Neurologic complications of cancer therapy

Quantum DFT analysis and molecular docking investigation of various potential breast cancer drugs

Breast cancer is among the deadliest cancers worldwide, highlighting the urgent need for effective treatments. This study employs density functional theory (DFT) and molecular docking analyses to evaluate the anti-cancer efficacy and specificity of drug molecules lapatinib, tucatinib, neratinib, anastrozole, and letrozole. DFT analysis provides comprehensive insights into the structural, electronic, optical, and vibrational properties of these drugs, helping to elucidate their molecular stability and reactivity through global reactivity descriptors. Additionally, molecular docking simulations reveal the binding conformations and interaction profiles of these drugs with key breast cancer targets, underscoring their therapeutic potential. Docking results indicate that lapatinib, tucatinib, and neratinib have high binding affinities for HER2, with lapatinib exhibiting the strongest overall binding, particularly with PDK1 (PDB ID: 1UU7), PAK4 (PDB ID: 2X4Z), GSK3 (PDB ID: 1GNG), and HER2 (PDB ID: 2IOK). The stable hydrogen bonding and other interactions observed with lapatinib support its effectiveness in treating HER2-positive breast cancers, tucatinib's selective HER2 binding reduces off-target effects, while neratinib's irreversible binding provides prolonged inhibition, making it useful for overcoming resistance in HER2-positive cases. In contrast, anastrozole and letrozole show lower binding affinities for HER2 and EGFR due to their simpler structures but are potent aromatase inhibitors, making them effective in treating estrogen receptor-positive (ER-positive) breast cancers. In conclusion, DFT and molecular docking studies affirm the suitability of lapatinib, tucatinib, and neratinib for HER2-positive cancers, while anastrozole and letrozole are effective in ER-positive cancers, emphasizing the role of molecular structure and binding affinity in optimizing cancer treatment strategies.

Pain associated with breast cancer: etiologies and therapies

Pain associated with breast cancer is a prevalent problem that negatively affects quality of life. Breast cancer pain is not limited to the disease course itself but is also induced by current therapeutic strategies. This, combined with the increasing number of patients living with breast cancer, make pain management for breast cancer patients an increasingly important area of research. This narrative review presents a summary of pain associated with breast cancer, including pain related to the cancer disease process itself and pain associated with current therapeutic modalities including radiation, chemotherapy, immunotherapy, and surgery. Current pain management techniques, their limitations, and novel analgesic strategies are also discussed.

Cancer Telerehabilitation

Telemedicine has clear benefits to the cancer population, including reducing the risk of contracting communicable disease, reaching remote populations, and added convenience. With adequate preparation, cancer rehabilitation telemedicine can serve as a suitable substitute for in-person encounters in several situations. There are limits with technologic deficits, reimbursement questions, and the inability to conduct hands-on physical examinations. It is important to appropriately triage patients to the most suitable visit type, whether telemedicine or in person, with aims of reducing unnecessary risks, monitoring for potential complications, and having productive encounters.

Contribution of Immune-Mediated Paraneoplastic Syndromes to Neurological Manifestations of Neuroendocrine Tumours: A Retrospective Study

INTRODUCTION

Neurological symptoms associated with neuroendocrine tumours (NETs) may be related to metastatic disease or paraneoplastic syndromes (PNSs); these last are often associated with autoantibodies targeting various onconeural antigens. To better characterize neurological PNSs related to NETs, we report the largest case-series study to date.

METHODS

We retrospectively reviewed the charts of all patients diagnosed with NETs of the gastrointestinal tract who presented with neurological symptoms at either of 2 tertiary academic hospitals (Henri Mondor and Beaujon, France) between 1994 and 2016. All patients underwent extensive neurological tests including clinical, laboratory, and radiological investigations. The clinical response to immunomodulating agents was recorded.

RESULTS

In the 13 identified patients, the most common presentations were peripheral neuropathy (46.2%) and encephalopathy (26.6%). Of the 6 (53.3%) patients whose serum anti-neuronal antibodies were assayed, 5 had high titres. Short-term oral corticosteroid and immunosuppressant drug therapy was given to 4 of these patients, of whom 3 had a clinical response and 1 no response. Repeated high-dose intravenous immunoglobulin therapy induced a complete clinical response in 1 patient. Encephalopathy resolved fully after hepatectomy or intrahepatic chemoembolization for liver metastases in another 2 patients.

DISCUSSION

The neurological symptoms associated with NETs may be due in part to autoimmune PNS. Based on experience at our 2 centres, we estimate that autoimmune PNS occurs in about 1% of patients with NETs. Early symptom recognition allows the initiation of effective treatments including corticosteroids, immunosuppressive drugs, and/or intravenous immunoglobulins.

Protective role of anticancer drugs in neurodegenerative disorders: A drug repurposing approach

The disease heterogeneity and little therapeutic progress in neurodegenerative diseases justify the need for novel and effective drug discovery approaches. Drug repurposing is an emerging approach that reinvigorates the classical drug discovery method by divulging new therapeutic uses of existing drugs. The common biological background and inverse tuning between cancer and neurodegeneration give weight to the conceptualization of repurposing of anticancer drugs as novel therapeutics. Many studies are available in the literature, which highlights the success story of anticancer drugs as repurposed therapeutics. Among them, kinase inhibitors, developed for various oncology indications evinced notable neuroprotective effects in neurodegenerative diseases. In this review, we shed light on the salient role of multiple protein kinases in neurodegenerative disorders. We also proposed a feasible explanation of the action of kinase inhibitors in neurodegenerative disorders with more attention towards neurodegenerative disorders. The problem of neurotoxicity associated with some anticancer drugs is also highlighted. Our review encourages further research to better encode the hidden potential of anticancer drugs with the aim of developing prospective repurposed drugs with no toxicity for neurodegenerative disorders.

Incidence of vincristine induced neurotoxicity in children with acute lymphoblastic leukemia and its correlation with nutritional deficiencies

Injection vincristine is an important component of therapy for acute lymphoblastic leukemia (ALL). An important adverse effect of vincristine is neurotoxicity. The incidence of this adverse effect is well studied. The present was undertaken to determine the incidence of vincristine-induced neurotoxicity in children with ALL after the induction of remission phase of chemotherapy and to ascertain its correlation with undernutrition, vitamin B12, folate and iron deficiency. Thirty children (1-18 years) with ALL were enrolled at the commencement of chemotherapy. The electrophysiological evaluation was done at baseline and repeated after four doses of vincristine (1.5 mg/m²/dose). Clinical evaluation was done regularly. Anthropometry and serum B12, folate and ferritin levels were assessed at baseline. Twelve children over a 4-week period of observation had peripheral neuropathy clinically. The autonomic system was most commonly involved followed by motor and sensory system respectively. On electrophysiological testing, half of the patients had evidence of neuropathy. Micronutrient deficiencies were present in a significant number of patients-63.3% had a B12 deficiency, 20% were deficient in folate and 43.3% in iron. The incidence of vincristine-induced neuropathy in patients with/without these micro-nutrient deficiencies was not statistically significantly different. Vincristine-induced neuropathy is common in Indian children with ALL. The present study did not find any correlation between the occurrences of vincristine-induced neuropathy and nutritional deficiencies. Larger studies are warranted to evaluate the contribution of micronutrient deficiencies to the development of peripheral neuropathy in childhood ALL.

Role of Sonification and Rhythmic Auditory Cueing for Enhancing Gait Associated Deficits Induced by Neurotoxic Cancer Therapies: A Perspective on Auditory Neuroprosthetics

Patients undergoing chemotherapy, radiotherapy, and immunotherapy experience neurotoxic changes in the central and peripheral nervous system. These neurotoxic changes adversely affect functioning in the sensory, motor, and cognitive domains. Thereby, considerably affecting autonomic activities like gait and posture. Recent evidence from a range of systematic reviews and meta-analyses have suggested the beneficial influence of music-based external auditory stimulations i.e., rhythmic auditory cueing and real-time auditory feedback (sonification) on gait and postural stability in population groups will balance disorders. This perspective explores the conjunct implications of auditory stimulations during cancer treatment to simultaneously reduce gait and posture related deficits. Underlying neurophysiological mechanisms by which auditory stimulations might influence motor performance have been discussed. Prompt recognition of this sensorimotor training strategy in future studies can have a widespread impact on patient care in all areas of oncology.

Choice of antiepileptic drugs affects the outcome in cancer patients with seizures

BACKGROUND

Seizures in cancer patients may occur as a result of CNS primary or metastatic tumor, brain surgery, vascular disease, pharmacologic treatment (including chemotherapy), radiation therapy, or metabolic disorders. The aims of the study were to a) determine whether seizures in cancer patients have prognostic implications and b) study patient outcome based on the antiepileptic drug used.

METHOD

This is a prospective comparative study that included adult cancer patients with and without seizures from May 2010 to November 2016 seen by the neuro-oncology unit at a cancer referral center. Variables included age, gender, oncologic characteristics, seizure features, treatment, and outcome. Parametric and non-parametric tests were used to compare groups, and Kaplan-Meier curves with the log-rank test were used to analyze survival. Cox multivariate regression tests were used to describe survival and compare groups.

RESULTS

A total of 823 patients were included; 419 (51%) patients had at least one seizure and were compared with 404 (49%) who did not experience seizures. Of the seizure group, 53% had brain metastases, 36% did not have a brain tumor, and 11% had a primary brain tumor. No survival differences were noted among patients with brain metastases or primary tumor with or without seizures. In the seizure group, 249 (59%) required only one antiepileptic drug, whereas 134 (32%) required 2 or more. A better overall survival was identified for patients prescribed carbamazepine (p = 0.02), lamotrigine (p = 0.015), levetiracetam (p = 0.03), and valproic acid (p = 0.009).

CONCLUSIONS

Patients with primary or metastatic brain tumors have the same overall survival with or without seizures. However, patients with seizures not treated with antiepileptics exhibit worse overall survival.

Anticonvulsant therapy in brain-tumor related epilepsy

Background. The lifetime risk of patients with brain tumors to have focal epileptic seizures is 10-100%; the risk depends on different histology. Specific guidelines for drug treatment of brain tumor-related seizures have not yet been established.

Aim. This review addresses the special aspects of antiepileptic drug (AED) therapy in brain tumor-related epilepsy.

Methods. We analyzed the literature up to December 2015.

Results. Based on current evidence the management of tumor-related seizures does not differ substantially from that applied to epilepsies from other etiologies. Therefore, the choice of an AED is based, above all, on tolerability and pharmacokinetic interactions with chemotherapeutic drugs. Levetiracetam is recommended by many authors as first-line therapy in brain tumor-related epilepsy. Due to the possibility of interactions, the combination of enzyme-inducing AEDs and chemotherapeutic drugs, is usually not recommended as a first choice. Currently there is no evidence that prophylactic prescription of long-term AEDs in brain tumor-patients who did not present with seizures is justified. Because of the high risk of recurrence, however, AED treatment should be strongly considered after a single brain tumor-related seizure. The decision to withdraw AEDs must carefully consider the risk of seizure recurrence.

Conclusion. At present levetiracetam is the preferred drug in brain tumor-related epilepsy, especially when drug interactions need to be avoided. In the future we hope to acquire more targeted drugs against this disorder by uncovering its pathogenesis.

Cancer-treatment-induced neurotoxicity--focus on newer treatments

Neurotoxicity caused by traditional chemotherapy and radiotherapy is widely recognized in patients with cancer. The adverse effects of newer therapeutics, such as biological and immunotherapeutic agents, are less well established, and are associated with considerable neurotoxicity in the central and peripheral nervous systems. This Review addresses the main neurotoxicities of cancer treatment with a focus on the newer therapeutics. Recognition of these patterns of toxicity is important because drug discontinuation or dose adjustment might prevent further neurological injury. Knowledge of these toxicities also helps to differentiate treatment-related symptoms from progression of cancer or its involvement of the nervous system. Familiarity with the neurological syndromes associated with cancer treatments enables clinicians to use the appropriate treatment for the underlying malignancy while minimizing the risk of neurological damage, which might preserve patients' quality of life.

Opportunities for rehabilitation of patients with radiation fibrosis syndrome

This review discusses the pathophysiology, evaluation, and treatment of neuromuscular, musculoskeletal, and functional disorders that can result as late effects of radiation treatment. Although radiation therapy is often an effective method of killing cancer cells, it can also damage nearby blood vessels that nourish the skin, ligaments, tendons, muscles, nerves, bones and lungs. This can result in a progressive condition called radiation fibrosis syndrome (RFS). It is generally a late complication of radiotherapy which may manifest clinically years after treatment. Radiation-induced damage can include "myelo-radiculo-plexo-neuro-myopathy," causing muscle weakness and dysfunction and contributing to neuromuscular injury. RFS is a serious and lifelong disorder which, nevertheless, may often be decremented when identified and rehabilitated early enough. This medical treatment should be a complex procedure consisting of education, physical therapy, occupational therapy, orthotics as well as medications.

[Central nervous system complications in patients undergoing cytotoxic chemotherapy and targeted therapies]

Anti-cancer treatments (cytotoxic chemotherapies, targeted therapies and hormonotherapies) are known to induce early and delayed neurological toxicities. Acute encephalopathies and posterior reversible encephalopathies are better known and described, physiopathological hypotheses are emerging. It is difficult to discriminate what drug is causing the symptoms in patients treated with multiple cytotoxic drugs. Methotrexate and ifosfamide are responsible for acute encephalopathies. L-asparaginase and methotrexate or targeted therapies may induce cerebrovascular complications. As life expectancy increases and more complex regimen including innovative targeted therapies are developed, new toxicity profiles can be expected. To be able to provide an early diagnosis, prevention, and treatment (when existing) of these pathologies remains a tremendous challenge that would allow a good quality of life with social and professional life after their cancer is cured.

[Late-onset leukoencephalopathy induced by long-term chemotherapy with capecitabine and cyclophosphamide for liver metastasis from breast cancer]

A 55-year-old woman with a 3-year and 4-month history of liver metastasis from breast cancer underwent chemotherapy with capecitabine and cyclophosphamide for following 10-months. She did not have hypertension and was not pregnant. She showed dysarthria and mild somnolence, and her conscious level developed to semicoma after 6 days. She had pyrexia. Cerebrospinal fluid (CSF) demonstrated increased cell-count and elevated protein but no evidence of positive cytological finding and cultivation of bacteria was found in the CSF. Brain magnetic resonance imaging (MRI) revealed multiple lesions with hyperintensity in the brain stem, bilateral middle cerebellar peduncles, left splenium of corpus callosum, bilateral basal ganglia, bilateral thalami, bilateral corona radiata, and bilateral subcortical white matters of parietal lobes on the T(2) weighted and fluid attenuated inversion recovery (FLAIR) images. These lesions demonstrated mild hyperintensity on the diffusion weighted images but did not demonstrate hypointensity on the T(1) weighted images. Capecitabine and cyclophosphamide were discontinued at 4th day after onset of symptoms, and her conscious disturbance showed improvement slowly since day 12 after cessation of these drugs and hyperintensity areas detected on FLAIR image of MRI showed decreasing intensity after three weeks of onset. Capecitabine is an oral prodrug converted to 5-fluorouracil (5-FU). 5-FU and cyclophosphamide are known to induce leukoencephalopathy. Reversible multiple lesions with leukoencephalopathy on brain MRI which is called as a posterior reversible encephalopathy syndrome (PRES). Capecitabine is also reported to induce PRES in rare cases. Combination of these drugs was considered for the possible cause to induce leukoencephalopathy like PRES. Usually leukoencephalopathy occurs in relatively early time after start of chemotherapy with capecitabine or cyclophosphamide, but we consider that late-onset leukoencephalopathy can be induced by long-term chemotherapy with these drugs. It is necessary to observe leukoencephalopathy by brain MRI regularly when these drugs are used.

Brain tumor headaches: from bedside to bench

Although most people who have headache pain do not present with an underlying mass lesion, a large number of patients with brain tumors do report headache (as many as 60% in our institution). The problem for clinicians is that the tumor-headache association is not universal, as evidenced by anecdotal reports of patients with large tumors and increased intracranial pressure, but a complete absence of headache pain. In this review, we examine more than 80 years of research on brain tumor headaches, delineating the link between tumor location, laterality, growth rate, and pain. Most importantly, we position our review within the context of current etiological theories and propose new models involving the peripheral and central sensitization of nociresponsive neurons. This review will help clinicians understand why debulking surgery sometimes fails to alleviate neoplastic headache pain in select patients. A brief examination of headaches as a result of surgery and adjuvant chemoradiation therapy is also provided. Headaches can be an early indicator of central nervous system tumors. However, headaches are present in a wide variety of other condition, and are sometimes (surprisingly) absent in patients with primary neoplasms or metastatic tumors. This observation complicates the possibility of linking headaches to brain tumors. Nevertheless, some generalizations concerning brain tumor headaches can be drawn. The following sections review these generalizations, presenting caveats where appropriate. Lingering questions in the field are also addressed and presented together with promising future research avenues.

[Pharmacologically-induced neurocatastrophes]

Drug-induced adverse reactions represent a significant health problem in developed countries. These events cause 5% of hospital admissions and are one of the main causes of mortality. Neurological manifestations are among the most frequent. This article reviews catastrophic cerebrovascular situations and confusional syndromes, as well as epilepsy, structural encephalopathy, neuromuscular disorders, catastrophic movement disorders and infections, all of which can be drug-induced.

Neurotoxicity of cancer treatment

Cancer therapy--including brain-directed surgery, brain or spine irradiation, or chemotherapy--may affect the nervous system in a deleterious manner, affecting either the central or peripheral nervous systems. The causation of encephalopathy (eg, radiation, chemotherapy) is most relevant for the differential diagnosis of central nervous system (CNS) disorders, as defining a specific cause determines further treatment and outcome. Peripheral nervous system disorders (ie, steroid myopathy, spindle poison, or platinum neuropathy) are predominantly treatment related and respond best to discontinuation of the neurotoxic agent.

Physiological aging in older adults with cancer: implications for treatment decision making and toxicity management

Because the risk of cancer increases with age, the growth of the aging population will lead to a larger number of older adults with cancer. Standard cancer treatments can be safe and effective in older adults and result in improved survival and enhanced quality of life. Because physiological decline varies among older adults, cancer treatment requires an individualized approach. Consideration of physiological age, rather than chronological age alone, is required to guide treatment decision making and prevent and manage treatment toxicities and other complications. This article examines the impact of physiological aging on treatment decision making and toxicity management in older adults with cancer.

Voxel-based analysis of T2 hyperintensities in white matter during treatment of childhood leukemia

BACKGROUND AND PURPOSE

White matter (WM) hyperintensities on T2-weighted MR imaging are the most common imaging manifestation of neurotoxic effects of therapy for central nervous system (CNS) prophylaxis in childhood acute lymphoblastic leukemia (ALL). This study uses voxel-based analyses (VBA) of T2-weighted imaging of patients during treatment to identify which WM regions are preferentially damaged.

MATERIALS AND METHODS

Two sets of conventional T2-weighted axial images were acquired on a 1.5T MR imaging scanner from 197 consecutive patients (85 female, 112 male; aged 1.0-18.9 years) enrolled on an institutional ALL treatment protocol. Images were acquired after completion of induction therapy and after the final of the 4 courses of intravenous high-dose methotrexate in consolidation therapy (3.9 +/- 0.8 months apart). Voxel-wise statistical testing of the incremental change between normalized longitudinal T2 images was performed with radiologist reading (normal or abnormal) and treatment risk-group as covariates.

RESULTS

Two highly significant bilateral clusters of T2 signal intensity change were identified in both 1-group and 2-group analyses. The regions were symmetric in size, shape, and average signal intensity. Increased T2-weighted signal intensity from these regions both within and between examinations were nonlinear functions of age at examination, and the difference between the examinations was greater for older subjects who received more intense therapy.

CONCLUSIONS

These analyses identified specific WM tracts involving predominantly the anterior, superior, and posterior corona radiata and superior longitudinal fasciculus, which were at increased risk for the development of T2-weighted hyperintensities during therapy for childhood ALL. These vulnerable regions may be the cause of subsequent cognitive difficulties consistently observed in survivors.

Chemotherapy-induced peripheral neuropathy

Recent advances in the development and administration of chemotherapy for malignant diseases have led to prolonged survival of patients and the promise of a return to normal lives. This progress comes with a price, however, and the nervous system is frequently the target of therapy-induced toxicity. Unlike more immediate toxicities that affect the gastrointestinal tract and bone marrow, chemotherapy-induced neurotoxicity is frequently delayed in onset and may progress over time. In the peripheral nervous system, the major brunt of the toxic attack is directed against the peripheral nerve, targeting the neuronal cell body, the axonal transport system, the myelin sheath, and glial support structures, resulting in chemotherapy-induced peripheral neuropathy.

Ascending sensory motor polyradiculoneuropathy with cranial nerve involvement following administration of intrathecal methotrexate and intravenous cytarabine in a patient with acute myelogenous leukemia: a case report*

Background

Acute inflammatory polyradiculoneuropathy secondary to chemotherapy for leukemia has been described in the pediatric literature. However, the reports are rare and have been mainly from intrathecal methotrexate in pediatric acute lymphoblastic leukemia patients who developed demyelinating polyradiculoneuropathy.

Case presentation

A case report is presented of an unfortunate 53 year old Hispanic woman with acute myelogenous leukemia who developed profound weakness with cranial nerve palsies following both intravenous and intrathecal chemotherapy.

Conclusion

This is an interesting and unusual case of predominantly axonal ascending sensory motor polyradiculoneuropathy with cranial nerve involvement in an adult patient with acute myelogenous leukemia following intravenous Cytosine arabinoside and intrathecal methotrexate.

Chemotherapy-induced peripheral neuropathy

Recent advances in the development and administration of chemotherapy for malignant diseases have led to prolonged survival of patients and the promise of a return to normal lives. The cost of progress comes with a price, however, and the nervous system is frequently the target of therapy-induced toxicity. Unlike more immediate toxicities that affect the gastrointestinal tract and bone marrow, chemotherapy-induced neurotoxicity is frequently delayed in onset and may progress over time. In the peripheral nervous system, the major brunt of the toxic attack is directed against the peripheral nerve, targeting the neuronal cell body, the axonal transport system, the myelin sheath, and glial support structures, resulting in chemotherapy-induced peripheral neuropathy.

Anti-cancer drug induced neurotoxicity and identification of Rho pathway signaling modulators as potential neuroprotectants

Many chemotherapy drugs are known to cause significant clinical neurotoxicity, which can result in the early cessation of treatment. To identify and develop more effective means of neuroprotection it is important to understand the toxicity of these drugs at the molecular and cellular levels. In the present study, we examine the effects of paclitaxel (taxol), cisplatin, and methotrexate on primary rat neurons including hippocampal, cortical, and dorsal horn/dorsal root ganglion neuronal cultures. We found that all of these anti-cancer drugs induce substantial neurotoxicity evidenced by neurite degeneration. The neurons are capable of recovering after treatment withdrawal, but taxol exerts a biphasic effect that results in the collapse of processes days after treatment is withdrawn. After cisplatin and methotrexate treatment, we observed the degeneration of neuronal processes including the reduction of dendritic branching, length, and altered growth cone formation, indicating an abnormal arrangement of the actin cytoskeleton consistent with the involvement of Rho family small GTPases. Inhibiting RhoA downstream effector p160 ROCK/Rho kinase using Y-27632, or activating p75 neurotrophin receptor (p75 NTR) using non-peptide mimetic LM11A-31, were able to reverse the degeneration caused by cisplatin and methotrexate. Therefore, the neurotoxicity resulting from exposure to the anti-cancer drugs cisplatin and methotrexate can be alleviated by inhibiting Rho signaling pathway.

An Overview of Chemotherapy-Induced Peripheral Neuropathy

Peripheral neuropathy remains a major limitation of chemotherapeutic agents used in cancer treatment. This neurologic complication from chemotherapy occurs frequently and can be debilitating. Although difficult to predict, both chemotherapeutic and patient-specific risk factors may contribute to this adverse event. Symptoms of peripheral neuropathy may appear acutely after treatment or persist chronically upon drug discontinuation. The taxanes, vinca alkaloids, and immunomodulatory drugs commonly cause peripheral nervous system toxicity. Prompt recognition and evaluation of this neurological adverse event by those who provide care to patients with cancer can prove to have a positive impact on the quality of life of those patients.

Leukemia and the nervous system

Leukemia affects the central and peripheral nervous system. Neurologic complications are a consequence of direct leukemic infiltration, as occurs with leukemic meningitis, and due to complications of either antileukemic treatment (thrombocytopenic or disseminated intravascular coagulation-related intracranial hemorrhage, steroid myopathy, vinca alkaloid peripheral neuropathy) or immune compromise (Herpes zoster shingles or Aspergillus meningitis).

Quantitative morphologic evaluation of magnetic resonance imaging during and after treatment of childhood leukemia

INTRODUCTION

Medical advances over the last several decades, including CNS prophylaxis, have greatly increased survival in children with leukemia. As survival rates have increased, clinicians and scientists have been afforded the opportunity to further develop treatments to improve the quality of life of survivors by minimizing the long-term adverse effects. When evaluating the effect of antileukemia therapy on the developing brain, magnetic resonance (MR) imaging has been the preferred modality because it quantifies morphologic changes objectively and noninvasively.

METHOD AND RESULTS

Computer-aided detection of changes on neuroimages enables us to objectively differentiate leukoencephalopathy from normal maturation of the developing brain. Quantitative tissue segmentation algorithms and relaxometry measures have been used to determine the prevalence, extent, and intensity of white matter changes that occur during therapy. More recently, diffusion tensor imaging has been used to quantify microstructural changes in the integrity of the white matter fiber tracts. MR perfusion imaging can be used to noninvasively monitor vascular changes during therapy. Changes in quantitative MR measures have been associated, to some degree, with changes in neurocognitive function during and after treatment.

CONCLUSION

In this review, we present recent advances in quantitative evaluation of MR imaging and discuss how these methods hold the promise to further elucidate the pathophysiologic effects of treatment for childhood leukemia.

Barriers to rehabilitation of the neurosurgical spine cancer patient

The treatment of metastatic spine tumors has evolved significantly over the past 20 years due largely to improvements in magnetic resonance imaging; decompressive surgical techniques, spinal instrumentation, and high-dose conformal radiation. These advances have improved our ability to provide meaningful palliation for patients who often have significant medical and cancer-related issues. Despite technical advances that have improved our ability to maintain neurologic function, stabilize the spine, and prevent local tumor recurrences, significant barriers to rehabilitation remain. This article reviews these primary barriers to rehabilitation of the cancer patient following spine surgery and emphasizes the importance of diagnostic accuracy and a comprehensive team approach to the treatment of pain and other disorders in this population.

Management of chemotherapy-induced peripheral neuropathy

Recent advances in the development and administration of chemotherapy for malignant diseases have been rewarded with prolonged survival rates. The cost of progress has come at a price and the nervous system is frequently the target of chemotherapy-induced neurotoxicity. Unlike more immediate toxicities that effect the gastrointestinal tract and bone marrow, chemotherapy-induced neurotoxicity is frequently delayed in onset and may progress over time. In the peripheral nervous system, the major brunt of the toxicity is directed against the peripheral nerve, resulting in chemotherapy-induced peripheral neuropathy (CIPN). Chemotherapeutic agents used to treat hematologic and solid tumors target a variety of structures and functions in the peripheral nervous system, including the neuronal cell body, the axonal transport system, the myelin sheath, and glial support structures. Each agent exhibits a spectrum of toxic effects unique to its mechanism of toxic injury, and recent study in this field has yielded clearer ideas on how to mitigate injury. Combined with the call for a greater recognition of the potentially devastating ramifications of CIPN on quality of life, basic and clinical researchers have begun to investigate therapy to prevent neurotoxic injury. Preliminary studies have shown promise for some agents including glutamine, glutathione, vitamin E, acetyl-L-carnitine, calcium, and magnesium infusions, but final recommendations await prospective confirmatory studies.

Neurologic complications of cancer chemotherapy

Neurotoxicity related to cancer therapy is a common problem in oncology practice. Neurologic side effects can be dose-limiting, can inhibit treatment, and can substantially diminish quality of life. Symptoms may appear acutely after treatment, or remotely after therapy has been discontinued. Multiple therapies may share similar toxicities, and certain agents may potentiate symptoms. When faced with the development of neurologic complaints, familiarity with the most common complications is helpful in determining the etiology of these symptoms. This review will discuss the common complications of both established and novel agents used to treat cancer.

Paraneoplastic mononeuritis multiplex in non-small-cell lung carcinoma

A 60-year-old man developed two selective peripheral mononeuropathies of the peroneal and later the radial nerve, shortly after a diagnosis of large-cell lung carcinoma. Nerve conduction studies and electromyography confirmed isolated lesions in both nerves, and in the case of the peroneal nerve lesion, focal conduction block was localised to the level of the fibula neck. Subsequent magnetic resonance imaging of the lower limb excluded focal compression or malignant infiltration along the course of the peroneal nerve, and there was no signal change within the nerve, prompting a diagnosis of paraneoplastic mononeuritis multiplex. Anti-neuronal antibodies and serological markers of systemic vasculitis were negative. Neither the patient's large-cell lung carcinoma nor mononeuritis multiplex responded to chemotherapy, and he died within 6 months of the initial diagnosis.

An Electrodiagnostic Evaluation of the Effect of Pre-existing Peripheral Nervous System Disorders in Patients Treated with the Novel Proteasome Inhibitor Bortezomib

AIMS

Bortezomib (Velcade), a novel proteasome inhibitor, has shown promise in the treatment of malignancies, including multiple myeloma and non-Hodgkin's lymphoma. Several studies have identified neuropathy as a potentially dose-limiting side effect of treatment with bortezomib. We report the clinical and electrodiagnostic data from four patients who developed signs and symptoms of peripheral neuropathy from treatment with bortezomib.

MATERIALS AND METHODS

Patients were included if they were enrolled in active phase 2 trials of bortezomib for non-Hodgkin's lymphoma or prostate cancer, developed signs and symptoms of peripheral neuropathy, and were referred for electrodiagnostic evaluation.

RESULTS

Four patients, including two with non-Hodgkin's lymphoma and two with prostate cancer, underwent electrodiagnostic testing. Electrodiagnostic evaluation showed pre-existing peripheral nervous system disorders in three out of four patients. Multiple peripheral nervous system disorders were present in two out of four patients.

CONCLUSIONS

Bortezomib can cause a predominately sensory axonal polyneuropathy. Pre-existing peripheral nervous system disorders, such as neuropathy and radiculopathy, are common in patients with cancer, and may pre-dispose to the development of symptomatic neuronal toxicity when treated with bortezomib. Baseline electrodiagnostic evaluation may identify patients with pre-existing peripheral nervous system disorders at risk for additive neuronal toxicity from neurotoxic chemotherapeutic agents.

Headache related to brain tumors

Headache is one of the most common somatic complaints of patients seeking medical care. Most headaches are not of serious cause and can be diagnosed easily with a good history and physical examination. The challenges to the physician are to determine when underlying intracranial pathology may be causing the symptoms and signs, and to identify the few patients in whom a tumor is the cause of the headache. The subject of headache in patients with brain tumors has been reviewed in neurologic textbooks and in several investigations before, as well as after, modern imaging diagnostic techniques became available. Headache can also manifest as an acute or chronic complication of radiation treatment and/or chemotherapy in patients with intracranial neoplasm, but there are few data in the literature specifically addressing this subject. This article provides an overview of headache in patients with primary and secondary brain tumor, including headache characteristics, the putative mechanism for these headaches, the role of diagnostic testing, and the general principles of management.

Prospective evaluation of clinical and laboratory effects of intrathecal chemotherapy on children with acute leukemia

The objective of this prospective 18-month study was to evaluate the clinical and laboratory effects of repeated intrathecal injections of chemotherapy in children with acute leukemia. All procedures were performed under general anesthesia, and complications were prospectively recorded. Laboratory measurements included lumbar puncture opening pressure, cerebrospinal fluid (CSF) chemistry, and cell count and morphology. Central venous pressure and ophthalmologic examinations were also performed. Forty-seven children underwent 247 intrathecal injections of chemotherapy. Adverse effects (13.7% of the procedures) included nausea and vomiting, back pain, and headache. One child each had transient cauda equina syndrome, transient communicating hydrocephalus, and persistent sacral plexus injury. The mean lumbar puncture opening pressure was significantly higher after intrathecal therapy than before (22 +/- 8 vs. 15 +/- 9 cm H2O, P = 0.02) and higher than reported in age-matched children without leukemia. All CSF chemistries, cell count, and morphology were normal. The overall incidence of complications was 13.7%. Most were mild and resolved quickly, but significant neurologic complications did occur. Lumbar puncture opening pressure was significantly higher in children with acute leukemia after intrathecal chemotherapy.

Quality of life in patients receiving treatment for gynecologic malignancies: Special considerations for patient care

Advances in the treatment of gynecologic cancer have extended the duration of survival of many patients. However, these patients frequently experience a variety of treatment- and disease-related side effects that diminish their quality of life (QOL) during and after treatment; among these are pain, nausea and vomiting, anemia, fatigue, peripheral neuropathy, emotional distress, and sexual dysfunction. Given the gains in survival time, patient care is being expanded to include enhancement or preservation of QOL in addition to early diagnosis and disease treatment, thus treating the whole person. In parallel with this evolution in cancer care, supportive measures are being increasingly recognized as crucial to effective patient management. This paper reviews some of the potential causes of diminished QOL in gynecologic cancer patients and basic treatment strategies for their control, with a focus on short-term QOL issues. It is important that clinicians monitor QOL during the course of the disease and its treatment, utilize procedures and therapeutic agents that take patient preferences and QOL into account, and proactively prevent and treat relevant symptoms.

Headaches and brain tumors

A careful history and physical examination remain the most important aspects of headache assessment. enabling the neurologist to decide if any further studies are necessary. Only a minority of patients who have headaches have brain tumors; however, recognition of the headaches characteristically associated with tumors is most important. Some locations are more likely to produce headache (eg, a posterior fossa tumor causes headache more often than a supratentorial tumor). Rapidly growing tumors are more likely to be associated with headache. Uncommon headache presentations can occur with tumors, includin paroxysmal cough, cluster headache, and TACs. The classic brain tumor headache is not as common as a tension-type presentation or migraine. Patients who have prior primary headaches may have more headache symptoms if they have a tumor and of course they still have their primary headache disorder. Mass lesions progress and inevitably develop other symptoms and signs besides headache, and these new symptoms and signs must be sought and found. Metastatic leptomeningeal involvement can present with headache and spinal pain in the neck and back. Imaging of headache patients for tumors, if they have primary headache disorders, such as migraine and typical cluster, generally is not cost effective but is necessary if there are any atypical features. Treatment of headache in patients who have metastatic brain tumors should be aggressive in terms of pain and symptoms control. Treatment of primary CNS tumors is dictated by the kind of neoplasm and site, but control of headache should not be ignored.

Neurologic complications of solid tumors

This article reviews the neurologic complications of the most common solid tumors, including lung, breast, gastrointestinal, genitourinary, gynecologic, head and neck cancers, melanoma and sarcomas. As systemic therapy improves for many of these tumors, patients are surviving longer and the incidence of neurologic complications is increasing.