Chemotherapy for acute lymphoblastic leukemia may cause subtle changes of the spinal cord detectable by somatosensory evoked potentials

Clinical utility of complex assessment with evoked potentials in acute lymphoblastic leukemia survivors: comparison of various treatment protocols

BACKGROUND

One of the greatest success of pediatric hematology is a prominent improvement of survival in acute lymphoblastic leukemia (ALL). Therefore, special attention needs to be paid to long-term side effects of the treatment such as neurotoxicity. One of the few diagnostic methods that allow an objective assessment of sensory systems are evoked potentials (EP).

METHODS

The analyzed group consisted of 167 ALL long-term survivors, aged 4.9-28.4 years, without auditory, visual and sensory deviations. Patients were treated with New York (NY, n = 35), previous modified Berlin-Frankfurt-Münster (pBFM, n = 47) and BFM95 (n = 85) protocols. In order to assess the impact of radiotherapy on recorded EP, a joint analysis of NY and pBFM groups was performed. The control group consisted of 35 patients, aged 6-17 years. The analyzed patients underwent a complex assessment with visual EP (VEP), somatosensory EP (SEP) and brainstem auditory EP (BAEP) in accordance with current standards.

RESULTS

ALL treatment contributed to the shortening of wave I latency (1.59 vs 1.90, P = 0.003) and prolongation of I-III (2.23 vs 2.04, P = 0.004) and I-V (4.57 vs 4.24, P = 0.002) interwave latencies of BAEP. A significant effect was also noticed in P100 (106.32 vs 101.57, P < 0.001) and N135 (151.42 vs 138.22, P < 0.001) latencies of VEP and N18 amplitude (3.24 vs 4.70, P = 0.007) and P25 latency (21.32 vs 23.39, P < 0.001) of SEP. The distribution of abnormalities between protocols was similar in BAEP (NY - 68.6%, pBFM - 61.7%, BFM95-69.4%, P = 0.650), VEP (NY - 68.6%, pBFM - 42.5%, BFM95-58.3%, P = 0.053) and significantly different for SEP (NY - 62.9%, pBFM - 36.2%, BFM95-53.0%, P = 0.045). The harmful effect of radiotherapy was most clearly marked in numerous disturbances of SEP parameters.

CONCLUSIONS

The presented analysis indicates a high frequency of subclinical abnormalities in EP regardless of the analyzed protocol. To our knowledge current study is the largest and one of the most complex research examining the role of EP in ALL patients. The obtained results indicate the possibility of using a single, objective and non-invasive measurement of EP in ALL survivors in order to stratify the risk of developing sensory abnormalities in adulthood.

Decreased postural control in adult survivors of childhood cancer treated with chemotherapy

The objective of cancer treatment is to secure survival. However, as chemotherapeutic agents can affect the central and peripheral nervous systems, patients must undergo a process of central compensation. We explored the effectiveness of this compensation process by measuring postural behaviour in adult survivors of childhood cancer treated with chemotherapy (CTS). We recruited sixteen adults treated with chemotherapy in childhood for malignant solid (non-CNS) tumours and 25 healthy age-matched controls. Subjects performed posturography with eyes open and closed during quiet and perturbed standing. Repeated balance perturbations through calf vibrations were used to study postural adaptation. Subjects were stratified into two groups (treatment before or from 12 years of age) to determine age at treatment effects. Both quiet (p = 0.040) and perturbed standing (p ≤ 0.009) were significantly poorer in CTS compared to controls, particularly with eyes open and among those treated younger. Moreover, CTS had reduced levels of adaptation compared to controls, both with eyes closed and open. Hence, adults treated with chemotherapy for childhood cancer may suffer late effects of poorer postural control manifested as reduced contribution of vision and as reduced adaptation skills. These findings advocate development of chemotherapeutic agents that cause fewer long-term side effects when used for treating children.

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.

Dorsal column myelopathy following intrathecal chemotherapy for acute lymphoblastic leukemia

OBJECTIVE/CONTEXT: To describe a distinctive clinical and radiographic pattern of myelopathy following intrathecal chemotherapy. Myelopathy is a rare complication of intrathecal chemotherapy used in the treatment of acute lymphoblastic leukemia (ALL). We present a 42-year-old female with T-cell ALL who developed a myelopathy primarily involving the dorsal columns.

METHOD

Case report and literature review.

FINDINGS

Within 24 hours of an injection of intrathecal methotrexate, cytarabine, and hydrocortisone, the patient developed ascending lower limb numbness and balance difficulties progressing to the inability to ambulate. Clinical examination showed profound loss of lower limb proprioception and light touch sensation below T5, mild proximal limb weakness, but preserved pinprick and temperature sensation with intact bowel and bladder function. Initial thoracic and lumbar spine magnetic resonance imaging (MRI) at 1 week revealed no abnormalities. However, repeat imaging at 6 weeks showed abnormal signal in the posterior cord with sparing of the anterior and lateral columns, diffusely involving the lower cervical cord through the conus medullaris. Dermatomal somatosensory-evoked potential (DSEP) conduction abnormalities were consistent with thoracic myelopathy. An empiric trial of high-dose intravenous corticosteroids during inpatient rehabilitation more than 6 weeks later produced no significant clinical improvement.

CONCLUSION/CLINICAL RELEVANCE

Preferential and persistent dorsal column myelopathy is a distinctive clinical and radiographic presentation of a rare complication of intrathecal chemotherapy. The MRI abnormalities were initially absent, but evolved to consist of multi-level spinal cord T2 and STIR hyperintensity with regional gadolinium enhancement. DSEPs more accurately reflected the clinical level of spinal cord dysfunction.

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.

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.

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.

Central Nervous System Disease in Acute Lymphoblastic Leukemia: Prophylaxis and Treatment

Improved treatment for acute lymphoblastic leukemia (ALL) has virtually eliminated testicular relapse. However, the control of central nervous system (CNS) leukemia remains a therapeutic challenge in childhood ALL, partly because of the late complications arising from cranial irradiation. In most current pediatric protocols, cranial irradiation (12 to 18 Gy) is given to 5% to 25% of patients—those with T-cell ALL, overt CNS disease (CNS3 status) or high-risk cytogenetics. CNS control is a less urgent concern in adults with ALL, in whom systemic relapse remains the major problem. With current approaches, approximately 2% to 10% of patients can be expected to develop CNS relapse. Children with B-cell precursor ALL who have a late CNS relapse (after an initial remission of 18 months or more) and did not receive cranial irradiation have an excellent outcome after retrieval therapy, with a 5-year event-free survival (EFS) rate approaching that in newly diagnosed patients. Innovative treatment options are needed for children who develop CNS relapses after a short initial remission or after receiving cranial irradiation, and in any adults with CNS leukemia at diagnosis or relapse.

Myelopathy due to intrathecal chemotherapy: report of six cases

Intrathecal chemotherapy and systemic chemotherapy are used for both prophylaxis and treatment of central nervous system disease in hematologic malignancies. However, intrathecal treatment has some adverse effects, such as arachnoiditis, progressive myelopathy, and leukoencephalopathy. The authors describe six children in whom myelopathy and adhesive arachnoiditis developed after administration of intrathecal chemotherapy including methotrexate, cytosine arabinoside, and prednisolone. Urinary retention and incontinence, the main presenting complaints in all patients, developed within 12 hours after intrathecal therapy and spontaneously resolved within 7 days. Two patients were unable to walk. In these two, weakness in the lower extremities gradually recovered by 1 month but urinary incontinence did not improve. None of the children had sensory loss. On follow-up periodic recurrent urinary tract infection was noted in four patients. MRI findings corresponded to arachnoiditis. No response was recorded on tibial nerve somatosensory evoked potentials in all patients. Intrathecal chemotherapy, especially methotrexate, can cause spinal cord dysfunction in children with acute lymphoblastic leukemia and non-Hodgkin's lymphoma. Arachnoiditis should be kept in mind as a causative factor in recurrent urinary tract infection in patients receiving intrathecal chemotherapy.

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.

Methotrexate treatment protocols and the central nervous system: significant cure with significant neurotoxicity

Methotrexate can influence the central nervous system through several metabolic toxic pathways. These effects can be categorized as immediate, acute to subacute, or chronic neurologic syndromes. The acute to subacute syndrome occurs frequently in acute lymphoblastic leukemia treatment protocols, generally manifesting with focal neurologic signs and changes seen on magnetic resonance imaging and single photon emission computed tomography. While in some patients the neurotoxicity is transient and benign and allows for continuation of chemotherapy, in others it can be quite severe and debilitating, leading to permanent neurologic deficits. The need to modify the treatment protocols when neurotoxicity appears is not fully established. It is also unknown whether the use of sufficient amounts of leucovorin can overcome the toxic effects of the drug.

Motor performance of children during treatment for acute lymphoblastic leukemia

BACKGROUND

Daily life motor skills of children with acute lymphoblastic leukemia (ALL) were studied during treatment using the Movement Assessment Battery for Children (Movement ABC). In addition, the possible relation with vincristine treatment was investigated.

PROCEDURE

Seventeen children treated for ALL, aged 4-12 years, were compared to an age- and sex-matched control group.

RESULTS

The leukemia group performed more poorly than the control group on both fine and gross motor skills. In looking at the number of children with ALL who scored in the clinical range of the different subtests, problems in balance skills were found to be most pronounced at the end of induction therapy. Remarkably, half a year after reinduction therapy, problems with balance had decreased, whereas the number of children with fine motor problems had increased.

CONCLUSIONS

A relation between the gross motor problems and vincristine neurotoxicity seems plausible based on a descriptive analysis of the data, but this was not supported statistically.

Nerve lesions after therapy for childhood acute lymphoblastic leukemia

BACKGROUND

The objective of the current study was to use somatosensory evoked potentials (SEP) to detect signs of nerve lesions in the peripheral nerve and in the central nervous system (CNS) after 3 years of treatment for childhood acute lymphoblastic leukemia (ALL).

METHODS

The somatosensory potentials evoked by stimulation of the median nerve and posterior tibial nerve were recorded in 31 children with ALL after 3 years of therapy. All patients were examined clinically. The 14 standard risk patients had been treated with chemotherapy according to the Nordic regimen, and the 17 intermediate risk or high risk patients had been treated with chemotherapy and cranial irradiation according to the ALL BFM-83 protocol.

RESULTS

A decrease in amplitudes was observed at the brachial plexus and spinal cord (C7) in the median SEP, and at the knee, spinal cord (Th12), and cortex in the tibial SEP, indicating axonal injury within the entire CNS in the patients with ALL compared with healthy age-, gender-, and height-matched controls. Prolongation of the SEP latencies was found within the spinal cord, indicating demyelination. These SEP changes had persisted for 2 years since the last injection/infusion of vincristine or methotrexate, which are the principal neurotoxic drugs used in chemotherapy for ALL. Clinical signs of nerve injury such as depressed deep tendon reflexes and gross or fine motor difficulties were found in approximately 33% of the patients and dysdiadochokinesia in 50%.

CONCLUSIONS

Treatment of ALL in children principally with vincristine and methotrexate causes long-standing axonal injury throughout the nervous system and demyelination within the spinal cord. These changes are associated with clinical neurologic findings.