Anna Czlonkowska

doi:10.1007/s00062-017-0577-9

Abstract

IntroductionAlthough the nature of basal ganglia hyperechogenicity in transcranial sonography (TCS) examinations remains unclear, many studies have shown associations between hyperechogenicity and iron accumulation. The role of iron in basal ganglia hyperechogenicity raises interest in the use of TCS in forms of neurodegeneration with brain iron accumulation (NBIA). Here we analyzed TCS and magnetic resonance imaging (MRI) findings among patients affected by one type of NBIA, mitochondrial membrane protein-associated neurodegeneration (MPAN).MethodsInvestigations using MRI and TCS were performed on 13 patients exhibiting a C19orf12 gene mutation.ResultsThe use of T2/T2* MRI revealed hypointense lesions restricted to the globus pallidus and substantia nigra. Using TCS examination, 12 patients exhibited bilateral hyperechogenicity of the lenticular nucleus, while no patients showed substantia nigra hyperechogenicity.ConclusionInvestigations with TCS revealed a distinctive hyperechogenicity pattern of the basal ganglia in MPAN patients, which might be useful for differential diagnostics. The variable TCS imaging findings in NBIA patients may result from the presence of different iron content, iron binding partners, such as ferritin and neuromelanin, as well as structural changes, such as gliosis.

Highlights

The nature of basal ganglia hyperechogenicity in transcranial sonography (TCS) examinations remains unclear, many studies have shown associations between hyperechogenicity and iron accumulation
The neurodegeneration with brain iron accumulation (NBIA) are a group of genetic conditions characterized by a progressive hypokinetic and/or hyperkinetic movement disorder along with excessive iron deposition in the brain, in the globus pallidus (GP) and substantia nigra (SN) [9]
Our study revealed lenticular nucleus (LN) hyperechogenicity corresponding to the GP hypointensity shown in magnetic resonance imaging (MRI)

Summary

Introduction

The nature of basal ganglia hyperechogenicity in transcranial sonography (TCS) examinations remains unclear, many studies have shown associations between hyperechogenicity and iron accumulation. TCS is presently considered an additional diagnostic tool for corticobasal degeneration (CBD), Wilson’s disease (WD), primary restless legs syndrome (RLS) [2,3,4] and multiple sclerosis (MS) progression [5] This technique can detect hyperechogenicity of midbrain structures, including the thalamus, lenticular nucleus (LN), and caudate nucleus, and can be used to determine the diameter of the third ventricle or the frontal horn of the lateral ventricle [2]. The exact nature of basal ganglia hyperechogenicity is unclear, but many post-mortem and animal studies show associations between hyperechogenicity and iron and/or other ion accumulation diseases [6,7,8] This potential role of iron in basal ganglia hyperechogenicity raises great interest in the TCS findings in cases of neurodegeneration with brain iron accumulation (NBIA). The major known forms of NBIA are pantothenate kinase-as-

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Discussion

Conclusion