Genetic heterogeneity in familial idiopathic basal ganglia calcification (Fahr disease)

Familial idiopathic basal ganglia calcification (IBGC, Fahr disease) is an inherited neurologic condition characterized by basal ganglia and extra-basal ganglia brain calcifications, parkinsonism, and neuropsychiatric symptoms. The authors examined six families for linkage to the previously identified genetic locus (IBGC1) located on chromosome 14q. The authors found evidence against linkage to IBGC1 in five of the six families supporting previous preliminary studies demonstrating genetic heterogeneity in familial IBGC.     

Familial idiopathic basal ganglia calcification: Histopathologic features of an autopsied patient with an SLC20A2 mutation

Idiopathic basal ganglia calcification (IBGC), or Fahr's disease, is a neurological disorder characterized by widespread calcification in the brain. Recently, several causative genes have been identified, but the histopathologic features of the brain lesions and expression of the gene products remain unclear. Here, we report the clinical and autopsy features of a 62‐year‐old Japanese man with familial IBGC, in whom an SLC20A2 mutation was identified. The patient developed mild cognitive impairment and parkinsonism. A brain CT scan demonstrated abnormal calcification in the bilateral basal ganglia, thalami and cerebellum. An MRI study at this point revealed glioblastoma, and the patient died 6 months later. At autopsy, symmetric calcification in the basal ganglia, thalami, cerebellar white matter and deeper layers of the cerebral cortex was evident. The calcification was observed in the tunica media of small arteries, arterioles and capillaries, but not in veins. Immunohistochemistry using an antibody against type III sodium‐dependent phosphate transporter 2 (PiT‐2), the SLC20A2 product, demonstrated that astrocytic processes were labeled in several regions in control brains, whereas in the patient, reactivity in astrocytes was apparently weak. Immunoblotting demonstrated a marked decrease of PiT‐2 in the patient. There are few autopsy reports of IBGC patients with confirmation of the genetic background. The autopsy features seem informative for better understanding the histogenesis of IBGC lesions.     

Idiopathic basal ganglia calcification presenting as hypomania

A sixty-four-year-old lady manifested a hypomanic psychosis and later developed features of a subcortical dementia and movement disorders of Parkinsonism and chorea. Computerized tomography revealed bilateral basal ganglia calcification. No evidence of parathyroid disorder or any other cause for the calcification was present. There has been only one previously reported case of organic mood disorder of a manic type presentation of idiopathic basal ganglia calcification (IBGC). The oldest reported age of onset of IBGC presenting with psychosis is 53 years and with dementia is 68 years.     

Calcification of the basal ganglia: computerized tomography and clinical correlation

During a 1-year period, 4219 consecutive computerized tomograms (CT) were reviewed for basal ganglia calcification; 14 patients with such calcification were identified. Calcifications on CT scan were bilateral in 12 of these cases and unilateral in 2. All bilateral calcifications were symmetric. The globus pallidus was the site of calcification in 13 of the 14 patients. Bilateral dentate nucleus calcification was seen in one patient. Skull radiograms were normal in all but one. Patients had diverse symptoms that were often explained by other findings, suggesting that calcifications may be coincidental and that basal ganglia calcification may not be a nosologic entity. Disturbances of calcium metabolism were not found in these patients, minimizing the pathophysiologic significance of altered calcium metabolism and the need for extensive endocrinologic evaluation. The finding of basal ganglia calcification alone does not justify invasive diagnostic procedures. Extrapyramidal signs may be associated with basal ganglia calcification; parkinsonism associated with basal ganglia calcification differs from idiopathic parkinsonism in being resistant to levodopa therapy.     

Psychosis revealing familial idiopathic basal ganglia calcification

We describe the case of a 39-year-old woman presenting with auditory hallucinations and delusions responsive to antipsychotic drugs. Computerized tomography scans revealed basal ganglia calcifications in the proband and in her two asymptomatic parents. Extensive etiological clinicobiological assessment allowed us to exclude known causes of brain calcifications and diagnose familial idiopathic basal ganglia calcification (IBGC).     

Parkinsonism,basal ganglia calcification and epilepsy as late complications of postoperative hypoparathyroidism

Summary A patient with post-thyroidectomy hypoparathyroidism, basal ganglia calcification, parkinsonism and seizures is reported. The parkinsonism was resistant to levodopa therapy but was not significantly improved by the correction of hypoparathyroidism. Previously reported cases are discussed, as well as the relationship between hypoparathyroidism, calcification of basal ganglia, parkinsonism and epilepsy.     

Exclusion of linkage to chromosomes 14q, 2q37 and 8p21.1-q11.23 in a Serbian family with idiopathic basal ganglia calcification

In this study we report clinical and imaging data from a multigenerational Serbian family with idiopathic basal ganglia calcification (IBGC) and exclusion of linkage to chromosome 14q, 2q37 and 8p21.1-q11.23. Fourteen out of 18 family members were personally examined and 11 of them were scanned with computed tomography (CT). CT scans revealed existence of symmetrical calcifications in six family members from three generations (four symptomatic and two asymptomatic). Age at onset of clinical symptoms varied between 22.0 and 55.4 years. The main clinical findings included parkinsonism, severe gait disturbances with freezing of gait, and dyskinesia. Hyperechogenicities identified by transcranial sonography corresponded well to the CT images of hyperintense calcifications in the same structures, whereas brain perfusion single photon emission computed tomography demonstrated predominant hypoperfusion in the frontal cortex and the basal ganglia. After exclusion of linkage to known loci, our pedigree with IBGC further demonstrates locus heterogeneity in this disorder. Analysis of clinically affected individuals supports observation that the clinical features of IBGC appear to be varied both within and between families. The age at onset of the clinical symptoms appeared to be decreasing in two observed transmissions, suggestive of possible genetic anticipation.     

SLC20A2 and THAP1 deletion in familial basal ganglia calcification with dystonia

Idiopathic basal ganglia calcification (IBGC) is characterized by bilateral calcification of the basal ganglia associated with a spectrum of neuropsychiatric and motor syndromes. In this study, we set out to determine the frequency of the recently identified IBGC gene SLC20A2 in 27 IBGC cases from the Mayo Clinic Florida Brain Bank using both Sanger sequencing and TaqMan copy number analysis to cover the complete spectrum of possible mutations. We identified SLC20A2 pathogenic mutations in two of the 27 cases of IBGC (7 %). Sequencing analysis identified a p.S113* nonsense mutation in SLC20A2 in one case. TaqMan copy number analysis of SLC20A2 further revealed a genomic deletion in a second case, which was part of a large previously reported Canadian IBGC family with dystonia. Subsequent whole-genome sequencing in this family revealed a 563,256-bp genomic deletion with precise breakpoints on chromosome 8 affecting multiple genes including SLC20A2 and the known dystonia-related gene THAP1. The deletion co-segregated with disease in all family members. The deletion of THAP1 in addition to SLC20A2 in the Canadian IBGC family may contribute to the severe and early onset dystonia in this family. The identification of an SLC20A2 genomic deletion in a familial form of IBGC demonstrates that reduced SLC20A2 in the absence of mutant protein is sufficient to cause neurodegeneration and that previously reported SLC20A2 mutation frequencies may be underestimated.     

Clinical features of bipolar disorder with idiopathic basal ganglia calcification: a review of case reports in the literature

Although idiopathic basal ganglia calcification (IBGC) is associated with various neuropsychiatric disturbances including several cases of bipolar disorder (BD), there has been no systematic review of clinical features of patients with BD and comorbid IBGC. We undertook a literature search to identify case reports of these patients. Most cases showed complex syndromes comprising not only mood disturbance but also cognitive disability and motor symptoms limited to depressive state and had favorable treatment response. These patients should have a careful and repeated psychiatric, neurological, and cognitive assessment to determine an optimal diagnostic and treatment approaches at each clinical stage.     

特发性基底节钙化的临床分析

目的探讨特发性基底节钙化的临床特点与头部CT表现,防止漏诊及误诊。方法分析24例特发性基底节钙化的临床特点与头部CT的表现。结果(1)24例病例均为散发;(2)临床表现主要为癫癎发作、锥体外系症状、进行性痴呆、头昏、失眠等,亦可无临床表现,血清钙、磷均正常;(3)头颅CT主要表现为对称性双侧基底节钙化。结论特发性基底节钙化的临床表现无特异性。在排除其它可引起基底节钙化的相关疾病的基础上,头颅CT及实验室检查对本病诊断有重要意义,尤其对无症状者更有意义。     

AIDS: calcification of the basal ganglia in infants and children

CT or postmortem examination demonstrated calcification of the basal ganglia in eight infants and children with acquired immune deficiency syndrome. Serial CT studies documented progression of both bilateral symmetric calcium densities and cerebral atrophy. Clinical features included progressive encephalopathy with dementia, and pyramidal tract signs. Postmortem examination of four children revealed variable degrees of calcific vasopathy of the basal ganglia, involving predominantly the putamen and globus pallidus.     

Quetiapine responsive catatonia in an autistic patient with comorbid bipolar disorder and idiopathic basal ganglia calcification

Background: Bipolar disorder (BD) has been linked with the manifestation of catatonia in subjects with autism spectrum disorders (ASD). Idiopathic basal ganglia calcification (IBGC) is characterized by movement disorders and various neuropsychiatric disturbances including mood disorder. Case: We present a patient with ASD and IBGC who developed catatonia presenting with prominent dystonic feature caused by comorbid BD, which was treated effectively with quetiapine. Conclusion: In addition to considering the possibility of neurodegenerative disease, careful psychiatric interventions are important to avoid overlooking treatable catatonia associated with BD in cases of ASD presenting with both prominent dystonic features and apparent fluctuation of the mood state.     

Analysis of Candidate Genes at the IBGC1 Locus Associated with Idiopathic Basal Ganglia Calcification (“Fahr’s Disease”)

Basal ganglia calcification (striatopallidodentate calcifications) can be caused by several systemic and neurological disorders. Familial Idiopathic Basal Ganglia Calcification (IBGC, “Fahr’s disease”), is characterized by basal ganglia and extrabasal ganglia calcifications, parkinsonism and neuropsychiatric symptoms. Because of an increased use of neuroimaging procedures, calcifications of the basal ganglia are visualized more often and precociously. In 1999, a major American family with IBGC was linked to a locus on chromosome 14q (IBGC1). Another small kindred, from Spain, has also been reported as possibly linked to this locus. Here we report the main findings of the first 30 candidate genes sequenced at the IBGC1 locus during the process of searching for a mutation responsible for familial IBGC. During the sequencing process, we identified a heterozygous nonsynonymous single nucleotide polymorphism (exon 20 of the MGEA6/c-TAGE gene) shared by the affected and not present in the controls. This SNP was randomly screened in the general population (348 chromosomes) in a minor allele frequency to 0.0058 (two heterozygous among 174 subjects). Another variation in this gene, in the exon 9, was found in the Spanish family. However, this variation was extremely common in the general population. Functional and population studies are necessary to fully access the implications of the MGEA6 gene in familial IBGC, and a complete sequencing of the IBGC1 locus will be necessary to define a gene responsible for familial IBGC.     

Neuroradiologic Evidence of Pre‐Synaptic and Post‐Synaptic Nigrostriatal Dopaminergic Dysfunction in Idiopathic Basal Ganglia Calcification: A Case Report

Idiopathic basal ganglia calcification (IBGC) is a neuropathological condition known to manifest as motor disturbance, cognitive impairment, and psychiatric symptoms. The pathophysiology of the psychiatric symptoms of IBGC, however, remains controversial. A previous biochemical study suggested that dopaminergic impairment is involved in IBGC. We thus hypothesized that dopaminergic dysfunction might be related with the psychiatric manifestations of IBGC. We used positron emission tomography to measure glucose metabolism and dopaminergic function in the basal ganglia of an IBGC patient with psychiatric symptoms. The results showed that widespread hypometabolism was evident in the frontal, temporal, and parietal cortices while the decline in dopaminergic function was severe in the bilateral striatum. The functional decline of the dopamine system in the calcified area of the bilateral striatum and the disruption of cortico‐subcortical circuits may contribute to clinical manifestations of IBGC in our patient.     

Delayed parkinsonism with a selective symmetric basal ganglia lesion after manual strangulation

A 21-year-old woman, who experienced manual strangulation, developed delayed parkinsonism associated with a selective symmetric basal ganglia lesion. The patient had recovered completely one year after early combination therapy. This case emphasizes the need for greater attention in detecting early brain injuries in those afflicted with strangulation so as to provide optimal management.     

Neurological deficits are associated with increased brain calcinosis, hypoperfusion, and hypometabolism in idiopathic basal ganglia calcification.

We report two familial cases of idiopathic basal ganglia calcification. A 60-year-old proband with choreoathetosis, dysarthria, and cognitive decline showed more extensive brain calcinosis, hypoperfusion, and hypometabolism than did his asymptomatic 82-year-old mother. The mother had no frontal lobe calcinosis but basal ganglia and dentate nucleus depositions were detectable. Perfusion neuroimaging, however, was normal in the asymptomatic mother and abnormal in the clinically impaired proband. The presence of calcinosis cannot be used as an index of neurological impairment but the extent of calcinosis and reduction in perfusion and metabolism may be useful for separating symptomatic from asymptomatic subjects with IBGC. These findings suggest that an interruption of neuronal circuitry may cause neurological deficits. The degree of neurological deficits may correlate with the severity of calcinosis and the reduction of perfusion and metabolism.     

Cortical myoclonus and epilepsy in a family with a new SLC20A2 mutation

Journal of Neurology - Idiopathic basal ganglia calcification (IBGC) or primary familial brain calcification is a rare genetic condition characterized by an autosomal dominant inheritance pattern...     

Functional anatomy of the basal ganglia in X-linked recessive dystonia-parkinsonism

Dystonia is a neurological syndrome characterized by sustained muscle contractions that produce repetitive twisting movements or abnormal postures. X-linked recessive dystonia parkinsonism (XDP; DYT3; Lubag) is an adult-onset disorder that manifests severe and progressive dystonia with a high frequency of generalization. In search for the anatomical basis for dystonia, we performed postmortem analyses of the functional anatomy of the basal ganglia based on the striatal compartments (ie, the striosomes and the matrix compartment) in XDP. Here, we provide anatomopathological evidence that, in the XDP neostriatum, the matrix compartment is relatively spared in a unique fashion, whereas the striosomes are severely depleted. We also document that there is a differential loss of striatal neuron subclasses in XDP. In view of the three-pathway basal ganglia model, we postulate that the disproportionate involvement of neostriatal compartments and their efferent projections may underlie the manifestation of dystonia in patients with XDP. This study is the first to our knowledge to show specific basal ganglia pathology that could explain the genesis of dystonia in human heredodegenerative movement disorders, suggesting that dystonia may result from an imbalance in the activity between the striosomal and matrix-based pathways.     

It's not just the basal ganglia: Cerebellum as a target for dystonia therapeutics

Dystonia is a common movement disorder that devastates the lives of many patients, but the etiology of this disorder remains poorly understood. Dystonia has traditionally been considered a disorder of the basal ganglia. However, growing evidence suggests that the cerebellum may be involved in certain types of dystonia, raising several questions. Can different types of dystonia be classified as either a basal ganglia disorder or a cerebellar disorder? Is dystonia a network disorder that involves the cerebellum and basal ganglia? If dystonia is a network disorder, how can we target treatments to alleviate symptoms in patients? A recent study by Chen et al, using the pharmacological mouse model of rapid‐onset dystonia parkinsonism, has provided some insight into these important questions. They showed that the cerebellum can directly modulate basal ganglia activity through a short latency cerebello‐thalamo‐basal ganglia pathway. Further, this article and others have provided evidence that in some cases, aberrant cerebello‐basal ganglia communication can be involved in dystonia. In this review we examine the evidence for the involvement of the cerebellum and cerebello‐basal ganglia interactions in dystonia. We conclude that there is ample evidence to suggest that the cerebellum plays a role in some dystonias, including the early‐onset primary torsion dystonia DYT1 and that further studies examining the role of this brain region and its interaction with the basal ganglia in dystonia are warranted. © 2017 International Parkinson and Movement Disorder Society     

Bilateral basal ganglia calcifications visualised on CT scan.

Thirty-eight cases of basal ganglia calcification imaged on computed axial tomography were reviewed. Most cases were felt to represent senescent calcification. The possibility of a vascular aetiology in this group is discussed. A less common group of patients was identified with calcification secondary to abnormalities in calcium metabolism or radiation therapy. Three cases of basal ganglia calcifications were detected in juvenile epileptic patients receiving chronic anticonvulsants. These cases may be related to abnormalities in calcium metabolism and alkaline phosphatase activity. Clinical evidence of basal ganglia abnormality was generally absent demonstrating the preservation of neuronal pathways in most cases.