Thalidomide-induced neuropathy: a ganglionopathy?

Adverse effects of thalidomide administration in patients with neoplastic diseases

Thalidomide, a glutamic acid derivative, was withdrawn from clinical use in 1962 due to its severe teratogenic effects. Its recent reinstitution in clinical practice was related to its benefits in leprosy and multiple myeloma. Moreover, the antiangiogenic and immunomodulatory properties of thalidomide have led to its evaluation in several malignant diseases, including myelofibrosis, renal cell cancer, prostate cancer, and Kaposi sarcoma. However, thalidomide use is associated with several side effects: somnolence and constipation are the most common, while deep vein thrombosis and peripheral neuropathy are the most serious. A combination of thalidomide with steroids or chemotherapy is being evaluated in several phase 2 studies. While it is not yet clear whether these combinations will enhance efficacy, they appear to increase the toxicity of thalidomide, and thalidomide analogs are being developed to minimize this toxicity. Ongoing studies will clarify the potential advantages of these agents in the treatment of neoplastic diseases.

Thalidomide neuropathy: clinical, electrophysiological and neuroradiological features

OBJECTIVE

Thalidomide is a promising therapy for multiple myeloma. Sensory neuropathy is a side effect of thalidomide and resulted to be partially reversible in 50% of cases, suggesting a sensory ganglionopathy. Spinal cord magnetic resonance imaging (MRI) was found to be useful in the diagnosis of sensory ganglionopathies and we use it to determine if thalidomide neuropathy has features of a ganglionopathy.

MATERIAL AND METHODS

Six patients with multiple myeloma developed thalidomide-induced polyneuropathy. Nerve conduction studies, somatosensory-evoked potentials (SEPs) and cervical and dorsal spinal cord MRI were obtained in all.

RESULTS

All patients had a sensory neuropathy, with clinical or electrophysiological abnormalities involving all four limbs. Spinal cord MRI showed high signal intensity in the posterior columns in only one patient, with abnormal central conduction time at SEPs.

CONCLUSION

Our results suggest that thalidomide can induce either an axonal length-dependent neuropathy or, less frequently, a ganglionopathy.

Neuromuscular symptoms in cancer patients

The neuromuscular system is often affected in patients with cancer. This can be due to a direct effect of cancer, neurotoxic treatment, radiation therapy or paraneoplastic phenomena. This review focuses on the sites of involvement, such as cranial nerves, nerve roots, and plexus, mono- and polyneuropathies disorders at neuromuscular transmission, and muscle disease. At each site of the peripheral nervous system, the most common types of involvement and therapeutic issues are discussed. Knowledge of neuromuscular symptoms is important for medical oncologists, neurologists and neuro-oncologist alike, as precise diagnosis may have therapeutic consequences for the patients. Immunologic therapies, or in some cases anticancer treatment may decrease the individual's burden of disease in paraneoplastic syndromes. Conventional cancer therapies, such as chemotherapy and radiation therapy, also have neurotoxic side effects which need to be outweighed against their therapeutic effect. Several other less well-defined complications such as infection, hemorrhage or metabolic disorders have to be considered as a differential diagnosis. Complications of surgical and other interventions will not be discussed in this context.