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.

Polyneuropathy in Acute Lymphoblastic Leukemia Long-Term Survivors: Clinical and Electrophysiological Characteristics With the Impact of Radiotherapy

Introduction: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer with one of the highest survival rates. Long-term complications that occur after intensive oncological treatment often impair normal daily functioning. However, existing data on peripheral nervous system condition in ALL survivors remain conflicting. Materials and Methods: The study group consisted of 215 ALL survivors. Patients were treated with New York (NY, n = 45), previous modified Berlin-Frankfurt-Münster (pBFM, n = 64), and BFM95 (n = 106) protocols. Time elapsed between the end of the treatment and the control examination varied from 0.3 to 20.9 years. The analyzed patients underwent a neurophysiological analysis with electroneurography (ENG) of motor (median and peroneal) and sensory (median and sural) nerves as well as electromyography (EMG) of tibialis anterior, vastus lateralis, and interosseous I muscles. To estimate the influence of radiotherapy on recorded neurophysiological responses, a joint analysis of NY, and pBFM groups was performed. Results: Clinical symptoms of polyneuropathy were noted among 102 (47.4%) children during the ALL therapy and in 111 (51.6%) during follow-up. At the time of treatment, polyneuropathy was diagnosed in 57.8% participants from NY group, 35.9%-pBFM and 50.0%-BFM95 (p = 0.145). A significantly higher incidence of polyneuropathy was observed during a follow-up in the NY group (68.9%; p < 0.001 vs. pBFM, p = 0.002 vs. BFM95). The most frequent abnormality within all the protocols was demyelination (NY: 44.4%, pBFM: 59.4%, BFM95: 41.5%), in contrast to the least frequently registered isolated axonal changes. The negative influence of oncological treatment on neurophysiological parameters in ALL survivors was observed. Complex disorders of motor nerves, sensory nerves, and motor unit potentials were registered. Motor-sensory neuropathy was the most frequently found pathology in all analyzed protocols. The harmful effect of radiotherapy was also observed in EMG results. Conclusions: Detailed neurophysiological analysis in long-term childhood ALL survivors has shown generalized abnormalities in registered parameters. To our knowledge, the current study is the largest and one of the most comprehensive ones among those examining disturbances in ENG and EMG in this group of patients. Moreover, we are the first ones to demonstrate the negative influence of radiotherapy on peripheral nerve conduction parameters.

Pharmacodynamic interactions between antiepileptic drugs: preclinical data based on isobolography

BACKGROUND

At least 20 - 30% of epileptic patients do not sufficiently respond to monotherapy. Some of them can benefit from drug combinations; hence, animal data may provide some useful novel clues for rational polytherapy.

OBJECTIVE

To review combinations of antiepileptic drugs, evaluated with the help of isobolographic analysis, in terms of their efficacy and adverse effects.

METHODS

A literature search, on the basis of experimental studies, with no time limit was carried out.

RESULTS/CONCLUSION

Preclinical data indicate that a synergy occurred for the combinations of valproate + phenytoin, valproate + ethosuximide, lamotrigine + valproate, gabapentin + valproate, gabapentin + carbamazepine, topiramate + carbamazepine, topiramate + valproate, topiramate + oxcarbazepine, levetiracetam + topiramate, levetiracetam + oxcarbazepine, oxcarbazepine + gabapentin, tiagabine + gabapentin and lamotrigine + topiramate. On the other hand, lamotrigine combined with carbamazepine or oxcarbazepine resulted in a clear-cut antagonism. Interestingly, a combination of oxcarbazepine + clonazepam produced variable responses, including synergy, additivity or antagonism, depending on the dose ratio of these drugs. In no case did pharmacokinetic factors contribute to the final analysis of the effects of drug combinations. Pharmacokinetic factors can contribute to the final effect of drug combinations,such as when stiripentol is added to valproate, or clobazam is added to valproate. It may be concluded that the rational treatment of drug-resistant epilepsy needs to consider the results of preclinical studies.

Pyridoxine-dependent seizures caused by alpha amino adipic semialdehyde dehydrogenase deficiency: the first polish case with confirmed biochemical and molecular pathology

Pyridoxine-dependent seizures are a rare condition recognized when numerous seizures respond to pyridoxine treatment and recur on pyridoxine withdrawal. For decades the diagnosis was confirmed only with pyridoxine treatment withdrawal trial. Recently described biochemical and molecular pathology improved the diagnostic process for those cases in which seizures are caused by alpha amino adipic semialdehyde dehydrogenase deficiency. This article presents a girl with recurrent status epilepticus episodes resistant to phenobarbital and phenytoin and partly responding to midazolam. Eventually the seizures were completely controlled with pyridoxine; however, due to the severe condition of this child when seizing, no trial of withdrawal has been performed. The diagnosis of pyridoxine-dependent seizures was confirmed with biochemical and molecular testing revealing elevated alpha-AASA excretion and the presence of 2 different mutations in the antiquitin ( ALDH7A1) gene. Due to the availability of reliable laboratory testing, confirmation of the diagnosis was made without the life-threatening trial of pyridoxine withdrawal.

[Auditory evoked potentials in patients after acute children's lymphoblastic leukemia treatment]

BACKGROUND

Acute lymphoblastic leukaemia (ALL), and especially its treatment often leads to irreversible consequences in the central and peripheral nervous system. ALL and its treatment as well, may cause disturbances of central transmission of acoustic stimuli.

THE AIM

To establish, if testing of egzogenic provoked brain stem potentials can be useful for evaluation of complications of ALL treatment. The issue of analysis was the influence of past ALL and type of therapy on parameters of egzogenic potentials triggered by acoustic stimulus (BAEP) in patients after termination of treatment.

RESULTS

In the group of patients treated with NY program results of middle latencies of the wave I and III were normal, however latencies of wave V and interlatencies of waves I-III, I-IV and III-V were mildly elongated. Latencies and interlatencies elongated above the upper normal range were detected in 4 patients of this group: in one patient elongation of the wave V and interlatencies of waves I-IV and III-V was detected, while in the other one interlatencies of waves I-III and I-V and in the last two patients only interlatencies of waves I-III. In the group of patients treated with BFM 86/87 programs results were similar. Latencies of waves I and III were normal, while mean latencies of wave V and interlatencies of waves I-III, I-V and III-V were mildly elongated. In this group mild pathological elongation of BAEP interlatencies were detected in 5 patients. Non of them had elongation of latencies of waves I, III or V. In one patient elongated interlatencies of waves I-V and III-V were detected, in another one interlatencies of waves I-III, while in other 3 patients elongation of latencies of waves I-V. In the group of patients treated with BFM 95 program latencies of waves I, III and V were normal, while interlatencies of waves I-III, I-V and III-V were mildly elongated. In 2 patients of this group mild elongation of interlatencies of waves I-III or III-V were detected. In each patient of this group, similar as in the group BFM 86/87, latencies of waves I, III and V were normal.

CONCLUSIONS

(1) BAEP abnormalities in 22.4% of patients after the treatment of childhood ALL suggest that hearing monitoring in these patients is recommended. (2) Elongation of BAEP interlatencies and latency of wave V in patients after radiation OUN therapy warrant to develop new and less toxic therapies.

[Assessment of congitive functions in patients post acute lymphoblastic leukemia treatment used P300 event related potential]

BACKGROUND

Acute Lymphoblastic Leukaemia (ALL) and its treatment can be involved in generation of cognitive function disorders. Assessment and monitoring of this side effect can be performed by endogenous evoked potential P300. The aim of the study was to show the changes of P300 potential in patients after ALL treatment.

MATERIAL AND METHODS

There were 36 children admitted to P300, but 3 of them were unable to perform it because of developmental delay and one child due to attention deficits. The study was performed on 32 patients with no influence on cognitive functions, aged 6 to 22 years (average 14,2), 13 girls and 19 boys, after ALL treatment finished before 0,3 to 11 years ago (average 3,2 years). The patients were divided into 3 groups, 9 children treated with New York program, 7 with older BFM program with chemio and radiotherapy of CNS, and 16 children with BFM 95 without radiotherapy. In the control group there were 20 persons aged 11-18 (average 14,1 years), consulted in the Neuropediatric Out-patient Clinic. P300 evoked potentials were performed due to IFCN recommendations. Latency, amplitude of P300 and time reaction were assessed with U Mann-Whitney test.

RESULTS

The children treated with older BFM programs had significant lower onset age of disease, and the age of P300 data was higher than other. Time reaction was shorter in this group. There were no significant differences between latency and amplitude of P300 in comparison to control group. Patient with NY and BFM 95 programmes had normal latency, but amplitude of P300 was significantly lower than in control group and time reaction was non-significantly longed. Patients with additional radiotherapy of CSN (NY and BFM) in the moment of assessment were older. The amplitude of P300 was significantly lower and latency similar to these parameters in control group. The statistic analyses were performed to eliminate the age influence on latency. The mean age of control group was established as 13,5 years with correction of 10ms per year to this age for each patient. There was no statistic significance in these groups even though the difference in children with radiotherapy was nearly statistical.

CONCLUSION

1. It is important to establish new, less toxic ALL treatment programs, because of significant cognitive impairment in 11% of examined children. 2. The mild modification of ALL treatment programs is necessary due to observation of decreased of P300 amplitude, what may influence education abilities.

[A case of congenital muscular dystrophy with changes in the white matter of the brain]

A case of cerebro-muscular disease is reported in a 5-year-old girl with normal mental development. The changes resembled those in Fukuyama dystrophy, but the clinical picture differs from that dystrophy in normal mental development and absence of other pathological changes in the central nervous system.