Published online Mar 16, 2015. doi: 10.12998/wjcc.v3.i3.293
Peer-review started: July 27, 2014
First decision: November 27, 2014
Revised: December 15, 2014
Accepted: January 9, 2015
Article in press: January 15, 2015
Published online: March 16, 2015
Processing time: 230 Days and 16.6 Hours
Voltage gated calcium channel (VGCC) antibodies are generally associated with Lambert-Eaton myasthenic syndrome. However the presence of this antibody has been associated with paraneoplastic as well as non-paraneoplastic cerebellar degeneration. Most patients with VGCC-antibody-positivity have small cell lung cancer (SCLC). Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease of the presynaptic part of the neuromuscular junction. Its classical clinical triad is proximal muscle weakness, areflexia and autonomic dysfunction. Fifty to sixty percent of LEMS patients have a neoplasia, usually SCLC. The co-occurrence of SCLC and LEMS causes more severe and progressive disease and shorter survival than non-paraneoplastic LEMS. Treatment includes 3,4 diaminopyridine for symptomatic purposes and immunotherapy with prednisolone, azathioprine or intravenous immunoglobulin in patients unresponsive to 3,4 diaminopyridine. Paraneoplastic cerebellar degeneration (PCD) is a syndrome characterized with severe, subacute pancerebellar dysfunction. Serum is positive for VGCC antibody in 41%-44% of patients, usually with the co-occurrence of SCLC. Clinical and electrophysiological features of LEMS are also present in 20%-40% of these patients. Unfortunately, PCD symptoms do not improve with immunotherapy. The role of VGCC antibody in the immunopathogenesis of LEMS is well known whereas its role in PCD is still unclear. All patients presenting with LEMS or PCD must be investigated for SCLC.
Core tip: Voltage gated calcium channel (VGCC) antibodies are generally associated with Lambert-Eaton myasthenic syndrome, but also with paraneoplastic or non-paraneoplastic cerebellar degeneration. The autoimmune nature of non-tumour Lambert-Eaton myasthenic syndrome is reflected in its association with various HLA subtypes and other autoimmune diseases such as vitiligo, myasthenia gravis and diabetes mellitus. The most common tumour associated with VGCC-antibody-positivity is small cell lung cancer. Knowledge on the relation between cerebellar degeneration and VGCC is limited, and treatment response is poor in this group of patients.