The central nervous system in childhood leukemia. III. Mineralizing microangiopathy and dystrophic calcification

Long-term consequences of CNS treatment for childhood cancer, Part I: Pathologic consequences and potential for oncogenesis

The pathologic changes associated with the treatment of cancer of the nervous system are reviewed. Computed tomographic, magnetic resonance imaging, and positron emission tomographic findings of these abnormalities are described, followed by discussion of the known histopathologic features. For the most part, pathologic effects are primary vascular and/or demyelinating. We review each of these effects at all levels of the neural axis. This review concludes with a discussion of the risk of developing second malignancies. Although this complication is infrequent, the likelihood that survivors of childhood cancer will develop a second malignancy is 10 times that of age-matched controls. This phenomenon in part relates to genetic predisposition, environmental factors, and host susceptibility. These qualifications not withstanding, most studies implicate central nervous system radiation with and without chemotherapy as the primary etiology for second malignancies.

Stroke as a late sequela of cranial irradiation for childhood brain tumors

Cerebrovascular disease involving large and medium-size vessels is thought to be an uncommon sequela of treatment of childhood brain tumors. We reviewed 11 children who developed cerebrovascular disease manifested by strokes or transient ischemic attacks 6 months to 4 years after treatment of brain tumors, while their tumors were in remission. All had received radiation therapy, and seven had received chemotherapy. One child died of acute bilateral cerebral infarctions due to carotid occlusion on one side and marked stenosis on the other 2 years after receiving radiation therapy for an incompletely resected craniopharyngioma. Pathologically, there was marked subendothelial fibrosis of the vessels of the circle of Willis, with inflammatory changes surrounding some of the vessels. In addition to the widely recognized small-vessel damage caused by radiation and chemotherapy in children (mineralizing microangiopathy), damage to medium and large intracranial vessels may result in late sequelae, manifested by stroke or transient ischemic attacks.

Asymptomatic cerebral calcification--a previously unrecognized feature

While investigating the radiological appearances of globus pallidus calcification in an autopsy case, cortical-pia mater calcification was detected. There was no documentation of its existence in the literature of radiology, neurology and neuropathology. To establish its incidence and clinical significance, 20 consecutive autopsy brains (15 males, 5 females, age 32-73 years, mean age 56.7) were studied with high resolution radiography and histology. Clinical records, autopsy findings, in-life plain skull films and computed tomography of the brain (if available) were reviewed. Radiologically, the calcifications appeared as 1-2 mm irregular spots or tiny pin-point opacities in the pia mater and subcortical regions, either unilaterally or bilaterally in the frontal (15 cases), temporal (15), parietal (3) and occipital lobes (1). Similar calcification was detected in 1 of the 3 in-life computed tomographic scans available. Histologically, these cortical-pia mater calcifications were extracellular amorphous calcified masses of various sizes in necrotic neural tissue, frequently associated with microscopic haemorrhage and hypoxic neuronal changes in the adjacent brain tissue. Blood vessels in the region were not hyalinized or calcified. The occurrence was not related to age. Hospital stay was less than 7 days in 14 and less than 30 days in 2; 50% of patients died within 48 hours after admission. None of the patients had records of long term cytotoxic chemotherapy, radiotherapy or central nervous system infection. Two had stroke, one had cerebellar atrophy and one mild hypercalcaemia. The high incidence of calcifications in the temporal lobes, while asymptomatic, suggests that cortical calcification may be a pointer to the aetiology of idiopathic epilepsies in the elderly.

Methotrexate-related multifocal axonopathy. Report of an autopsy case

A case of multifocal axonopathy associated with intrathecal methotrexate (IT MTX) and radiation therapy is presented. A 33-year-old woman suffering from meningeal carcinomatosis of breast cancer origin had developed prominent multifocal axonal degeneration in the cerebral white matter after treatment with IT MTX therapy and cranial irradiation. The principal features of this axonal degeneration were segmental hydropic swellings, macrophage infiltration of swollen axons, and scattered spheroid formation associated with reactive astrocytosis. These features were similar to those observed in our previous experimental study using cats treated with IT MTX alone. This "multifocal axonopathy" without necrotizing lesions seems to be different from disseminated necrotizing leukoencephalopathy, and, therefore, may be another form of MTX-related leukoencephalopathy. IT MTX and cranial irradiation seem to have exerted synergistic effects in producing the "multifocal axonopathy" in this case.

Radiation-induced cerebral lesions in childhood

Post-irradiation cerebral pathologies may appear in various forms from localized radiation necrosis to a plurifocal type or from local to diffuse vasculopathies. Contrary to the current prevalent opinion, these lesions are not rare in children since young nerve tissue is particularly sensitive to ionizing radiation. Given the seriousness of some of these lesions, the authors recommend careful evaluation of the risk involved in relation to the real necessity of administering irradiation therapy in childhood.

An animal model to detect the neuropsychological toxicity of anticancer agents

The unexpected discovery that certain chemotherapeutic agents used in the treatment of childhood cancers have neurocognitive side effects has prompted a search for techniques that identify those medications that place children at risk. An animal model for the assessment of resultant neurocognitive toxicity is described which makes use of simple classical conditioning. We have shown that rats learn about environmental events more slowly following neonatal administration of methotrexate. The changes after methotrexate exposure are not related to stimulus characteristics or to perceptual abilities, but rather to damage to the neural systems involved in acquisition, retention, or recall. Similar problems with learning have been observed in children treated with methotrexate. An effective animal model such as the one described here may help detect and avoid antineoplastic agents that produce severe cognitive defects in childhood cancer patients.

Neurodevelopmental delay and focal seizures as presenting symptoms of human immunodeficiency virus I infection

Three children presenting with neurological symptoms were subsequently diagnosed as being infected with the human immunodeficiency virus I (HIV). All children showed normal development for about 12-18 months of age but later developed psychomotor and developmental regression. One child presented with generalised hypotonia, another with focal seizures, and the third with spastic quadriplegia. Two of the children showed areas of abnormal brain density on computed tomography and in one case there was calcification of the basal ganglia. In two of the children cerebrospinal fluid contained reduced amounts of total folate and elevated concentrations of neopterin. The possibility of a link between the deranged folate metabolism and the neurological symptoms in HIV infection is discussed.

Experimental study on subacute neurotoxicity of methotrexate in cats

An experimental study on the pathogenesis of methotrexate (MTX)-related neurotoxicity including disseminated necrotizing leukoencephalopathy (DNL) was conducted in cats. MTX was administered to the cerebrospinal fluid (CSF) of adult cats using either an intracisternal intermittent instillation (ICI) model or an intraventricular continuous instillation (IVC) model. Furthermore, the synergistic effects of CSF-flow disturbance with kaolin-induced hydrocephalus, and 60Co irradiation were morphologically examined in these models. None of the animals from either the ICI and IVC groups showed DNL, but all animals showed segmental axonal degeneration, suggesting that MTX had a direct toxic effect on the axon. In the ICI groups, no apparent synergistic effect of CSF-flow disturbance and radiation was noted on this axonal change. In the IVC groups, CSF-flow disturbance augmented the degree of the axonal injury. Axonal degeneration and fibrin exudation in the walls of small blood vessels occurred in one animal of the IVC groups with CSF-flow disturbance, suggesting that a toxic effect of MTX on blood vessels is another mechanism of MTX-induced neurotoxicity.

Neurobehavioral effects of central nervous system prophylactic treatment of cancer in children

This article reviews 41 studies of the effects of prophylactic CNS treatment on the neurobehavioral development of children with cancer. This research is classified according to studies of (a) children in treatment; (b) long-term survivors; and (c) longitudinal follow-ups of children from the time of diagnosis. Studies vary considerably in design, sample, and outcome variables, so firm conclusions regarding the morbidity of CNS prophylaxis are not currently possible. However, the studies do suggest that CNS prophylaxis does impair cognitive development, particularly when cranial radiation therapy is part of the treatment. There is also evidence of greater impairment in younger children and some suggestion of more frequent impairment of non-language skills relative to language skills. The possible relationships among age, radiation, and non-language cognitive skills may be linked to disruption of white matter CNS structures apparent on autopsy and cerebral tomography following treatment.

Intracerebral bilateral symmetrical calcifications, demonstrated in a patient with pseudohypoparathyroidism

Bilateral Symmetrical Calcifications (B.S.C.) in cerebro represent calcium deposits usually found in the basal ganglia and/or dentate nucleus. They can be the result of diverse disorders, but can also present themselves without any underlying disease. Most often they are asymptomatic, but if the calcifications are extensive, extrapyramidal and cerebellar signs may arise. The following case concerns a patient with pseudohypoparathyroidism. Besides the usual signs and symptoms found in this disease, the patient also showed extensive B.S.C. The etiology and clinical symptoms of B.S.C. will be discussed. Furthermore, attention will be given to the syndrome of the pseudohypoparathyroidism and the effects of hypocalcemia.

Dihydrofolate reductase-activity in brain tissue. Effect of X-irradiation

The mechanism responsible for the toxic late effects of cranial irradiation, followed by the administration of systemic methotrexate (MTX) on brain tissue, is still under discussion. We studied the influence of X-irradiation on dihydrofolate reductase (E.C. 1.5.1.3) activity (DHFR), the enzyme inhibited by MTX. New Zealand white rabbits, 6-9 weeks old, underwent 24 Gy fractionated or 20 Gy single-dose brain irradiation using a 60Co source. Before, immediately following, and 1, 2, 4, 12 weeks after irradiation, DHFR was measured in brain and liver tissue by a photometric assay. DHFR in brain tissue was 11.9 +/- 2.9 mU/g wet weight (ww) X h and in liver tissue 121.8 +/- 24.2 mU/g ww X h. Fractionated brain irradiation with 2 Gy per day produced no significant changes in brain DHFR. Single-dose cranial irradiation significantly decreased brain DFHR (7.3 +/- 0.6 mU/g ww X h). Suppression of the developmental increase of DHFR by X-irradiation in young rabbits could be excluded by determining the unchanged brain-to-liver ratios of DHFR in the animals with fractionated brain irradiation.

Effects of local irradiation and i.v. methotrexate on brain morphology in rabbits: early changes

Brain damage following cranial radiation therapy can be crippling or even life-threatening and has been studied in both patients and animals. An additional toxic effect of chemotherapy has been found in children, who died following brain irradiation and systemic chemotherapy for the treatment of acute lymphoblastic leukemia. To study the interaction of radiation and drugs on brain tissue, we treated rabbits with brain irradiation and/or i.v. methotrexate. For a period of up to 3 months following radiation therapy, brain morphology was compared in seven treatment groups. Weekly doses of methotrexate administered i.v. produced no brain damage. Histological examination showed myelin swelling and beading 14 weeks after fractionated brain irradiation with 24 Gy. Combination of brain irradiation and methotrexate produced additional hypertrophy of microglia and pyknosis of adventitial cells. In none of these groups, even after doses of 48 Gy brain irradiation, was calcification or brain necrosis observed during the first 14 weeks following irradiation.

Long-term psychological effects of childhood leukemia and its treatment

We report the results of a 5-year follow-up of the cognitive development of 19 survivors of acute lymphoblastic leukemia, all of whom received 24 Gy cranial irradiation and a course of intrathecal methotrexate. Assessment was made before radiotherapy and annually thereafter. Cognitive impairment was found to be transient in children who did not manifest somnolence who were under 5 years at the time of treatment. Despite having normal IQs and normal CT scans, 9 of 18 survivors in continuous complete remission were having learning problems at school 5 years after diagnosis. Assessment of their intellectual and memory functions revealed that as compared with matched healthy children, patients had lowered IQs but also had a specific auditory learning deficit independent of IQ. Long-term memory was found to be impaired for verbal auditory but not for verbal visual material. Results are discussed in terms of possible remediation of the learning disability.

Long-term sequelae of cancer treatment on the central nervous system in childhood

Increasing numbers of children with cancer, including those with acute lymphocytic leukemia and medulloblastoma, are experiencing long-term disease control. As survival increases, so does the recognition that the treatment used to prolong survival may have significant detrimental effects on the central nervous system (CNS). Because of the slow replication rate of most constituents of the CNS, these effects tend to be delayed. Radiotherapy, and to a lesser extent, chemotherapy (primarily methotrexate) have been implicated in the causation of such sequelae. The pathogenesis of CNS damage is only partially understood and evidence suggests that direct effects on intracranial endothelial cells and brain white matter and immunologic mechanism play a role. A spectrum of clinical syndromes may occur, including radionecrosis, necrotizing leukoencephalopathy, mineralizing microangiopathy with dystrophic calcification, cerebellar sclerosis and spinal cord dysfunction. The two most common forms of sequelae are neuropsychological and neuroendocrinologic damage. The frequency, degree of and etiology of neurocognitive dysfunction is less than completely elucidated. Radiotherapy has been implicated as the major cause of damage, but the relationship between radiotherapy and the type of damage caused and the volume and dose of radiotherapy and degree of cognitive damage is unclear. Cognitive deficits are progressive in nature. Younger children are more likely to suffer the severest damage; but no patient of any age is free of risk of damage. Growth hormone impairment is the most common form of neuroendocrinologic dysfunction. There is increasing evidence that children with cancer who are long-term survivors are at increased risk for the development of secondary CNS tumors; possibly due, in part, to previous treatment. Much work needs to be done to characterize the sequelae which may occur, develop means of earlier detection, investigate ways to ameliorate sequelae and devise less toxic treatment.

Computed tomography findings of severe mineralizing microangiopathy in the brain

The intracranial CT findings of mineralizing microangiopathy, a rare condition, are described in seven patients. The underlying pathology was posterior fossa medulloblastoma (four patients), cerebelloastrocytoma (two patients), and acute lymphatic leukemia (one patient). Each of the seven patients was less than 10 years old. Dystrophic calcification was present in the corticomedullary junction, lentiform nucleus of the basal ganglia, corticomedullary junction, and dentate nucleus of the cerebellum. Three of the patients had subtle neurologic signs related to the mineralizing microangiopathy, but none died of central nervous system disease. Although three factors--radiation therapy, chemotherapy, and increased intracranial pressure--probably have a synergistic role in the pathogenesis, radiation is believed the dominant factor. The minimum dose required to induce this damage is 2000 rad.

A model of methotrexate encephalopathy: neurotransmitter and pathologic abnormalities

Methotrexate may cause seizures, dementia, and leukoencephalopathy when given in toxic doses to children with leukemia or solid tumors. Even in therapeutic doses, treatment with this drug is associated with an increased incidence of seizures in children with leukemia. To study mechanisms of injury, juvenile rats were given multiple intraventricular injections of methotrexate and the brains were analyzed for histopathology and biogenic amine metabolites of dopamine and serotonin. Disruption of monoamine metabolism has been proposed as a cause of brain dysfunction from this chemotherapy. Multiple injections (1 or 2 mg/kg) produced convulsions in an increasingly larger percentage of animals at higher cumulative doses, and five doses produced the neuropathological changes seen in human leukoencephalopathy. A single dose reduced the concentration of brain metabolites of dopamine, but not serotonin, six hours later. The effect was less pronounced after five doses. This rodent model should be useful for studying the metabolic basis of methotrexate encephalopathy.

Magnetic resonance imaging in the evaluation of treatment-related central nervous system damage

Neurologic and neuropsychologic treatment related sequelae are increasingly encountered in children with cancer, but conventional means of neurologic investigation are insensitive to the presence and extent of damage. Magnetic resonance imaging (MRI) has shown brain damage not demonstrable by other means of investigation. For this reason, 11 children with cancer and with nontumor-related neurologic dysfunction were studied on a 1.5 Tesla MRI unit. All had concurrent computed tomography (CT). MRI abnormalities were seen in all (100%) patients. In 10 of 11 patients, abnormalities were of greater extent on MRI than on CT. White matter changes were frequently seen on MRI without corresponding CT abnormality. Those patients with the most severe forms of neurologic compromise had the most extensive changes on MRI. Focal neurologic findings correlated well with regions of focal signal change. Milder forms of neurologic compromise occurred in patients with definite, but less extensive, periventricular and/or subcortical change on MRI. MRI is more sensitive than CT in demonstrating treatment-related neurologic damage in children with cancer, and the type of change seen on MRI seems to correlate well with the type and severity of neurologic dysfunction present.

Central nervous system prophylactic treatment for childhood leukemia: neuropsychological outcome studies

The cognitive sequelae of central nervous system treatments for leukemia have become a major concern as more leukemic children survive the initial consequences of the disease. A review of 28 neuropsychological outcome studies published in the past nine years shows that the preponderance of evidence from the better designed studies suggests that leukemic children who do not suffer overt Central Nervous System (CNS) complications, such as CNS relapse, do not experience significant cognitive deficits as a consequence of their treatment. Also, these studies do not unequivocally suggest that cranial irradiation as a treatment technique results in greater cognitive impairment than treatment without irradiation. Many studies are consistent in finding that leukemic children younger than 8 years of age have a worse outcome than older ones although both groups perform in the average to bright normal range. It is currently difficult to conclude that such differences in intellectual outcome were caused by the CNS treatment alone or other psychosocial aspects of acquiring leukemia. The confusion present in the literature could be greatly reduced by combining the research efforts on the psychosocial aspects of acquiring leukemia with the studies examining neuropsychological outcome.

Computerized tomography scan findings in children with acute lymphocytic leukemia treated with three different methods of central nervous system prophylaxis

Computerized tomography (CT) scans of the head were done on 93 children with acute lymphocytic leukemia in continuous complete remission who had been randomly assigned to three different methods. of central nervous system (CNS) prophylaxis. Twenty-nine children had received six doses of intrathecal methotrexate, 30 had received six doses of intrathecal methotrexate plus 2400 rad of cranial irradiation, and 34 had received six doses of intrathecal methotrexate plus three courses of intermediate-dose intravenous methotrexate. The overall incidence of abnormal scans was 35%, of which 91% were felt to represent minimal abnormalities. CT scan abnormalities were noted in 30% of the children receiving intrathecal methotrexate only, in 40% of those receiving intrathecal methotrexate plus cranial irradiation, and in 35% of those receiving intrathecal methotrexate plus intermediate dose methotrexate. These differences were not statistically significant. None of the three methods of CNS prophylaxis resulted in significant CT scan abnormalities. However, the few moderately or markedly abnormal scans evaluated were restricted to patients who received intrathecal methotrexate plus cranial irradiation. The clinical significance of CT scan abnormalities in leukemic children receiving these treatments remains unclear.

Effects of intrathecal methotrexate and cytosine arabinoside on the radiation tolerance of the rat spinal cord

The effect of intrathecally or intravenously administered methotrexate (MTX) or cytosine arabinoside (ara-C) on the early and late delayed radiation response of the rat cervical spinal cord has been studied. A technique has been developed for intrathecal administration of drugs into the rat lumbar spinal canal. When given shortly before irradiation, intrathecal ara-C significantly reduces the isoeffect doses for the early delayed white matter necrosis syndrome by a factor of 1.2-1.3, while no effect is observed for the late delayed vascular syndrome. The effect disappears when ara-C is given intravenously or 24 h after irradiation. In addition, intrathecal ara-C seems to impair the capacity of long-term regeneration. Intrathecal administration of MTX is limited by severe acute neurotoxicity. At a maximally tolerated intrathecal MTX dose, no modification of the early or late radiation response of the spinal cord was observed. In contrast to ara-C, intravenous MTX seems to interact with the induction of the late delayed vascular damage in the rat cervical spinal cord, with a dose-modifying factor of 1.1-1.2.

Sequential quantitative EEG analysis in acute lymphocytic leukemia of children

Potential brain toxicity is a major concern in the treatment of acute lymphocytic leukemia with cranial irradiation or intrathecal methotrexate. We used quantitative EEG analysis based on the Fourier transform to study 13 children at the time of diagnosis, after induction, and following consolidation which included extended intrathecal chemotherapy. None had detectable CNS infiltration by leukemia. Nonetheless, initial EEG frequencies were markedly depressed compared to expected values for age (p less than .001), and improved dramatically after induction (p less than .001). Following consolidation, EEG frequencies remained significantly lower than predicted from a control population (p less than .05). Quantitative EEG is a sensitive procedure that appears useful in assessing subtle neurologic effects of acute leukemia and its treatment.

Long-term neuropsychologic sequelae of childhood leukemia: correlation with CT brain scan abnormalities

Previous studies have failed to establish a direct relationship between behavioral disorders and organic pathology in long-term survivors of childhood acute lymphoblastic leukemia. We evaluated 23 long-term survivors who received central nervous system preventive therapy with cranial irradiation and intrathecal chemotherapy, using neuropsychologic tests and computed tomographic brain scans. The patients were in continuous first remission for 7 to 11 years, and none were receiving chemotherapy. On the basis of their CT scan findings, they were divided into three groups: 10 with normal CT findings, five with intracerebral calcifications, and eight with cortical atrophy. Neuropsychologic test results allowed prediction of CT scan findings with an 87% accuracy (P less than 0.001), indicating a strong correlation between the presence and type of CT scan abnormality and neuropsychologic functioning. Tests that measured verbal memory, attention, and functions correlated with frontal lobe integrity were most powerful in discriminating between groups.

Risk factors in long-term sequelae of central nervous system prophylaxis in successfully treated children with acute lymphocytic leukemia

Seventy-two successfully treated patients with acute lymphocytic leukemia, all in first complete remission and all off therapy, who had received CNS prophylaxis (radiotherapy, 2,400 rad, plus intrathecal methotrexate), were studied by computed tomography (CT) of the brain, EEGs, and neurologic evaluations 3 to 9 years after the end of prophylaxis. Thirty-five patients showed CT brain scan abnormalities: intracranial calcifications (twelve); widening of the subarachnoid spaces (eight); isolated dilatation of ventricular spaces (three) and with frontal periventricular hypodensity (two); dilatation of ventricular and subarachnoid spaces (nine); and a hypodense area (one). Only 17 patients showed aspecific EEG abnormalities which were never linked to CT scan findings. None of our patients presented major motor deficits at the neurologic examination. A stepwise logistic regression technique showed that age less than 5 years at the time of prophylaxis was the most important risk factor (p = 0.008) of CT brain scan abnormalities followed by neurets (p = 0.037) and sex (p = 0.10). Furthermore, the multivariate analysis pointed out that the interactions between these variables were not significant and the effects were only of the first order.

Brain sarcoma of meningeal origin after cranial irradiation in childhood acute lymphocytic leukemia. Case report

The authors report their experience with an unusual case of intracerebral sarcoma of meningeal cell origin in an 8 1/2-year-old girl. This tumor occurred 6 1/2 years after cranial irradiation at relatively low dosage (2200 rads) had been delivered to the head in the course of a multimodality treatment for acute lymphocytic leukemia. The tumor recurred approximately 10 months after the first surgical intervention. Macroscopic total excision of the recurrent growth followed by whole-brain irradiation (4500 rads) failed to eradicate it completely and local recurrence prompted reoperation 18 months later. This complication of treatment in long-term childhood leukemia survivors is briefly discussed, as well as the pathology of meningeal sarcomas.

Computed tomography of the brain following prophylactic treatment with irradiation therapy and intraspinal methotrexate in children with acute lymphoblastic leukemia

In 28 children with acute lymphoblastic leukemia (ALL) computed tomography (CT) was performed in order to demonstrate possible cerebral changes following treatment with prophylactic irradiation and intraspinal methotrexate (MTX). The time of CT-scan examination varied from 1 year and 1 month to 10 years and 1 month after diagnosis of ALL. The age of the children ranged from 3 years and 11 months to 14 years and 5 months. Six children had normal CT scans, 12 children had slight atrophy-like changes, and nine had severe cerebral atrophy. Two patients in the latter group presented an enlarged ventricular system as well. In one patient intracerebral calcification was the only pathologic finding. The severe changes were seen in children of all age groups, but predominantly in children with a short duration of their disease, severe symptoms, and frequent marrow relapse. Changes induced by steroid therapy may be reversible. No satisfactory explanation of the demonstrated cerebral pathologic findings can be given, except that they are the consequences of the combination of total therapy and severity of disease in the individual patient. Measurement of attenuation coefficients in grey and white matter shows increasing values with age during childhood. A combination of decreasing attenuation coefficients, especially in the white matter, and the finding of severe atrophy seems to be a bad prognostic sign.

Attentional deficits in long-term survivors of childhood acute lymphoblastic leukemia (ALL)

Simple alerted auditory reaction time (SRT) behavior with various foreperiods was investigated in a group of long-term survivors of childhood ALL who were in continuous first remission. As part of therapy, the patients had received cranial irradiation and intrathecal chemotherapy to prevent the development of central nervous system leukemia. The patients were divided into three groups on the basis of CT brain scan findings: (1) those with normal CT scans (n = 10); (2) those with evidence of cortical atrophy (n = 8), and (3) those with intracerebral calcifications (n = 5). The SRT results indicated significant differences between patients with normal and abnormal CT scans. Specifically, patients with abnormal scans reacted slower, and this latency was exaggerated by increasing the length of the warning interval. Furthermore, they reacted with larger variability which increased with the prolongation of testing. Moreover, the severity of impairment was related to the type of CT-scan abnormality: patients with calcifications performed more poorly than patients with evidence of atrophy. The present results revealed a strong correlation between the presence and type of CT-scan abnormalities and attentional performance in long-term survivors of childhood ALL.

Intrathecal therapy with 198Au-colloid for meningosis prophylaxis

Telecobalt irradiation in combination with intrathecal (IT) methotrexate has been replaced by IT 198Au-colloid and methotrexate for meningosis prophylaxis in leukemia. Seventy-seven children received 56-200 MBq 198Au-colloid. The distribution was measured with a scintillation camera having a data processing facility. The radiopharmaceutical is adsorbed at the surface of the spaces with cerebrospinal fluid (CSF) 10-20 h after application. The normal retention of the administered radioactivity in the intracranial subarachnoid space (ISS) and in the spinal subarachnoid space (SSS) were 52 +/- 10% and 26 +/- 9%, respectively. An impairment of the normal distribution was observed after IT methotrexate and also postinjection CSF leakage. The calculated radiation absorbed doses in the cerebral and spinal meninges at a depth of 0.01 cm, i.e. the thickness of the pia, were 45 +/- 17 mGy and 189 +/- 91 mGy, respectively, for 1 MBq administered 198Au-colloid. The dosimetry shows that an effective radiation absorbed dose of 18 Gy can be delivered to the cerebral meninges by the application of 400 MBq 198Au-colloid.

Are cognitive and educational development affected by age at which prophylactic therapy is given in acute lymphoblastic leukaemia?

Altogether 129 children with acute lymphoblastic leukaemia in remission, all of whom had completed treatment, were assessed using standardised intelligence and attainment tests. A control group of 67 healthy siblings was also assessed. Results showed that the patients were functioning within the average range of intelligence several years after completing treatment but that they had significantly lower intelligence quotients (IQs) than their siblings. Only patients who received cranial irradiation when aged 7 years or more were no different in intelligence from their siblings. Patients who were treated under the age of 3 years were found to have significantly lower IQs than patients who received the same treatment at an older age and a group of healthy children matched for age, sex, and parental occupation. This finding has practical implications for the management and education of younger patients with acute lymphoblastic leukaemia.

Intracranial calcification in survivors of childhood medulloblastoma

Computerised tomography scans of the brain have been performed on 5 children who have survived at least 5 years after treatment with surgery and radiotherapy for medulloblastoma. Intracranial calcification of varying degrees of the basal ganglia and of the frontal and parietal cortex was detected in the 3 children who were irradiated under age 5 years.

Meningosis prophylaxis with intrathecal 198Au-colloid and methotrexate in childhood acute lymphocytic leukemia

Since 1972, telecobalt irradiation plus intrathecal methotrexate (ITMTX) has been successfully replaced in Jena by intrathecal colloidal radioactive gold (198Au) plus ITMTX for meningosis prophylaxis in leukemia. Seventy-three children with acute lymphocytic leukemia (ALL) were given 1.24-4.89 mCi (45.8-181 MBq) of colloidal 198Au IT after successful initiation of remission. During cytostatic therapy, the following relapses occurred: meningosis leucaemica, five patients (6.8%); bone-marrow relapse and the meningosis leucaemica, one patient; and bone-marrow relapse, 20 patients (27.4%). In 18 children, combination chemotherapy was terminated after two and a half or three years of treatment. After that time, one meningeal relapse and six bone-marrow relapses occurred. Within the first 24 hours after application of radioactive gold, headaches, vomiting, and fever occurred in less than 10% of the children. An apathy syndrome, leukecephalopathy, or severe infections, were not observed in a single case. Radioactive gold spreads in the subarachnoid space and is phagocytized by the arachnoidea. The tumoricide effect extends selectively over the space of distribution of the latent meningosis leucaemia. The cerebral parenchyma remains unaffected by radiation. Thus, radioactive gold may be preferable to telecobalt irradiation in preventing central nervous system leukemia.

Irradiation decreases vascular prostacyclin formation with no concomitant effect on platelet thromboxane production

Effects of irradiation on vascular tissue include endothelial cell degeneration, vasoconstriction, and thrombus formation. The effect of irradiation on the in-vitro production of prostacyclin (PGI2) was evaluated, since it is a potent antithrombotic metabolite and vasodilator. After a single dose of 200 rad, umbilical artery PGI2 levels were much decreased when estimated both be bioassay and by evaluation of the stable end-product of PGI2, 6-keto-prostaglandin in Fl alpha. The mean PGI2 production in control tissue was 0.94 +/- 0.14 (1SEM) ng/mg vascular tissue compared with 0.18 +/- 0.07 ng/mg in paired irradiated vessels (p less than 0.001). However, irradiation had no effect on platelet thromboxane formation in a dose rage of 200-2000 rad. Since radiotherapy is routinely administered for the whole period of therapy in daily dose fractions similar to the in-vitro experimental dose used in this study, recovery of vascular PGI2 production may be inhibited for the total period of radiotherapy.

[Calcification of basal nuclei of the brain. Anatomo-pathological study of 4 cases]

The paper reports the pathological study of 4 autopsied cases of massive basal ganglia calcifications, an entity that although related to hypoparathyroidism or pseudohypoparathyroidism, sometimes can be considered as idiopathic. In our cases no metabolic disturb or any common related disease could be found in association. Interesting is to point out that the lesion is confined to the central nervous system, with no foci of calcification outside the brain. There is a characteristic perivascular distribution of the deposits that, as demonstrated by histochemical study are composed by iron besides calcium.

Normal computed tomograms of the brain in osteosarcoma patients treated with high-dose methotrexate

Eighteen patients with osteosarcoma, most of whom were adolescents, were examined for abnormalities of the brain by use of computed axial tomography. These studies were performed at 15-60 months (median 47 months) after the completion of adjuvant chemotherapy, which included high-dose methotrexate, cyclophosphamide, and Adriamycin. No abnormalities were found. The results of this study, together with the absence of brain lesions in published reports in children receiving high-dose methotrexate but no cranial irradiation, indicate that delayed neurotoxicity is not a major complication of this form of therapy in older children.

Progression of methotrexate-induced leukoencephalopathy in children with leukemia

From 1972-1974, 228 children began treatment for acute lymphocytic leukemia and were prospectively assessed for neurologic complications. After CNS irradiation (2,400 rad) and intrathecal methotrexate (MTX), they received weekly intravenous maintenance therapy with MTX alone (40-60 mg/m2; 20 patients) or MTX (10-30 mg/m2) with other drugs (208 patients). Signs of leukoencephalopathy appeared in 11 children (nine without CNS leukemia) after 4-15 months of IV MTX alone, and included lethargy, seizures, spasticity, paresis, drooling, and dementia. Before or during the clinical onset, EEG frequencies slowed (all ten patients tested). Radionuclide scans showed periventricular accumulation of 99mTc (9/11 patients) and remained abnormal for greater than or equal to six months in eight patients. Cranial computed tomograms or neuropathology findings (five patients each) demonstrated leukoencephalopathy (nine patients) and radiation-related microangiopathy (ten patients). Severe neurologic and neuropsychologic dysfunctions were present in four long-term survivors.

Computed tomography brain scans in long term survivors of childhood acute lymphoblastic leukemia

There have been varying frequencies cited for the occurrence of abnormal brain CT scans in leukemic patients and conflicting evidence about the significance of these abnormalities and their relationship to sanctuary therapy. Our study of CT brain scans in 26 long survivors of acute lymphoblastic leukemia showed an overall prevalence of 35% abnormal scans. There was no statistically significant difference between the number of abnormal scans in patients given radiotherapy as part of their CNS prophylaxis and those receiving only intrathecal methotrexate. Because the children in each treatment group were evenly matched with respect to other treatment variables possibly relevant to the causation of abnormal brain scans, a strong case is made for more rigorous design of such studies, preferably in a prospective fashion, looking simultaneously at other parameters of brain structure and function.

Iatrogenic damage to the central nervous system in malignant systemic disease

The various ways in which the central nervous system can become affected in the course of malignant systemic disease are discussed, with particular emphasis on iatrogenic damage. Examples of presumably iatrogenic damage are presented. It is suggested that minor alterations may be much more frequent than is assumed at present. The need for systematic investigation is stressed--with a view on assessing the frequency of such damage and on unravelling the aetiology and pathogenesis of the lesions.

CT studies before and after CNS treatment for acute lymphoblastic leukemia and malignant non-hodgkin's lymphoma in childhood

CT was performed on 72 children with acute lymphoblastic leukemia or non-Hodgkin's lymphoma. Thirty-two of these patients were investigated prior to CNS radiation and intrathecal methotrexate therapy. Ten of these patients (31%) were known to have hydrocephalic dilatation of the CSF spaces. Clinical data and subsequent observations with analysis of the CT findings show that no difference in the attenuation values of brain tissue occurs in the absence of a CNS relapse. The percentage of abnormal findings before and after therapy remains constant. The adverse late effect described in the CT literature seem principally to be damage diagnosed too late. It is questionable if the CT demonstration of dilated CSF spaces before treatment has a prognostic significance.

Long-term neurological implications of somnolence syndrome in children with acute lymphocytic leukemia

A longitudinal study of 49 children with acute lymphocytic leukemia (ALL) assessed the long-term effects of central nervous system (CNS) prophylaxis on brain function. From 10 to 12 electroencephalograms (EEGs) were done before and at intervals during after 30 months of treatment that included 2,400 rads of CNS irradiation plus intrathecal methotrexate therapy. None of the children had CNS leukemia, and all remained in first complete remissions. All 49 had abnormally slow EEG background frequencies during the four-year study, and 29 (60%) developed somnolence syndrome six to eight weeks after CNS prophylaxis. During this syndrome, EEG background frequencies decreased more than 3 standard deviations below the expected mean values for normal children. Thereafter, 7 of the 29 began to show signs of learning disabilities and 7 developed recurrent seizures. Of the 20 children who did not have the syndrome, none showed later evidence of CNS dysfunction. Somnolence may be an early indicator of long-term neurological sequelae after cranial irradiation.

The eye as a sanctuary in acute lymphoblastic leukaemia

Leukaemic infiltration of the anterior chamber of the eye was the only sign of relapse in two children with acute lymphoblastic leukaemia who had been off treatment for two and four months. The malignant cells had probably been present in the eye since the onset of the disease.