Motor nervous pathway function is impaired after treatment of childhood acute lymphoblastic leukemia: a study with motor evoked potentials

Clinical Considerations in Returning Pediatric and Young Adults With Cancer to Physical Activity

ABSTRACT

There is a gap in the literature on the best treatment of clinical sequelae within adolescent and young adult pediatric cancer populations. Children, adolescents, and young adults are at risk for a multitude of immediate and late effects of their disease and treatment that warrant a comprehensive, multidisciplinary team approach to optimize care. Sports medicine providers are well-equipped with their background to join the oncology rehabilitation team in diagnosing and managing cancer-related impairments to help these populations live a healthier and more active lifestyle. In this manuscript, four essential clinical components to consider when returning children, adolescents, and young adults with cancer history to physical activity are discussed: chemotherapy-induced peripheral neuropathy, cardiotoxicity, nutritional deficiencies, and deconditioning.

Motor Functioning and Intelligence Quotient in Paediatric Survivors of a Fossa Posterior Tumor Following a Multidisciplinary Rehabilitation Program

BACKGROUND

Short- and long-term consequences after treatment for childhood fossa posterior tumors are extensively reported in the literature; however, papers highlighting physical function throughout rehabilitation and its correlation with Intelligence Quotient (IQ) are sparse. This study aims to describe the physical functioning and IQ of these survivors, their progression during rehabilitation, and the association with histopathological tumor classification. Additionally, the correlation between gross motor functioning and cognitive functioning was investigated.

METHODS

This retrospective single-center cohort study included 56 children (35 (62.5%) males and 21 (37.5%) females, with an average age of 6.51 years (SD 4.13)) who followed a multidisciplinary program at the Child Rehabilitation Centre, Ghent University Hospital in the period from 2005 to 2020. Descriptive statistical analysis was performed with the use of non-parametric tests and linear regression to determine the relationship between gross motor functioning and IQ.

RESULTS

This report shows impaired motor and intelligence performance in children with a fossa posterior tumor. Although multidisciplinary rehabilitation is beneficial, it is not able to counteract the further decline of several motor skills and intelligence during oncological treatment, more specifically in children with a medulloblastoma. A correlation between gross motor function and total IQ was found.

CONCLUSION

Pediatric survivors of a fossa posterior tumor experience impaired physical and intellectual functions, with more decline during oncological treatment despite simultaneous multidisciplinary rehabilitation.

The Impact of a Precision-Based Exercise Intervention in Childhood Hematological Malignancies Evaluated by an Adapted Yo-Yo Intermittent Recovery Test

During cancer treatments in childhood hematological malignancies, reduced exercise tolerance is one of the main hardships. Precision-based training programs help children, adolescents, and young adults and their families to resume regular physical activity, exercise, and sports once they return to their communities after the intensive phases spent in hospital. This study was aimed at verifying whether an intermittent recovery test, the Yo-Yo AD, could provide a simple and valid way to evaluate an individual’s capacity to perform repeated intense exercise and to follow up on the impact of tailored exercise in children, adolescents, and young adults with hematological malignancies. The Yo-Yo AD involved the repetition of several shuttles to muscle exhaustion, at pre-established speeds (walking and slow running). The heart rate (HR) and oxygen saturation (SaO2) were monitored during the test. The total distance and the walking/running ability, measured as the slope of the HR vs. distance correlation, were investigated before (T0) and after 11 weeks (T1) of precision exercise intervention. The Yo-Yo AD was also performed by healthy children (CTRL). Ninety-seven patients (10.58 ± 4.5 years, 46% female) were enrolled. The Yo-Yo AD showed the positive impact of the exercise intervention by increasing the distance covered by the individuals (T0 = 946.6 ± 438.2 vs. T1 = 1352.3 ± 600.6 m, p < 0.001) with a more efficient walking/running ability (T0 = 2.17 ± 0.84 vs. T1 = 1.73 ± 0.89 slope, p < 0.0164). CTRLs performed better (1754.0 ± 444.0 m, p = 0.010). They were equally skillful (1.71 ± 0.27 slope) when compared to the patients after they received the precision-based intervention. No adverse events occurred during the Yo-Yo AD and it proved to be an accurate way of correctly depicting the changes in performance in childhood hematological malignancies.

The Efficacy of Targeted Exercise on Gross Motor and Neuromuscular Performance in Survivors of Childhood Leukemia: A Pilot Study

OBJECTIVES

This quasi-experimental study examined the efficacy of targeted exercise training on gross motor performance and neuromuscular impairments in survivors of childhood acute lymphoblastic leukemia (ALL CCS).

MATERIALS AND METHODS

Ten ALL CCS (median age: 10 years; range: 6-14 years) performed a 6-week training program three times per week (five in-person sessions), including a warm-up, total body stretching, progressive jump rope training, and a cool down. Gross motor performance (test of gross motor proficiency) and lower extremity rate of muscle activation (electromyography), joint torques (motion capture and force plate), and jump height (motion capture) were measured during a countermovement jump at baseline and post-training.

RESULTS

Post-training, ALL CCS demonstrated improvements in body coordination, strength and agilty, bilateral coordination, running speed and agility, and strength gross motor performance (mean change: 1.6-8.1; p < 0.05), the rate of muscle activation of the tibialis anterior and vastus lateralis muscles (mean change: 0.58-0.75; p < 0.05), hip and ankle joint torques (mean change: 0.07; p < 0.05), and jump height (mean change: 0.05; p < 0.05).

CONCLUSION

This study demonstrated that targeted exercise training can improve gross motor performance and neuromuscular impairments in ALL CCS post-medical treatment.

Osteopathic Treatment and Evaluation in the Clinical Setting of Childhood Hematological Malignancies

Simple Summary

Children: adolescents, and young adults who are affected by hematological malignancies and who are undergoing intensive phases of cancer treatment including hematopoietic stem cell transplantation, experience diminished functional ability. This study was aimed at assessing if osteopathic treatment and evaluation can be used when an 11-week precision-based exercise program is run inside the hospital. Our results support that osteopathy plus precision-based intervention could be a desirable support in the clinical prise en charge of these children and adolescents. Osteopathy is a safe method for the evaluation of clinical conditions and requires strong multidisciplinary synergy between pediatricians and exercise physiologists.

Abstract

Children: adolescents, and young who are adults affected with hematological malignancies (CAYA-H) and who are undergoing intensive phases of cancer treatment, including hematopoietic stem cell transplantation (HSCT), experience diminished functional ability. This study was aimed at assessing the feasibility, efficacy, safety, and satisfaction of an osteopathic intervention in CAYA-H attending an 11-week precision-based exercise program (PEx). All of the participants were given 4–10 treatments according to the prescription ordered by the sports medicine doctor in charge of the PEx, and the following outcomes were assessed: (1) spinal column range of motion (ROM) by palpation; (2) lower and upper limb joints ROM by a goniometer; (3) orthostatic posture by plumb line assessment; (4) chest and abdomen mobility by inspection and palpation; (5) cranial-sacral rhythmic impulse (CRI) by palpation; and (6) adverse effects. Goal attainment scaling (GAS) was used to identify the accomplishment of a desired clinical result. Moreover, HSCT patients who were affected with graft-versus-host disease and/or osteonecrosis had their joints assessed in terms of ROM as tools to monitor the effectiveness of immunosuppressive treatment. A total of 231 CAYA-H were identified, and 104 participated in the study (age 10.66 ± 4.51 yrs; 43% F). PEx plus osteopathy reached positive GAS scores by improving the ROMs of the spinal column and/or limbs (81% and 78%, respectively), chest and abdomen mobility (82%), and CRI (76%). Only minor reversible adverse effects were noticed during the study. Together, our data seem to initiate a new course where osteopathy could be useful in evaluating structural edges due to the clinical history of each CAYA-H. Given the contributions that were obtained by the GAS scores, osteopathic treatment seems to reveal interesting potential that can be targeted in the future.

Oncological Children and Well-Being: Occupational Performance and HRQOL Change after Fine Motor Skills Stimulation Activities

Cancer children experience long periods of hospitalization, which are associated with limited performance in several developmental domains and participation restrictions in age appropriate occupations. Fine motor abilities represent building blocks in performing daily life skills and have been found to be closely connected with later academic success. Moreover, medical and psychological sequelae for cancer inpatients may result in diminished daily activities functioning, poor perceived health related quality of life (HRQOL), and increase the likelihood of long-term impairments. This study examines the variations in the occupational performance of children hospitalized for acute lymphoblastic leukemia (ALL) after their participation to a stimulation program designed to enhance fine motor skills. Parents reported significant gains in children's motor functioning, a slight improvement in overall occupational performance related to an increase in the area of productivity and self-care, and a better quality of life perception following the stimulation activities. Feasibility of the stimulation program in a health care setting are discussed evaluating its benefits for cancer children and their families.

Neuromuscular mechanisms that contribute to gross motor performance in survivors of childhood acute lymphoblastic leukemia

PURPOSE

This study explored neuromuscular mechanisms and clinical measures that contribute to countermovement jump performance in survivors of childhood acute lymphoblastic leukemia (ALL CCS) compared to age- and sex-matched peers.

METHODS

This exploratory cross-sectional observational study examined 12 participants, six ALL CCS and six age- and sex-matched peers (7-16 years). During a countermovement jump, rates of muscle activation of lower leg muscles were measured with electromyography, and joint torques and peak jump height with force plates and a motion capture system. Clinical measures included muscle extensibility, balance, and mobility measured by active ankle dorsiflexion, Bruininks-Oseretsky Motor Proficiency (BOT-2), and Timed Up and Go (TUG) tests.

RESULTS

Compared to peers, ALL CCS demonstrated reduced gastrocnemius muscle extensibility and tibialis anterior rate of muscle activation, decreased jump height, and poorer performance on the BOT-2 and TUG. Jump height was significantly correlated with clinical measures of the BOT-2 and TUG.

CONCLUSION

These ALL CCS demonstrated neuromuscular impairments that may impact jump performance, an essential childhood physical activity. Further research is needed to explore intervention strategies to improve the neuromuscular mechanisms that contribute to high-level gross motor skills in ALL CCS.

Brainstem auditory pathway of children with acute lymphoid leukemia on chemotherapy with methotrexate

OBJECTIVE

Investigate the auditory pathway in the brainstem of children with acute lymphoblastic leukemia submitted to chemotherapy (by intravenous or intrathecal infusion).

METHODS

Fourteen children aged between 2 and 12 years with diagnosis of acute lymphoid leukemia were evaluated. The following procedures were used: meatoscopy, acoustic immitance measurements, tonal audiometry, vocal audiometry, transient otoacoustic emissions, and auditory brainstem response.

RESULTS

From the 14 children with normal auditory thresholds, 35.71% showed an alteration in auditory brainstem response, with a predominance of hearing impairment in the lower brainstem. It was found that 80% of the children with alteration had used intrathecal methotrexate less than 30 days and that 40% had the highest cumulative intravenous methotrexate doses.

CONCLUSION

Children with acute lymphoblastic leukemia submitted to chemotherapy, present auditory pathway impairment in the brainstem, with a predominance of a low brainstem.

Precision-based exercise as a new therapeutic option for children and adolescents with haematological malignancies

Children and adolescents with haematological malignancies (PedHM) are characterized by a severe loss of exercise ability during cancer treatment, lasting throughout their lives once healed and impacting their social inclusion prospects. The investigation of the effect of a precision-based exercise program on the connections between systems of the body in PedHM patients is the new frontier in clinical exercise physiology. This study is aimed at evaluating the effects of 11 weeks (3 times weekly) of combined training (cardiorespiratory, resistance, balance and flexibility) on the exercise intolerance in PedHM patients. Two-hundred twenty-six PedHM patients were recruited (47% F). High or medium frequency participation (HAd and MAd) was considered when a participant joined; > 65% or between 30% and < 64% of training sessions, respectively. The “up and down stairs'' test (TUDS), “6 min walking” test (6MWT), the “5 Repetition Maximum strength” leg extension and arm lateral raise test (5RM-LE and 5RM-ALR), flexibility (stand and reach), and balance (stabilometry), were performed and evaluated before and after training. The TUDS, the 5RM-LE and 5RM-ALR, and the flexibility exercises showed an increase in HAd and MAd groups (P < 0.05), while the 6MWT and balance tests showed improvement only in HAd group (P < 0.0001). These results support the ever-growing theory that, in the case of the treatment of PedHM, ‘exercise is medicine’ and it has the potential to increase the patient’s chances of social inclusion.

Childhood Leukemia Survivors and Metabolic Response to Exercise: A Pilot Controlled Study

Background: Leukemia is the most common cancer in pediatrics, with many late effects such as higher risk of dyslipidemia, insulin resistance, obesity, and metabolic syndrome. The objective of this work was to investigate substrate oxidation during submaximal exercise in survivors of childhood acute leukemia. Methods: A total of 20 leukemia survivors and 20 healthy children were matched by sex, age, and Tanner stage. They all took a submaximal incremental exercise test to determine fat and carbohydrate oxidation rates. Results: Cardiorespiratory fitness was significantly lower in leukemia survivors, with lower relative VO₂ peaks (p < 0.001), lower heart rate values (p = 0.02), and lower exercise power (p = 0.012), whereas rest metabolism and body mass index did not differ between the two groups. During exercise, upward of heart rate relative to VO₂ peak was significantly higher (p < 0.001) in childhood leukemia survivors. We found lower carbohydrate and fat oxidation rates (p = 0.07) in leukemia survivors compared with healthy children, and also a significantly lower relative maximal fat oxidation rate (p = 0.014). Conclusion: Despite impaired physical fitness and metabolic response to exercise, childhood leukemia survivors remained sensitive to physical activity interventions, and could readily adapt to submaximal exercise intensity.

Motor functioning and associated cognitive outcomes in pediatric survivors of acute lymphoblastic leukemia

Pediatric acute lymphoblastic leukemia survivors are at risk for developing neurocognitive late effects following intensive medical treatment. Motor impairments have been highlighted as a common neurocognitive late effect, including fine-, gross-, and visual-motor skills. The severity of these motor deficits is variable in the existing literature, warranting additional investigations with more homogenous samples. In addition, there is an even greater paucity regarding the interrelations between motor deficits and the impact motor challenges may have on other domains of functioning, such as academics. Therefore, the present study aimed to characterize motor functioning in children who were treated for acute lymphoblastic leukemia with chemotherapy (n = 13) in comparison to healthy controls (n = 13). Additionally, this study investigated the relationship between primary (e.g., visual-spatial, fine-motor), secondary (e.g., visual-motor), and tertiary (e.g., academics) skills. The results revealed that oncology survivors had significantly lower fine- and gross-motor skills compared to healthy controls. No significant differences were observed between the groups on visual-perception and visual-motor tasks. Fine-motor functioning was significantly associated with visual-motor functioning in ALL survivors. Motor skills were not related to academic outcomes. The present findings provide evidence for motor impairments in pediatric ALL survivors, along with initial findings highlighting the cascading effect of primary motor impairments on other cognitive domains. This research sheds light on the need for clinical screening and intervention of motor skills in the survivorship population. Future research is warranted to examine the effect of motor deficits on cognitive and psychosocial functioning in pediatric oncology.

Neonatal vincristine administration modulates intrinsic neuronal excitability in the rat dorsal root ganglion and spinal dorsal horn during adolescence

Our recent work has shown that the early-life administration of vincristine (VNC), commonly used to treat pediatric cancers, evokes mechanical pain hypersensitivity in rats that emerges during adolescence and persists into adulthood. However, the underlying mechanisms remain unclear, as nothing is known about how neonatal VNC treatment influences peripheral and central nociceptive processing at the cellular level. Here, we used in vitro intracellular microelectrode and whole-cell patch-clamp recordings to evaluate the consequences of early-life VNC administration on the intrinsic membrane properties of adolescent dorsal root ganglion and spinal superficial dorsal horn neurons. The results demonstrate that VNC treatment increased the prevalence and rate of repetitive firing in both large- and medium-diameter sensory neurons, while reducing repetitive firing in small-diameter neurons, in comparison with vehicle-treated littermate controls. By contrast, passive membrane properties and peripheral conduction velocities were similar between experimental groups across all classes of primary afferents. Within the adolescent superficial dorsal horn, neonatal VNC exposure significantly enhanced the intrinsic membrane excitability of lamina I spinoparabrachial neurons, as evidenced by a decrease in rheobase and elevation of repetitive firing frequency compared with controls. Meanwhile, putative interneurons within lamina I exhibited a reduction in repetitive action potential discharge after early-life chemotherapy. Collectively, these findings suggest that neonatal VNC treatment evokes cell type-specific changes in intrinsic excitability at multiple levels of the ascending pain pathway. Overall, this work lays an essential foundation for the future exploration of the ionic mechanisms that drive chemotherapy-induced chronic pain in children and adolescents.

Motor function in survivors of pediatric acute lymphoblastic leukemia treated with chemotherapy-only

BACKGROUND

Up to 43% of survivors of pediatric acute lymphoblastic leukemia (ALL) may exhibit fine-motor problems. Information on manual dexterity in this cohort is still limited.

OBJECTIVES

We tested survivors of childhood ALL treated with chemotherapy-only for fine-motor function in terms of drawing and handwriting abilities using a Digitizing Tablet (DT) with three tasks for drawing and handwriting of varying complexity, for ataxia using the International Cooperative Ataxia Rating Scale (ICARS), and for tremor and hand-eye coordination using the Nine Hole Steadiness Tester (NHST).

RESULTS

We examined a cohort of non-irradiated survivors (n = 31) after a median time of 3.5 years after end of therapy. In all tasks of the DT the cohort demonstrated significant (p < 0.05) impairment of speed, automation, and variability in at least two tasks and significantly more pressure. Impaired speed (SPV) inversely correlated with lag time since end of therapy. Dexterity performance of six survivors (19%) lay below the 5th percentile. No survivor exhibited ataxia, tremor, or impaired hand-steadiness.

CONCLUSION

Despite the absence of gross ataxia, tremor, and impaired hand-eye coordination, we nevertheless detected significant fine-motor impairment in a relevant number of survivors of childhood ALL. Prospective studies are needed to reveal the pathophysiological underpinnings and genetic risk factors for development of such deficits due to ALL and its treatment.

Peripheral neuropathy in children and adolescents treated for cancer

Peripheral neuropathy is a well recognised treatment-related toxicity in children with cancer, associated with exposure to neurotoxic chemotherapy agents. Acute damage can occur in sensory, motor, or autonomic neurons, with symptoms that are rarely life threatening, but often severe enough to interfere with function during therapy and after treatment ends. The type of neuropathy and specific symptoms are associated with multiple factors including age at time of therapy, genetic predisposition, chemotherapy type and cumulative dose, and exposure to other agents during therapy. In this Review, we describe the peripheral neuropathy phenotype in children during cancer therapy and among survivors who have completed therapy, to summarise genetic and treatment-related risk factors for neuropathy, and to outline strategies to monitor and detect neuropathy during and after therapy. Additionally, we outline strategies for medical management of neuropathy during treatment and potential rehabilitation interventions to prevent or remediate functional loss.

Testing physical function in children undergoing intense cancer treatment-a RESPECT feasibility study

BACKGROUND

The physical function of children with cancer is reduced during treatment, which can compromise the quality of life and increase the risk of chronic medical conditions. The study, "REhabilitation, including Social and Physical activity and Education in Children and Teenagers with cancer" (Clinicaltrials.gov: NCT01772862) examines the efficacy of multimodal rehabilitation strategies introduced at cancer diagnosis. This article addresses the feasibility of and obstacles to testing physical function in children with cancer.

METHODS

The intervention group comprised 46 males and 29 females aged 6-18 years (mean ± SD: 11.3 ± 3.1 years) diagnosed with cancer from January 2013 to April 2016. Testing at diagnosis and after 3 months included timed-up-and-go, sit-to-stand, flamingo balance, handgrip strength, and the bicycle ergometer cardiopulmonary exercise test (CPET).

RESULTS

Of the 75 children, 92% completed a minimum of one test; two children declined testing and four were later included. Completion was low for CPET (38/150, 25%) but was high for handgrip strength (122/150, 81%). Tumor location, treatment-related side effects, and proximity to chemotherapy administration were primary obstacles for testing physical function. Children with extracranial solid tumors and central nervous system tumors completed significantly fewer tests than those with leukemia and lymphoma. Children with leukemia demonstrated reduced lower extremity function, that is, 24% reduction at 3 months testing in timed-up-and-go (P = 0.005) and sit-to-stand (P = 0.002), in contrast with no reductions observed in the other diagnostic groups.

CONCLUSION

Children with cancer are generally motivated to participate in physical function tests. Future studies should address diagnosis specific obstacles and design testing modalities that facilitate physical function tests in this target group.

Small-fiber neuropathy and pain sensitization in survivors of pediatric acute lymphoblastic leukemia

BACKGROUND

Chemotherapy-induced Peripheral Neuropathy (CIPN) of large-fibers affects up to 20% of survivors of pediatric acute lymphoblastic leukemia (ALL). We aimed to describe small-fiber toxicity and pain sensitization in this group.

METHODS

In a cross-sectional, bicentric study we assessed 46 survivors of pediatric ALL (Mean age: 5.7 ± 3.5 years at diagnosis, median 2.5 years after therapy; males: 28).

INCLUSION CRITERIA

≥6 years of age, ≥3 months after last administration of Vincristine, and cumulative dose of Vincristine 12 mg/m². We used a reduced version of the Pediatric-modified Total Neuropathy Score (Ped-mTNS) as bedside test and Quantitative Sensory Testing (QST) for assessment of small- and large-fiber neuropathy as well as pain sensitization. We employed Nerve Conduction Studies (NCS) as the most accurate tool for detecting large-fiber neuropathy.

RESULTS

Fifteen survivors (33%) had abnormal rPed-mTNS values (≥4 points) and 5 survivors (11%) reported pain. In QST, the survivor group showed significant (p < 0.001) inferior large-fiber function and pain sensitization when compared to healthy matched peers. We identified deficits of vibration in 33 (72%) and tactile hypoesthesia in 29 (63%), hyperalgesia to blunt pressure in 19 (41%), increased mechanical pain sensitivity in 12 (26%) and allodynia in 16 (35%) of 46 survivors. Only 7 survivors (15%) had pathologic NCS.

CONCLUSION

QST is a sensitive tool that revealed signs of large-fiber neuropathy in two thirds, small-fiber neuropathy and pain sensitization in one third of survivors. Prospective studies using QST in pediatric oncology may help to elucidate the pathophysiology of small-fiber neuropathy and pain sensitization as well as their relevance for quality of survival.

Balance in children with acute lymphoblastic leukemia

BACKGROUND

Treatment for acute lymphoblastic leukemia (ALL) can affect balance via different mechanisms, including sensory and motor peripheral neuropathy, cognitive impairment, and reduced muscle strength and flexibility. To provide an overview of what is currently known about the effects of cancer treatment on balance in pediatric ALL patients and survivors, and of the predictors of poor balance, a review of the literature was conducted.

METHODS

Five databases were searched for English-language original research articles on balance during or after treatment for pediatric ALL.

RESULTS

From a total of nine studies, six identified significant balance problems in children with ALL during or after treatment. The percentage of patients or survivors with impaired balance varied between 27% and 69% during treatment, 7% and 65% a few years after completion of treatment, and 14% and 17% many years after the completion of treatment. Factors associated with impaired balance were higher body mass index; higher intrathecal methotrexate dose; cranial radiation; knee extensor weakness; and impaired cognition.

CONCLUSION

Although heterogeneity between the studies regarding patient age; age at diagnosis; time since completion of treatment; and methods of quantifying balance make it difficult to reach a single conclusion, the evidence suggests that survivors may experience short- and/or long-term balance difficulties. While there is a need for additional studies to better understand the effects of impaired balance in survivors, clinicians treating both child and adult survivors of ALL need to be aware of these potential risks.

Impairments of Lower Extremity Muscle Strength and Balance in Childhood Cancer Patients and Survivors: A Systematic Review

This review aims to summarize the evidence for impairments of muscle strength and balance during and after treatment for childhood cancer. Thirty-two articles, identified in scientific databases by means of a structured search for investigations of muscle strength and balance in pediatric cancer patients and survivors, are evaluated. A summary of results is given with respect to matching reporting items to provide a qualitative analysis of the evidence. The majority of the studies reached a level 3 rating according to Oxford Centre for Evidence-Based Medicine (OCEBM) 2011 levels of evidence. Muscle strength and balance seem to be impaired in varying degrees depending on the diagnosis, treatment received, and time elapsed between treatment and evaluation. Drawing specific conclusions from the identified studies is difficult because of heterogeneous study samples and methods of research. Individual targeted exercise therapy programs during treatment and follow-up of childhood cancer could help to prevent and further diminish impairments of muscle strength and balance function among childhood cancer patients and survivors.

Challenges Evaluating Chemotherapy-Induced Peripheral Neuropathy in Childhood Cancer Survivors

Children treated for cancer are exposed to a variety of chemotherapeutic agents with known toxicity to the peripheral nervous system. The side effect of peripheral neuropathy can cause changes in sensation, function, and even cause pain. Although peripheral neuropathy is recognized by pediatric oncology nurses as an important and significant side effect, measuring neuropathy can be quite complex for clinical care and research efforts. With more children surviving a cancer diagnosis today, this issue is increasingly important for childhood cancer survivors. This article has reviewed existing literature examining peripheral neuropathy in childhood cancer survivors with particular interest paid to measurement tools available and needs for future research. It is important for nurses to choose appropriate measures for clinical care and research methods in order to have an impact on patients experiencing this condition.

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia

PURPOSE/OBJECTIVES

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
.

DESIGN

A prospective, repeated-measures design
.

SETTING

Two pediatric oncology settings in the southwestern United States.

SAMPLE

89 children with ALL were followed from diagnosis to the end of chemotherapy.

METHODS

Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times.

MAIN RESEARCH VARIABLES

Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
.

FINDINGS

Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
.

CONCLUSIONS

Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
.

IMPLICATIONS FOR NURSING

Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

The Association Between Motor Skills and Academic Achievement Among Pediatric Survivors of Acute Lymphoblastic Leukemia

OBJECTIVE

Assess the association between fine motor (FM) and visual-motor integration (VMI) skills and academic achievement in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

In this 28-site cross-sectional study of 256 children in first remission, a mean of 8.9 ± 2.2 years after treatment for standard-risk precursor-B ALL, validated measures of FM, VMI, reading, math, and intelligence were administered at mean follow-up age of 12.8 ± 2.5 years. 

RESULTS

 VMI was significantly associated with written math calculation ability (p < .0069) after adjusting for intelligence (p < .0001). VMI was more strongly associated with math in those with lower intelligence (p = .0141). Word decoding was also significantly associated with VMI but with no effect modification by intelligence. FM skills were not associated with either reading or math achievement.

CONCLUSION

These findings suggest that VMI is associated with aspects of math and reading achievement in leukemia survivors. These skills may be amenable to intervention.

Non-pharmacological interventions to manage fatigue and psychological stress in children and adolescents with cancer: an integrative review

Cancer-related fatigue (CRF) is the most stressful and prevalent symptom in paediatric oncology patients. This integrative review aimed to identify, analyse and synthesise the evidence of non-pharmacological intervention studies to manage fatigue and psychological stress in a paediatric population with cancer. Eight electronic databases were used for the search: PubMed, Web of Science, CINAHL, LILACS, EMBASE, SCOPUS, PsycINFO and the Cochrane Library. Initially, 273 articles were found; after the exclusion of repeated articles, reading of the titles, abstracts and the full articles, a final sample of nine articles was obtained. The articles were grouped into five categories: physical exercise, healing touch, music therapy, therapeutic massage, nursing interventions and health education. Among the nine studies, six showed statistical significance regarding the fatigue and/or stress levels, showing that the use of the interventions led to symptoms decrease. The most frequently tested intervention was programmed physical exercises. It is suggested that these interventions are complementary to conventional treatment and that their use can indicate an improvement in CRF and psychological stress.

Effect of an Ankle Foot Orthosis Intervention for Children With Non-Central Nervous System Cancers: A Pilot Study

PURPOSE

Children with cancer are at risk for physical performance limitations. In this pilot study we investigated the feasibility and initial efficacy of an ankle foot orthosis (AFO) in children with non-central nervous system cancer with peripheral weakness.

METHODS

Participants included children aged 5 to 11 years diagnosed with cancer. Children wore AFOs for 1 cycle of chemotherapy. Pre- and postintervention adverse events, adherence, gait, strength, range of motion, activity, and fatigue were measured.

RESULTS

Six of 7 children completed the study; none of the 7 reported adverse events. Positive trends were observed in step length (46.23-49.25 cm), dorsiflexion strength (19.25-24.50 lb), ankle dorsiflexion range of motion (0.5-8°), and activity (7850-9857 epochs). Negative trends observed included cadence and fatigue ratings. No change was observed in the 6-minute walk or parent-reported fatigue.

CONCLUSIONS

An AFO intervention is feasible in children with cancer. Initial efficacy results warrant further study.

Skeletal, neuromuscular and fitness impairments among children with newly diagnosed acute lymphoblastic leukemia

This study describes skeletal, neuromuscular and fitness impairments among 109 children (median age 10 [range 4-18] years, 65.1% male, 63.3% white) with acute lymphoblastic leukemia (ALL). Outcomes were measured 7-10 days after diagnosis and compared to age- and sex-specific expected values. Associations between function and health-related quality of life (HRQL) were evaluated with logistic regression. Children with ALL had sub-optimal bone mineral density (BMD) Z-score/height (mean ± standard error: - 0.53 ± 0.16 vs. 0.00 ± 0.14, p < 0.01), body mass index percentile (57.6 ± 3.15 vs. 50.0 ± 3.27%, p = 0.02), quadriceps strength (201.9 ± 8.3 vs. 236.1 ± 5.4 N, p < 0.01), 6 min walk distance (385.0 ± 13.1 vs. 628.2 ± 7.1 m, p < 0.001) and Bruininks-Oseretsky Test of Motor Proficiency scores (23 ± 2.5 vs. 50 ± 3.4%, p < 0.01). Quadriceps weakness was associated with a 20.9-fold (95% confidence interval 2.5-173.3) increase in poor physical HRQL. Children with newly diagnosed ALL have weakness and poor endurance and may benefit from early rehabilitation that includes strengthening and aerobic conditioning.

Vincristine-induced neuropathy in childhood ALL (acute lymphoblastic leukemia) survivors: prevalence and electrophysiological characteristics

The prevalence and the burden of vincristine-induced neuropathy have been poorly documented in childhood acute lymphoblastic leukemia survivors. This cross-sectional study was carried out at a tertiary care center in northern India from October 2011 to June 2012. Eighty consecutive acute lymphoblastic leukemia survivors aged 5 to 18 years, within 3 years of completion of their chemotherapy, were enrolled. After clinical evaluation, detailed nerve conduction studies were performed and the reduced version of the Total Neuropathy Score was calculated. The mean age at the time of evaluation was 11.2 ± 3.2 years. 33.75% had neuropathy electrophysiologically. Symmetric motor axonal polyneuropathy was the most common pattern of involvement seen in 19 (23.8%) children. There was significant improvement with time, as revealed by lower prevalence of neuropathy with increasing interval following vincristine injection. 33.75% of the children had Reduced version of Total Neuropathy Score ≥ 1.

Visuomotor function in children treated for acute lymphoblastic leukaemia with chemotherapy only

This study aimed to evaluate visuomotor function in children treated for acute lymphoblastic leukaemia (ALL). The performance of 64 children, 1-7 years post-chemotherapy for ALL, was compared to that of their healthy peers (n = 56) on visuomotor integration (VMI) and motor coordination (MC) tasks. Children posttreatment for ALL displayed significantly reduced VMI, but not MC, performances as compared to controls. Children treated on chemotherapy-only ALL regimes are at heightened risk for visuomotor integration deficits. Monitoring of visuomotor skills and implementation of appropriate interventions targeting higher level visuomotor integration skills should form an important component of any ALL long-term effects program.

Multifocal central nervous system demyelination and Lhermitte's phenomenon secondary to combination chemotherapy for chronic lymphocytic leukaemia

The CRF regime (cyclophosphamide, rituximab and fludarabine) is used for the treatment of chronic lymphocytic leukaemia. We report a case of diffuse CNS demyelination following treatment with CRF, presenting with Lhermitte's phenomenon, and imaging and neurophysiological evidence of demyelination. Fludarabine is the most likely causative agent, although CNS demyelination has not been previously described in low dose therapy.

Metabolic syndrome in pediatric cancer survivors: a mechanistic review

Pediatric cancer survivors have increased risk of obesity, hypertension, dyslipidemia, and type 2 diabetes, leading to premature cardiovascular disease (CVD). Multiple tissues that are involved in glucose homeostasis and lipid metabolism are adversely affected by chemotherapy. This review highlights the relevant tissue and molecular end-organ effects of therapy exposures and synthesizes the current understanding of the mechanisms underlying CVD risk in this vulnerable population. The review also approaches the topic from a developmental perspective, with the goal of providing a translational approach to identifying the antecedents of overt CVD among survivors of pediatric cancer.

Motor functioning during and following treatment with chemotherapy for pediatric acute lymphoblastic leukemia

This systematic review evaluated empirical studies examining motor skills in children during and following treatment for acute lymphoblastic leukemia. Most studies indicated that children on-treatment display poorer gross and fine motor abilities than healthy peers, but generally have intact visual-motor integration skills. Studies have reported gross motor difficulties in 5-54% of survivors. There is some limited evidence for long-term fine motor deficits. The evidence for visual-motor integration difficulties in the survivor population is less consistent. Larger studies with a longitudinal design are needed to further specify the onset and timing of motor difficulties and ascertain risk factors.

Chemotherapy-related neuropathic symptoms and functional impairment in adult survivors of extracranial solid tumors of childhood: results from the St. Jude Lifetime Cohort Study

OBJECTIVES

To ascertain prevalence of peripheral sensory and motor neuropathy, and to evaluate impairments in relation to function.

DESIGN

St. Jude Lifetime Cohort Study, a clinical follow-up study designed to evaluate adverse late effects in adult survivors of childhood cancer.

SETTING

A children's research hospital.

PARTICIPANTS

Eligibility required treatment for an extracranial solid malignancy between 1962 and 2002, age ≥ 18 years, ≥ 10 years postdiagnosis, and no history of cranial radiation. Survivors (N=531) were included in the evaluation with a median age of 32 years and a median time from diagnosis of 25 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Primary exposure measures were cumulative doses of vinca-alkaloid and platinum-based chemotherapies. Survivors with scores ≥ 1 on the sensory subscale of the Modified Total Neuropathy Score were classified with prevalent sensory impairment. Those with sex-specific z scores of ≤-1.3 for dorsiflexion strength were classified with prevalent motor impairment. Participants completed the 6-minute walk test (endurance), the Timed Up & Go test (mobility), and the Sensory Organization Test (balance).

RESULTS

The prevalence of sensory and motor impairment was 20% and 17.5%, respectively. Vinca-alkaloid exposure was associated with an increased risk of motor impairment (adjusted odds ratio [OR]=1.66; 95% confidence interval [CI], 1.04-2.64) without evidence for a dose response. Platinum exposure was associated with increased risk of sensory impairment (adjusted OR=1.62; 95% CI, .97-2.72) without evidence of a dose response. Sensory impairment was associated with poor endurance (OR=1.99; 95% CI, .99-4.0) and mobility (OR=1.65; 95% CI, .96-2.83).

CONCLUSIONS

Vincristine and cisplatin exposure may increase risk for long-term motor and sensory impairment, respectively. Survivors with sensory impairment are at increased risk for functional performance limitations.

Gross and fine motor skills in children treated for acute lymphoblastic leukaemia

OBJECTIVE

Chemotherapy treatment for acute lymphoblastic leukaemia (ALL) may disrupt motor development, with suggestions that gross and fine motor deficits are different depending on time since treatment.

METHODS

Thirty-seven participants aged between 2.5 to 5 years at the time of diagnosis were assessed using the Movement Assessment Battery for Children, 2nd Edition (MABC-2) and the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition, Short Form (BOT-2 SF), and divided into groups (i.e., months-off-treatment): (1) 0-12, (2) 13-24, and (3) 25-60 for comparison.

RESULTS

MABC-2 and BOT-2 SF mean total scores fell within the average range. Twenty-six percent of the sample performed in the impaired range on the MABC-2. Group 2 had significantly lower Manual Dexterity scores than the normative population and lower BOT-2 SF scores than Group 1.

CONCLUSION

Most children treated for ALL display appropriate motor skills, yet around a quarter experience general motor difficulties. Time-off-treatment did not affect the prevalence of motor impairments on any measure.

A rare case of peripheral neuropathy from relapse of acute lymphoblastic leukemia to the brachial plexus

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. ALL frequently involves the central nervous system and testicles, but has also been reported to metastasize to the liver and lung. We report a case of a 4-year-old African-American male with a previous history of ALL and hematopoietic stem cell transplant who presented with decreased arm movement and abdominal pain with relapse of primary disease into the brachial plexus and pancreas.

Chemotherapy-induced polyneuropathy. Part I. Pathophysiology

Chemotherapy-induced peripheral neuropathy (CIPN) is a toxic neuropathy, a syndrome consisting of highly distressing symptoms of various degrees of severity. It includes numbness of distal extremities, long-term touch, heat, and cold dysaesthesia and, in more severe cases, motor impairment affecting daily functioning. Each form of the syndrome may be accompanied by symptoms of neuropathic stinging, burning, and tingling pain. In the case of most chemotherapeutic agents, the incidence and severity of CIPN are dependent on the cumulative dose of the drug. The syndrome described is caused by damage to the axons and/or cells of the peripheral nervous system.

Chemotherapeutic agents have distinct mechanisms of action in both neoplastic tissue and the peripheral nervous system; therefore, CIPN should not be regarded as a homogeneous disease entity. The present article is an attempt to systematize the knowledge about the toxic effects of chemotherapy on the peripheral nervous system.

Neuromuscular impairments in adult survivors of childhood acute lymphoblastic leukemia: associations with physical performance and chemotherapy doses

BACKGROUND

Treatment regimens for childhood acute lymphoblastic leukemia (ALL) contain neurotoxic agents that may interfere with neuromuscular health. In this study, the authors examined associations between neuromuscular impairments and physical function and between neuromuscular impairments and doses of vincristine and intrathecal methotrexate used to treat leukemia among survivors of childhood ALL.

METHODS

ALL survivors >10 years from diagnosis participated in neuromuscular performance testing. Treatment data were abstracted from medical records. Regression models were used to evaluate associations between treatment factors, neuromuscular impairments, and physical performance.

RESULTS

Among 415 survivors (median age, 35 years; age range, 21-52 years), balance, mobility, and 6-minute walk (6MW) distances were 1.3 standard deviations below age-specific and sex-specific values in 15.4%, 3.6%, and 46.5% of participants, respectively. Impairments included absent Achilles tendon reflexes (39.5%), active dorsiflexion range of motion (ROM) <5 degrees (33.5%), and impaired knee extension strength (30.1%). In adjusted models (including cranial radiation), survivors who received cumulative intrathecal methotrexate doses ≥215 mg/m(2) were 3.4 times more likely (95% confidence interval, 1.2-9.8 times more likely) to have impaired ROM than survivors who received no intrathecal methotrexate, and survivors who received cumulative vincristine doses ≥39 mg/m(2) were 1.5 times more likely (95% CI, 1.0-2.5 times more likely) to have impaired ROM than survivors who received lower cumulative doses of vincristine. Higher intrathecal methotrexate doses were associated with reduced knee extension strength and 6MW distances.

CONCLUSIONS

Neuromuscular impairments were prevalent in childhood ALL survivors and interfered with physical performance. Higher cumulative doses of vincristine and/or intrathecal methotrexate were associated with long-term neuromuscular impairments, which have implications on future function as these survivors age.

Adverse effects of treatment in childhood acute lymphoblastic leukemia: general overview and implications for long-term cardiac health

Survival of childhood acute lymphoblastic leukemia (ALL) is one of the greatest medical success stories of the last four decades. Unfortunately, childhood ALL survivors experience medical late effects that increase their risk of morbidity and premature death, often due to heart and vascular disease. Research has helped elucidate the mechanisms and trajectory of direct damage to the heart from treatment exposure, particularly to anthracyclines, and has also contributed knowledge on the influences of related chronic conditions, such as obesity and insulin resistance on heart health in these survivors. This article summarizes the key issues associated with early morbidity and mortality from cardiac-related disease in childhood ALL survivors and suggests directions for interventions to improve long-term outcomes.

Physical activity and fitness in adolescent and young adult long-term survivors of childhood acute lymphoblastic leukaemia

INTRODUCTION

There is a lack of data on physical activity (PA) and fitness of adolescent and young adult very long-term survivors of childhood acute lymphoblastic leukemia (ALL).

METHODS

We studied 21 childhood ALL long-term survivors (aged 16-30 years, median time since diagnosis 15.9 y), diagnosed in 1986-1996, with age- and sex-matched controls. Peak oxygen uptake (VO(2 peak)) and muscle strength were measured and physical activity index (PAI; MET h/week) calculated.

RESULTS

Mean VO(2 peak) of the ALL survivors was 34.8 ± 9.3 ml/kg/min. This was 14% lower than that of the controls (-5.7 ml/kg/min, 95% CI -9.4 to -1.9, p=0.01), and all the 11 female survivors performed below the age-adjusted reference values. The survivors also performed poorer in the sit-up and maximal jump tests (p=0.02 and p=0.004). Body mass index and PAI were similar in survivors and controls (p=0.34 and p=0.52). Nonetheless, as much as 30% of the male survivors and 36% of the female survivors had PAI  ≤ 5 indicating very low levels of physical activity (PA).

CONCLUSIONS

Insufficient PA and poor physical fitness are clinically important issues in childhood ALL long-term survivors treated with modern protocols. Girls seem to be especially at risk. PA and better physical fitness decrease cardiovascular mortality irrespective of weight. Thus, PA should be promoted throughout and after the treatment for ALL.

IMPLICATIONS FOR CANCER SURVIVORS

Since insufficient PA and poor physical fitness are an issue in very long-term ALL survivors, they should be informed on the benefits of physical activity, and be strongly encouraged to adopt a physically active lifestyle.

Somatosensory evoked potential for detection of subclinical neuropathy in Egyptian children with acute lymphoblastic leukaemia

To evaluate neurological changes developing during paediatric Acute Lymphoblastic Leukaemia (ALL) therapy clinically and through electrophysiological Study of Somatosensory Evoked Potentials (SSEPs) changes in different phases of therapy. Thirty five-ALL patients with age range from 3-14 years were included compared to 30 healthy controls. History, neurological examination, complete blood counts, cytological examination of bone marrow aspirate and cerebrospinal fluid with Measurement of Serum Methotrexate (MTX) were done. The SSEPs were performed and patients subjected to another SSEP with measurement of serum MTX level before and 10 days after intra-thecal injection (IMTX). Clinical neurological findings in patients after induction were depressed deep tendon reflexes (43.3%), hypotonia (28.6%), lost pain sensation (28.6%), muscle weakness (17.1%) and movement disorders (17.1%). Percentage of delayed SSEPs after induction were at levels of brachial plexus (28.6%), spinal cord (68.6%), cortical conduction (31.4%), ERB-N13 Inter Peak Latency (IPL) (74.3%) and N13-N20 IPL (17.1%) in the studied patients. Significant prolonged latency of N13 (p = 0.005), N20 (p = 0.04) and IPL of ERB-N 13 (p = 0.005), N13-N20 (p = 0.01), Inter-Side Difference (ISD) of N13 (p = 0.01), ERB-N13 (p = 0.02) and N13-N20 (p = 0.03) after induction compared to values at diagnosis. Significant positive correlation were found between serum MTX after IMTX with N13-N20 IPL (p = 0.01), N20 ISD (p = 0.03) with significant prolongation in N20 latency, N13-N20 IPL and ISD of N20 compared to values before injection. ALL patients have prolonged latency of SSEPs at cervical cord and cortical levels which increased after IMTX due to axonal injury throughout the cord. SSEPs could be an early diagnostic tool for subclinical neuropathy.

Development, feasibility and efficacy of a community-based exercise training program in pediatric cancer survivors

OBJECTIVE

The aim of this study was to develop a 12-week exercise training program (comprising aerobic and strength exercises), and to study the feasibility and efficacy of this exercise program in children who survived acute lymphoblastic leukemia.

SAMPLE AND METHODS

A 12-week exercise program was developed and tested for feasibility in nine children who survived cancer.

RESULTS

From the 16 eligible children for the intervention, 9 participated, while 4 were able to complete the entire program. Feasibility of the program was scored by five children, two of them reported the program as being too demanding. The participating physiotherapists were satisfied with training methodology and training progress. The efficacy of the program on muscle strength, exercise capacity, functional mobility and fatigue showed no significant differences between pre and post training.

CONCLUSION

In designing a community-based exercise training program, not only the stage of the disease needs to be considered, but more so the age of the children, the variety of exercises, the location of implementation and even more importantly the views and motivation of the parents concerning the execution of an exercise training program. A careful balance between these parameters could lead to a greater adherence and by that, to a better outcome of these programs.

Physical function and fitness in long-term survivors of childhood leukaemia

OBJECTIVE

To evaluate the physical function and fitness in survivors of childhood leukaemia 5-6 years after cessation of chemotherapy.

MATERIALS AND METHODS

Thirteen children (six boys and seven girls; mean age 15.5 years) who were treated for leukaemia were studied 5-6 years after cessation of therapy. Physical function and fitness were determined by anthropometry, motor performance, muscle strength, anaerobic and aerobic exercise capacity.

RESULTS

On motor performance, seven of the 13 patients showed significant problems in the hand-eye co-ordination domain. Muscle strength only showed a significantly lower value in the mean strength of the knee extensors. The aerobic and the anaerobic capacity were both significantly reduced compared to reference values.

CONCLUSION

Even 5-6 years after cessation of childhood leukaemia treatment, there are still clear late effects on motor performance and physical fitness. Chemotherapy-induced neuropathy and muscle atrophies are probably the prominent cause for these reduced test results. Physical training might be indicated for patients surviving leukaemia to improve fitness levels and muscle strength.

Chemotherapy-induced neuropathy

Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.

Are survivors of acute lymphoblastic leukemia (ALL) at increased risk of cardiovascular disease?

Through a variety of different mechanisms, it appears that survivors of childhood acute lymphoblastic leukemia have an increased prevalence of several cardiovascular risk factors and thus are at increased risk for developing cardiovascular disease. The aim of this paper is to describe the current understanding of particular risk factors, including obesity, physical inactivity, dyslipidemia, insulin resistance, and metabolic syndrome, that may contribute to cardiovascular disease in survivors of childhood ALL. The potential roles of different cancer therapies in the development of these risk factors are discussed. In addition, two other late effects that may affect cardiovascular health are discussed: late-onset anthracycline-induced left ventricular dysfunction and methotrexate-mediated elevations of homocysteine during therapy with the potential for endothelial dysfunction. Lastly, areas needing further investigation to elucidate these risks are highlighted.

Visuomotor control in survivors of childhood acute lymphoblastic leukemia treated with chemotherapy only

Treatment for childhood acute lymphoblastic leukemia (ALL), which includes CNS prophylaxis, is associated with central and peripheral neurotoxicity. The purpose of the present study was to analyze the effects of chemotherapy on various levels of visuomotor control in survivors of childhood ALL treated without cranial irradiation, and to identify risk factors for possible deficits. Visuomotor function was compared between children after treatment for ALL (n = 34), children after treatment for Wilms tumor, which consists of non-CNS directed chemotherapy (n = 38), and healthy controls (n = 151). Three tasks were administered: a simple visual reaction time task and two tasks measuring visuomotor control with one requiring a higher level of cognitive control than the other. Visuomotor deficits were detected only in the ALL group, with poorer performance restricted to the condition requiring the highest level of control. Significant risk factors for poorer performance were female gender and a short time since end of treatment, and a trend was found for a young age at diagnosis. A high cumulative methotrexate dose was an adverse predictive factor in girls. The results indicate that chemotherapy-induced central neurotoxicity in childhood ALL treatment is associated with higher order visuomotor control deficits. Girls appear to be particularly vulnerable.

Biochemical and clinical aspects of methotrexate neurotoxicity

Acute, subacute and chronic neurotoxicity have been observed after the administration of high-dose and/or intrathecal methotrexate (MTX). Acute toxicity is usually transient without permanent damage. Subacute and chronic toxicity are associated with changes in the brain and/or the spinal cord which may be progressive and even lead to coma and death in severe cases. It is believed that MTX can induce direct toxic effects to the CNS by damaging the neuronal tissue. Moreover, MTX interferes with the metabolic pathways of folates, excitatory amino acids, homocysteine, S-adenosylmethionine/S-adenosylhomocysteine, adenosine and biopterins, inducing biochemical alterations which have been associated with neurotoxic symptoms. It has been suggested that acute toxicity is partly mediated by adenosine, whereas homocysteine, S-adenosylmethionine/S-adenosylhomocysteine, excitatory amino acids and biopterins may play an important role in the development of subacute and chronic toxicity. A better understanding of the pathogenesis of MTX neurotoxicity would offer the possibility of developing new therapeutic strategies for its treatment or prevention.

Motor nervous system impairment persists in long-term survivors of childhood acute lymphoblastic leukemia

BACKGROUND

The objective of the current study was to determine whether therapy for childhood acute lymphoblastic leukemia (ALL) results in long-lasting neurologic signs or electrophysiologic injuries within the motor tracts.

METHODS

Twenty-seven children who were treated for ALL were studied clinically 5 years after the cessation of therapy by means of motor-evoked potentials (MEPs) elicited by magnetic stimulation transcranially and peripherally. An equal number of healthy children matched with regard to age, gender, and height served as the control group.

RESULTS

The MEP latencies to the hands and legs elicited by stimulation at the cortex were prolonged significantly in the children treated for ALL compared with the control group, with the differences being 2.2 milliseconds [ms] (P < 0.001) from the cortex to the thenar on the right side and 2.0 ms (P < 0.001) on the left, and 1.4 ms (P = 0.004) from the cortex to the leg on the right side and 1.3 ms (P = 0.004) on the left. Correspondingly, the MEP latency from the fifth lumbar vertebrae (LV) level to the leg also was prolonged, by 1.0 ms (P = 0.005) on the right side and 0.8 ms (P = 0.005) on the left side. The calculated latency between the cortex and the LV level was not found to be significantly longer in those patients treated for ALL compared with the healthy controls. Neurologic signs, in the form of depressed deep tendon reflexes, were observed in 8% of the patients, whereas approximately 33% of the patients were found to have fine or gross motor difficulties and dysdiadochokinesia.

CONCLUSIONS

Neurologic signs still persisted 5 years after therapy for ALL. Approximately 33% of the patients had fine or gross motor difficulties and dysdiadochokinesia, and demyelinative injuries to the peripheral nerve tracts were found proximally but not within the central nervous system.