Neuromuscular disorders in systemic malignancy and its treatment

Abstract

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.

Pancreatic adenocarcinoma presenting as a monomelic motor neuronopathy

“…7 Our patient initially had electrodiagnostic and imaging studies implying an acute, right L5 radiculopathy due to degenerative disk disease and spinal stenosis, although she had no back or leg pain and numbness. She underwent surgical decompression with some improvement, suggesting that root compression contributed to at least part of the initial electrodiagnostic abnormalities.…”

“…3,6,7 A sensory neuronopathy has been described with pancreatic adenocarcinoma and a sensory neuronopathy and atypical MND have been reported with small cell carcinoma of the lung. 1,3,7 Paraneoplastic SMN may go into remission and improve with chemotherapy. 7 Our patient's neuropathy progressed along with the malignancy, despite chemotherapy.…”

“…1,3,7 Paraneoplastic SMN may go into remission and improve with chemotherapy. 7 Our patient's neuropathy progressed along with the malignancy, despite chemotherapy. The normal postmortem appearance of the spinal cord essentially ruled out ALS or neoplastic polyradiculopathy, since there was no evidence of anterior horn cell or motor neuron necrosis or leptomeningeal tumor invasion.…”

“…[5][6][7] We describe a novel case of a patient presenting initially as an apparent radiculopathy, later developing into a monomelic motor neuronopathy several months before the discovery of a large pancreatic adenocarcinoma. …”

“…7 Subacute motor neuronopathy (SMN) and atypical motor neuron disease (MND) have been reported infrequently as a remote complication of several malignancies, including lymphoma and small cell carcinoma of the lung. [5][6][7] We describe a novel case of a patient presenting initially as an apparent radiculopathy, later developing into a monomelic motor neuronopathy several months before the discovery of a large pancreatic adenocarcinoma.…”