Childhood adrenoleukodystrophy - Classic and variant - Review of clinical manifestations and magnetic resonance imaging

Childhood Dementia: A Collective Clinical Approach to Advance Therapeutic Development and Care

Childhood dementias are a group of over 100 rare and ultra-rare pediatric conditions that are clinically characterized by chronic global neurocognitive decline. This decline is associated with a progressive loss of skills and shortened life expectancy. With an estimated incidence of one in 2800 births and less than 5% of the conditions having disease-modifying therapies, the impact is profound for patients and their families. Traditional research, care, and advocacy efforts have focused on individual disorders, or groups classified by molecular pathogenesis, and this has established robust foundations for further progress and collaboration. This review describes the shared and disease-specific clinical changes contributing to childhood dementia and considers these as potential indicators of underlying pathophysiologic processes. Like adult neurodegenerative syndromes, the heterogeneous phenotypes extend beyond cognitive decline and may involve changes in eating, motor function, pain, sleep, and behavior, mediated by physiological changes in neural networks. Importantly, these physiological phenotypes are associated with significant carer stress, anxiety, and challenges in care. These phenotypes are also pertinent for the development of therapeutics and optimization of best practice management. A collective approach to childhood dementia is anticipated to identify relevant biomarkers of prognosis or therapeutic efficacy, streamline the path from preclinical studies to clinical trials, increase opportunities for the development of multiple therapeutics, and refine clinical care.

Magnetic resonance imaging of disorders with white matter changes in children and adolescents: a pictorial essay

White matter changes are seen in a spectrum of disorders in children and adolescents. Understanding their distribution and appearance helps to reach diagnoses in daily radiologic practice. This pictorial essay will outline the magnetic resonance imaging (MRI) appearances of diseases with white matter changes including demyelinating diseases, dysmyelinating disorders/leukodystrophies, infections, autoimmune diseases, vascular causes, mitochondrial disorders and neurocutaneous syndromes, along with a brief overview of clinical aspects of the diseases such as typical age of presentation, etiology, symptoms and signs and treatment options. This article highlights important features in common white matter diseases in children and adolescents.

Management of adrenoleukodystrophy: From pre-clinical studies to the development of new therapies

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurodegenerative disorder associated with mutations of the ABCD1 gene that encodes a peroxisomal transmembrane protein. It results in accumulation of very long chain fatty acids in tissues and body fluid. Along with other factors such as epigenetic and environmental involvement, ABCD1 mutation-provoked disorders can present different phenotypes including cerebral adrenoleukodystrophy (cALD), adrenomyeloneuropathy (AMN), and peripheral neuropathy. cALD is the most severe form that causes death in young childhood. Bone marrow transplantation and hematopoietic stem cell gene therapy are only effective when performed at an early stage of onsets in cALD. Nonetheless, current research and development of novel therapies are hampered by a lack of in-depth understanding disease pathophysiology and a lack of reliable cALD models. The Abcd1 and Abcd1/Abcd2 knock-out mouse models as well as the deficiency of Abcd1 rabbit models created in our lab, do not develop cALD phenotypes observed in human beings. In this review, we summarize the clinical and biochemical features of X-ALD, the progress of pre-clinical and clinical studies. Challenges and perspectives for future X-ALD studies are also discussed.

The Spectrum of MR Imaging Patterns Suggestive of Pediatric Posterior Reversible Encephalopathy Syndrome in Children With Cerebral X-Linked Adrenoleukodystrophy

BACKGROUND AND PURPOSE

Children receiving chemotherapy, or immunosuppression have an increased risk for pediatric posterior reversible encephalopathy syndrome (pPRES); pPRES is scantly described in cerebral X-linked adrenoleukodystrophy (cALD) patients, for which hematopoietic stem cell transplantation improves outcomes. This study aimed to describe distinctive lesion patterns, distribution, and evolution of neuroimaging findings in PRES in a single-center pediatric cohort of cALD.

METHODS

We retrospectively identified all clinically acquired brain MRIs of children with cALD at a tertiary care university hospital between 1995 and 2020. We reviewed clinical features, conventional MRI, and diffusion-weighted imaging findings of patients with gray matter and white matter (WM) changes suggestive of concurrent PRES-cALD. Associations between the distinctive anatomic features, distribution, and abnormal signal intensity on MRI were examined with regard to the etiology and clinical outcome.

RESULTS

Our search revealed a series of eight pediatric cALD patients presenting with seizures, headache, or altered mental status with MRI findings suggestive of both PRES and cALD simultaneously. In each, the cortical-subcortical vasogenic edema on fluid-attenuated inversion recovery was consistent with pPRES, overlying the periventricular WM (PVWM) involvement typical of cALD. Of these 8 patients, the cortical-subcortical lesions on FLAIR were completely reversible on follow-up MRI in 7, but only partially reversible in 1.

CONCLUSIONS

It is crucial to recognize that pPRES can occur in cALD, notably, the cortical edema and leptomeningeal enhancement can accelerate the diagnosis of superimposed pPRES, while the PVWM lesions of cALD remain following the resolution of pPRES.

Childhood cerebral X-linked adrenoleukodystrophy with atypical neuroimaging abnormalities and a novel mutation

Childhood cerebral X-linked adrenoleukodystrophy (XALD) typically manifests with symptoms of adrenocortical insufficiency and a variety of neurocognitive and behavioral abnormalities. A major diagnostic clue is the characteristic neuroinflammatory parieto-occipital white matter lesions on magnetic resonance imaging. This study reports a 5-year 10-month old boy presenting with generalized skin hyperpigmentation since 3 years of age. Over the past 9 months, he had developed right-sided hemiparesis and speech and behavioral abnormalities, which had progressed over 5 months to bilateral hemiparesis. Retrospective analyses of serial brain magnetic resonance images revealed an unusual pattern of lesions involving the internal capsules, corticospinal tracts in the midbrain and brainstem, and cerebellar white matter. The clinical diagnosis of childhood cerebral adrenoleukodystrophy was confirmed by elevated basal levels of adrenocorticotropin hormone and plasma very long chain fatty acid levels. Additionally, sequencing of the ABCD1 gene revealed a novel mutation. The only specific palliative therapy that could be offered after diagnosis was dietary intervention. The patient died within 16 months of onset of neurological symptoms. Awareness that childhood cerebral XALD can present with atypical neuroimaging patterns early in its course may aid diagnosis at a stage when definitive treatment can be attempted and timely genetic counseling be offered to the family.

Cerebral palsy: not always what it seems

Cerebral palsy (CP) is not a disease, but a neurological syndrome, a combination of signs and symptoms, some of which may occur in neurodegenerative or metabolic disorders, particularly those with an onset in the first 2 years of life. There are many different causes of the syndrome. All children with CP should undergo brain MRI, even with an identified antenatal or perinatal insult. Children with CP should be referred to a paediatric neurologist or a clinical geneticist, or both, if appropriate and particularly in the absence of a known perinatal cerebral insult, with brain MRI that is reported to be normal, a progression in, or new, signs or where there is a reported 'family history of CP'. Finally, a few of the CP syndromes may be readily treatable and potentially prevent irreversible neurological and cognitive impairment.

Unusual brain images of a boy with adolescent cerebral X-linked adrenoleukodystrophy presenting with exhibitionism: A CARE-compliant case report

RATIONALE

The respective involvements of both the thalamus and exhibitionism in cerebral X-linked adrenoleukodystrophy (X-ALD) have not been reported.

PATIENT CONCERNS

An 11-year-old boy initially presented with exhibitionism and progressive neurobehavioral symptoms. He subsequently developed transient urinary and fecal incontinence, and an unwillingness to eat or communicate.

DIAGNOSES

We conducted contrast-enhanced brain magnetic resonance imaging (MRI), which revealed symmetrical altered signal intensities in bilateral frontal white matter, the basal ganglia, and dorsal thalami, as well as a peripheral rim of contrast enhancement. Diagnosis of adolescent cerebral X-ALD was confirmed on the basis of next generation genetic sequencing analysis.

INTERVENTIONS

We initiated the patient on hormonal replacement therapy.

OUTCOMES

We observed rapidly progressive neurologic deterioration in this patient, and the boy fell into a vegetative state 10 months after discharge.

LESSONS

We recommend that physicians should not disregard X-ALD in patients with isolated psychiatric symptoms, including hypersexual behavior. The combination of detailed clinical evaluation, MRI, and next generation genetic sequencing can expedite the diagnostic process of atypical variant of X-ALD.

Perspectives in Pediatric Pathology, Chapter 21. Testicular Pathology in Heritable Metabolic Disease

Inborn errors of metabolism have wide and profound effects in many or all organs, and especially so in those with endocrine functions. The testes are greatly affected by systemic metabolic disorders, leading to specific histological findings that generally reveal the nature of the underlying disorder. Here we describe the main testicular changes seen in the setting of metabolic disease.

Neurometabolic Diagnosis in Children who referred as Neurodevelopmental Delay (A Practical Criteria, in Iranian Pediatric Patients)

OBJECTIVE

We aimed to investigate the clinical and para clinical manifestations of neuro metabolic disorders, in patients who presented by neuro developmental delay in their neuro developmental milestones.

MATERIALS & METHODS

The patients diagnosed as neuro developmental delay and regression with or without seizure at the Neurology Department of Mofid Children Hospital in Tehran, Iran between 2004 and 2014 were included in our study. These patients diagnosed as neuro developmental delay by pediatric neurologists in view of diagnostic /screening neuro developmental assessment tests. The patients who completed our inclusion criteria as neuro metabolic disorders were evaluated in terms of metabolic and genetic study in referral lab.

RESULTS

Overall, 213 patients with neurometabolic disorders were diagnosed. 54.3% of patients were male. The average age of patients was 41 +-46.1 months. 71.4% of parent's patients had consanguinity of marriages. Eighty seven percent of patients had developmental delay (or/and) regression. 55.5% of them had different type of seizures. Overall, 213 patients with 34 different neurometabolic disorders were diagnosed and classified in the 7 sub classes, consisting of: 1- organic acidemia and aminoacidopathy (122 patients), 2-storage disease (37 patients) 3- eukodystrophy (27 patients), other classes consisted: lipid oxidation disorders, urea cycle disorders, progressive myoclonic epilepsy; and peroxizomal disorders (27 patients).

CONCLUSION

In patients with developmental delay or regression, with or without seizure, abnormal neurologic exam along with positive family history of similar disorder or relative parents, abnormal brain imaging with specific patterns, neurometabolic disorders should be considered as one of the important treatable diseases.

Mechanisms of Antioxidant Induction with High-Dose N-Acetylcysteine in Childhood Cerebral Adrenoleukodystrophy

BACKGROUND

Childhood cerebral adrenoleukodystrophy (CCALD), a progressive demyelinating disease affecting school-aged boys, causes death within a few years. Oxidative stress is an important contributing factor. N-acetylcysteine (NAC; 280 mg/kg/day) added as adjunctive therapy to reduced-intensity hematopoietic cell transplantation (HCT) improves survival in advanced cases. However, the mechanisms underlying the benefits of NAC are unclear.

OBJECTIVE

The aim of this study was to understand the mechanism of action of NAC in the setting of HCT in CCALD.

METHODS

Immunoassays were carried out to determine changes in heme oxygenase-1 (HO-1) and ferritin expression in plasma samples collected from boys with CCALD at three different timepoints during the course of transplantation. In addition, the induction of HO-1 was also confirmed in normal fibroblasts following incubation with 10-100 µmol/L NAC for 4 h.

RESULTS

Following NAC therapy we observed an increase in expression of the antioxidants HO-1 (~4-fold) and its effector ferritin (~160-fold) in patient samples as compared with baseline. We also observed that NAC exposure significantly increased HO-1 expression in fibroblasts.

CONCLUSION

Our data suggest that HO-1 is a possible target protein of NAC and a mediator of its cytoprotective effects in these patients.