Pictorial essay: Acute neurological complications in children with acute lymphoblastic leukemia

Neurologic Complications in Patients With Lymphoreticular Malignancy: A Descriptive Cohort Study

OBJECTIVES

The objectives of this study were to study the spectrum of neurologic complications in children with lymphoreticular malignancy (acute lymphoblastic leukemia, Hodgkin, and non-Hodgkin lymphoma) at diagnosis and during treatment and to determine the etiology of these complications.

MATERIALS AND METHODS

In this descriptive cohort study, conducted between November 2018 and March 2020, 204 children with a diagnosis of lymphoreticular malignancy were enrolled. The baseline investigations were done in all the cases. Those who developed neurological symptoms were evaluated with cerebrospinal fluid examination and radiologic and electrophysiologic studies as per indication and were managed according to standard management guidelines.

RESULTS

Of the 204 patients, 30 (14.7%) developed neurological complications. The majority of these complications (n=20/30; 87%) occurred during the intensive chemotherapy period. Common complications included acute methotrexate neurotoxicity (n=7), vincristine-induced neurotoxicity (n=7), central nervous system (CNS) relapse (n=4), and posterior reversible encephalopathy syndrome (n=2). L-asparaginase-induced thrombosis (n=1), intramedullary compression syndrome (n=1), CNS infection (n=2), CNS hemophagocytic lymphohistiocytosis (n=1), and steroid-induced myopathy (n=1) were also observed. The complications resolved in 21/30 (70%) patients after receiving appropriate treatment while the neurological complication persisted in 2/30 (6.7%) patients. Three patients (10%) abandoned the treatment, and 4 (13.3%) patients expired.

CONCLUSIONS

Neurologic complications in patients with lymphoreticular malignancy are quite variable, having common presenting symptoms but varying imaging abnormalities. By close follow-up and effective treatment, the morbidity and mortality of these complications can be minimized.

Pharmacogenetics of the Central Nervous System-Toxicity and Relapse Affecting the CNS in Pediatric Acute Lymphoblastic Leukemia

Simple Summary

Despite recent improvements in cure rates, pediatric acute lymphoblastic leukemia (ALL) patients remain at risk to develop relapse disease or suffer from therapy-associated side effects. Over 5% of adverse events appear in the central nervous system (CNS) and can impact survival or quality of life of the patients. Inherited genetic variations are possible predictive factors for these adverse events. This retrospective study aimed to investigate if inherited genetic variations in genes encoding drug-metabolizing enzymes and drug transporters localized in the blood-brain barrier are predictive for CNS events. Our results suggest that certain ABCB1, ABCG2 and GSTP1 gene polymorphisms influence CNS toxicity and CNS relapse. A more effective drug-clearance could lead to less toxicity but contribute to a higher chance of relapse and vice versa. Genetic variants in ABCB1, ABCG2 or GSTP1 genes are promising candidates for personalized medicine.

Abstract

Despite improving cure rates in childhood acute lymphoblastic leukemia (ALL), therapeutic side effects and relapse are ongoing challenges. These can also affect the central nervous system (CNS). Our aim was to identify germline gene polymorphisms that influence the risk of CNS events. Sixty single nucleotide polymorphisms (SNPs) in 20 genes were genotyped in a Hungarian non-matched ALL cohort of 36 cases with chemotherapy related acute toxic encephalopathy (ATE) and 544 controls. Five significant SNPs were further analyzed in an extended Austrian-Czech-NOPHO cohort (n = 107 cases, n = 211 controls) but none of the associations could be validated. Overall populations including all nations’ matched cohorts for ATE (n = 426) with seizure subgroup (n = 133) and posterior reversible encephalopathy syndrome (PRES, n = 251) were analyzed, as well. We found that patients with ABCB1 rs1045642, rs1128503 or rs2032582 TT genotypes were more prone to have seizures but those with rs1045642 TT developed PRES less frequently. The same SNPs were also examined in relation to ALL relapse on a case-control matched cohort of 320 patients from all groups. Those with rs1128503 CC or rs2032582 GG genotypes showed higher incidence of CNS relapse. Our results suggest that blood-brain-barrier drug transporter gene-polymorphisms might have an inverse association with seizures and CNS relapse.

Role of magnetic resonance imaging in characterization of central nervous system lesions in pediatric patients with leukemia and post-treatment complications

Background

Leukemia is one of the most common fatal diseases in pediatric oncology. Recently, advances in drug therapy have improved the prognosis of acute leukemia with event-free survival of up to 60%; however, complications and adverse effects of the disease and anti-leukemic treatment have also increased. The CNS complications of leukemia can be classified into those that developed directly or indirectly from the underlying leukemic process and those that can be related to antileukemic therapy. MRI had improved early detection of CNS complications and proper management. The study aims to characterize the MRI findings caused by the leukemic involvement of CNS structures and treatment-associated CNS complications and assess its value in early management and avoidance of long-term side effects.

Results

The patient’s age ranged from 2 to 18 years with different types of leukemia classified regarding the time of presentation as pretreatment, during treatment phases, and post-treatment. Different MRI abnormalities were recorded and clinically correlated.

Conclusion

The neurological complications of leukemia have common presenting symptoms but varying imaging abnormalities. To reach the correct diagnosis, the presenting signs, symptoms, and laboratory data must be considered along with the radiologic findings. A diagnostic algorithm using conventional, post-contrast MRI, MR venography, along with diffusion-weighted MRI was of great value in early detection and differentiation of different CNS lesions detected in pediatric patients with leukemia and post-treatment CNS complications.

A Retrospective Analysis of Invasive Fungal Diseases (IFD) of the Central Nervous System in Children With Lymphoid Malignancies

BACKGROUND

Outcomes of childhood hematolymphoid malignancies have improved several fold because of immunosuppressive chemotherapy and broad-spectrum antibiotics for managing febrile neutropenia. An apparent trade-off has been an increase in invasive fungal disease (IFD), affecting multiple organs. We report the diagnostic and therapeutic challenges in 8 children with lymphoid cancers who developed intracranial (IC) fungal abscesses between 2010 and 2017.

METHODS

Children below 15 years of age undergoing treatment for leukemia/lymphoma with clinicoradiologic and microbiologic evidence of IC fungal abscess were included. Demographic details, clinical profile, and management were retrospectively audited. Treatment was guided by European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) definitions for IFD with therapeutic drug monitoring (TDM)-directed azole dosing, and surgical intervention.

RESULTS

Eight patients (4 B-cell acute lymphoblastic leukemia, 2 relapsed B-cell acute lymphoblastic leukemia, and 2 non-Hodgkin lymphoma) were eligible for analysis. Proven, probable, and possible IFDs were seen in 2 (25%), 4 (50%), and 2 (25%) patients, respectively. Proven IFDs were invasive mucormycosis with remaining having mold infections. Cerebrospinal fluid galactomannan was positive in all 4 patients in whom it was tested. TDM was possible in 5/8 (63%) patients. Antifungal therapy was given for a median period of 4.2 months with 5 (63%) patients having complete resolution. Three (37%) patients expired, of which 2 were attributable to IFDs.

CONCLUSIONS

IC fungal abscesses in children can cause significant morbidity and mortality in children with hematolymphoid cancers. Evaluation of cerebrospinal fluid galactomannan may help in early diagnosis and therapy. Prolonged antifungal therapy steered by TDM can help achieve resolution in some cases.

Mechanical role of a growing solid tumor on cortical folding

Cortical folding, or convolution of the brain, is a vital process in mammals that causes the brain to have a wrinkled appearance. The existence of different types of prenatal solid tumors may alter this complex phenomenon and cause severe brain disorders. Here we interpret the effects of a growing solid tumor on the cortical folding in the fetal brain by virtue of theoretical analyses and computational modeling. The developing fetal brain is modeled as a simple, double-layered, and soft structure with an outer cortex and an inner core, in combination with a circular tumor model imbedded in the structure to investigate the developmental mechanism of cortical convolution. Analytical approaches offer introductory insight into the deformation field and stress distribution of a developing brain. After the onset of instability, analytical approaches fail to capture complex secondary evolution patterns, therefore a series of non-linear finite element simulations are carried out to study the crease formation and the influence from a growing solid tumor inside the structure. Parametric studies show the dependency of the cortical folding pattern on the size, location, and growth speed of a solid tumor in fetal brain. It is noteworthy to mention that there is a critical distance from the cortex/core interface where the growing tumor shows its pronounced effect on the cortical convolution, and that a growing tumor decreases the gyrification index of cortical convolution while its stiffness does not have a profound effect on the gyrification process.

Paediatric brainstem: A comprehensive review of pathologies on MR imaging

The brainstem is a midline structure formed by the midbrain, pons and medulla and is a home for various vital neurological centres of the human body. A diverse spectrum of disease entities can involve the brainstem, which includes infections, metabolic disorders, demyelination, vascular conditions, neurodegenerative disorders and tumours. Brainstem involvement can be primary or secondary, i.e., as part of systemic disorders. Due to the overlapping clinical presentation and symptomatology, imaging plays a decisive role in the detection, localisation and characterisation of brainstem pathologies. Magnetic resonance imaging (MRI) is the modality of choice and the use of advanced MR techniques such as diffusion-weighted imaging and spectroscopy can be especially helpful in providing a tenable diagnoses. This article is a compilation of the MR imaging manifestations of a spectrum of common and uncommon brainstem pathologies that can be encountered in the paediatric age group.

Teaching Points

• The paediatric brainstem can be afflicted by many pathologies that may overlap clinico-radiologically.

• MRI is the best modality for the localisation and diagnosis of brainstem pathologies.

• Diffusion-weighted imaging is useful in the diagnosis of vascular and metabolic disorders.

• Occasionally, demyelination and neoplasms can be indistinguishable on imaging.