Clinical, neuroimaging and genetic findings in Brazilian patients with neurodegeneration with brain iron accumulation.

Neurodegeneration with brain iron accumulation (NBIA) encompasses a clinically and genetically heterogeneous group of rare disorders. Here, we report clinical, neuroimaging and genetic studies in twenty three Brazilian NBIA patients. In thirteen subjects, deleterious variants were detected in known NBIA-causing genes (PANK2, PLA2G6, C9ORF12, WDR45 and FA2H), including previously unreported variants in PANK2 and PLA2G6. Two patients carried rare, likely pathogenic variants in genes not previously associated with NBIA: KMT2A c.11785A > C (p.Ile3929Leu), and TIMM8A c.127T > C (p.Cys43Arg), suggesting an expansion of their associated phenotypes to include NBIA. In eight patients the etiology remains unsolved, suggesting variants undetectable by the adopted methods, or the existence of additional NBIA-causing genes.

7T MRI detects widespread brain iron deposition in neuroferritinopathy.

Neuroferritinopathy is a disorder of neurodegeneration with brain iron accumulation that has no proven disease-modifying treatments. Clinical trials require biomarkers of iron deposition. We examined brain iron accumulation in one presymptomatic FTL mutation carrier, two individuals with neuroferritinopathy and one healthy control using ultra-high-field 7T MRI. There was increased magnetic susceptibility, suggestive of iron deposition, in superficial and deep gray matter in both presymptomatic and symptomatic neuroferritinopathy. Cavitation of the putamen and globus pallidus increased with disease stage and at follow up. The widespread brain iron deposition in presymptomatic and early disease provides an opportunity for monitoring disease-modifying intervention.

MR imaging for the quantitative assessment of brain iron in aceruloplasminemia: A postmortem validation study.

AIMS: Non-invasive measures of brain iron content would be of great benefit in neurodegeneration with brain iron accumulation (NBIA) to serve as a biomarker for disease progression and evaluation of iron chelation therapy. Although magnetic resonance imaging (MRI) provides several quantitative measures of brain iron content, none of these have been validated for patients with a severely increased cerebral iron burden. We aimed to validate R2* as a quantitative measure of brain iron content in aceruloplasminemia, the most severely iron-loaded NBIA phenotype. METHODS: Tissue samples from 50 gray- and white matter regions of a postmortem aceruloplasminemia brain and control subject were scanned at 1.5 T to obtain R2*, and biochemically analyzed with inductively coupled plasma mass spectrometry. For gray matter samples of the aceruloplasminemia brain, sample R2* values were compared with postmortem in situ MRI data that had been obtained from the same subject at 3 T - in situ R2*. Relationships between R2* and tissue iron concentration were determined by linear regression analyses. RESULTS: Median iron concentrations throughout the whole aceruloplasminemia brain were 10 to 15 times higher than in the control subject, and R2* was linearly associated with iron concentration. For gray matter samples of the aceruloplasminemia subject with an iron concentration up to 1000 mg/kg, 91% of variation in R2* could be explained by iron, and in situ R2* at 3 T and sample R2* at 1.5 T were highly correlated. For white matter regions of the aceruloplasminemia brain, 85% of variation in R2* could be explained by iron. CONCLUSIONS: R2* is highly sensitive to variations in iron concentration in the severely iron-loaded brain, and might be used as a non-invasive measure of brain iron content in aceruloplasminemia and potentially other NBIA disorders.

Quantification of different iron forms in the aceruloplasminemia brain to explore iron-related neurodegeneration.

AIMS: Aceruloplasminemia is an ultra-rare neurodegenerative disorder associated with massive brain iron deposits, of which the molecular composition is unknown. We aimed to quantitatively determine the molecular iron forms in the aceruloplasminemia brain, and to illustrate their influence on iron-sensitive MRI metrics. METHODS: The inhomogeneous transverse relaxation rate (R2*) and magnetic susceptibility obtained from 7 T MRI were combined with Electron Paramagnetic Resonance (EPR) and Superconducting Quantum Interference Device (SQUID) magnetometry. The basal ganglia, thalamus, red nucleus, dentate nucleus, superior- and middle temporal gyrus and white matter of a post-mortem aceruloplasminemia brain were studied. MRI, EPR and SQUID results that had been previously obtained from the temporal cortex of healthy controls were included for comparison. RESULTS: The brain iron pool in aceruloplasminemia detected in this study consisted of EPR-detectable Fe3+ ions, magnetic Fe3+ embedded in the core of ferritin and hemosiderin (ferrihydrite-iron), and magnetic Fe3+ embedded in oxidized magnetite/maghemite minerals (maghemite-iron). Ferrihydrite-iron represented above 90% of all iron and was the main driver of iron-sensitive MRI contrast. Although deep gray matter structures were three times richer in ferrihydrite-iron than the temporal cortex, ferrihydrite-iron was already six times more abundant in the temporal cortex of the patient with aceruloplasminemia compared to the healthy situation (162 µg/g vs. 27 µg/g), on average. The concentrations of Fe3+ ions and maghemite-iron in the temporal cortex in aceruloplasminemia were within the range of those in the control subjects. CONCLUSIONS: Iron-related neurodegeneration in aceruloplasminemia is primarily associated with an increase in ferrihydrite-iron, with ferrihydrite-iron being the major determinant of iron-sensitive MRI contrast.

Association of Habitual Dietary Intake with Liver Iron-A Population-Based Imaging Study.

Iron-related disorders of the liver can result in serious health conditions, such as liver cirrhosis. Evidence on the role of modifiable lifestyle factors like nutrition in liver iron storage is lacking. Thus, we aimed to assess the association of habitual diet with liver iron content (LIC). We investigated 303 participants from the population-based KORA-MRI study who underwent whole-body magnetic resonance imaging (MRI). Dietary habits were evaluated using repeated 24 h food lists and a food frequency questionnaire. Sex-stratified multiple linear regression models were applied to quantify the association between nutrition variables of interest and LIC, adjusting for liver fat content (LFC), energy intake, and age. Mean age of participants was 56.4 ± 9.0 years and 44.2% were female. Mean LIC was 1.23 ± 0.12 mg/g dry weight, with higher values in men than in women (1.26 ± 0.13 and 1.20 ± 0.10 mg/g, p < 0.001). Alcohol intake was positively associated with LIC (men: ß = 1.94; women: ß = 4.98, p-values < 0.03). Significant negative associations with LIC were found for fiber (ß = -5.61, p < 0.001) and potassium (ß = -0.058, p = 0.034) for female participants only. Furthermore, LIC was highly correlated with liver fat content in both sexes. Our findings suggests that there are sex-specific associations of habitual dietary intake and LIC. Alcohol, fiber, and potassium may play a considerable role in liver iron metabolism.

Intracranial iron distribution and quantification in aceruloplasminemia: A case study.

OBJECTIVES: Aceruloplasminemia (ACP) is a rare autosomal recessive disorder characterized by intracranial and visceral iron overload. With R2*-based imaging or quantitative susceptibility mapping (QSM), it is feasible to measure iron in the brain quantitatively, although to date this has not yet been done for patients with ACP. The aim of this study was to provide quantitative iron measurements for each affected brain region in an ACP patient with the potential to do so in all future ACP patients. This may shed light on the link between brain iron metabolism and the territories affected by ceruloplasmin function. METHODS: We imaged a patient with ACP using a 3T magnetic resonance imaging scanner with a fifteen-channel head coil. We manually demarcated gray matter and white matter on the Strategically Acquired Gradient Echo (STAGE) images, and calculated values for susceptibility and R2* in these regions. Correlation analysis was performed between the R2* values and the susceptibility values. RESULTS: Besides the usual territories affected in ACP, we also discovered that the mammillary bodies and the lateral habenulae had significant increases in iron, and the hippocampus was severely affected both in terms of iron content and abnormal tissue signal. We also noted that the iron in the cortical gray matter appeared to be deposited in the inner layers. Moreover, several pathways between the superior colliculus and the pulvinar thalamus, between the caudate and putamen anteriorly and between the caudate and pulvinar thalamus posteriorly were also evident. Finally, R2* correlated strongly with the QSM data (R2 = 0.67, t = 6.78, p < 0.001). CONCLUSION: QSM and R2* have proven to be sensitive and quantitative means by which to measure iron content in the brain. Our findings included several newly noted affected brain regions of iron overload and provided some new aspects of iron metabolism in ACP that may be further applicable to other pathologic conditions. Furthermore, our study may pave the way for assessing efficacy of iron chelation therapy in these patients and for other common iron related neurodegenerative disorders.

Clinical and Imaging Presentation of a Patient with Beta-Propeller Protein-Associated Neurodegeneration, a Rare and Sporadic form of Neurodegeneration with Brain Iron Accumulation (NBIA).

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group of inherited neurologic disorders with iron accumulation in the basal ganglia, which share magnetic resonance (MR) imaging characteristics, histopathologic and clinical features. According to the affected basal nuclei, clinical features include extrapyramidal movement disorders and varying degrees of intellectual disability status. The most common NBIA subtype is caused by pathogenic variants in PANK2. The hallmark of MR imaging in patients with PANK2 mutations is an eye-of-the-tiger sign in the globus pallidus. We report a 33-year-old female with a rare subtype of NBIA, called beta-propeller protein-associated neurodegeneration (BPAN) with a hitherto unknown missense variant in WDR45. She presented with BPAN's particular biphasic course of neurological symptoms and with a dominant iron accumulation in the midbrain that enclosed a spotty T2-hyperintensity.

Coexistence of Copper in the Iron-Rich Particles of Aceruloplasminemia Brain.

The interaction between iron and copper has been discussed in association with human health and diseases for many years. Ceruloplasmin, a multi-copper oxidase, is mainly involved in iron metabolism and its genetic defect, aceruloplasminemia (ACP), shows neurological disorders and diabetes associated with excessive iron accumulation, but little is known about the state of copper in the brain. Here, we investigated localization of these metals in the brains of three patients with ACP using electron microscopes equipped with an energy-dispersive x-ray analyzer. Histochemically, iron deposition was observed mainly in the basal ganglia and dentate nucleus, and to lesser degree in the cerebral cortex of the patients, whereas copper grains were not detected. X-ray microanalysis identified two types of iron-rich particles in their brains: dense bodies, namely hemosiderins, and their aggregated inclusions. A small number of hemosiderins and most inclusions contained a significant amount of copper which was enough for distinct Cu x-ray images. These copper-containing particles were observed more frequently in the putamen and dentate nucleus than the cerebral cortex. Coexistence of iron and copper was supported by good correlations in the molecular ratios between these two metals in iron-rich particles with Cu x-ray image. Iron-dependent copper accumulation in iron-rich particles may suggest that copper recycling is enhanced to meet the increased requirement of cuproproteins in iron overload brain. In conclusion, the iron-rich particles with Cu x-ray image were found in the ACP brain.

A diagnostic approach for neurodegeneration with brain iron accumulation: clinical features, genetics and brain imaging.

Neurodegeneration with brain iron accumulation (NBIA) represents a heterogeneous and complex group of inherited neurodegenerative diseases, characterized by excessive iron accumulation, particularly in the basal ganglia. Common clinical features of NBIA include movement disorders, particularly parkinsonism and dystonia, cognitive dysfunction, pyramidal signs, and retinal abnormalities. The forms of NBIA described to date include pantothenase kinase-associated neurodegeneration (PKAN), phospholipase A2 associated neurodegeneration (PLAN), neuroferritinopathy, aceruloplasminemia, beta-propeller protein-associated neurodegeneration (BPAN), Kufor-Rakeb syndrome, mitochondrial membrane protein-associated neurodegeneration (MPAN), fatty acid hydroxylase-associated neurodegeneration (FAHN), coenzyme A synthase protein-associated neurodegeneration (CoPAN) and Woodhouse-Sakati syndrome. This review is a diagnostic approach for NBIA cases, from clinical features and brain imaging findings to the genetic etiology.

A diagnostic approach for neurodegeneration with brain iron accumulation: clinical features, genetics and brain imaging / Uma orientação diagnóstica para neurodegeneração com acúmulo cerebral de ferro: aspectos clínicos, genéticos e de neuroimagem

ABSTRACT Neurodegeneration with brain iron accumulation (NBIA) represents a heterogeneous and complex group of inherited neurodegenerative diseases, characterized by excessive iron accumulation, particularly in the basal ganglia. Common clinical features of NBIA include movement disorders, particularly parkinsonism and dystonia, cognitive dysfunction, pyramidal signs, and retinal abnormalities. The forms of NBIA described to date include pantothenase kinase-associated neurodegeneration (PKAN), phospholipase A2 associated neurodegeneration (PLAN), neuroferritinopathy, aceruloplasminemia, beta-propeller protein-associated neurodegeneration (BPAN), Kufor-Rakeb syndrome, mitochondrial membrane protein-associated neurodegeneration (MPAN), fatty acid hydroxylase-associated neurodegeneration (FAHN), coenzyme A synthase protein-associated neurodegeneration (CoPAN) and Woodhouse-Sakati syndrome. This review is a diagnostic approach for NBIA cases, from clinical features and brain imaging findings to the genetic etiology.

RESUMO A neurodegeneração com acúmulo cerebral de ferro (sigla em inglês NBIA) representa um grupo heterogêneo e complexo de doenças neurodegenerativas hereditárias, caracterizada pelo acúmulo cerebral de ferro, especialmente nos núcleos da base. O quadro clínico das NBIAs em geral inclui distúrbios do movimento, particularmente parkinsonismo e distonia, disfunção cognitiva, sinais piramidais e anormalidades da retina. As formas de NBIA descritas até o momento incluem neurodegeneração associada a pantothenase kinase (PKAN), neurodegeneração associada a phospholipase A2 (PLAN), neuroferritinopatia, aceruloplasminemia, neurodegeneração associada a beta-propeller protein (BPAN), síndrome de Kufor-Rakeb, neurodegeneração associada a mitochondrial membrane protein (MPAN), neurodegeneração associada a “fatty acid hydroxylase” (FAHN), neurodegeneração associada a coenzyme A synthase protein (CoPAN) e síndrome de Woodhouse-Sakati. Esta revisão é uma orientação para o diagnóstico das NBIAs, partindo das características clínicas e achados de neuroimagem, até a etiologia genética.

Liver iron concentration is not raised in patients with dysmetabolic hyperferritinemia.

Background &amp;amp;amp; aims. Hyperferritinemia (HF) is frequently present in patients with metabolic syndrome (MS). MS associated with HF is named dysmetabolic hyperferritinemia (DH). There are some publications that propose that DH is associated with a raised liveriron concentration (LIC). We studied the LIC in patients referred for HF to a secondary hospital to determine if there are differences between patients with or without MS. MATERIAL AND METHODS: We conducted a prospective study of 132 consecutive patients with HF from January to December 2010. The MS was defined by the International Diabetes Federation criteria (2005). LIC was determined by Magnetic resonance imaging (MRI). RESULTS: The number of patients for which there was enough data to determine MS was 97, out of which 54 had MS and 43 had no MS (NMS). In 54/97 patients, MRI for LIC determination was performed. From the MS group, 44 were men (27 underwent MRI) and 10 women (9 MRI). The mean LIC was 27.83 ± 20.90 ?mol/g for the MS group. In the NMS group, 36 were men (13 MRI), and 7 women (5 MRI). In 18 patients from the NMS group, LIC was determined by MRI. The mean LIC was 33.16 ± 19.61 ?mol/g in the NMS group. We compared the mean values of LIC from both groups (MS vs. NMS) and no significant differences were found (p = 0.067). CONCLUSION: Patients with DH present a mean LIC within normal values and their values do not differ from those of patients with HF but without MS.

Neuroferritinopathy.

Neuroferritinopathy remains the only autosomal dominant syndrome of neurodegeneration with brain iron accumulation (NBIA). While the majority of identified cases appear to be part of an extended pedigree in the northeast of England, patients are increasingly being identified across the globe. Since its discovery in 2001, there have been significant developments in our understanding of the pathological, radiological, and clinical aspects of the condition, though several key pathomechanistic questions, and crucially treatment paradigms, remain unaddressed. This chapter summarizes the genetic etiology, pathological, radiological, and clinical data from all published data to date and suggested potential new avenues for therapy.

A pilot trial of deferiprone for neurodegeneration with brain iron accumulation.

Deferiprone was shown to reverse iron deposition in Friedreich's ataxia. This multi-center, unblinded, single-arm pilot study evaluated safety and efficacy of deferiprone for reducing cerebral iron accumulation in neurodegeneration with brain iron accumulation. Four patients with genetically-confirmed pantothenate kinase-associated neurodegeneration, and 2 with parkinsonism and focal dystonia, but inconclusive genetic tests, received 15 mg/kg deferiprone bid. Magnetic resonance imaging and neurological examinations were conducted at baseline, six and 12 months. Chelation treatment caused no apparent hematologic or neurological side effects. Magnetic resonance imaging revealed decreased iron accumulation in the globus pallidus of 2 patients (one with pantothenate kinase-associated neurodegeneration). Clinical rating scales and blinded video rating evaluations documented mild-to-moderate motor improvement in 3 patients (2 with pantothenate kinase-associated neurodegeneration). These results underline the safety and tolerability of deferiprone, and suggest that chelating treatment might be effective in improving neurological manifestations associated with iron accumulation. (Clinicaltrials.gov Identifier: NTC00907283).