Motor neurone disease as a manifestation of neoplasm (with a note on the course of classical motor neurone disease)

1,2-Dehydropyrrolizidine Alkaloids: Their Potential as a Dietary Cause of Sporadic Motor Neuron Diseases

Sporadic motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS), can be caused by spontaneous genetic mutations. However, many sporadic cases of ALS and other debilitating neurodegenerative diseases (NDDs) are believed to be caused by environmental factors, subject to considerable debate and requiring intensive research. A common pathology associated with MND development involves progressive mitochondrial dysfunction and oxidative stress in motor neurons and glial cells of the central nervous system (CNS), leading to apoptosis. Consequent degeneration of skeletal and respiratory muscle cells can lead to death from respiratory failure. A significant number of MND cases present with cancers and liver and lung pathology. This Perspective explores the possibility that MNDs could be caused by intermittent, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids (1,2-dehydroPAs) that are increasingly recognized as contaminants of many foods consumed throughout the world. Nontoxic, per se, 1,2-dehydroPAs are metabolized, by particular cytochrome P450 (CYP450) isoforms, to 6,7-dihydropyrrolizines that react with nucleophilic groups (-NH, -SH, -OH) on DNA, proteins, and other vital biochemicals, such as glutathione. Many factors, including aging, gender, smoking, and alcohol consumption, influence CYP450 isoform activity in a range of tissues, including glial cells and neurons of the CNS. Activation of 1,2-dehydroPAs in CNS cells can be expected to cause gene mutations and oxidative stress, potentially leading to the development of MNDs and other NDDs. While relatively high dietary exposure to 1,2-dehydroPAs causes hepatic sinusoidal obstruction syndrome, pulmonary venoocclusive disease, neurotoxicity, and diverse cancers, this Perspective suggests that, at current intermittent, low levels of dietary exposure, neurotoxicity could become the primary pathology that develops over time in susceptible individuals, along with a tendency for some of them to also display liver and lung pathology and diverse cancers co-occurring with some MND/NDD cases. Targeted research is recommended to investigate this proposal.

Population-based risks for cancer in patients with ALS

OBJECTIVE

To estimate the risks for cancer (overall and site-specific) in an amyotrophic lateral sclerosis (ALS) cohort.

METHODS

In this observational longitudinal study, ALS and cancer cases were identified in a computerized Utah genealogy database (Utah Population Database) linked to a statewide cancer registry and death certificates. Hazard ratios (HRs) were estimated as the ratio of observed to expected number of cancers. Site-specific rates for cancer were estimated within the Utah Population Database; sex, birth year (5-year range), and birth state (Utah or not) cohorts were used to estimate the expected number of cancers among ALS cases. To account for an overall shortened lifespan, Cox regression was used to include years at risk in estimation of cancer risks for ALS cases.

RESULTS

An overall decreased hazard (hazard ratio [HR] 0.80, p = 0.014, 95% confidence interval [CI] 0.66-0.96) was found for cancer of any site in 1,081 deceased patients with ALS. A decreased hazard was found for lung cancer (HR 0.23, p = 0.002, CI 0.05-0.63). An increased hazard was found for salivary (HR 5.27, p = 0.041, 95% CI 1.09-15.40) and testicular (HR 3.82, p = 0.042, 95% CI 1.06-9.62) cancers. A nonsignificant hazard was observed for cutaneous malignant melanoma (HR 1.62, p = 0.12, 95% CI 0.88-2.71) for which increased risk has previously been reported.

CONCLUSIONS

Using a unique population database, the overall risk of cancer of any site was found to be significantly reduced in cases with ALS, as was the risk of lung cancer. Significantly increased risk was observed for salivary and testicular cancers.

Brca1 is expressed in human microglia and is dysregulated in human and animal model of ALS

Background

There is growing evidence that microglia are key players in the pathological process of amyotrophic lateral sclerosis (ALS). It is suggested that microglia have a dual role in motoneurone degeneration through the release of both neuroprotective and neurotoxic factors.

Results

To identify candidate genes that may be involved in ALS pathology we have analysed at early symptomatic age (P90), the molecular signature of microglia from the lumbar region of the spinal cord of hSOD1^G93A mice, the most widely used animal model of ALS. We first identified unique hSOD1^G93A microglia transcriptomic profile that, in addition to more classical processes such as chemotaxis and immune response, pointed toward the potential involvement of the tumour suppressor gene breast cancer susceptibility gene 1 (Brca1). Secondly, comparison with our previous data on hSOD1^G93A motoneurone gene profile substantiated the putative contribution of Brca1 in ALS. Finally, we established that Brca1 protein is specifically expressed in human spinal microglia and is up-regulated in ALS patients.

Conclusions

Overall, our data provide new insights into the pathogenic concept of a non-cell-autonomous disease and the involvement of microglia in ALS. Importantly, the identification of Brca1 as a novel microglial marker and as possible contributor in both human and animal model of ALS may represent a valid therapeutic target. Moreover, our data points toward novel research strategies such as investigating the role of oncogenic proteins in neurodegenerative diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13024-015-0023-x) contains supplementary material, which is available to authorized users.

Risk factors for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. It is typically fatal within 2-5 years of symptom onset. The incidence of ALS is largely uniform across most parts of the world, but an increasing ALS incidence during the last decades has been suggested. Although recent genetic studies have substantially improved our understanding of the causes of ALS, especially familial ALS, an important role of non-genetic factors in ALS is recognized and needs further study. In this review, we briefly discuss several major genetic contributors to ALS identified to date, followed by a more focused discussion on the most commonly examined non-genetic risk factors for ALS. We first review factors related to lifestyle choices, including smoking, intake of antioxidants, physical fitness, body mass index, and physical exercise, followed by factors related to occupational and environmental exposures, including electromagnetic fields, metals, pesticides, β-methylamino-L-alanine, and viral infection. Potential links between ALS and other medical conditions, including head trauma, metabolic diseases, cancer, and inflammatory diseases, are also discussed. Finally, we outline several future directions aiming to more efficiently examine the role of non-genetic risk factors in ALS.

Motor neuron disease with selective degeneration of anterior horn cells associated with non-Hodgkin lymphoma

INTRODUCTION

We describe an autopsy-confirmed case of motor neuron disease with selective degeneration of the anterior horn cells associated with a non-Hodgkin lymphoma.

METHODS

Case report, including extensive autopsy studies.

RESULTS

The patient developed severe fasciculations and then progressive atrophy and weakness several months after the diagnosis and initial treatment of non-Hodgkin lymphoma. As the disease progressed, needle electromyography showed diffuse severe denervation changes including thoracic paraspinal muscles. Autopsy showed severe loss of anterior horn cells with associated gliosis and preservation of cortical spinal tracts and Betz cells.

CONCLUSIONS

This case provides an autopsy evidence of severe anterior horn cell degeneration in the course of non-Hodgkin lymphoma, raising the possibility that the neurologic syndrome, characterized by lower motor neuron disease, may represent a paraneoplastic process. Similar cases have been reported previously.

Is the risk of motor neuron disease increased or decreased after cancer? An Australian case-control study

Cancer appears to be inversely associated with both Alzheimer's and Parkinson's disease. The relationship between cancer and sporadic motor neuron disease (SMND), however, remains uncertain. Most previous cancer-SMND studies have been undertaken in northern hemisphere populations. We therefore undertook a case-control study to see if a link between cancer and SMND exists in an Australian population. A questionnaire was used to compare past cancer diagnoses in 739 SMND patients and 622 controls, recruited across Australia. Odds ratios with 95% confidence intervals were calculated to look for associations between cancer and SMND. A history of cancer was not associated either positively or negatively with a risk of subsequent SMND. This result remained when age, gender, smoking status, and the four SMND diagnostic subgroups were taken into account. No association was observed between SMND and specific tumours, including melanoma, a common malignancy in Australia. In conclusion, this Australian case-control study does not support an association between a past history of cancer and the development of SMND. This suggests that some pathogenetic mechanisms, such as apoptosis, are less relevant in SMND than in other neurodegenerative diseases where negative associations with cancer have been found.

Amyotrophic lateral sclerosis and cancer: a register-based study in Sweden

Comorbidity of cancer with ALS has been studied previously. Detailed description of the temporal relationship between cancer and ALS is, however, lacking. We conducted a nested case-control study of ALS in Sweden during 1987-2009, including 5481 cases of ALS identified from the Swedish Patient Register and 27,405 controls randomly selected from the general Swedish population. Odds ratios (ORs) for association of ALS with previous cancer diagnosis and incidence rate ratios (IRRs) of cancer after diagnosis were calculated to compare ALS patients with ALS-free individuals. Overall, a previous cancer diagnosis was not associated with subsequent risk of ALS (OR 1.00; 95% CI 0.91-1.10). No overall association was observed for any specific cancer type. An increased risk of ALS was observed during the first year after cancer diagnosis (OR 1.50; 95% CI 1.17-1.92). In contrast, a lower risk of cancer was observed in ALS patients after diagnosis compared with ALS-free individuals (IRR 0.84; 95% CI 0.69-1.02). The risk reduction was seen primarily two or more years after ALS diagnosis (IRR 0.64; 95% CI 0.45-0.88). Our results provide no evidence for comorbidity of cancer and ALS overall. Surveillance biases seem the most likely explanation for the limited associations detected.

Cancer and neurodegeneration: between the devil and the deep blue sea

Cancer and neurodegeneration are often thought of as disease mechanisms at opposite ends of a spectrum; one due to enhanced resistance to cell death and the other due to premature cell death. There is now accumulating evidence to link these two disparate processes. An increasing number of genetic studies add weight to epidemiological evidence suggesting that sufferers of a neurodegenerative disorder have a reduced incidence for most cancers, but an increased risk for other cancers. Many of the genes associated with either cancer and/or neurodegeneration play a central role in cell cycle control, DNA repair, and kinase signalling. However, the links between these two families of diseases remain to be proven. In this review, we discuss recent and sometimes as yet incomplete genetic discoveries that highlight the overlap of molecular pathways implicated in cancer and neurodegeneration.

Breast cancer and motor neuron disease: clinical study of seven cases

We report seven women, aged 52-78 years, with motor neuron disease (MND) associated with breast cancer. In five, cancer preceded MND by 30 years to 24 months, while in the remaining two it occurred from 8.5 years to one month after MND onset. Three patients were considered cured of their cancer at the time of the study. Four patients have died, one from associated colonic cancer, and three from MND. As in a previous report, the clinical pattern of MND in these patients was that of predominant upper motor neuron involvement in 6/7 cases. Three had frontotemporal dementia. No anti-neuronal antibodies were found. Although there is no recognized pathophysiological link between breast cancer and UMN-predominant MND we suggest there may be comorbidity between the two diseases.

Absence of paraneoplastic antineuronal antibodies in sera of 145 patients with motor neuron disease

BACKGROUND

Well characterised antineuronal antibodies (ANAbs) have been shown to be highly specific markers of neurological syndromes with a paraneoplastic aetiology. Previous reports indicate that pure motor neuron disease (MND) is rarely of paraneoplastic origin.

OBJECTIVE

To screen systematically for the prevalence of well characterised paraneoplastic ANAbs in a large collective of patients with pure MND.

METHODS

In a cohort of 145 patients with MND, the frequency of ANAbs was estimated by ELISA, employing recombinant antigens (HuD, Yo, Ri, CV2/CRMP5, Ma2 and amphiphysin).

RESULTS

None of the sera revealed high antineuronal antigen reactivity. Very low reactivity was detected in only five sera, in all probability representing background activity.

CONCLUSION

According to these data, routine analysis for ANAbs in patients with isolated MND is not mandatory.

Paraneoplastic syndromes affecting the nervous system

The paraneoplastic neurologic disorders (PND) are a diverse group of diseases characterized by the presence of neurologic dysfunction in the setting of a remote cancer. PND can affect almost any part of the nervous system, and are most commonly associated with lung cancer (small cell) and gynecologic tumors. Laboratory studies have demonstrated that an autoimmune response links the neurologic disorder and the cancer, and established a model whereby the cancer is believed to initiate the syndrome by expressing a protein antigen normally expressed in the nervous system, leading to anti-tumor immune response followed by autoimmune neurologic symptoms. We review the currently known PND and their pathogenesis.

The neuropathology of paraneoplastic syndromes

The term "paraneoplastic neurological syndromes" encompasses a number of uncommon disorders associated with systemic malignancies. In order to be classified a paraneoplastic neurological syndrome, the malignancies must not invade, compress, or metastasize to the nervous system. They can either focally or diffusely involve the central and peripheral nervous system or the neuromuscular junction. This paper reviews the neuropathology of the syndrome. It will first describe the clinical presentation and give an account of the systemic tumors most commonly associated with the various types of disorders. Then it will review the general pathological features that consist of an inflammatory process predominantly affecting the gray matter. Finally, it will describe in detail the main clinico-pathological types, including 1) encephalomyelitis, 2) cortical cerebellar degeneration, 3) peripheral neuropathy, 4) opsoclonus-myoclonus and 5) retinopathy. The Lambert-Eaton myasthenic syndrome will be dealt with separately in another paper in this symposium.

A case of amyotrophic lateral sclerosis and breast cancer

We report a case of breast cancer occurring in a patient with amyotrophic lateral sclerosis (ALS). A 58-year-old Japanese woman diagnosed with ALS 6 years previously noticed a mass in the left breast. We performed a modified radical mastectomy for the mass lesion. Invasive ductal carcinoma without lymph node metastasis was diagnosed. During the operation, she had no worsening of her neurological symptoms. The patient has been cancer-free for 11 months since her operation and no improvement has been seen in her neurological condition. To the best of our knowledge, this is the first case of breast cancer occurring in a patient with ALS in Japan.

Paraneoplastic syndromes of the spinal cord, nerve, and muscle

Cancer can affect the peripheral nervous system by non-metastatic, sometimes immune-mediated mechanisms. Recognition of these paraneoplastic syndromes is important because it can lead to the detection of the tumor, and also helps to avoid unnecessary studies to determine the cause of the neurologic symptoms in patients with cancer. Many paraneoplastic syndromes of the peripheral nervous system are not associated with serum antibodies that serve as markers of paraneoplasia. For this group of disorders the diagnosis depends on the clinician's index of suspicion and conventional electrophysiologic and laboratory tests. Treatment of the tumor, immunotherapy, or both may improve some of these syndromes. This review focuses on paraneoplastic syndromes of the spinal cord, peripheral nerve, and muscle.

Lower motor neuron disease associated with myelofibrosis

We present a patient who has signs pointing to the involvement of lower motor neurons and myelofibrosis. To our knowledge, unlike lymphoproliferative disorders, co-occurrence of myelofibrosis and lower motor neuron disease (MND) has not been reported so far. A 64-year-old male patient was admitted to our hospital with the complaint of painful cramps in his neck and forearms. On physical examination marked hepatomegaly and splenomegaly were found. On neurologic examination nasal quality of the voice and slight palatal weakness were detected. There were generalised slight weakness and atrophy in both proximal and distal muscle groups. Fasciculations were observed especially in forearm muscles and it was observed that he had been avoiding head movements because of painful muscle cramps. Deep tendon reflexes were hypoactive. Nerve conduction studies were normal. By needle electromyography, giant motor unit action potentials (amplitudes up to 8 mV), fibrillation potentials, positive sharp waves and fasciculation potentials were detected in all muscles which were investigated. A hypercellular bone marrow (100%) was determined by bone marrow biopsy. In addition to increased production of the myeloid and megakaryocytic lines, abnormal aggregation and grouping of megakaryocytes were seen. Reticular fibers were increased. He had some benefit of dyphenilhydantoin treatment given for the painful cramps in his neck and forearm muscles. Hydroxyurea treatment was started for myelofibrosis. Six months later, his general condition was better, and the painful cramps were completely resolved. No marked deterioration has been detected in neurologic examination and electromyography for 1 year.

Multifocal polyradiculoneuropathy and carcinoma of the thymus

We studied a patient with polyradiculoneuropathy with anaplastic carcinoma of the thymus. Motor manifestations dominated. Postmortem examinations indicated that the primary changes were in the spinal nerve roots, peripheral nerves and, possibly, the spinal anterior horn cells. The posterior funiculi and posterior root ganglia were also affected, implying multifocal and multiphasic degeneration. This unusual polyradiculoneuropathy is a form of carcinomatous neuropathy.

A review of the therapy of paraneoplastic neurologic syndromes

The therapy of paraneoplastic neurologic syndromes remains unclear and warrants a systematic review of the literature. Reports in English and foreign language literature were abstracted. Data were sorted by the primary paraneoplastic neurologic syndrome, the primary malignancy, and the methods of treatment. Neurologic improvement follows surgical, chemotherapeutic, and radiation treatments. Adjuvant immunosuppressive therapy with steroids, plasmapheresis, or immunoglobulin may help stabilize the progression of neurologic symptoms. Syndromes characterized by inflammation or neurotransmitter production without neuronal loss are most responsive to therapy. While treatment of the underlying cancer with appropriate surgery, chemotherapy, and radiation is recommended, the paraneoplastic syndrome should probably be managed with immunosuppressive therapy.

Diagnosis of amyotrophic lateral sclerosis

This review of the differential diagnosis of amyotrophic lateral sclerosis focuses on two themes. The first is practical, how to establish the diagnosis based primarily on clinical findings buttressed by electrodiagnosis. The main considerations are multifocal motor neuropathy and cervical spondylotic myelopathy. The second theme is the relationship of motor neuron disease to other conditions, including benign fasciculation (Denny-Brown, Foley syndrome), paraneoplastic syndromes, lymphoproliferative disease, radiation damage, monomelic amyotrophy (Hirayama syndrome), as well as an association with parkinsonism, dementia and multisystem disorders of the central nervous system.

Acquired motor neuron disorders

The acquired motor neuron disorders are a heterogeneous group of conditions in which motor neuron degeneration or dysfunction produces the predominant manifestation of weakness, while the sensory system is clinically spared. The disorders most commonly seen in clinical practice are amyotrophic lateral sclerosis, late manifestations of poliomyelitis, and lower motor neuron syndromes, including motor neuropathy. Less often, acquired motor neuron disorders may complicate metabolic, toxic, or systemic disorders. The pathogenesis of most acquired motor neuron disorders is poorly understood, and treatment is mainly supportive; however clues to understanding the pathogenesis of amyotrophic lateral sclerosis are emerging, and new pharmacologic therapies are available. There is a growing sense of hope that combinations of drugs that are currently being tested may impact the survival of amyotrophic lateral sclerosis.

Motor neuron syndromes in cancer patients

Previous reports indicate that motor neuron disease (MND) may rarely be associated with systemic cancer. We have encountered 14 patients with MND and cancer who formed three distinct groups. Group 1: Three patients developed a rapidly progressive MND, less prominent symptoms of involvement of other areas of the nervous system, and anti-Hu antibodies. Group 2: Five women developed signs of upper motor neuron (UMN) disease, initially resembling primary lateral sclerosis (PLS), and breast cancer. In 4, symptoms of UMN occurred within 3 months of cancer diagnosis or tumor recurrence. They had no metastases or spinal cord compression. Serum anti-neuronal antibodies were negative. Three patients are alive (follow-up of 156, 15, and 12 months), and 2 remain without lower motor neuron signs. Group 3: Six patients developed MND resembling amyotrophic lateral sclerosis between 47 months before and 48 months after their cancer diagnosis. In group 1, the MND associated with the anti-Hu antibody is unequivocally paraneoplastic. In group 2, the proximate onset of MND with the diagnosis of cancer or its recurrence, its pure or long-lasting UMN signs, and its association with breast cancer, suggest that the disorder may be paraneoplastic. Although for most cancer patients who develop MND the occurrence of both disorders is probably coincidental, in some patients with MND a careful search for an underlying cancer is warranted (ie, patients in groups 1 and 2).

Motor neuron disease: a paraneoplastic process associated with anti-hu antibody and small-cell lung carcinoma

Although isolated lower motor neuron disease has been reported as a paraneoplastic complication, it has not been previously described, in association with anti-Hu antibody. We report a 51-year-old man in whom weakness heralded the presence of a small-cell cancer of the lung. His neurological disorder was characterized by an unremitting progression of limb, neck, and chest wall weakness and wasting that commenced and remained predominant in the upper limbs. Electrophysiological studies demonstrated widespread denervation and examination of a muscle biopsy specimen showed evidence of acute and chronic denervation. High titers of anti-Hu antibody were detected in the serum and cerebrospinal fluid. Neither objective measures of strength nor titers of anti-Hu antibody responded to corticosteroids, cyclophosphamide, intravenous immunoglobulins, or plasmapheresis. Death from the complications of motor neuron disease ensued 23 months after the onset of weakness. Autopsy revealed tumor in the lung and on pleural and peritoneal surfaces. There was a loss of anterior horn cells in the spinal cord. Despite the absence of symptomatic cerebellar disease, a decrease in the number of Purkinje cells was also detected.

Lower motor neuron degeneration and familial predisposition to colonic neoplasia in two adult siblings

A previously unreported association between a familial predisposition to colonic neoplasia and familial adult onset lower motor neuron (LMN) degeneration is reported. Two brothers presented at the ages of 53 and 44 years with multiple colonic adenomata and invasive colonic carcinoma respectively. Subsequently both developed a virtually identical pattern of motor neuron disease of progressive muscular atrophy type. At presentation both had LMN weakness affecting predominantly the upper limb and neck muscles. The disease progressed rapidly to involve the lower limb and bulbar musculature and both brothers died after a 15 month course. Necropsy was performed on one brother and showed pathological changes confined to the LMNs with no evidence of involvement of the pyramidal tracts or motor cortex. The combination of these diseases in two brothers may be of importance in the search for genes responsible for familial motor neuron disorders. It is suggested that a genomic search should be directed initially to the vicinity of known colon neoplasia genes, particularly 5q, 17q and 18q.

Lymphoma, motor neuron diseases, and amyotrophic lateral sclerosis

We studied 9 patients with motor neuron disease and lymphoma. The following several observations have not been recognized in the past: (1) Motor neuron syndromes are associated with either Hodgkin's disease or non-Hodgkin's lymphoma. (2) The syndromes are not restricted to lower motor neuron disorders; 8 of 9 patients had definite or probable upper motor neuron signs as well, qualifying for the diagnosis of amyotrophic lateral sclerosis. Corticospinal tracts were affected in both postmortem examinations. (3) The combination of motor neuron disease and lymphoma is often accompanied by paraproteinemia (3 of 7 patients studied), increased cerebrospinal fluid protein content (6 of 9 patients), and cerebrospinal fluid oligoclonal bands (3 of 9 patients). (4) In 2 patients, asymptomatic non-Hodgkin's lymphoma was found only because the discovery of paraproteinemia gave impetus to examine the bone marrow. (5) Patients with both upper and lower motor neuron signs (amyotrophic lateral sclerosis) may show physiological evidence of conduction block in peripheral nerves or autopsy abnormalities in peripheral nerves. The cause of this syndrome is not known. Both lymphoma and motor neuron disease could have a common cause, possibly a retroviral infection. The frequency of paraproteinemia suggests that an immunological disorder may play a role in the pathogenesis of the neurological disorder.

Motor neuron disease (amyotrophic lateral sclerosis)

Amyotrophic lateral sclerosis is an insidiously developing, adult-onset, progressive anterior horn cell degeneration with associated degeneration of descending motor pathways. It has been recognized as an important clinical syndrome since the middle of the 19th century. Despite increasing clinical and research interest in this condition, its cause remains obscure, even in the broadest terms. Epidemiologic characteristics of the disease have been interpreted as evidence of both genetic and environmental causes. A major change in the view of this disease is the widely developing perception that it is a disease of elderly persons more than of middle-aged adults as was previously taught. Etiologic hypotheses encompass a broad range of postulated pathophysiologic mechanisms, and we review these in detail. The clinical limits of the disease can now be better defined by using modern diagnostic techniques. Although interest in supportive symptomatic therapy is growing, no intervention has yet been shown to modify the biologically determined motor system degeneration.

Motor neuron disease and malignancies: results of a population-based study

Eight cases of malignancies with concurrent motor neuron disease (MND), derived from an unselected population representing all cases of MND diagnosed during a 15-year period in two Italian provinces, were studied to verify the existence of paraneoplastic forms of the disease. No statistically significant association between the two diseases was found. Therefore, from our findings the occurrence of a neoplasm in a patient affected by MND can be considered a chance association.

Peripheral neuropathy with predominantly motor manifestations in a patient with carcinoma of the uterus

An autopsy case of a 56-year-old woman who had carcinoma of the corpus uteri and peripheral neuropathy with predominantly motor manifestations is described. The neurological abnormalities included subacute weakness of the limbs and loss of deep reflexes, which improved after the surgical removal of the uterine carcinoma. Neuropathologically, peripheral nerves mainly presented features of axonal degeneration with a mild loss of myelinated fibres. Anterior horns of the spinal cord showed central chromatolysis of the motor nerve cells and many spheroids without neuronal loss. Axonopathy of peripheral nerves was considered to be the main pathological process in this paraneoplastic syndrome.

Amyotrophic lateral sclerosis: Part 2. Etiopathogenesis

The pathogenesis of the motor neuronal degeneration in amyotrophic lateral sclerosis (ALS) is unclear, though several possible etiological factors are currently being investigated. A unifying hypothesis will have to explain the diverse geographical occurrence, clinical features, and selective vulnerability and relative resistance of different neuronal populations in the disease. It is possible that different biochemical defects underlie this diversity, or alternatively that the many factors incriminated in the etiology may act upon an underlying genetic-biochemical abnormality to trigger premature neuronal death. Viruses, metals, endogenous toxins, immune dysfunction, endocrine abnormalities, impaired DNA repair, altered axonal transport, and trauma have all been etiologically linked with ALS, but convincing research evidence of a causative role for any of these factors is yet to be demonstrated.

Epidemiology of motor neuron disease in northern Sweden

All cases of motor neuron disease (MND), encompassing amyotrophic lateral sclerosis (ALS), progressive bulbar paralysis (PBP) and progressive spinal muscular atrophy (PSMA), in northern Sweden, diagnosed between 1969-1980 have been analysed. 128 cases were found, corresponding to an average annual incidence rate of 1.67 per 100,000. The prevalence on December 31, 1980 was 4.8 per 100,000. Age-specific incidence rates were higher in the high age groups with a maximum at 60-64 years for males, at 70-74 years for females and at 65-69 years for the sexes combined. The median age at onset was 61 years. Clustering was not found in mining districts and overrepresentation of miners and stone treaters was not observed. Minor differences in incidence rates, as measured by the standardized morbidity ratio, SMR, were found between the inland, coastal and mountain areas. The median survival time after onset of disease was 32 months for ALS, 30 months for PBP and 70 months for PSMA. The combined survival rate for all MND cases was 28% after 5 years and 15% after 10 years. The male to female ratio was 1.1:1, and 4.7% were familial cases.

Lower motor neuron syndrome following radiotherapy

A 33 year old man developed bilateral leg weakness two years following radiotherapy to the pelvis and lower abdomen for the treatment of a seminoma. Clinical and electrophysiological examinations and nerve and muscle biopsies suggest that this is an example of either post-irradiation myelopathy selectively affecting the anterior horn cells in the lower spinal cord or a purely motor lumbo-sacral radiculopathy.

Remission of the Lambert-Eaton syndrome and small cell anaplastic carcinoma of the lung induced by chemotherapy and radiotherapy

A patient presented with the Lambert-Eaton syndrome and small cell anaplastic carcinoma of the lung was subsequently diagnosed. Treatment with cytotoxic chemotherapy and radiotherapy resulted in remission of both the cancer and the neuromuscular disorder. This case represents the first documented remission of the Lambert-Eaton syndrome following nonoperative treatment of the primary malignancy and emphasizes the therapeutic value of early diagnosis of this disorder.

Amyotrophic lateral sclerosis: a study of systemic complications in autopsy cases in Japan

In a retrospective study involving 277 autopsy cases of amyotrophic lateral sclerosis (ALS) which had been published in the Annual of the Pathological Autopsy Cases in Japan, an investigation was made of concurrent visceral lesions. The results indicated that complications involving the digestive organs, urinary tract and supportive connective tissues were less frequent in ALS than in patients with degenerative diseases of the central nervous system who served as controls. Since a similar discrepancy was observed between patients with ALS and with encephalitis, it was postulated that the difference in incidences might not be simply explained by differences in patients' ages and the duration of illness.

Motor neurone disease with elevated cerebrospinal fluid protein

The correlation between age and CSF protein in 38 patients with pathologically proven motor neurone disease was the reverse of that described for normal subjects by Tibbling et al in 1977. Eight had CSF protein ranging from 0.75 g/1 to 1.52 g/L. These patients were younger, but other clinical and gross and light microscopy pathological features were not significantly different from those with lower CSF protein. Transudation from serum may be only one of the mechanisms underlying this elevation in CSF protein.

Identification of lactate dehydrogenase-elevating virus as the etiological agent of genetically restricted, age-dependent polioencephalomyelitis of mice

The etiological agent of genetically restricted, age-dependent polioencephalomyelitis of mice (the ADPE agent) and several isolates of lactate dehydrogenase-elevating virus (LDV) were compared by biological, physical-chemical and antigenic criteria. The data indicate that the ADPE agent is a strain of LDV. Like LDV, the ADPE agent induced a selective elevation of plasma enzymes and splenomegaly in mice. The enzyme-elevating activity and the paralytogenic activity of the ADPE agent preparations were shown to belong to the same virus. The ADPE agent demonstrated LDV-like replication kinetics in vivo and in vitro. Moreover, the ADPE agent required primary mouse macrophages for in vitro replication, as does LDV. In turn, the LDV isolates induced a paralytic disease with ADPE-like lesions in the spinal cords of immunosuppressed C58 mice. However, the LDV isolates showed a stronger dependence on strain and age of mouse for the induction of paralysis than did the ADPE agent. The LDV isolates and the ADPE agent exhibited indistinguishable morphologies, buoyant densities, structural protein patterns, and virion ribonucleic acid sedimentation rates. Furthermore, they displayed strong antigenic cross-reactivity, as determined by cross-protection in vivo and by radioimmunoassay.

Subacute motor neuronopathy: a remote effect of lymphoma

Ten patients developed a subacute lower motor neuron syndrome as a remote effect of Hodgkin's disease or other lymphoma. The illness usually followed a benign course independent of the activity of the underlying neoplasm. Seven of the patients improved spontaneously, and 3 became neurologically normal. Two patients died of intercurrent infections related to immunosuppression. Neuropathological examination of these 2 patients and 3 previously reported cases showed prominent neuronal degeneration restricted to the anterior horns of the spinal cord and mild posterior column demyelination. Demyelination was also present in the anterior roots of our autopsied patients and was accompanied by large, hyperchromatic Schwann cells. The cause of the illness is obscure, but both radiation therapy and opportunistic infection may be contributing factors. Attempts at virus isolation have been unsuccessful. The syndrome should be distinguished from the more common direct effects of lymphoma on the nervous system, since its identification spares the patient additional, potentially harmful therapy.

Weakness in malignancy: evidence for a remote effect of tumor on distal axons

Malignant tumors are known to have a "remote" or nonmetastatic effect on the central and peripheral nervous systems. Eight patients were seen with proximal muscle weakness in association with bronchogenic carcinoma (5), carcinoma of breast (2), and leukemia (1). Electromyography demonstrated small polyphasic motor unit potentials. Muscle biopsy, however, showed evidence of denervation. Electron microscopy revealed morphological abnormalities in the intramuscular segments of axons. This combination of EMG and biopsy findings is presented as evidence for a remote effect of tumor on the intramuscular distal axons.

Subclinical myopathic findings in patients affected by malignant tumours. An autopsy study

Histoenzymologic studies on representative muscles and the peripheral microcirculation from selected autopsies of non cachectic patients dying of neoplasms, without signs of neuromuscular involvement, demonstrate a high incidence of neuromuscular and microcirculatory changes. A correlation between neuromuscular changes and the peripheral microcirculation particularly evident in myopathic cases is discussed.