White matter disorders with cerebral calcification in adulthood.

This chapter provides a comprehensive overview of adult-onset leukoencephalopathies with cerebral calcification (CC), emphasizing the importance of age at presentation, systemic clinical features, and neuroimaging patterns for accurate diagnosis. CC is a multifaceted phenomenon associated with various neurologic, developmental, metabolic, and genetic conditions, as well as normal aging. Here, we explore the distinction between primary familial brain calcification (PFBC) and secondary forms, including metabolic and mitochondrial causes. We discuss genetic causes, e.g., SLC20A2, XPR1, PDGFB, PDGFRB, MYORG, NAA60 and JAM2, in the context of autosomal dominant and recessive PFBC and other inherited conditions. The chapter delineates the diagnostic approach involving family history, clinical assessments, and detailed investigations of calcium-phosphate metabolism. Neuroimaging modalities, including computed tomography and magnetic resonance imaging, are crucial for assessing calcification patterns and localizations. Genetic testing, especially next-generation sequencing, plays a pivotal role in providing a final molecular diagnosis. The management of patients with CC encompasses symptomatic treatment and cause-specific approaches, requiring a multidisciplinary care approach. In conclusion, this chapter highlights the complexity of leukoencephalopathies with CC, emphasizing the need for integrated and evolving management to optimize patient care.

White matter abnormalities in amino acid disorders and organic acidurias.

Inborn errors of metabolism (IEMs) are traditionally the domain of pediatricians and internists for metabolic diseases. In general, neurologists only become involved when these disorders are complicated by neurologic symptoms such as seizures, developmental delay, or motor problems. However, in recent years and mainly due to the successes of next-generation sequencing, the number of IEMs primarily presenting with neurologic symptoms and not detected by classic biochemical testing has grown significantly. This in particular relates to disorders in the biosynthesis of amino acids. Therefore, I will start by discussing defects in the synthesis pathways of the amino acids serine, glutamine, proline, and asparagine. In these disorders, the amino acid can be low in body fluids with biochemical testing, but more frequently are completely normal and although are in different metabolic pathways, they share many clinical features such as hypomyelination and white matter abnormalities. Next, I will discuss classic amino acid disorders and organic acid disorders due to defects in breakdown pathways characterized by elevations of key metabolites in body fluids and associated with neurologic abnormalities and white matter changes on MRI.

General approach to treatment of genetic leukoencephalopathies in children and adults.

Despite the enormous advancements seen in recent years, curative therapies for patients with genetic leukoencephalopathies are available for only a relatively small number of disorders. Therefore, symptomatic treatment and preventive management of the multiple clinical manifestations of patients with genetic leukoencephalopathies are critical in their care. The goals of the symptomatic treatment are to improve patients' quality of life, increase their survival, and reduce the impact on medical resources and related expenses. The coordinated work of a multidisciplinary team, including all specialists involved in the care of these patients, is the gold standard approach to manage and treat their complex and evolving clinical picture. Along with a multidisciplinary team, the relationship and close collaboration with the patient and their caregivers are essential. Their insight into the disease manifestations and management of the different issues should be integrated with the assessments of the multidisciplinary team to prevent clinical complications and preserve the quality of life of patients and their caregivers. Genetic leukoencephalopathies are very heterogeneous in terms of age of onset, clinical features, and disease course. However, many clinical features and problems are shared by most forms. Consequently, common therapeutic strategies apply to the majority of these diseases. This chapter presents the symptomatic approach for shared core clinical features presented by patients with genetic leukoencephalopathies divided by systems and, for each system, the specificities of some genetic leukoencephalopathies.

Toxic leukoencephalopathies.

Toxic-metabolic encephalopathies are a group of disorders in which an exogenous or endogenous substance leads to transient or permanent neuronal damage. It is an important cause of potentially reversible acute encephalopathy syndrome. The signs and symptoms of toxic encephalopathies may be relatively nonspecific, and toxicologic tests are not always widely available. Imaging plays a key role in determining the most probable diagnosis, pointing to the next steps of investigation, and providing prognostic information. In this chapter, we review the main acquired toxic-metabolic leukoencephalopathies, commenting on their pathophysiology, imaging patterns, and rationale for an adequate diagnosis in detail.

Lysosomal storage diseases.

Lysosomal storage disorders (LSDs) are a group of inherited metabolic diseases caused by dysfunction of the lysosomal system, with subsequent progressive accumulation of macromolecules, activation of inflammatory response, and cell death. Neurologic damage is almost always present, and it is usually degenerative. White matter (WM) involvement may be primary or secondary. Diseases with primary WM involvement are leukodystrophies, demyelinating (Krabbe disease and metachromatic leukodystrophy), and hypomyelinating leukodystrophies (free sialic acid storage disease, fucosidosis, and mucolipidosis type IV). LSDs with secondary WM involvement are classified as leukoencephalopathies and include gangliosidosis, mucopolysaccharidosis (MPS), ceroid neuronal lipofuscinosis, multiple sulfatase deficiency, alpha-mannosidosis, Pompe disease, and Fabry disease. Neurologic manifestations may overlap among LSDs and include developmental delays, motor, cognitive and speech impairments, seizures, visual failure, ataxia, and extrapyramidal signs. Most of LSDs are typically present in early or late infancy, but juvenile and adult forms also exist and are associated with predominantly neuropsychiatric and behavioral symptoms. The outcome of these disorders is generally poor and specific treatments (enzyme replacement therapy, hematopoietic stem cell transplantation, or gene therapy) are only available in a small number of them.

Case report: A frameshift mutation in CLCN2-related leukoencephalopathy and retinopathy.

Background: Leukoencephalopathy and visual impairment have been linked to loss-of-function mutations in the CLCN2 gene (MIM #600570). However, the ocular features caused by the CLCN2 mutations remain poorly understood and seldom reported. This study aims to present a novel mutation and characterize the ocular phenotype in a Chinese female diagnosed with CLCN2-related leukoencephalopathy (CC2L), also known as leukoencephalopathy with ataxia (LKPAT; MIM #615651). Case presentation: A 20-year-old Chinese female presented with bilateral blurred vision persisting for 2 years, which had worsened over the past 6 months. Ophthalmologic examination revealed bilateral post-capsular cataracts, macular retinal atrophy, and peripheral retinal pigmentation. Swept-source optical coherence tomography (SS-OCT) showed bilateral choroidal capillary atrophy, loss of the outer retinal layer, and a novel noteworthy sign of vacuole-like vitreoretinopathy. Cranial magnetic resonance imaging confirmed leukoencephalopathy. Genetic testing identified a novel homozygous pathogenic c.1382_1386del (p.P461Lfs*13) mutation in exon 13 of the CLCN2 gene. Conclusion: This case report expands the knowledge of CLCN2 mutations and their associated ocular manifestations in patients with CC2L. The identified ophthalmic features may serve as crucial indicators for early diagnosis in individuals with CC2L, especially in the absence of evident neurological symptoms.

Management of Inherited CNS Small Vessel Diseases: The CADASIL Example: A Scientific Statement From the American Heart Association.

Lacunar infarcts and vascular dementia are important phenotypic characteristics of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, the most common inherited cerebral small vessel disease. Individuals with the disease show variability in the nature and onset of symptoms and rates of progression, which are only partially explained by differences in pathogenic mutations in the NOTCH3 gene. Recognizing the disease early in its course and securing a molecular diagnosis are important clinical goals, despite the lack of proven disease-modifying treatments. The purposes of this scientific statement are to review the clinical, genetic, and imaging aspects of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, contrasting it with other inherited small vessel diseases, and to provide key prevention, management, and therapeutic considerations with the intent of reducing practice variability and encouraging production of high-quality evidence to support future treatment recommendations.

Comparison of the clinical value of MRI and plasma markers for cognitive impairment in patients aged ≥75 years: a retrospective study.

Background: Dementia has become the main cause of disability in older adults aged ≥75 years. Cerebral small vessel disease (CSVD) is involved in cognitive impairment (CI) and dementia and is a cause of vascular CI (VCI), which is manageable and its onset and progression can be delayed. Simple and effective markers will be beneficial to the early detection and intervention of CI. The aim of this study is to investigate the clinical application value of plasma amyloid ß1-42 (Aß42), phosphorylated tau 181 (p-tau181) and conventional structural magnetic resonance imaging (MRI) parameters for cognitive impairment (CI) in patients aged ≥75 years. Methods: We retrospectively selected patients who visited the Affiliated Hospital of Xuzhou Medical University and were clinically diagnosed with or without cognitive dysfunction between May 2018 and November 2021. Plasma indicators (Aß42 and p-tau181) and conventional structural MRI parameters were collected and analyzed. Multivariate logistic regression and receiver operator characteristic (ROC) curve were used to evaluate the diagnostic value. Results: One hundred and eighty-four subjects were included, including 54 cases in CI group and 130 cases in noncognitive impairment (NCI) groups, respectively. Univariate logistic regression analysis revealed that the percentages of Aß42+, P-tau 181+, and Aß42+/P-tau181+ showed no significant difference between the groups of CI and NCI (all P > 0.05). Multivariate logistic regression analysis showed that moderate/severe periventricular WMH (PVWMH) (OR 2.857, (1.365-5.983), P = 0.005), lateral ventricle body index (LVBI) (OR 0.413, (0.243-0.700), P = 0.001), and cortical atrophy (OR 1.304, (1.079-1.575), P = 0.006) were factors associated with CI. The combined model including PVWMH, LVBI, and cortical atrophy to detect CI and NCI showed an area under the ROC curve (AUROC) is 0.782, with the sensitivity and specificity 68.5% and 78.5%, respectively. Conclusion: For individuals ≥75 years, plasma Aß42 and P-tau181 might not be associated with cognitive impairment, and MRI parameters, including PVWMH, LVBI and cortical atrophy, are related to CI. The cognitive statuses of people over 75 years old were used as the endpoint event in this study. Therefore, it can be considered that these MRI markers might have more important clinical significance for early assessment and dynamic observation, but more studies are still needed to verify this hypothesis.

Síndrome de Aicardi-Goutieres: Diagnóstico genético en una lactante

El Síndrome de Aicardi-Goutieres (SAG) se caracteriza por una encefalopatía genética, progresiva, de inicio temprano, que se asocia a un proceso inflamatorio. Además del SNC, puede afectar a la piel, con erupciones tipo sabañones, y presentar microcefalia, talla baja, disfunción hepática, disfunción tiroidea, reactantes de fase aguda elevados, anticuerpos autoinmunes positivos y asociaciones para enfermedades sistémicas autoinmunes como él LES. El SAG presenta locus heterogénicos, con mutaciones identificadas en los genes que codifican el exonucleasa TREX1 3´â†’5´ y las tres subunidades del complejo de endonucleasa RNASEH2. Se presenta el caso de una paciente de 2 años de edad, con retraso del desarrollo psicomotor, sin otras manifestaciones sistémicas, diagnosticada como SAG, con variante c.529G(A (p.Ala177Thr) con efecto patogénico en homocigosis en el gen RNASEH2B.

Aicardi-Goutieres Syndrome (AGS) is characterized by an early-onset, progressive, genetic encephalopathy associated with an inflammatory process. In addition to the CNS, it can affect the skin, with chilblain-like eruptions, and present with microcephaly, short stature, liver dysfunction, thyroid dysfunction, elevated acute phase reactants, positive autoimmune antibodies, and associations for autoimmune systemic diseases such as SLE. SAG presents heterogeneous loci, with mutations identified in the genes encoding the TREX1 3'→5' exonuclease and the three subunits of the RNASEH2 endonuclease complex. We present the case of a female 2-year-old patient, with delayed psychomotor development, without other systemic manifestations, diagnosed as SAG, with variant c.529G>A (p.Ala177Thr) with a pathogenic effect in homozygosis in the RNASEH2B gene.

Adult-onset leukodystrophy with vanishing white matter: a case series of 19 patients.

BACKGROUND: Leukodystrophy with vanishing white matter (LVWM) is an autosomal recessive disease with typical pediatric-onset caused by mutations in one of the five EIF2B genes. Adult-onset (AO) cases are rare. METHODS: In this observational study, we reviewed clinical and laboratory information of the patients with AO-LVWM assessed at two referral centers in Italy and Portugal from Jan-2007 to Dec-2019. RESULTS: We identified 18 patients (13 females) with AO-LVWM caused by EIF2B5 or EIF2B3 mutations. Age of neurological onset ranged from 16 to 60 years, with follow-ups occurring from 2 to 37 years. Crucial symptoms were cognitive and motor decline. In three patients, stroke-like events were the first manifestation; in another, bladder dysfunction remained the main complaint across decades. Brain MRI showed white matter (WM) rarefaction in all cases, except two. Diffusion-weighted imaging documented focal hyperintensity in the acute stage of stroke-like events. 1H-spectroscopy primarily showed N-acetyl-aspartate reduction; 18fluorodeoxyglucose-PET revealed predominant frontoparietal hypometabolism; evoked potential studies demonstrated normal-to-reduced amplitudes; neuro-ophthalmological assessment showed neuroretinal thinning, and b-wave reduction on full-field electroretinogram. Interestingly, we found an additional patient with LVWM-compatible phenotype and monoallelic variants in two distinct eIF2B genes, EIF2B1 and EIF2B2. CONCLUSIONS: AO-LVWM presents varying clinical manifestations at onset, including stroke-like events. WM rarefaction is the most consistent diagnostic clue even in the latest onset cases. Spectroscopy and electrophysiological features are compatible with axon, rather than myelin, damage. Cerebral glucose metabolic abnormalities and retinal alterations can be present. LVWM might also be caused by a digenic inheritance affecting the eIF2B complex.

Age-related white matter hyperintensities and overactive bladder: A systematic review.

INTRODUCTION: Age-related white matter hyperintensities (ARWMHs) on brain magnetic resonance imaging have been associated with lower urinary tract symptoms/dysfunction (LUTS/LUTD), namely overactive bladder (OAB) and detrusor overactivity. We aimed to systematically review existing data on the association between ARWMH and LUTS and which clinical tools have been used for this assessment. MATERIALS AND METHODS: We searched PubMed/MEDLINE, Cochrane Library, and clinicaltrials.gov (from 1980 to November 2021) and considered original studies reporting data on ARWMH and LUTS/LUTD in patients of both sexes aged 50 or above. The primary outcome was OAB. We calculated the unadjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for the outcomes of interest using random-effects models. RESULTS: Fourteen studies were included. LUTS assessment was heterogeneous and mainly based on the use of nonvalidated questionnaires. Urodynamics assessment was reported in five studies. ARWMHs were graded using visual scales in eight studies. Patients with moderate-to-severe ARWMHs were more likely to present with OAB and urgency urinary incontinence (UUI; OR = 1.61; 95% CI: 1.05-2.49, p = 0.03), I2 = 21.3%) when compared to patients with similar age and absent or mild ARWMH. DISCUSSION AND CONCLUSIONS: High-quality data on the association between ARWMH and OAB is scarce. Patients with moderate to severe ARWMH showed higher levels of OAB symptoms, including UUI, when compared to patients with absent or mild ARWMH. The use of standardized tools to assess both ARWMH and OAB in these patients should be encouraged in future research.

Complex neurological and multisystem presentations in mitochondrial disease.

Mitochondrial diseases typically involve organs highly dependent on aerobic metabolism and are often progressive with high morbidity and mortality. In the previous chapters of this book, classical mitochondrial phenotypes and syndromes are extensively described. However, these well-known clinical pictures are more the exception rather than the rule in mitochondrial medicine. In fact, more complex, unspecified, incomplete, and/or overlap clinical entities may be even more frequent, with multisystem appearance or progression. In this chapter, we describe some complex neurological presentations, as well as the multisystem manifestations of mitochondrial diseases, ranging from the brain to the other organs.

Association of white matter lesions and brain atrophy with the development of dementia in a community: the Hisayama Study.

AIM: To investigate the association of white matter lesions volume (WMLV) levels with dementia risk and the association between dementia risk and the combined measures of WMLV and either total brain atrophy or dementia-related gray matter atrophy in a general older population. METHODS: One thousand one hundred fifty-eight Japanese dementia-free community-residents aged ≥65 years who underwent brain magnetic resonance imaging were followed for 5.0 years. WMLV were segmented using the Lesion Segmentation Toolbox. Total brain volume (TBV) and regional gray matter volume were estimated by voxel-based morphometry. The WMLV-to-intracranial brain volume ratio (WMLV/ICV) was calculated, and its association with dementia risk was estimated using Cox proportional hazard models. Total brain atrophy, defined as the TBV-to-ICV ratio (TBV/ICV), and dementia-related regional brain atrophy defined based on our previous report were calculated. The association between dementia risk and the combined measures of WMLV/ICV and either total brain atrophy or the number of atrophied regions was also tested. RESULTS: During the follow-up, 113 participants developed dementia. The risks of dementia increased significantly with higher WMLV/ICV levels. In addition, dementia risk increased additively both in participants with higher WMLV/ICV levels and lower TBV/ICV levels and in those with higher WMLV/ICV levels and a higher number of dementia-related brain regional atrophy. CONCLUSION: The risk of dementia increased significantly with higher WMLV/ICV levels. An additive increment in dementia risk was observed with higher WMLV/ICV levels and lower TBV/ICV levels or a higher number of dementia-related brain regional atrophy, suggesting the importance of prevention or control of cardiovascular risk factors.

The impact of antidepressants on human neurodevelopment: Brain organoids as experimental tools.

The use of antidepressants during pregnancy benefits the mother's well-being, but the effects of such substances on neurodevelopment remain poorly understood. Moreover, the consequences of early exposure to antidepressants may not be immediately apparent at birth. In utero exposure to selective serotonin reuptake inhibitors (SSRIs) has been related to developmental abnormalities, including a reduced white matter volume. Several reports have observed an increased incidence of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) after prenatal exposure to SSRIs such as sertraline, the most widely prescribed SSRI. The advent of human-induced pluripotent stem cell (hiPSC) methods and assays now offers appropriate tools to test the consequences of such compounds for neurodevelopment in vitro. In particular, hiPSCs can be used to generate cerebral organoids - self-organized structures that recapitulate the morphology and complex physiology of the developing human brain, overcoming the limitations found in 2D cell culture and experimental animal models for testing drug efficacy and side effects. For example, single-cell RNA sequencing (scRNA-seq) and electrophysiological measurements on organoids can be used to evaluate the impact of antidepressants on the transcriptome and neuronal activity signatures in developing neurons. While the analysis of large-scale transcriptomic data depends on dimensionality reduction methods, electrophysiological recordings rely on temporal data series to discriminate statistical characteristics of neuronal activity, allowing for the rigorous analysis of the effects of antidepressants and other molecules that affect the developing nervous system, especially when applied in combination with relevant human cellular models such as brain organoids.

Cochlear implantation in a profoundly deaf child with cystic leukoencephalopathy without megalencephaly.

BACKGROUND: Cochlear implantation candidacy criteria have continued to evolve over the years, and cochlear implantation is possible with many inner-ear and brain anomalies with good hearing and linguistic outcomes. Cystic leukoencephalopathy without megalencephaly is a rare disease in children, with only 30 cases reported in the literature, but it is associated with hearing loss in only three cases. Radiological investigations can help in diagnosing this rare entity before proceeding with cochlear implantation. CASE REPORT: A four-year-old female child born out of consanguinity with normal psychomotor development, bilateral sensorineural hearing loss and an incidental magnetic resonance imaging finding of cystic leukoencephalopathy without megalencephaly underwent successful cochlear implantation. Her post-operative period was uneventful with successful mapping of the cochlear implant. CONCLUSION: This is the first reported case of cystic leukoencephalopathy without megalencephaly and with sensorineural hearing loss in which cochlear implantation was performed successfully. White matter and temporal lobe abnormalities should not deter paediatric cochlear implantation.

Clinical and genetic characteristics of adrenomyeloneuropathy / 中华神经科杂志

Objective:To summarize and analyze the clinical and genetic characteristics of Chinese patients with adrenomyeloneuropathy (AMN).Methods:Clinical data were collected and analyzed retrospectively on AMN patients who were diagnosed by genetic testing in Shanghai Sixth People′s Hospital, Shanghai Jiao Tong University School of Medicine from May 2008 to August 2022. Clinical characteristics of AMN patients with different types of gene mutations were compared. Loe score was used to evaluate the severity of white matter demyelinating, and the serum levels of very long-chain fatty acids (VLCFA) in patients with or without white matter demyelinating were compared. The motor function of the AMN patients was assessed using the Expanded Disability Status Scale (EDSS), and the association between EDSS scores and the course of disease was analyzed.Results:A total of 23 male patients with onset age of (29.52±9.91) years were included in this study. The first symptom of all patients was abnormal lower extremities, of which 17 patients showed stiffness and weakness in their lower limbs (73.9%, 17/23), and 6 patients showed numbness and pain in both lower limbs (26.1%, 6/23). The occurrence of symptoms was not related to the type of gene mutation. White matter demyelination occurred in 33.3% (7/21) of patients over a disease duration of (7.67±4.46) years. There was no statistically significant difference in serum VLCFA level between the white-matter demyelination group and the non-demyelination group. The EDSS score was positively correlated with the disease duration ( r=0.57, P=0.006). Sixteen ABCD1 gene mutations were found in this study, among which c.5_19delinsTCTCCAGG (p.P2Lfs *12) was reported for the first time. Four probands belonging to different families carried the c.1415_1416del (p.Q472Rfs *83) variant. Conclusions:Lower limb movement disorders and sensory dysfunction are the prominent clinical manifestations in AMN patients, with deterioration of motor function associated with the course of disease. AMN may be converted to cerebral type and VLCFA concentration is not associated with the phenotypic changes. The c.1415_1416del (p.Q472Rfs *83) mutation is a hot spot mutation of the disease.

Multiple mitochondrial dysfunction syndrome type 3 with dyspnea and hypoxemia as early manifestation: a case report / 中华围产医学杂志

This article reported a case of multiple mitochondrial dysfunction syndrome type 3 with the early manifestation of dyspnea and hypoxemia. The patient was a male newborn who had dyspnea, which was manifested as nasal flaring, three concave sign, and hypoxemia after birth. These manifestations were improved after oxygen support through nasal cannula, but continuous low-flow oxygen therapy was needed. Chest X-ray indicated a bell-shaped thorax with pulmonary hypertension. Whole-exome sequencing identified compound heterozygous variants of c.341+1G>A and c.785G>A (p.G262D) in IBA57 gene of the patient, which were pathogenic and inherited from his mother and father, respectively. Symptomatic epilepsy, nystagmus, and central respiratory failure appeared at the age of 3 months. Cranial magnetic resonance image findings were consistent with the signs of mitochondrial leukoencephalopathy. The patient still had recurrent convulsions despite the treatment with levocarnitine, vitamin B 2, vitamin B 1, vitamin E, coenzyme Q10, levetiracetam, and mechanical ventilation through a tracheal tube. The patient showed a poor response to the treatment and died after withdrawing from treatment.

Unilateral delayed post-hypoxic leukoencephalopathy: a case report.

BACKGROUND: Delayed post-hypoxic leukoencephalopathy is a rare entity following hypoxia. Clinical and radiological signs of delayed post-hypoxic leukoencephalopathy have not previously been reported following acute ischemic stroke. CASE PRESENTATION: We report a case of an 81-year-old Central European man who presented with a dissection-related occlusion of the left carotid artery. He showed clinical improvement immediately after endovascular stroke therapy, followed by a significant clinical and especially cognitive deterioration thereafter and a clinical recovery after several weeks. The clinical course of the patient was accompanied by morphological changes on magnetic resonance imaging characteristic of delayed post-hypoxic leukoencephalopathy; that is, strictly limited and localized unilaterally to the left anterior circulation. CONCLUSION: This case demonstrates that clinical symptoms and morphological changes on magnetic resonance imaging compatible with delayed post-hypoxic leukoencephalopathy do not necessarily only occur with global hypoxia, but can also occur in patients with a large vessel occlusion in the corresponding vascular territories.