Methotrexate-related multifocal axonopathy. Report of an autopsy case

Myelopathy mimicking subacute combined degeneration in a Down syndrome patient with methotrexate treatment for B lymphoblastic leukemia: report of an autopsy case

We report clinicopathological features of a 23-year-old woman with Down syndrome (DS) presenting with subacute myelopathy treated with chemotherapy, including intravenous and intrathecal administration of methotrexate (MTX), and with allogenic bone-marrow transplantation for B lymphoblastic leukemia. Autopsy revealed severe demyelinating vacuolar myelopathy in the posterior and lateral columns of the spinal cord, associated with macrophage infiltration, marked axonal loss and some swollen axons. Pathological changes of posterior and lateral columns were observed from the medulla oblongata to lumbar cord. Proximal anterior and posterior roots were preserved. Cerebral white matter was relatively well preserved. There were no vascular lesions or meningeal dissemination of leukemia. Longitudinal extension of cord lesions was extensive, unlike typical cases of subacute combined degeneration (SACD), but distribution of lesions and histological findings were similar to that of SACD. DS patients show heightened sensitivity to MTX because of their genetic background. Risk factors for toxic myelopathy of DS are discussed, including delayed clearance of MTX despite normal renal function, alterations in MTX polyglutamation and enhanced folic acid depletion due to gene dosage effects of chromosome 21. Alteration of folate metabolism and/or vitamin B12 levels through intravenous or intrathecal administration of MTX might exist, although vitamin B12 and other essential nutrients were managed using intravenous hyperalimentation. To the best of our knowledge, this is the first report of an autopsy case that shows myelopathy mimicking SACD in a DS patient accompanied by B lymphoblastic leukemia. The case suggests a pathophysiological mechanism of MTX-related myelopathy in DS patients with B lymphoblastic leukemia mimicking SACD.

Chemotherapy-induced polyneuropathy. Part I. Pathophysiology

Chemotherapy-induced peripheral neuropathy (CIPN) is a toxic neuropathy, a syndrome consisting of highly distressing symptoms of various degrees of severity. It includes numbness of distal extremities, long-term touch, heat, and cold dysaesthesia and, in more severe cases, motor impairment affecting daily functioning. Each form of the syndrome may be accompanied by symptoms of neuropathic stinging, burning, and tingling pain. In the case of most chemotherapeutic agents, the incidence and severity of CIPN are dependent on the cumulative dose of the drug. The syndrome described is caused by damage to the axons and/or cells of the peripheral nervous system.

Chemotherapeutic agents have distinct mechanisms of action in both neoplastic tissue and the peripheral nervous system; therefore, CIPN should not be regarded as a homogeneous disease entity. The present article is an attempt to systematize the knowledge about the toxic effects of chemotherapy on the peripheral nervous system.

Chemotherapy-induced neuropathy

Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.

An autopsy case of drug-induced diffuse cerebral axonopathic leukoencephalopathy: the pathogenesis in relation to reversible posterior leukoencephalopathy syndrome

An autopsy case of diffuse axonopathic leukoencephalopathy induced by drug treatment is reported. A 70-year-old woman with multiple myeloma developed encephalopathy several days after completing a course of intravenous human immunoglobulin (IVIg) and granulocyte-colony stimulating factor (G-CSF), and died within I month. T2-weighted MRI demonstrated multifocal high-signal areas in the bilateral cerebral white matter, especially in the right frontal lobe. Neuropathologically, multifocal hydropic axonal swelling with a poor glial reaction was recognized diffusely in the bilateral deep cerebral white matter, being especially marked in the frontal lobe. The cortex, subcortical U-fibers, corpus callosum, and anterior commissure were spared. The cerebellar white matter also showed similar changes, albeit less marked, but the brainstem was spared. Microscopically, the myeloma involvement of the CNS was limited to the dura, and the cerebral arteries showed slight atherosclerosis, but neither thrombi nor angitis. This case, although ultimately fatal, neurologically and neuroradiologically resembled reversible posterior leukoencephalopathy syndrome (RPLS) induced by IVIg and/or G-CSF, and the nature and selective distribution of the neuropathological changes suggested that the pathogenesis involved vasospasm of the bilateral internal carotid artery and the main trunks of the cerebral arteries, due to unknown cause, inducing ischemia in the deep white matter, which is supplied by long nutrient arteries.

Methotrexate-related nonnecrotizing multifocal axonopathy detected by beta-amyloid precursor protein immunohistochemistry

We describe a 64-year-old woman with biphenotypic leukemia involving the meninges who received 2 doses of intrathecal methotrexate. Soon after treatment, the patient developed postural rigidity and a marked decline in mental status. The patient died of respiratory failure 1 month after methotrexate treatment was initiated. At autopsy, the brain was grossly normal. Routine microscopy showed no evidence of leukemic infiltrates or necrotizing lesions. However, when stained with beta-amyloid precursor protein, multifocal axonal injury was evident in the brain, spinal cord, and nerve roots. Our findings show that immunohistochemical staining for beta-amyloid precursor protein can effectively demonstrate axonal injury associated with methotrexate neurotoxicity, even when conventional staining procedures are negative. This technique may therefore reveal a possible pathologic substrate for some of the neurological complications seen in patients with methotrexate neurotoxicity.

Intrathecal leucovorin after intrathecal methotrexate overdose

PURPOSE

Intrathecal methotrexate is a standard and important therapy in acute leukemia. Unfortunately, overdose is a well reported complication of this therapy. We report a fatal event secondary to intrathecal leucovorin.

PATIENTS, METHODS, AND RESULTS

An 11-year-old boy with a 6-month history of treatment of acute lymphocytic leukemia received an "overdose" of 20 mg of intrathecal methotrexate. He was treated with intrathecal leucovorin and subsequently experienced severe neurotoxicity and died. This was attributed to the use of intrathecal leucovorin, the first such case reported in the medical literature.

CONCLUSION

A review of the literature indicates that a careful definition of overdose needs to be applied in cases of intrathecal methotrexate: those <100 mg need less intervention, >500 mg will not respond to any intervention, and the middle group, 100-500 mg, can be treated with a variety of approaches, which are outlined. The standard treatment includes the use of ventriculolumbar washout, CSF exchange, or intravenous pharmacotherapy with leucovorin. Recently, the use of carboxypeptidase has been under investigation. All clinicians who administer intrathecal medications should be aware of these complications and the appropriate treatments of them (including rescue). Leucovorin should not be given intrathecally.

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.

Acute ascending myelitis and encephalopathy after intrathecal cytosine arabinoside and methotrexate in an adolescent boy with acute lymphoblastic leukemia

A 14-year-old boy with acute lymphoblastic leukemia developed acute ascending myelitis followed by encephalopathy after intrathecal administration of methotrexate 15 mg and cytosine arabinoside 50 mg. The patient had none of the risk factors noted previously in other patients with intrathecal therapy (IT) induced neurotoxicity. The doses administered were within the standard scales, and toxicity developed in the second boost of IT 20 days after the first one. There may not be any parameters to predict the occurrence of such severe and rare form of CNS neurotoxicity attributed to IT.