Intracranial calcifications in childhood: Part 1

Zika virus as a new pathogenic agent within the Toxoplasma gondii, Rubella virus, Cytomegalovirus, and Herpes simplex (TORCH) virus family: where do we stand?

Viral infections in low-income countries such as Brazil pose a significant challenge for medical authorities, with epidemics such as Zika virus infection having lasting effects. The increase in microcephaly among newborns has prompted investigations into the association between Zika virus and this congenital syndrome. The severity and prevalence of microcephaly led to the declaration of national and international emergencies. Extensive research has been conducted to understand the teratogenic effects of Zika virus, particularly its impact on neural progenitor cells in the fetal brain. Various pre- and postnatal imaging techniques, such as ultrasound, magnetic resonance imaging (MRI), and postnatal computed tomography (CT), have played crucial roles in diagnosing and monitoring malformations linked to congenital Zika virus infection in the central nervous system (CNS). These modalities can detect brain parenchymal abnormalities, calcifications, cerebral atrophy, and callosal anomalies. Additionally, three-dimensional ultrasound and fetal MRI provide detailed anatomical images, while CT can identify calcifications that are not easily detected by other methods. Despite advancements in imaging, there are still unanswered questions and ongoing challenges in comprehending the long-term effects and developmental impairments in children affected by Zika virus. Radiologists continue to play a crucial role in diagnosing and assisting in the management of these cases.

Toxoplasma gondii infections in pediatric neurosurgery

Toxoplasma gondii is a parasite that is estimated to infect one-third of the world's population. It is acquired by ingesting contaminated water and food specially undercooked meat, contact with domestic or wild feline feces, and during pregnancy by transplacental transmission.Immunocompetent hosts are usually asymptomatic, and infection will be self-limited, while those patients whose immune system is debilitated by HIV infection, immunosuppressive therapy, long-term steroid treatment, and fetuses infected during gestation will show evidence of systemic activity which is more severe in the central nervous system and eyes due to insufficient immune response caused by their respective blood barriers. Congenital toxoplasmosis has an estimated incidence of 8% in mothers who were seronegative at the beginning of their pregnancy. Infection in the first trimester may result in spontaneous abortion or stillbirth; however, it is estimated that the highest risk for vertical transmission is during the second and third trimesters when blood flow and placenta thickness favor parasitic transmission.Congenital toxoplasmosis can be detected with periodic surveillance in endemic areas, and with appropriate treatment, the risk of vertical transmission can be reduced, and the severity of the disease can be reversed in infected fetuses.While most infected newborns will show no evidence of the disease, those who suffer active intrauterine complications will present with cerebral calcifications in 8-12% of cases, hydrocephalus in 4-30%, and chorioretinitis in 12-15%. Also, seizure disorders, spasticity, and varying degrees of neurocognitive deficits can be found in 12%.Four distinct patterns of hydrocephalus have been described: aqueductal stenosis with lateral and third ventricle dilatation, periforaminal calcifications leading to foramen of Monro stenosis with associated asymmetrical ventricle dilatation, a mix of aqueductal and foramen of Monro stenosis, and overt hydrocephalus without clear evidence of obstruction with predominant dilatation of occipital horns (colpocephaly).While all patients diagnosed with congenital toxoplasmosis should undergo pharmacological treatment, those presenting with hydrocephalus have traditionally been managed with CSF shunting; however, there are reports of at least 50% success when selected cases are treated with endoscopic third ventriculostomy. Successful hydrocephalus management with appropriate treatment leads to better intellectual outcomes.

Congenital hydrocephalus diagnosed in a nonagenarian: Case report

Congenital hydrocephalus after peripartum infection usually presents early in life; however, we present a 92-year-old female patient with newly diagnosed hydrocephalus secondary to peripartum infection. Intracranial imaging showed ventriculomegaly, calcifications bilaterally throughout the cerebral hemispheres, and findings suggesting a chronic process. This presentation is most likely to occur in low-resource settings, and given the risks of operation, conservative management was preferred.

Imaging features of neurosyphilis

Syphilis is an infectious disease caused by the spirochete Treponema pallidum, subspecies pallidum. Although its incidence has declined after the widespread availability of penicillin, it has recently re-emerged, especially in men who have sex with men and in people living with human immunodeficiency virus (HIV). The neurological manifestations of syphilis, generally known as neurosyphilis, may appear at any time during the infection, including the initial years after the primary infection. Neurosyphilis can be asymptomatic, only with cerebrospinal fluid abnormalities, or symptomatic, characterized by several different clinical syndromes, such as meningitis, gumma, meningovascular, brain parenchyma involvement, meningomyelitis, tabes dorsalis, and peripheral nervous system involvement. However, these syndromes may simulate several other diseases, making the diagnosis often a challenge. In addition, syphilis can also be vertically transmitted from mother to child during pregnancy, leading to neurological manifestations. Neuroimaging is essential to demonstrate abnormal brain or spinal cord findings in patients with neurosyphilis, aiding in the diagnosis, treatment, and follow-up of these patients. This article aims to review the imaging features of neurosyphilis, including the early and late stages of the infection.

Retinal Findings in Haemorrhagic Destruction of the Brain, Subependymal Calcification, and Congenital Cataracts (HDBSCC): Case Report and Review

We describe a child from a consanguineous family born with a rare autosomal recessive disorder affecting junctional adhesion molecule 3 (JAM3) causing profound neurological and ophthalmological injury known as haemorrhagic brain destruction, subependymal calcifications, and congenital cataracts (HDBSCC; MIM# 613730). She was the product of an unremarkable pregnancy and was born near to term but was noted shortly after birth to have congenital cataracts, poor vision, increased muscle tone, seizures, and developmental delay. Her older sister had an identical syndrome and had previously been documented to have homozygous mutations in JAM3. Examination in our patient, although difficult because of bilateral central cataracts, revealed very poor vision, attenuated retinal vessels, optic atrophy, and a retinal haemorrhage in the right eye, implying that abnormal development of the retinas and/or optic nerves may at times play a significant role in the poor vision noted in children with HDBSCC.

Mitochondrial Dysfunction and Oxidative Stress in Hereditary Ectopic Calcification Diseases

Ectopic calcification (EC) is characterized by an abnormal deposition of calcium phosphate crystals in soft tissues such as blood vessels, skin, and brain parenchyma. EC contributes to significant morbidity and mortality and is considered a major health problem for which no effective treatments currently exist. In recent years, growing emphasis has been placed on the role of mitochondrial dysfunction and oxidative stress in the pathogenesis of EC. Impaired mitochondrial respiration and increased levels of reactive oxygen species can be directly linked to key molecular pathways involved in EC such as adenosine triphosphate homeostasis, DNA damage signaling, and apoptosis. While EC is mainly encountered in common diseases such as diabetes mellitus and chronic kidney disease, studies in rare hereditary EC disorders such as pseudoxanthoma elasticum or Hutchinson-Gilford progeria syndrome have been instrumental in identifying the precise etiopathogenetic mechanisms leading to EC. In this narrative review, we describe the current state of the art regarding the role of mitochondrial dysfunction and oxidative stress in hereditary EC diseases. In-depth knowledge of aberrant mitochondrial metabolism and its local and systemic consequences will benefit the research into novel therapies for both rare and common EC disorders.

The role of type I IFN in autoimmune and autoinflammatory diseases with CNS involvement

Type I interferons (IFNs) are major mediators of innate immunity, with well-known antiviral, antiproliferative, and immunomodulatory properties. A growing body of evidence suggests the involvement of type I IFNs in the pathogenesis of central nervous system (CNS) manifestations in the setting of chronic autoimmune and autoinflammatory disorders, while IFN-β has been for years, a well-established therapeutic modality for multiple sclerosis (MS). In the present review, we summarize the current evidence on the mechanisms of type I IFN production by CNS cellular populations as well as its local effects on the CNS. Additionally, the beneficial effects of IFN-β in the pathophysiology of MS are discussed, along with the contributory role of type I IFNs in the pathogenesis of neuropsychiatric lupus erythematosus and type I interferonopathies.

Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications

PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.

Hippocampal calcification and its effects on cognitive function and symptoms in dementia

BACKGROUND

Hippocampal calcification (HC), highly prevalent in older people, has not attracted attention until recently. Despite its potential effects on cognition and behaviour, and its possible impact on the diagnosis and severity of dementia, it has not been investigated. This study aimed to evaluate the prevalence of HC and its influence on cognition and behavioural symptoms in patients with dementia.

METHODS

Data from consecutive patients who visited a medical centre for dementia, for the first time between April 2016 and September 2018, were extracted and analysed. These data included the patients' demographics, the presence of HC and hippocampal thickness as measured on computed tomography, the diagnosis of dementia and its type, cognitive function measured using the Mini-Mental State Examination and the Clock Drawing Test, and the chief complaints or symptoms prompting the visit.

RESULTS

A high incidence of HC (85/267 patients) was observed. There was no significant difference in the ages of patients with and without HC. Patients with HC had higher cognitive function than those without HC at their first visit. This result was contrary to our expectations as it was not explained by the chief complaints recorded at the first visit.

CONCLUSIONS

Our study showed a high prevalence of HC in older patients with dementia. Patients with HC had better cognitive function than did those without HC during their first hospital visit. This study suggests that HC may not affect the cognitive functions related to dementia. However, further research is needed to evaluate the long-term consequences of dementia with HC.

Delineating the epilepsy phenotype of NRROS-related microgliopathy: A case report and literature review

BACKGROUND

Negative regulator of reactive oxygen species (NRROS) related microgliopathy, a rare and recently recognized neurodegenerative condition, is caused by pathogenic variants in the NRROS gene, which plays a major role in the regulation of transforming growth factor-beta 1.

METHODS

We report a child presenting with infantile spasms syndrome (ISS) with subsequent progressive neurodegeneration who was identified to harbour a novel likely pathogenic NRROS variant (c.1359del; p.Ser454Alafs*11). The previously published reports of patients with this disorder were also reviewed systematically.

RESULTS

Including our index patient, 11 children (6 girls) were identified in total. Early development was normal in seven of these eleven children. All had a history of drug-resistant epilepsy, with 3 having epileptic spasms. The median age at seizure onset and developmental regression was 12 months, and the median age at death was 36 months. Intracranial calcifications were described in eight of eleven children. Neuroimaging revealed progressive cerebral atrophy and white matter loss in all children. The most common reported genetic variation was c.1981delC; (p.Leu661Serfs*97) observed in two families (likely due to a founder effect).

CONCLUSIONS

Pathogenic variants in NRROS should be suspected in children with neuro-regression and drug-resistant epilepsy including ISS with onset in the first two years of life. Punctate or serpiginous calcifications at the grey-white matter junction and acquired microcephaly are further clues towards the diagnosis.

Intracranial calcification and psychotic symptoms after irradiation in a patient with Fanconi anemia: A case report

Background

Patients with Fanconi anemia (FA) are at high risk for the development of malignancies, and are often treated with radiation therapy. Radiation therapy during childhood can cause intracranial calcification after a latent period, which has been associated with psychiatric symptoms. Despite the high sensitivity of patients with FA to radiation, intracranial calcification has rarely been reported in these patients.

Case Presentation

A 17-year-old girl presented with psychiatric symptoms and cognitive impairment. She had been diagnosed with FA at 3 years old, and had received a bone marrow transplant at 5 years old with a preparative regimen that included total body irradiation. Results of IQ tests revealed a characteristic pattern of decline between the ages of 15 and 17 years. Computed tomography indicated multiple intracranial calcifications in regions associated with psychotic symptoms, including the frontal lobe and thalamus. The patient's psychiatric symptoms improved with the administration of blonanserin.

Limitations

The patient did not have regular intracranial imaging, making it difficult to confirm a direct relationship between intracranial calcification, psychiatric symptoms, and cognitive impairment. It is unclear whether the intracranial calcification in this case can be explained entirely by irradiation.

Conclusion

This case suggests a link between FA, intracranial calcification, and psychosis, in which intracranial calcification may have caused psychiatric symptoms. At present, evidence regarding the characteristics of psychiatric symptoms of intracranial calcification and its treatment is lacking. The current case will be helpful for elucidating the pathogenesis of this disorder and developing appropriate treatment protocols.

The Interplay Between Brain Vascular Calcification and Microglia

Vascular calcifications are characterized by the ectopic deposition of calcium and phosphate in the vascular lumen or wall. They are a common finding in computed tomography scans or during autopsy and are often directly related to a pathological condition. While the pathogenesis and functional consequences of vascular calcifications have been intensively studied in some peripheral organs, vascular calcification, and its pathogenesis in the central nervous system is poorly characterized and understood. Here, we review the occurrence of vessel calcifications in the brain in the context of aging and various brain diseases. We discuss the pathomechanism of brain vascular calcification in primary familial brain calcification as an example of brain vessel calcification. A particular focus is the response of microglia to the vessel calcification in the brain and their role in the clearance of calcifications.

Intracranial Calcification Associated with 3-Methylcrotonyl-CoA Carboxylase Deficiency

3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency is the most frequent organic aciduria detected in newborn screening programs. It demonstrates a variable heterogeneous clinical phenotype, ranging from neonatal onset with severe neurological disorders to asymptomatic adult forms. Herein, we report the first 2 related cases of 3-MCC deficiency presenting with intracranial calcification in the literature. A girl and a boy aged 3 years, 9 months and 4 years were included in the study. The main clinical manifestations were acquired microcephaly, global developmental delay, intractable seizures, mild feeding difficulty, and intermittent dystonic contractions. On physical and neurological examinations, their weights, heights, and head circumferences were below the 3rd percentile, they had acquired microcephaly, truncal hypotonia, upper and lower limb spasticity, hyperreflexia, positive bilateral Babinski signs, and clonus. The detailed biochemical and metabolic tests were unremarkable, except blood 3-hydroxyisovalerylcarnitine (C5OH) was slightly increased in case 1. Cranial computed tomography demonstrated mild cerebral and cerebellar atrophy as well as bilateral periventricular and thalamic calcifications in both cases. We identified a homozygous mutation of c.1015G>A (p.V339M) in the MCCC2gene, and the mutation was confirmed by Sanger sequencing. To the best of our knowledge, our cases are the first reported describing intracranial calcification in cases with 3-MCC deficiency. This report expands on the underlying causes of intracranial calcifications and suggests that 3-MCC deficiency may have intracranial calcifications on bilateral thalamus and periventricular white matters. If clinical findings show intracranial calcification, 3-MCC deficiency should also be kept in mind.