Neuromuscular Complications of Systemic Cancer

Dermatomyositis: A Cancer Red Flag

Dermatomyositis is an inflammatory disease that affects muscle strength and causes skin manifestations. There is an increased incidence of cancer in patients with this diagnosis although the pathophysiology of this association is still not completely understood. We report a case of a 65-year-old man who presented to the emergency department with proximal muscle weakness, weight loss, dysphagia, enlarged supraclavicular lymph nodes, an erythematous rash in the malar and supraciliary regions, and papules in the extensor metacarpophalangeal and interphalangeal joints. He had elevated creatine kinase and positive anti-nuclear matrix protein-2 autoantibodies. The skin and muscle biopsies performed confirmed the diagnosis of dermatomyositis. A thorough investigation seeking an associated condition was conducted and a prostate adenocarcinoma was diagnosed. The patient was treated with glucocorticoids and intravenous immune globulin with dysphagia and muscle weakness improvement and therefore allowing hospital discharge. He is currently undergoing oncologic treatment. Myositis-specific antibodies have proved to be extremely useful in the diagnosis, prognosis, and management of patients with dermatomyositis. Various phenotypes of the disease can associate differently with a systemic condition (namely a malignant disease). This case illustrates a rare form of cancer presentation that every clinician, especially those who work in the emergency room or in primary care and therefore have immediate contact with many patients, must be able to recognize.

Management of metastatic tumors invading the peripheral nervous system

Object

The authors present the results of a retrospective review of 37 surgically treated metastases to nerve (malignant peripheral non–neural sheath nerve tumors). Tumor frequencies, presentations, management, and prognosis are discussed.

Methods

Thirty-seven patients who were treated for metastases to nerve between 1969 and 2006 at the Louisiana State University Health Sciences Center were identified in a review of patient records. Notes regarding patient history and physical examination findings were reviewed to provide information on presenting symptoms and signs. Imaging and histopathological examination results were also reviewed. Cases were analyzed depending on the primary tumor and the location of metastasis.

Results

There included 37 surgically treated lesions, 16 of which originated in the breast and 10 of which originated in the lung. In two cases melanomas had metastasized to nerve, and one tumor each had metastasized from the bladder, rectum, skin, head and neck, and thyroid, and from a primary Ewing sarcoma. There was a single lymphoma that had metastasized to the radial nerve and one chordoma and one osteosarcoma, each of which had metastasized to the brachial plexus.

Conclusions

The nervous system is involved in numerous ways by oncological process. Direct involvement of the peripheral nervous system occurs mostly from direct extension, although it occasionally occurs because of distant spread from the primary tumor to nerve. Surgical excision of the metastatic lesion with margins has been useful mostly in the control of pain. Nevertheless, patients eventually succumb to their primary malignancy.

Long-term medical effects of childhood and adolescent rhabdomyosarcoma: a report from the childhood cancer survivor study

BACKGROUND

This study was conducted to evaluate the incidence of adverse medical conditions and to assess the risk of developing these conditions in a cohort of long-term survivors of rhabdomyosarcoma (RMS) diagnosed before age 21.

PROCEDURE

Using data from the Childhood Cancer Survivor Study (CCSS), we evaluated the incidence of self-reported adverse medical conditions for 606 RMS survivors and 3,701 siblings of cancer survivors. Cancer and treatment data abstracted from medical records were used to evaluate the effects of primary tumor site and combined modality therapy on the risk of developing sequelae in survivors.

RESULTS

The relative risk (RR) for developing sequelae among survivors compared with siblings was greatest within 5 years after diagnosis. RR was elevated more than 5 years after diagnosis for several conditions (RR, 95% CI) as follows: eye impairment (cataract: 7.4, 2.9-18.9; visual disturbances: 3.2, 2.0-5.1; very dry eyes: 2.0, 1.2-3.3), endocrine impairment (growth hormone deficiency: 83.9, 33.0-213.6; hypothyroidism: 6.9, 4.1-11.3; need for medications to induce puberty: 90.4, 30.2-270.5), cardiopulmonary impairment (congestive heart failure: 43.0, 12.7-145.5; angina-like symptoms: 2.0, 1.3-2.9), neurosensory impairment (legal blindness: 9.8, 4.8-20.0; abnormal sensations: 1.5, 1.0-2.2), and neuromotor impairment (repeated seizures: 2.3, 1.2-4.4; motor problems: 3.7, 2.2-6.4; problems chewing or swallowing: 3.8, 1.9-7.5).

CONCLUSIONS

Survivors are at risk for developing sequelae many years after their initial diagnosis and treatment. Continued medical surveillance is necessary to ensure the long-term health and well-being of RMS survivors.

Leptomeningeal metastases

LM is an increasingly common neurologic complication of cancer with variable clinical manifestations. Although there are no curative treatments, currently available therapies can preserve neurologic function and potentially improve quality of life. Further research into the mechanisms of leptomeningeal metastasis will elucidate molecular and cellular pathways that may allow identification of potential targets to interrupt this process early or to prevent this complication. Animal models are needed to further define the pathophysiology of LM and to provide an experimental system to test novel treatments [242-245]. There is an urgent need to develop new drug-based or radiation-based treatments for patients with LM. Randomized clinical trials are the appropriate study design to determine the efficacy of new treatments for LM. However, surrogate markers for response must be developed to facilitate the identification of effective regimens. Survival is not the optimal end point for such studies as most patients who develop this complication already have advanced, incurable cancer. Prevention of or delay in neurologic progression is one objective that has been utilized in recent randomized trials in patients with LM, and this end point deserves further attention. Although the development of LM represents a poor prognostic marker in patients with cancer it is important for physicians to recognize the symptoms and signs of the disease and establish the diagnosis as early in the disease course as possible. This may provide an opportunity for effective intervention that can improve quality of life, prevent further neurologic deterioration and, for a subset of patients, improve survival.

Lambert-eaton myasthenic syndrome: a case report and review of the literature

Lambert-Eaton myasthenic syndrome (LEMS) is a type of paraneoplastic syndrome that may initially manifest with weakness and gait abnormalities. These symptoms may precede the diagnosis of malignancy by months or years, and morbidity and mortality may be significantly affected by early detection of the malignancy. A case report and review of the diagnosis, management, and treatment of these syndromes are presented, with particular emphasis on the rehabilitation management of these patients, often overlooked in medical treatment.

Delayed radiation-induced bulbar palsy mimicking ALS

We describe a patient presenting with progressive bulbar dysfunction and spasticity that clinically mimicked amyotrophic lateral sclerosis (ALS). Electromyography, however, showed no evidence of denervation and revealed a rare combination of peripheral and central myokymia. We feel that this pattern of myokymia represented a marker of neural injury from remote radiation therapy. Nervous system disorders resulting from therapeutic radiation are described, and potential pathophysiologic mechanisms underlying myokymia are discussed.

Camptocormia: a case of possible paraneoplastic aetiology

We present a patient with gradual development of camptocormia, three years before a non-Hodgkin's lymphoma was diagnosed. Lymphomas are known to produce neuromuscular symptoms through several indirect mechanisms. Recent studies regard camptocormia as a primary disease of the paravertebral muscles. To our knowledge this is the first report associating camptocormia with malignancy. The possibility of a paraneoplastic syndrome is discussed.

Paraneoplastic neuromuscular syndromes

Although paraneoplastic syndromes are rare, a number of well- defined, neuromuscular paraneoplastic syndromes have been described and their pathophysiology listed. Many different malignancies have been associated with these syndromes, but small-cell lung cancer is the most common. Features shared by these conditions include onset of the underlying malignancy, rapid progression, severe disability, and the potential for some improvement, owing to treatment of the cancer. This article discusses Lambert-Eaton myasthenic syndrome, motor neuron disorders, peripheral neuropathies, and disorders of continuous muscle fiber activity, such as Stiffman syndrome.

Neuropathic pain in cancer patients: mechanisms, syndromes, and clinical controversies

The identification of a neuropathic pain syndrome in a cancer patient requires a focused clinical evaluation based on knowledge of common neuropathic pain syndromes. If a tumor is directly involved in the etiology of the pain, oncologic treatment is an initial consideration and may include surgery, radiation, or chemotherapy. There is no single accepted algorithm for the analgesic treatment of neuropathic pain and a systematic approach utilizing therapeutic trials of specific agents at gradually increasing doses is warranted. A trial of opioids, perhaps in combination with an NSAID, is warranted. If the pain is relatively unresponsive to an opioid, a trial with an adjuvant analgesic is reasonable. For example, a tricyclic antidepressant might be selected early for patients with continuous dysesthesia, and early treatment with an anticonvulsant might be used if the pain is predominantly lancinating or paroxysmal. Other adjuvant analgesics can be selected if there is insufficient response to these agents. A trial of sympathetic blockade, pharmacologic, anesthetic or surgical, should be considered in patients with evidence of causalgia or reflex sympathetic dystrophy. Physiatric modalities such as massage, heat, or cold; counterstimulation or transcutaneous electrical nerve stimulation (TENS), and orthopedic interventions, such as braces and splints may be useful. Epidural injections or neurostimulation of the spinal cord or brain can be considered in selected cases where appropriate expertise is available. Treatment of neuropathic pain remains a challenge for both clinicians and patients. The complexity of syndromes and underlying etiologic mechanisms warrants further clinical trials to determine the best treatment modalities for individual pain syndromes.

Critical illness neuropathy: diagnosis and management

Critical illness neuropathy is a distinct form of polyneuropathy that develops as part of a syndrome often observed in critical care units consisting of septicemia with encephalopathy, respiratory failure with difficulty in weaning and an axonal degenerative polyneuropathy. Critical illness neuropathy (CIN) has been discussed in the recent neurological and critical care literature, but has not been discussed, to the best of our knowledge, in the rehabilitation literature. This article acquaints rehabilitation personnel with the methods used to diagnose CIN and differentiate it from other neuropathies and the impact that multidisciplinary rehabilitation may have on the outcome of this disorder. We found that with an appropriate history, and compatible physical findings, electrodiagnostic testing helped diagnose CIN and that intensive rehabilitation was advantageous in improving our patients conditions.

Neuromuscular disorders in systemic malignancy and its treatment

Neuromuscular dysfunction in patients with known or suspected malignancy has three basic etiologies: (1) a direct effect of the neoplasm, either by compression or infiltration; (2) a "remote," or paraneoplastic, effect of cancer; or (3) a side effect of anticancer treatment, radiation or chemotherapy. A variety of clinical features or syndromes are due to damage either at the level of the neuron (anterior horn cell or dorsal root ganglion neuron), nerve root(s), brachial or lumbosacral plexus, peripheral nerve (motor, sensory, and/or autonomic), neuromuscular junction, or muscle. A complex clinical picture evolves when dysfunction in due to more than one cause at more than one anatomical site.

Proximal muscle weakness in a patient with hepatocellular carcinoma

Asthenia and generalized weakness are common in cancer patients. There are multiple causes for these symptoms. We describe a case of rapid onset of proximal muscle weakness in a patient with hepatocellular carcinoma. The differential diagnosis of muscle weakness in the palliative care patient is reviewed. The discussion centers on steroid myopathy and its treatment.

Impaired muscle strength in female adolescents and young adults surviving leukemia in childhood

BACKGROUND

With the improving cure rate in childhood malignancies, increasing interest has been focused on long-term survivors. To evaluate late sequelae of childhood leukemia, the muscle strength of 43 young female survivors was investigated and compared with that of 69 healthy age-matched women. The patients had been off therapy for 1 to 19 years.

METHODS

The anthropometric characteristics measured were height and weight, and body mass index was calculated. The maximal isometric strengths for elbow flexion, knee extension, and hand grip were measured on a special dynamometer chair. Dynamic muscular endurance was measured by pushup and situp tests.

RESULTS

The mean height of the patients was 6.5 cm shorter (P < 0.001) and their mean weight 4.8 kg lighter (P = 0.011) than that of the reference subjects. Muscle strength was in most tests poorer in the patients than in the reference subjects. The differences were statistically significant in elbow flexion and knee extension, and in both muscular endurance tests. There was an association between the maximal isometric strengths and the anthropometric characteristics. Even when allowance was made for the smaller size of the patients, however, they still had less muscle strength than the reference subjects. Of the various treatment modalities, radiation therapy to the cranial area and chemotherapy with L-asparaginase were independently associated with the lower muscle strength values.

CONCLUSIONS

The muscle strength of female patients may be subnormal for many years after therapy for childhood leukemia. To compensate for these deficiencies, the possible benefits of prophylactic and individually planned exercise should be studied.