Diagnosing aceruloplasminemia: navigating through red herrings.

A 58-year-old female was found to have hyperferritinemia (Serum ferritin:1683 ng/mL) during work-up for mild normocytic anemia. Transferrin saturation(TSAT) was low-normal. Magnetic resonance imaging (MRI) abdomen showed evidence of hepatic iron deposition. Liver biopsy showed 4 + hepatic iron deposition without any evidence of steatosis or fibrosis. Quantitative liver iron was elevated at 348.3 µmol/g dry liver weight [Reference range(RR): 3-33 µmol/g dry liver weight]. She was presumptively diagnosed with tissue iron overload, cause uncertain. A diagnosis of ferroportin disease (FD) was considered, but the pattern of iron distribution in the liver, mainly within the hepatic parenchyma (rather than in the hepatic Kupffer cells seen in FD), and the presence of anemia (uncommon in FD) made this less likely. She was treated with intermittent phlebotomy for over a decade with poor tolerance due to worsening normocytic to microcytic anemia. A trial of deferasirox was done but it was discontinued after a month due to significant side effects. During the course of treatment, her ferritin level decreased. Over the past 1.5 years, she developed progressively worsening neurocognitive decline. MRI brain showed areas of susceptibility involving basal ganglia, midbrain and cerebellum raising suspicion for metabolic deposition disease. Neuroimaging findings led to testing for serum copper and ceruloplasmin levels which were both found to be severely low. Low serum copper, ceruloplasmin levels and neuroimaging findings led us to consider Wilson disease however prior liver biopsy showing elevated hepatic iron rather than hepatic copper excluded the diagnosis of Wilson disease. After shared decision making, ceruloplasmin gene analysis was not pursued due to patient's preference and prohibitive cost of testing. The diagnosis of aceruloplasminemia was ultimately made. The biochemical triad of hyperferritinemia, low-normal TSAT and microcytic anemia should raise the possibility of aceruloplasminemia. Since neurological manifestations are rare in most inherited iron overload syndromes, neurological symptoms in a patient with tissue iron overload should prompt consideration of aceruloplasminemia as a differential diagnosis.

Generation of a human induced pluripotent stem cell line NTUHi002-A from a patient with aceruloplasminemia harboring a homozygous splicing mutation c.607+1 delG in CP gene.

Aceruloplasminemia is a rare autosomal recessive disorder caused by mutations in the CP gene, encoding the copper-binding protein ceruloplasmin. A mutation in the CP gene results in brain and systemic iron overload, which is classified as a rare subtype of neurodegeneration with brain iron accumulation (NBIA). Here, we used the Sendai virus delivery system to generate induced pluripotent stem cells from peripheral blood mononuclear cells of a patient carrying the CP c.607+1 delG homozygous splicing mutation. The generated cell line retained the original genotype, expressed pluripotency markers, and differentiated into cells of the three germ layers.

Ceruloplasmin Deficiency Impaired Brain Iron Metabolism and Behavior in Mice.

Iron accumulation is an important cause of various brain diseases. As a ferroxidase, ceruloplasmin (Cp) plays a key role in iron homeostasis and its abnormal activity leads to iron accumulation. However, the detailed biological function of Cp in brain iron homeostasis needs to be investigated. In this study, Cp knockout mice were prepared and the changes in iron content and protein expression related to iron metabolism were detected. The results showed that iron accumulation occurred in multiple tissues and organs of Cp knockout mice, but there was no obvious change in brain tissues. However, Cp deficiency affected the expression of many iron metabolism-related proteins in midbrain, such as DMT1+IRE, heavy chain ferritin (H-ferritin) and light chain ferritin (L-ferritin). Cp deficiency also impaired the behavioral ability of mice, including weakened exercise ability and reduced motor coordination. In vitro cell experiment indicated that the sensitivity of Cp knockout neuron and astrocyte to hypoxia was higher than that of wild type, which means Cp deficiency leads to the damage of cell self-protection. All these results confirm that Cp exerts a protective effect on the brain by regulating iron metabolism.

Aceruloplasminemia: a multimodal imaging study in an Italian family with a novel mutation.

OBJECTIVE: Structural abnormalities in thalami and basal ganglia, in particular the globus pallidus (GP), are a neuroimaging hallmark of hereditary aceruloplasminemia (HA), yet few functional imaging data exit in HA carriers. This study investigated the iron-related structural and functional abnormalities in an Italian HA family. METHODS: Multimodal imaging was used including structural 3 T MRI, functional imaging (SPECT imaging with 123I-ioflupane (DAT-SPECT), cardiac 123I metaiodobenzylguanidine (123I-MIBG) scintigraphy, and 18F-fluorodeoxyglucose (18F-FDG)-PET imaging). In the proband, MRI and scintigraphic evaluations were performed at baseline, 2 and 4 years (structural imaging), and 2 years of follow-up period (functional imaging). RESULTS: We investigated two cousins carrying a novel splicing homozygous mutation in intron 6 (IVS6 + 1 G > A) of CP gene. Interestingly, MRI features in both subjects were characterized by marked iron accumulation in the thalami and basal ganglia nuclei, while GP was not affected. MRI performed in the proband at 2 and 4 years of follow-up confirmed progressive neurodegeneration of the thalami and basal ganglia without the involvement of GP. Functional imaging showed reduced putaminal DAT uptake in both cousins, whereas cardiac MIBG and FDG uptakes performed in the proband were normal. Longitudinal scintigraphic investigations did not show significant changes over the time. CONCLUSIONS: For HA carriers, our findings demonstrate that GP was spared by iron accumulation over the time. The nigrostriatal presynaptic dopaminergic system was damaged while the cardiac sympathetic system remained longitudinally preserved, thus expanding the imaging features of this rare inherited disorder.

Novel ceruloplasmin gene mutation causing aceruloplasminemia with diabetes in a Chinese woman: a case report.

Hereditary aceruloplasminemia (ACP) is a rare adult-onset autosomal recessive disease characterized by a ceruloplasmin (CP) gene mutation and defective or absent CP function. In the present study, we report a case of ACP in a 34-year-old Chinese woman with diabetes, fatigue, anxiety, and progressive membrane loss with low hemoglobin associated with microcytosis. The fasting glucose level was 5.6-7.96 mmol/L. Postprandial blood glucose ranged from 6.8 to 9.6 mmol/L. The Stumvoll first-phase and second-phase insulin secretion disposition indices were very low, and the serum iron content was low, even though transferrin levels were normal. Moreover, the transferrin saturation was low (5%), and the ferritin level was extremely high, above 2,000 µg/L in the patient. Furthermore, her serum CP level was extremely low (<0.0183 g/L). Abdominal computed tomography (CT) examination showed moderate iron overload in the liver. Brain CT also showed a mildly increased density of the bilateral thalami and basal ganglia. Finally, gene analysis showed a rare homozygous mutation (c.146+1G>A) in the CP gene and was diagnosed with ACP. To date, less than 60 family cases of ACP have been reported worldwide, and only two cases of ACP have been reported in China. Here, we report a case of ACP accompanied by diabetes with a novel mutation of the CP gene, which suggests that increased awareness should be highlighted in this disorder as diabetes is an important typical symptom.

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.

A novel ceruloplasmin mutation identified in a Chinese patient and clinical spectrum of aceruloplasminemia patients.

Aceruloplasminemia (ACP) is a rare disorder of iron overload resulting from ceruloplasmin (CP) variants. Because of its rarity and heterogeneity, the diagnosis of ACP is often missed or misdiagnosed. Here, we aim to present a clinical spectrum of ACP and raise more attention to the early diagnosis. Whole exome sequencing (WES) was performed in a Chinese female patient suspected with ACP and her clinical data were collected in detail. The PubMed databases was searched for published ACP patients within the last decade, and we present a systematic review of their clinical features with data extracted from these researches. A novel pathogenic variant (c.2689delC) and a known pathogenic variant (c.606dupA) within ceruloplasmin gene were identified in our patient and confirmed the diagnosis of ACP. Then we reviewed 51 ACP patients including the case we reported here. A possible timeline of symptoms was discovered, anemia appears first (29.7 years old on average), followed by diabetes (37.3 years old) and finally neurological symptoms (50.7 years old). The delay in diagnosis was significantly shortened in patients without neurological symptoms. Biochemical triad including anemia, low to undetectable serum ceruloplasmin, low serum iron and/or hyperferritinemia, showed better sensitivity in diagnosis than clinical triad including diabetes, neurological symptoms, and retinal degeneration. Due to the variable symptom spectrum, patients with ACP often visit different departments, which can lead to misdiagnosis. Clinical attention needs to be paid to symptoms and tests that have a warning effect. Prompt diagnosis in the early stage of the disease can be beneficial.

Copper, Iron, and Manganese Toxicity in Neuropsychiatric Conditions.

Copper, manganese, and iron are vital elements required for the appropriate development and the general preservation of good health. Additionally, these essential metals play key roles in ensuring proper brain development and function. They also play vital roles in the central nervous system as significant cofactors for several enzymes, including the antioxidant enzyme superoxide dismutase (SOD) and other enzymes that take part in the creation and breakdown of neurotransmitters in the brain. An imbalance in the levels of these metals weakens the structural, regulatory, and catalytic roles of different enzymes, proteins, receptors, and transporters and is known to provoke the development of various neurological conditions through different mechanisms, such as via induction of oxidative stress, increased α-synuclein aggregation and fibril formation, and stimulation of microglial cells, thus resulting in inflammation and reduced production of metalloproteins. In the present review, the authors focus on neurological disorders with psychiatric signs associated with copper, iron, and manganese excess and the diagnosis and potential treatment of such disorders. In our review, we described diseases related to these metals, such as aceruloplasminaemia, neuroferritinopathy, pantothenate kinase-associated neurodegeneration (PKAN) and other very rare classical NBIA forms, manganism, attention-deficit/hyperactivity disorder (ADHD), ephedrone encephalopathy, HMNDYT1-SLC30A10 deficiency (HMNDYT1), HMNDYT2-SLC39A14 deficiency, CDG2N-SLC39A8 deficiency, hepatic encephalopathy, prion disease and "prion-like disease", amyotrophic lateral sclerosis, Huntington's disease, Friedreich's ataxia, and depression.

Schwann Cells Provide Iron to Axonal Mitochondria and Its Role in Nerve Regeneration.

Iron is an essential cofactor for several metabolic processes, including the generation of ATP in mitochondria, which is required for axonal function and regeneration. However, it is not known how mitochondria in long axons, such as those in sciatic nerves, acquire iron in vivo Because of their close proximity to axons, Schwann cells are a likely source of iron for axonal mitochondria in the PNS. Here we demonstrate the critical role of iron in promoting neurite growth in vitro using iron chelation. We also show that Schwann cells express the molecular machinery to release iron, namely, the iron exporter, ferroportin (Fpn) and the ferroxidase ceruloplasmin (Cp). In Cp KO mice, Schwann cells accumulate iron because Fpn requires to partner with Cp to export iron. Axons and Schwann cells also express the iron importer transferrin receptor 1 (TfR1), indicating their ability for iron uptake. In teased nerve fibers, Fpn and TfR1 are predominantly localized at the nodes of Ranvier and Schmidt-Lanterman incisures, axonal sites that are in close contact with Schwann cell cytoplasm. We also show that lack of iron export from Schwann cells in Cp KO mice reduces mitochondrial iron in axons as detected by reduction in mitochondrial ferritin, affects localization of axonal mitochondria at the nodes of Ranvier and Schmidt-Lanterman incisures, and impairs axonal regeneration following sciatic nerve injury. These finding suggest that Schwann cells contribute to the delivery of iron to axonal mitochondria, required for proper nerve repair.SIGNIFICANCE STATEMENT This work addresses how and where mitochondria in long axons in peripheral nerves acquire iron. We show that Schwann cells are a likely source as they express the molecular machinery to import iron (transferrin receptor 1), and to export iron (ferroportin and ceruloplasmin [Cp]) to the axonal compartment at the nodes of Ranvier and Schmidt-Lanterman incisures. Cp KO mice, which cannot export iron from Schwann cells, show reduced iron content in axonal mitochondria, along with increased localization of axonal mitochondria at Schmidt-Lanterman incisures and nodes of Ranvier, and impaired sciatic nerve regeneration. Iron chelation in vitro also drastically reduces neurite growth. These data suggest that Schwann cells are likely to contribute iron to axonal mitochondria needed for axon growth and regeneration.

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.

Alteration of Iron Concentration in Alzheimer's Disease as a Possible Diagnostic Biomarker Unveiling Ferroptosis.

Proper functioning of all organs, including the brain, requires iron. It is present in different forms in biological fluids, and alterations in its distribution can induce oxidative stress and neurodegeneration. However, the clinical parameters normally used for monitoring iron concentration in biological fluids (i.e., serum and cerebrospinal fluid) can hardly detect the quantity of circulating iron, while indirect measurements, e.g., magnetic resonance imaging, require further validation. This review summarizes the mechanisms involved in brain iron metabolism, homeostasis, and iron imbalance caused by alterations detectable by standard and non-standard indicators of iron status. These indicators for iron transport, storage, and metabolism can help to understand which biomarkers can better detect iron imbalances responsible for neurodegenerative diseases.

[Aceruloplasminemia, a rare condition not to be overlooked]. / L'acéruléoplasminémie héréditaire, une pathologie à ne pas méconnaître.

Aceruloplasminemia is a rare iron-overload disease that should be better known by physicians. It is an autosomal recessive disorder due to mutations in ceruloplasmin gene causing systemic iron overload, including cerebral and liver parenchyma. The impairment of ferroxidase ceruloplasmin activity leads to intracellular iron retention leading aceruloplasminemia symptoms. Neurologic manifestations include cognitive impairment, ataxia, extrapyramidal syndrome, abnormal movements, and psychiatric-like syndromes. Physicians should search for aceruloplasminemia in several situations with high ferritin levels: microcytic anaemia, diabetes mellitus, neurological and psychiatric disorders. Diagnosis approach is based on the study of transferrin saturation and hepatic iron content evaluated by magnetic resonance imaging of the liver. Ceruloplasmin dosage is required in case of low transferrin saturation and high hepatic iron content and genetic testing is mandatory in case of serum ceruloplasmin defect. Neurological manifestations occur in the sixties decade and leads to disability. Iron chelators are widely used. Despite their efficacy on systemic and cerebral iron overload, iron chelators tolerance is poor. Early initiation of iron chelation therapy might prevent or slowdown neurodegeneration, highlighting the need for an early diagnosis but their clinical efficacy remains uncertain.

Effects of iron chelation therapy on the clinical course of aceruloplasminemia: an analysis of aggregated case reports.

BACKGROUND: Aceruloplasminemia is a rare genetic iron overload disorder, characterized by progressive neurological manifestations. The effects of iron chelation on neurological outcomes have only been described in case studies, and are inconsistent. Aggregated case reports were analyzed to help delineate the disease-modifying potential of treatment. METHODS: Data on clinical manifestations, treatment and neurological outcomes of treatment were collected from three neurologically symptomatic Dutch patients, who received deferiprone with phlebotomy as a new therapeutic approach, and combined with other published cases. Neurological outcomes of treatment were compared between patients starting treatment when neurologically symptomatic and patients without neurological manifestations. RESULTS: Therapeutic approaches for aceruloplasminemia have been described in 48 patients worldwide, including our three patients. Initiation of treatment in a presymptomatic stage of the disease delayed the estimated onset of neurological manifestations by 10 years (median age 61 years, SE 5.0 vs. median age 51 years, SE 0.6, p = 0.001). Although in 11/20 neurologically symptomatic patients neurological manifestations remained stable or improved during treatment, these patients were treated significantly shorter than patients who deteriorated neurologically (median 6 months vs. median 43 months, p = 0.016). Combined iron chelation therapy with deferiprone and phlebotomy for up to 34 months could be safely performed in our patients without symptomatic anemia (2/3), but did not prevent further neurological deterioration. CONCLUSIONS: Early initiation of iron chelation therapy seems to postpone the onset of neurological manifestations in aceruloplasminemia. Publication bias and significant differences in duration of treatment should be considered when interpreting reported treatment outcomes in neurologically symptomatic patients. Based on theoretical grounds and the observed long-term safety and tolerability in our study, we recommend iron chelation therapy with deferiprone in combination with phlebotomy for aceruloplasminemia patients without symptomatic anemia.

New mutation of the ceruloplasmin gene in the case of a neurologically asymptomatic patient with microcytic anaemia, obesity and supposed Wilson's disease.

BACKGROUND: Aceruloplasminaemia is a very rare autosomal recessive disorder caused by a mutation in the ceruloplasmin gene, which is clinically manifested by damage to the nervous system and retinal degeneration. This classical clinical picture can be preceded by diabetes mellitus and microcytic anaemia, which are considered to be early manifestations of aceruloplasminaemia. CASE PRESENTATION: In our report, we describe the case of a patient with aceruloplasminaemia detected in an early stage (without clinical symptoms of damage to the nervous system) during the search for the cause of hepatopathy with very low values of serum ceruloplasmin. Molecular genetic examination of the CP gene for ceruloplasmin identified a new variant c.1664G > A (p.Gly555Glu) in the homozygous state, which has not been published in the literature or population frequency databases to date. Throughout the 21-month duration of chelatase treatment, the patient, who is 43 years old, continues to be without neurological and psychiatric symptomatology. We observed a decrease in the serum concentration of ferritin without a reduction in iron deposits in the brain on magnetic resonance imaging. CONCLUSION: Currently, there is no unequivocal recommendation of an effective treatment for aceruloplasminaemia. Early diagnosis is important in the neurologically asymptomatic stage.

Deferasirox Might Be Effective for Microcytic Anemia and Neurological Symptoms Associated with Aceruloplasminemia: A Case Report and Review of the Literature.

The patient was a 64-year-old man presented with difficulty in walking, articulation, and swallowing, as well as cognitive impairment. He had refractory microcytic anemia and diabetes mellitus. His serum levels of iron, copper, and ceruloplasmin were low. Magnetic resonance imaging suggested iron deposition in the basal ganglia, thalami, cerebellar dentate nuclei, and cerebral and cerebellar cortices. He was diagnosed with aceruloplasminemia after a ceruloplasmin gene analysis. Iron chelation therapy with deferasirox improved his anemia and cerebellar symptoms, which included dysarthria and limb ataxia. The present study and previous reports indicate that cerebellar symptoms with aceruloplasminemia might respond to deferasirox in less than one year.

Genetic and Clinical Heterogeneity in Thirteen New Cases with Aceruloplasminemia. Atypical Anemia as a Clue for an Early Diagnosis.

Aceruloplasminemia is a rare autosomal recessive genetic disease characterized by mild microcytic anemia, diabetes, retinopathy, liver disease, and progressive neurological symptoms due to iron accumulation in pancreas, retina, liver, and brain. The disease is caused by mutations in the Ceruloplasmin (CP) gene that produce a strong reduction or absence of ceruloplasmin ferroxidase activity, leading to an impairment of iron metabolism. Most patients described so far are from Japan. Prompt diagnosis and therapy are crucial to prevent neurological complications since, once established, they are usually irreversible. Here, we describe the largest series of non-Japanese patients with aceruloplasminemia published so far, including 13 individuals from 11 families carrying 13 mutations in the CP gene (7 missense, 3 frameshifts, and 3 splicing mutations), 10 of which are novel. All missense mutations were studied by computational modeling. Clinical manifestations were heterogeneous, but anemia, often but not necessarily microcytic, was frequently the earliest one. This study confirms the clinical and genetic heterogeneity of aceruloplasminemia, a disease expected to be increasingly diagnosed in the Next-Generation Sequencing (NGS) era. Unexplained anemia with low transferrin saturation and high ferritin levels without inflammation should prompt the suspicion of aceruloplasminemia, which can be easily confirmed by low serum ceruloplasmin levels. Collaborative joint efforts are needed to better understand the pathophysiology of this potentially disabling disease.

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.

Different cortical excitability profiles in hereditary brain iron and copper accumulation.

BACKGROUND AND AIM: Neurodegeneration with brain iron accumulation (NBIA) and Wilson's disease (WD) is considered the prototype of neurodegenerative disorders characterised by the overloading of iron and copper in the central nervous system. Growing evidence has unveiled the involvement of these metals in brain cortical neurotransmission. Aim of this study was to assess cortical excitability profile due to copper and iron overload. METHODS: Three patients affected by NBIA, namely two patients with a recessive hereditary parkinsonism (PARK9) and one patient with aceruloplasminemia and 7 patients with neurological WD underwent transcranial magnetic stimulation (TMS) protocols to assess cortical excitability. Specifically, we evaluated the motor thresholds that reflect membrane excitability related to the voltage-gated sodium channels in the neurons of the motor system and the ease of activation of motor cortex via glutamatergic networks, and ad hoc TMS protocols to probe inhibitory-GABAergic (short interval intracortical inhibition, SICI; short-latency afferent inhibition, SAI; cortical silent period, CSP) and excitatory intracortical circuitry (intracortical facilitation, ICF). RESULTS: Patients with NBIA exhibited an abnormal prolongation of CSP respect to HC and WD patients. On the contrary, neurological WD displayed higher motor thresholds and reduced CSP and SICI. CONCLUSION: Hereditary conditions due to overload of copper and iron exhibited peculiar cortical excitability profiles that can help during differential diagnosis between these conditions. Moreover, such results can give us more clues about the role of metals in acquired neurodegenerative disorders, such as Parkinson disease, Alzheimer disease, and multiple sclerosis.