Quantitative EEG in long-term survivors of acute lymphoblastic leukemia

A comprehensive model of the development of mental handicap in children treated for acute lymphoblastic leukaemia: A synthesis of the literature

Most clinical studies addressing sequelae in children with leukaemia are not theory-driven. Nonetheless, the role of different mediating biological (e.g. cranial irradiation, chemotherapy) and psychosocial variables (e.g. family functioning) has been empirically acknowledged. In these studies, a cause-effect relationship between biological variables and cognitive deficits, sometimes complex due to multiple agents, has been hypothesised. As for the psychosocial consequences, adaptation to the cancer-related stress has been the main focus, at both the individual and family levels. In this paper, we advocate the use of a global model for the development of handicap, derived from the International Classification of Impairments, Disabilities and Handicaps (ICIDH) by the World Health Organisation. This revised model proposes that handicap is the result of complex interactions between the characteristics of a person’s impairment, disabilities, and the characteristics of the environment. At each of these levels, risk/resilience factors are defined. This means that depending on the environmental obstacles they face, persons with an impairment or a disability may or may not experience a situation creating a handicap which is no longer seen as a stable status resulting from a disease to which the individual must adapt. By reviewing animal and clinical studies, current knowledge pertaining to leukaemia sequelae are integrated into the different levels defined by the model: organic impairment, disabilities, environmental obstacles, and handicap situation. Practical implications for research, policies, and individual treatments, and comparisons with existing models, are also outlined.

Effect of high dose cytosine arabinoside on quantitative EEG in patients with acute myeloid leukemia

Background EEG activity is considered an index of functional state of brain. Chemotherapy (CT), used for non-central nervous system (CNS) cancer, can cross the blood brain barrier and contribute to changes in the functional state of brain that can alter background EEG activity. Quantitative EEG (qEEG) is superior to conventional EEG in the detection of subtle alterations of EEG background activity and for this reason, the use of qEEG might assist the clinician in evaluating the possible effect of CT on the CNS. The nucleoside analog cytosine arabinoside (Ara-C) is one of the milestone chemotherapeutic agents used for treatment of acute myeloid leukemia (AML). Our observational study evaluates the possible effect of Ara-C on the qEEG of patients with AML, without CNS involvement. We conducted an observational study on newly diagnosed AML patients without CNS involvement, undergoing treatment with Ara-C to analyze the possible effect of Ara-C high doses on EEG background activity using qEEG analyses. A total of nine AML patients, 5 with Ara-C i.v. high dose (≥3 g/m(2) die), 4 with standard dose (100 mg/m(2) die) underwent qEEG (at rest, during hyperpnoea, mental arithmetic task and blocking reaction). We compared the EEG background activity of the two groups at baseline and after 6 months. Statistical analysis showed no significant differences between the two groups in mean relative power for all frequency bands, at rest and during hyperpnoea, mental arithmetic task and blocking reaction. Our data indicate that high dose Ara-C i.v. did not induce significant changes on EEG background activity in our patients. Future research in this area could include prospective studies that would combine qEEG and neuropsychological testing to assess the impact of CT on brain functions.

Assessment of neuropsychological late effects in survivors of childhood leukemia

The neurologic dysfunctions caused by treatment may affect health and quality of life in survivors of childhood leukemia. The objective of this study was to identify the neuropsychological late effects of leukemia treatment to provide an assessment about the degree and incidence of these late effects. Neurological and ophtalmological examination, cranial magnetic resonance imaging (MRI), auditory and neurocognitive tests, and questionnaires of quality of life were performed to 44 acute leukemia survivors at least 5 years after diagnosis. Median time since completion of chemotherapy was 7.5 years (2-18) and median age at the time of the study was 16.4 years (8-31). At least one or more late effects detected by physical examination (PE), neurological tests, or neurocognitive tests encountered in 80% of the patients, and 64% of the patients specified at least one complaint in the quality of life questionnaire. MRI revealed pathological findings in 18% and electroencephalogram (EEG) abnormalities were present in 9% of the patients. Evaluation of total intelligence scores revealed that 30% of patients' IQ scores were <80 and 70% of the patients' scores demonstrated neurocognitive dysfunctions. The patients >6 years at the time of diagnosis were found to have more psychological problems and higher rates of smoking and alcohol consumption. The most frequent complaint was headache and the most common problem in school was denoted as difficulty in concentration. Our study demonstrated that most of the survivors of childhood leukemia are at risk of developing neuropsycological late effects.

Cortical sources of EEG rhythms in congestive heart failure and Alzheimer's disease

INTRODUCTION

The brain needs continuous oxygen supply even in resting-state. Hypoxia enhances resting-state electroencephalographic (EEG) rhythms in the delta range, and reduces those in the alpha range, with a pattern similar to that observed in Alzheimer's disease (AD). Here we tested whether resting-state cortical EEG rhythms in patients with congestive heart failure (CHF), as a model of acute hypoxia, present frequency similarities with AD patients, comparable by cognitive status revealed by the mini mental state examination (MMSE).

METHODS

Eyes-closed EEG data were recorded in 10 CHF patients, 20 AD patients, and 20 healthy elderly subjects (Nold) as controls. LORETA software estimated cortical EEG generators.

RESULTS

Compared to Nold, both AD and CHF groups presented higher delta (2-4Hz) and lower alpha (8-13Hz) temporal sources. The highest delta and lowest alpha sources were observed in CHF subjects. In these subjects, the global amplitude of delta sources correlated with brain natriuretic peptide (BNP) level in the blood, as a marker of disease severity.

CONCLUSIONS

Resting-state delta and alpha rhythms suggest analogies between the effects of acute hypoxia and AD neurodegeneration on the cortical neurons' synchronization.

SIGNIFICANCE

Acute ischemic hypoxia could affect the mechanisms of cortical neural synchronization generating resting state EEG rhythms, inducing the "slowing" of EEG rhythms typically observed in AD patients.

Almost normal cognitive function in patients during therapy for childhood acute lymphoblastic leukemia without cranial irradiation according to ALL-BFM 95 and COALL 06-97 protocols: results of an Austrian-German multicenter longitudinal study and implications for follow-up

In a multicenter study the authors prospectively investigated neurocognitive function in childhood ALL patients. Sixty-six patients (mean age at diagnosis 7.9 +/- 3.6 years, 34 female), treated with repeated intrathecal and systemical methotrexate administrations without cranial irradiation, underwent psychometric testing for intelligence, concentration, and visual-motor integration postdiagnosis and after reinduction therapy. Although there was a statistically significant decline of intellectual function after reinduction therapy for younger patients and girls (IQ scores still within normative data range), there were no differences in visual-motor performance and concentration over the time of induction therapy. Thus, neurocognitive examination should focus on younger ALL patients and girls.

Visual attention in long-term survivors of leukemia receiving cranial radiation therapy

The effect of cranial radiation therapy (CRT) on visual attention was examined in long-term survivors of childhood acute lymphoblastic leukemia (ALL) compared to peers with no history of ALL (n = 24) using a cued orienting task and a global-local task. ALL participants treated with CRT (n = 13) demonstrated an increased cost in response time with invalid spatial orienting cues and inefficient shifts of attention across hierarchical levels. ALL participants treated only with chemotherapy (n = 8) showed performance similar to the non-ALL comparison group. Participants with exposure to CRT early in life appeared to largely account for the attention deficits, and showed particular difficulties with shifting attention from the local level of stimuli to the global level. The data are consistent with prior reports emphasizing attention deficits following CRT, and suggest that attention shifting may be particularly affected by CRT early in life.

CNS late effects after ALL therapy in childhood. Part I: Neuroradiological findings in long-term survivors of childhood ALL--an evaluation of the interferences between morphology and neuropsychological performance. The German Late Effects Working Group

The effect of cranial irradiation on possible therapy-induced morphological central nervous system (CNS) side effects of children cured from acute lymphoblastic leukemia (ALL) is controversially discussed. In a retrospective multicenter study, 118 former ALL patients in first continuous remission were investigated using cranial computerised tomography (CCT) or magnetic resonance imaging (MRI) scans to evaluate CNS related impairments. Corresponding to the different kinds of CNS prophylaxis, the patient sample was divided: group A (n = 39) receiving intrathecal methotrexate (ITMTX) and systemical medium-high-dose methotrexate (SMHDMTX), group B (n = 41) cranial irradiated (in mean 16.8 Gy) and administering ITMTX and SMHDMTX, group C (n = 38) irradiated (in mean 17.1 Gy) and getting ITMTX. Pathologic scans showed atrophy, leukoencephalopathy, calcifications or grey matter changes. These findings were compared with the neuropsychological test results. Abnormal MRI or CCI scans were found in 61/118 patients (51.7%). Fifteen belonged to group A (38.5%), 23 to B (56.1%) and 23 to C (60.5%). Patients with definite CNS changes show reduced neuropsychological test results. The prevalence of brain alterations seems to appear twice increased after lengthening the posttherapeutic interval in irradiated patients as in nonirradiated patients. Irradiated patients as an age younger than 2 years at diagnosis may show a lower prevalence for developing CNS alterations. CNS alterations are not sex-related. Children treated with cranial irradiation in combination with SMHDMTX and/or ITMTX were at greater risk of developing morphological brain alterations than patients with chemotherapy alone. These alterations are partly correlated with reduced neuropsychological performances and seem to stay with a longer posttherapeutic interval.