Leukoencephalopathy following the administration of methotrexate into the cerebrospinal fluid in the treatment of primary brain tumors

Potential neurotoxicity associated with methotrexate

This study aimed to elucidate the incidence and characteristics of neurotoxicity in patients receiving methotrexate (MTX) treatment. A retrospective analysis was performed using data from the electronic cohort database spanning from January 1990 to December 2021. This review focused on patients who manifested neurotoxic symptoms post-MTX therapy, excluding patients with peripheral neuropathy. Of the 498 individuals who received MTX, 26 (5.22%) exhibited neurotoxicity. Pediatric patients (< 18 years) accounted for 18 cases (7.44%), whereas adults (> 18 years) comprised eight cases (3.13%). The median onset age was 11 years (range 4-15) in the pediatric cohort and 39.5 years (range 19-67) in the adult cohort. A predominant male predisposition was noted (21 patients, 80.77%). The majority of patients (21, 80.77%) experienced neurotoxic effects following multiple MTX administrations. Modes of MTX delivery included intrathecal (37.0%), intravenous (22.2%), and combined routes (40.7%). Clinical presentations were predominantly encephalopathy (69.2%), followed by encephalomyelopathy (15.4%), myelopathy (11.5%), and polyradiculopathy (3.8%). Fourteen patients recovered (53.85%). Risk factors were male sex, pediatric age (particularly above 10 years), and administration route (intrathecal in adults and intravenous in pediatrics). Although infrequent, MTX-related neurotoxicity has a substantial impact on patient prognosis, with potential development following even a single dose. Its radiological resemblance to diverse neuropathologies, such as cerebral infarction and subacute combined degeneration, necessitates vigilant diagnostic scrutiny.

TME-targeted approaches of brain metastases and its clinical therapeutic evidence

The tumor microenvironment (TME), which includes both cellular and non-cellular elements, is now recognized as one of the major regulators of the development of primary tumors, the metastasis of which occurs to specific organs, and the response to therapy. Development of immunotherapy and targeted therapies have increased knowledge of cancer-related inflammation Since the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCB) limit immune cells from entering from the periphery, it has long been considered an immunological refuge. Thus, tumor cells that make their way "to the brain were believed to be protected from the body's normal mechanisms of monitoring and eliminating them. In this process, the microenvironment and tumor cells at different stages interact and depend on each other to form the basis of the evolution of tumor brain metastases. This paper focuses on the pathogenesis, microenvironmental changes, and new treatment methods of different types of brain metastases. Through the systematic review and summary from macro to micro, the occurrence and development rules and key driving factors of the disease are revealed, and the clinical precision medicine of brain metastases is comprehensively promoted. Recent research has shed light on the potential of TME-targeted and potential treatments for treating Brain metastases, and we'll use that knowledge to discuss the advantages and disadvantages of these approaches.

Optimum Methotrexate Exposure in Patients With Suspected or Confirmed CNS Invasive Hematological Malignancies: A Systematic Critical Review

BACKGROUND AND METHODS

The present review aims to evaluate the current state-of-the-art dosing regimens of high-dose (HD) and intrathecal methotrexate (MTX) using therapeutic drug monitoring (TDM) to optimize its therapeutic response and minimize associated toxicity, particularly in the central nervous system (CNS).

RESULTS

MTX is administered systemically in a HD regimen (>1 g/m 2 ) for the treatment of various hematological neoplasms. HD-MTX treatment becomes complicated by marked interindividual drug elimination variability. TDM is specified to manage this high variability. Approximately 3%-7% of adults with acute lymphoblastic leukemia are diagnosed with CNS involvement, and the incidence of CNS relapse in patients, despite receiving prophylaxis, ranges from 5% to 10%. HD-MTX penetrates the blood-brain barrier and can be administered intrathecally, making this drug an important component of chemotherapy regimens for patients with hematologic malignancies involving the CNS or those at high risk of CNS relapse.

CONCLUSIONS

The major evidence found was that an MTX area under the curve target between 1000 and 1100 μmol hour -1 L is associated with better clinical outcomes. However, there seems to be a clinical gap in the prospective validation of HD and IT MTX management to optimize clinical outcomes and minimize toxicity, using the relationship between exposure level (area under the curve MTX) and optimal response to MTX, at systemic and CNS exposure.

Improving the Brain Delivery of Chemotherapeutic Drugs in Childhood Brain Tumors

The central nervous system (CNS) may be considered as a sanctuary site, protected from systemic chemotherapy by the meninges, the cerebrospinal fluid (CSF) and the blood-brain barrier (BBB). Consequently, parenchymal and CSF exposure of most antineoplastic agents following intravenous (IV) administration is lower than systemic exposure. In this review, we describe the different strategies developed to improve delivery of antineoplastic agents into the brain in primary and metastatic CNS tumors. We observed that several methods, such as BBB disruption (BBBD), intra-arterial (IA) and intracavitary chemotherapy, are not routinely used because of their invasiveness and potentially serious adverse effects. Conversely, intrathecal (IT) chemotherapy has been safely and widely practiced in the treatment of pediatric primary and metastatic tumors, replacing the neurotoxic cranial irradiation for the treatment of childhood lymphoma and acute lymphoblastic leukemia (ALL). IT chemotherapy may be achieved through lumbar puncture (LP) or across the Ommaya intraventricular reservoir, which are both described in this review. Additionally, we overviewed pharmacokinetics and toxic aspects of the main IT antineoplastic drugs employed for primary or metastatic childhood CNS tumors (such as methotrexate, cytosine arabinoside, hydrocortisone), with a concise focus on new and less used IT antineoplastic agents.

Cerebral radiation necrosis: a review of the pathobiology, diagnosis and management considerations

Radiation therapy forms one of the building blocks of the multi-disciplinary management of patients with brain tumors. Improved survival following radiation therapy may come with a cost, including the potential complication of radiation necrosis. Radiation necrosis impacts the quality of life in cancer survivors, and it is essential to detect and effectively treat this entity as early as possible. Significant progress in neuro-radiology and molecular pathology facilitate more straightforward diagnosis and characterization of cerebral radiation necrosis. Several therapeutic interventions, both medical and surgical, may halt the progression of radiation necrosis and diminish or abrogate its clinical manifestations, but there are still no definitive guidelines to follow explicitly that guide treatment of radiation necrosis. We discuss the pathobiology, clinical features, diagnosis, available treatment modalities, and outcomes in the management of patients with intracranial radiation necrosis that follows radiation used to treat brain tumors.

Intracerebral hematoma as a complication of intrathecal methotrexate administration

Neurotoxicity of methotrexate is a well-documented issue, but development of an intracerebral hematoma following administration of intrathecal methotrexate is an extremely rare entity. A 6-year-old male with the diagnosis of non-Hodgkin lymphoma was put on a treatment regimen, including intrathecal methotrexate. Six days following the last intrathecal methotrexate administration, the patient developed a deteriorating state of consciousness. There was no history of trauma. Coagulation studies and platelet count were normal. Magnetic resonance imaging of the brain demonstrated a large left frontoparietal hematoma. Intracerebral hematoma may be a very rare, but serious, complication of intrathecal methotrexate administration.

Intrathecal administration of Y-27632, a specific rho-associated kinase inhibitor, for rat neoplastic meningitis

The small GTP-binding protein Rho and its target Rho-associated kinase trigger an intracellular signaling cascade that controls actin cytoskeleton and plays an essential role in cell motility and adhesion. A specific Rho-associated kinase inhibitor, Y-27632, has been reported to inhibit cancer invasion. Clinically, disseminated tumor cells in the cerebrospinal fluid invade the intraparenchymal region, damaging the brain and nerves, resulting in fatal brain stem dysfunction, despite intrathecal chemotherapy. To expand therapeutic options for this devastating neoplastic meningitis, we evaluated the potential use of intrathecal Y-27632 administration by employing Walker 256 cells, a rat mammary cancer cell line. Y-27632 dose-dependently inhibited chemotactic and invasive activity of Walker 256 cells. Y-27632 also inhibited the phosphorylation level of regulatory myosin light chain in vitro, but the effect was temporary and was considerably diminished within 16 hours. Y-27632 induced striking morphologic changes in Walker 256 cells, as evidenced by decreased cell-matrix adhesion in culture dishes and three-dimensional collagen I gels, and slightly inhibited colony formation in soft agar. Nevertheless, this drug treatment did not affect Walker 256 cell growth rate. We were able to administer continuous delivery of this inhibitor using an osmotic pump and maintaining drug concentration of 10 mumol/L within the brain. Importantly, this concentration of Y-27632 showed minimal neurotoxicity both in vitro and in vivo. We found that an intrathecal therapy, combining 5-fluoro-2'-deoxyuridine with Y-27632, significantly increased the survival time of rats bearing meningeal carcinomatosis in comparison with animals treated with 5-fluoro-2'-deoxyuridine alone. Taken together, our findings indicate that continuous intrathecal administration of Y-27632 could be a promising therapeutic method when combined with chemotherapy for treating human neoplastic meningitis.

Severe complications after intrathecal methotrexate (MTX) for treatment of primary central nervous system lymphoma (PCNSL)

Primary central nervous system lymphoma (PCNSL) is a rare and highly malignant tumor with increasing incidence. Survival has improved with the use of nonsurgical treatment modalities, of which methotrexate (MTX)-based intrathecal chemotherapy has been an important option. Here, we describe devastating complications in three patients with diffuse large B-cell lymphomas. After intrathecal MTX therapy two patients died secondary to fulminant brain edema. A third patient developed severe dementia, gait disturbance and urinary incontinence due to leukencephalopathy. Since bulky disease was present in all three patients, CSF flow may have been impaired. This might have exposed adjacent tissue to prolonged toxic drug concentrations. Regarding the severe complications seen in these patients, it is useful to consider high-dose intravenous MTX treatment only in periventricular PCNSL.

Interventricular methotrexate therapy for carcinomatous meningitis due to breast cancer: a case with leukoencephalopathy

A 46-year-old woman presented with paraplegia and severe lumbago. She had had a radical mastectomy for left breast cancer 10 years earlier, and 6 months prior to presentation she completed CMF chemotherapy for treatment of retroperitoneal metastasis. CT and MRI to identify potential causes of the paraplegia and lumbago showed leptomeningeal carcinomatosis due to dissemination from invasive recurrence of the retroperitoneal tumor. An Ommaya reservoir was inserted, and infusion of intrathecal methotrexate (MTX; 5 mg twice weekly) began. Her clinical symptoms improved after receiving 53 mg MTX. However, after receiving 83 mg MTX, the patient became dizzy from leukoencephalopathy. Although administration of prednisolone mostly resolved her symptom, the patient died 9 months after the diagnosis of carcinomatous meningitis.

Intrathecal chemotherapy

An unforeseen consequence of improved disease-free survival in many hematologic and solid tumor malignancies has been an increase in the incidence of disease recurrence in the leptomeninges. The recognition of the central nervous system (CNS) as a unique 'sanctuary' site has resulted in the development of therapeutic strategies specifically directed at the leptomeninges. Although therapeutic strategies have been successful in the prevention and treatment of CNS leukemia, there are still a paucity of therapeutic options for patients with neoplastic meningitis due to solid tumors or recurrent CNS leukemia. This article provides an overview of the pharmacology and toxicity of intrathecal agents that are commonly employed in the treatment and prevention of leptomeningeal disease, and describes new agents that are in the early stages of clinical development.

In vitro study on intrathecal use of 5-fluoro-2'-deoxyuridine (FdUrd) for meningeal dissemination of malignant brain tumors

We investigated 5-fluoro-2'-deoxyuridine (FdUrd) as a potential agent for intrathecal treatment of malignant brain tumors with meningeal dissemination. We examined the neurotoxicity of FdUrd in vitro using primary cultures of neurons from C57BL/6 mice (ED14). Tumoricidal activity was also studied in four glioma cell lines and one medulloblastoma cell line. In addition, thymidine phosphorylase (TPase) and thymidine kinase (TK), which are key enzymes for FdUrd metabolism, were measured in the cerebrospinal fluid (CSF) of 36 patients with brain tumors. The antitumor activity of FdUrd for murine glioma cells was approximately 20- to 200-fold higher than that of 5-fluorouracil (5-FU). Against human cell lines, it was 3- to 500-fold higher than that of 5-FU. The neurotoxic effect of FdUrd on cultured neurons was far less than that of 5-FU or 5-fluorouridine (FUrd). Cerebrospinal fluid contained no detectable thymidine phosphorylase in most patients with brain tumors. Several studies have indicated that FdUrd is rapidly converted to 5-FU in the presence of thymidine phosphorylase, so that a high dose of FdUrd must be administered to obtain good efficacy. However, a high dose FdUrd frequently cause severe toxicity. In contrast, the data obtained here suggest that no enzymatic conversion of FdUrd to 5-FU should occur in the CSF. In addition, FdUrd has an excellent antitumor activity and minimal neurotoxicity. We therefore conclude that intrathecal FdUrd is a potential therapy for CSF dissemination of malignant brain tumors.

Atypical MRI findings in treatment-related leukoencephalopathy: case report

A patient with acute myeloblastic leukaemia showed atypical findings on MRI following combination therapy including intrathecal methotrexate and radiation. MRI findings not previously been reported are ring as well as patchy enhancement, marked mass effect and lesions extending to the putamen and corpus callosum.

A new familial disorder presenting with amyotrophic lateral sclerosis-like manifestation: a clinicopathological study

We studied a family in which three siblings had an identical clinical feature indistinguishable from familial amyotrophic lateral sclerosis (ALS), consisting of progressive generalized neurogenic muscular atrophy with hyporeflexia and normal sensations beginning in the fourth decade. The duration of illness was about 4 years in all affected members. Autopsy of one patient revealed multiple foci of spongy degeneration in the white matter of the spinal cord, brain stem, cerebellum, and the thalamus, characterized by vacuoles of various size, foamy macrophages and degenerating swollen axons. These changes were most marked in the spinal cord, where there was neither pyramidal tract involvement nor neuronal loss in the anterior horn. The pathological findings were different from those of ALS. A similar disease affected the siblings' mother, suggesting an autosomal dominant inheritance. The disease in the kindred, therefore, appears to be a unique hereditary disorder.

Diagnosis, management, and survival of patients with leptomeningeal cancer based on cerebrospinal fluid-flow status

BACKGROUND

The authors assessed cerebrospinal fluid (CSF) flow in patients with carcinomatous meningitis using technetium-99m-DTPA (Tc-99) ventriculography to determine the frequency of flow abnormalities, their reversibility with treatment, and the implications for successful therapy and survival.

METHODS

Technetium-99m-DTPA flow studies were performed in 31 patients after placement of Ommaya reservoirs (Baxter, McGaw Park, IL). Two millicuries of Tc-99 were injected into the reservoir. Planar images of the head and entire spine were obtained after 10 and 30 minutes and after 1, 4, 6, and 24 hours. Follow-up studies were performed for 12 patients whose initial studies were abnormal or who developed complications of therapy.

RESULTS

In 19 of the 31 patients (61%), ventricular-outlet, spinal, or convexity blocks were identified. In 11 of these 19 patients, focal radiotherapy to the site of the block restored normal flow. Survival among patients with initially normal, abnormal but correctable, and abnormal but uncorrectable CSF flow differed significantly (6.9, 13.0, and 0.7 months respectively; P < 0.001). Some patients who were treated intrathecally despite abnormal CSF flow experienced drug-related toxicity.

CONCLUSIONS

Cerebrospinal fluid-flow blocks are common in patients with carcinomatous meningitis and may occur at the skull base, in the spinal canal, and over the convexities. These flow abnormalities often can be corrected with appropriately directed radiotherapy. If untreated, CSF tumor progression (protected site effect), neurotoxicity (high concentration effect), and systemic toxicity (reservoir effect) can occur, resulting in shortened survival and treatment-related morbidity. Therefore, intrathecal chemotherapy should be preceded by a radionuclide flow study and should be delayed if abnormal flow is documented until appropriate radiotherapy reestablishes normal flow.

Fatal brain stem necrosis after standard posterior fossa radiation and aggressive chemotherapy for metastatic medulloblastoma

A 3-year-old girl received conventional-dose external beam posterior fossa irradiation (5400 cGy in 30 fractions over 40 days) for good-risk medulloblastoma. Soon thereafter, she experienced an extraneural (occipital scar, cervical lymph nodes) and central nervous system (CNS) recurrence. Intensive cisplatin and cyclophosphamide chemotherapy led to rapid disappearance of the extraneural disease. Methotrexate was administered via a ventricular reservoir. After 2 months of chemotherapy, CNS toxicity progressed rapidly from ataxia to paraplegia to quadriplegia to central respiratory failure. Radiographic scans and autopsy material revealed brain stem necrosis. This unusual toxicity raises concern about the safety of aggressive systemic chemotherapy and intrathecal therapy, when given after conventional radiotherapy.

Organic delusional syndrome associated with tamoxifen treatment

The authors describe two cases of tamoxifen-induced organic delusional syndrome that resulted from administration of 40 mg daily for the adjuvant treatment of breast carcinoma. After discontinuation of the tamoxifen therapy, the psychiatric episode resolved within 2 to 4 weeks. Because tamoxifen might cause delusional syndrome, the authors recommend full psychiatric evaluation in appropriate cases.

Intracerebral (parenchymal) infusion of methotrexate: report of a case

This report describes the neuropathological findings in a 32 year old woman with acute myelogenous leukemia (AML) and central nervous system (CNS) involvement, who received a total of 48 mg of methotrexate (MTX) intended to be delivered to the ventricle. At autopsy, the tip of the infusion catheter was found to have been inadvertently placed in the left basal ganglia. The delivery of the MTX at that site caused white matter lesions characteristic of those previously reported in MTX encephalopathy following diverse modes of administration. This case is unusual in that there was the direct infusion of MTX into cerebral parenchyma, circumventing both the blood:brain and cerebrospinal fluid:brain barriers. Axonal abnormalities were widespread in the MTX-infused tissue, frequently but not always accompanied by myelin loss. Since radiation therapy had not been employed, this case permitted the assessment of pathologic changes largely attributable to MTX.

Neuropsychological assessment outcomes of nonacquired immunodeficiency syndrome patients with primary central nervous system lymphoma before and after blood-brain barrier disruption chemotherapy

The risk of neurotoxicity was evaluated in eight consecutive patients with non-acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma who had survived disease free for more than 1 year after completion of treatment with osmotic opening of the blood-brain barrier and chemotherapy (methotrexate, cytoxan, procarbazine, and decadron). Trends in neuropsychological assessment results between baseline and follow-up (1 to 7 years) were analyzed for all eight nonradiated survivors. This serial assessment design addressed the specific issue of neurotoxic risk potential of treatment, when confounding factors of tumor persistence/recurrence and cranial irradiation were ruled out. Follow-up results of an extensive battery of tests to assess higher cortical function provided evidence of the safety of chemotherapy protocol with the blood-brain barrier disruption. These findings stand in contrast to well-known cognitive risks associated with cranial radiotherapy. Long-term follow-up suggests that chemotherapy can be given in conjunction with osmotic opening of the blood-brain barrier in nonradiated patients without cognitive manifestations of neurotoxicity.

Current pharmacological treatment approaches to central nervous system leukaemia

Significant advances in the treatment and prevention of meningeal leukaemia have been made in the past 3 decades. This progress has resulted from the development of innovative approaches to treatment as well as a better understanding of the pharmacokinetics and pharmacodynamics of the commonly used antileukaemic agents. Intrathecal therapy, via the intralumbar or intraventricular route, is a form of regional therapy that results in the delivery of very high drug concentrations to the principle target tumour site (the meninges) using a relatively small drug dose, thereby minimising both systemic drug exposure and systemic toxicity. The dosage and schedules, clinical pharmacology and toxicities of the commonly used intrathecal agents, methotrexate and cytarabine (cytosine arabinoside; Ara-C) are discussed in detail. Another approach which has been used to overcome the poor penetration of antileukaemic drugs into the CNS has been the use of high-dose systemic therapy. This strategy has been successfully applied in the treatment of meningeal leukaemia using both high-dose methotrexate and high-dose cytarabine. The clinical pharmacology, toxicities, and potential limitations of this approach are outlined. Finally, new agents that are currently undergoing clinical evaluation and future directions for research are also discussed.

Light and electron microscopic observations on the cerebellum of guinea pigs following low-dose methotrexate

The neurotoxicity of single and divided low-dose methotrexate (MTX) and the rescue effect of leucovorin (folic acid) were investigated by light and electron microscopic examination of the cerebellum of Guinea pigs. One group of animals received a single weekly intraperitoneal MTX in a dose of 10 mg/kg, a second received a similar dose divided into three equal fractions, and the third group received MTX rescued with an equal dose of leucovorin. The results showed degeneration of Purkinje cells indicated by shrinkage and distortion of perikarya, dissolution of mitochondrial cristae, and nuclear and nucleolar changes in all groups which received MTX. There was also astrocytic proliferation and perivascular edema. Lesser changes were found in the group which was rescued with leucovorin. The degenerative changes in the cerebellum particularly those of the Purkinje cells explain the neurological signs reported in cancer patients treated with MTX.

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.

The intracerebral penetration of intraventricularly administered methotrexate: a quantitative autoradiographic study

The local concentration and distribution of methotrexate following intraventricular administration were studied in the brains of New Zealand White rabbits. Tritiated methotrexate was injected through subcutaneous reservoirs connected to ventricular catheters, the animals were sacrificed one hour after administration of the drug, and the distribution of the radiolabelled compound was assessed using quantitative autoradiographic techniques. The intracerebral distribution of tritiated inulin delivered in an identical fashion was studied for comparison. One hour after intraventricular administration of radiolabelled methotrexate or inulin approximately 40% of the area of the brain sections contained appreciable concentrations of the radiolabelled tracer. Gray matter adjacent to the cerebrospinal fluid, including the hippocampus, thalamus, caudate nucleus, and periaquaductal gray contained the highest concentrations of 3H-methotrexate. Large white matter tracts contained smaller amounts of tracer activity. The rapid and extensive penetration of intraventricularly administered methotrexate and inulin into normal brain parenchyma and the high methotrexate concentrations in specific regions of the brain provide insight into the pathogenesis of methotrexate-induced neurotoxicity.

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.

Disseminated necrotizing encephalopathy induced by methotrexate therapy alone

This report describes the autopsy findings in a 62-year-old woman who died of pneumonia and disseminated necrotizing encephalopathy following intrathecal methotrexate (MTX) therapy for meningeal infiltration of lymphoma cells. Radiation therapy was not given. An interesting pathological finding was exudation of fibrin around the small vessels in the demyelinated foci, suggesting increased vascular permeability. This observation and analysis of previous reports of similar cases suggest that primary vascular injury, probably due to the direct effect of MTX, may be involved in the pathogenesis of MTX-related disseminated necrotizing encephalopathy.

Leukoencephalopathy complicating intraventricular catheters: clinical, radiographic and pathologic study of 10 cases

Ten patients with implanted Ommaya devices developed pericatheter white matter lesions, apparent as focal lucenaries on computed tomographic scan sometimes with contrast enhancement and/or mass effect. Some of the patients had significant neurological signs that related to the lesion. Three of the patients had not received cytotoxic drugs through the reservoir, and two had received neither intrathecal chemotherapy nor cranial radiation therapy. The process appears to be related to back flow of cerebrospinal fluid, with or without contained cytotoxic drugs into the periventricular white matter. Patients with elevated intracranial pressure are at particular risk. Removal of the catheter relieves the condition.

The chemotherapy of posterior fossa tumors in childhood

Conventional therapy for brain tumors, consisting of neurosurgical intervention and radiotherapy, has not resulted in the successes achievable in other childhood malignancies. The role of adjuvant chemotherapy, well defined in many childhood cancers, has not yet contributed significantly to the treatment of children with brain tumors. Chemotherapy of recurrent tumors has produced regressions but no cures. The most active agents identified to date in the treatment of recurrent posterior fossa tumors include cisplatinum, cyclophosphamide and methotrexate. Future efforts will need to focus on the rational selection of drugs for study in limited agent histology-stratified phase II trials, with advancement of active agents into large randomized phase III adjuvant therapy trials.

High dose Ara-C related leukoencephalopathy

Two patients with acute myelomonocytic leukemia in central nervous system relapse developed clinical signs and computerized tomographic evidence of leukoencephalopathy five to seven days after intravenous high dose Ara-C therapy. The first patient had received 30 gm of intravenous Ara-C with cranial irradiation (1680 rad in 2 fractions) and intrathecal Ara-C (100 mg X twice) for an intracerebral chloroma and leptomeningeal leukemia. In this patient the leukoencephatlopathy was probably a result of a synergistic effect of the concomitant triple therapy. The second patient had received intrathecal administration of Ara-C and methotrexate for five and one-half months prior to intravenous Ara-C therapy. He developed altered mental status after 24 gm of intravenous Ara-C infusion. CT scan showed changes in the white matter compatible with leukoencephalopathy. In this patient the intravenous Ara-C probably was the precipitating factor of the development of leukoencephalopathy. The possible mechanism of the Ara-C induced leukoencephalopathy is discussed.

Medulloblastomas: a review of modern management with a report on 75 cases

The authors summarize the 8-year experience of a tertiary medical center with 75 cases of medulloblastoma in Saudi Arabia. A discussion of the evolution of modern management of this difficult problem ensues. As 5-year survival statistics approach 80% in some institutions, attention is being focused on the long-term effects of modern therapy and the quality of life led by these children.

Late effects of treatment of cancer in children

Over the past two decades, owing to advances in surgical techniques, chemotherapy, and radiation therapy, there has been dramatic improvement in the survival of children with malignancies. Children cured of cancer will soon form a significant fraction of our adult population. As we follow such survivors, we have become more aware of long-term side effects of treatment. Therapy should not be withheld. Instead, careful follow-up of oncology patients is needed to document the adverse late effects, to identify the etiologic agents, and to alter treatment to give the least toxic therapy without sacrificing the quality or duration of survival.

High-dose neuroleptics for acute brain failure after intensive chemotherapy for acute leukemia

A 20-year-old Caucasian male with acute leukemia developed acute organic brain failure after treatment with intensive cytostatic chemotherapy. His delirious state was successfully controlled by neuroleptic therapy with intravenous haloperidol and lorazepam. We propose that this regimen may be useful in treating organic brain failure following intensive chemotherapy for malignant disease.

Necrotizing leukoencephalopathy and treated multiple myeloma. An autopsy case without intrathecal chemotherapy or irradiation of the brain

A 48-year-old woman with multiple myeloma, developed progressive neurological disturbances one year after the bone marrow remission. There was neither intrathecal chemotherapy nor brain irradiation. She received cyclophosphamide, phenylalanine mustard, urethane, and prednisolone intravenously or orally. At postmortem examination the cerebral hemispheres had a conspicuous destruction of white matter, consistent with a necrotizing leukoencephalopathy with focal and diffuse demyelination. No myeloma cells were found in the nervous system. Alzheimer type II glias and abnormal glias closely resembling Alzheimer type I glia were numerous in the affected white matter. No oligodendroglias with intranuclear inclusions were found. No virus particles were detected by electron microscope. The neuropathological changes had features similar to those seen in leukoencephalopathy with intrathecal administration of methotrexate. The glial abnormality, the most striking feature in the present case, strongly suggests toxic and metabolic disturbances. It appears that the leukoencephalopathy of the present case developed on the more complicated etiopathogenesis. However, it would be emphasized that the side-effects of the drugs could be considered as one of the etiologica factors causing the glial abnormality.

Late effects of treatment of cancer in children

Advances in surgical techniques, in chemotherapy, and in radiation therapy have led to improved survival in children treated for cancer. Children cured of cancer will soon form a significant fraction of our adult population. As we follow such survivors, we have become more aware of long-term side effects of treatment. This is not a reason to withhold therapy. Instead, careful followup of oncology patients is needed to document the late effects, to identify the etiologic agents, and to alter treatment to give the least toxic therapy without sacrificing quality or duration of survival.

Glutamic acid decarboxylase in cerebrospinal fluid in infancy and childhood Part II. Glutamic acid decarboxylase activity in cerebrospinal fluid of children with neurological diseases

Glutamic acid decarboxylase (GAD) activity in cerebrospinal fluid (CSF) was determined in 53 patients with neurological diseases as follows: Epilepsy (n:17), febrile convulsions (n:3), meningoencephalitis (n:17), encephalopathies (n:10), CNS leukemia (n:3), congenital hydrocephalus (n:2) and pseudoileus neonatorum (n:1). Compared with the mean normal value (5.2 +/- 2.5 pmol CO2 formed/hr/ml) reported in Part I, a significant increase of GAD activity in CSF was demonstrated in patients with uncontrolled epileptic seizures (11.4 +/- 3.9 pmol CO2 formed/hr/ml), febrile convulsions (13.5 +/- 8.7), viral meningitis with or without encephalitis (20.3 +/- 13.6), encephalopathies (30.0 +/- 25.9), CNS leukemia (11.1 +/- 5.0), congenital hydrocephalus (20.5 +/- 7.3) and pseudoileus neonatorum (28.6). Markedly high GAD activity was found in patients with CNS leukemia several days after intrathecal injection of methotrexate (39.8 +/- 18.0). On the other hand, significantly low GAD activity was shown in patients with bacterial meningitis or brain abscess (1.3 +/- 1.2). This suggests that some bacterial factors may be inhibitory toward GAD activity in CSF. High GAD activity in CSF may be useful as an indicator of aseptic brain dysfunction, although it was not always correlated with the severity of symptoms.

Cerebrospinal fluid flow abnormalities in patients with neoplastic meningitis. An evaluation using 111indium-DTPA ventriculography

Cerebrospinal fluid flow dynamics were evaluated by 111Indium-diethylenetriamine pentaacetic acid (111In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that 111In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis.

Pharmacokinetics and biochemical effects of a fatal intrathecal methotrexate overdose

A nine-year-old boy with non-Hodgkin's lymphoma inadvertantly received 54 times the standard dose of intrathecal methotrexate (650 mg vs 12 mg). He sustained an immediate and subsequently fatal necrotizing leukoencephalopathy despite an early cerebrospinal fluid (CSF) exchange, intravenous leucovorin and dexamethasone, and supportive care. Following the CSF exchange which removed 78% of the administered dose of methotrexate, the CSF and serum methotrexate levels were 50-100-fold higher than seen following standard therapy. A slightly prolonged CSF methotrexate half-life suggested a decreased rate of clearance of methotrexate from the CSF, either due to saturation or destruction of the transport mechanisms. CSF levels of myelin basic protein and serum levels of lactic dehydrogenase, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, and uric acid were all markedly increased, suggesting both white and grey matter necrosis.

Calcified cerebral necrosis following ALL therapy

Calcified cerebral necrosis was an unusual finding at the autopsy of a 13-year-old girl who died after prolonged therapy for ALL. The patient had shown symptoms of progressive cerebral damage subsequent to a second cycle of prophylactic high-dose cytostatic therapy combined with cranial irradiation. Pathoanatomic examination revealed extensive florid recurrency of meningosis and leukemic encephalosis with scalloped calcified necroses measuring up to 5 cm, in the medullar layer of brain and cerebellum. Located predominantly near the ventricular area, encapsulated necroses showed many fibrous vessels with thickened walls and stenosed or obstructed lumina. The cerebral cortex remained largely unaffected by tissue destruction. Besides methotrexate toxicity and the enhancing effect of irradiation the vascular involvement was interpreted as a particularly important factor. Formal pathogenesis is attributed to combined chemo- and radiotherapy in parallel to leukemic infiltration of vascular walls and partial obstruction of lumina by tumor emboli. Wall damage, severe fibrosis, and consecutive nutritional defects result in the destruction of cerebral tissue. The preferential occurrence of necroses in cortex-adjacent medullar layers is explained by the relatively poor blood supply of this border zone between meningeal and intracerebral tissue, no safe conclusion can be drawn pathoanatomically with regard to the actually fatal factor, whether it is the leukemic infiltration of vascular walls, the effect of cytostatic agents, or that of irradiation. The proposed multifactorial pathogenesis of cerebral calcification may be supported by computed tomography (CT) intra vitam.

Central and peripheral myelinopathy associated with systemic neoplasia and chemotherapy

Three adult patients with leukemia and a patient with cutaneous melanoma were treated with a variety of therapeutic agents administered systemically. Three of these patients received either cytosine arabinoside or thio-TEPA, by intrathecal injection and radiotherapy to the cranium or spine. Three patients developed progressive motor and sensory deficits and the fourth became confused and disoriented. These symptoms were chronologically related to the time when chemotherapy was begun. Death occurred 11/2, 2, 5 and 7 months, respectively, after the beginning of neurologic deficit. The spinal white matter showed vacuolation, myelin disintegration, axonal swelling, fibrillary gliosis, and infiltration by macrophages. Vesicular disintegration of the myelin lamellae seems to be the earliest lesion affecting both central and peripheral myelin. Gliosis and macrophages were visible only in the two patients who survived at least five months from the time of the neurologic deficit.

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.

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.