Multiple myeloma (MM) rarely presents with a primary neurological dysfunction, 
and if it does it is usually due to a plasmacytoma. This is the first case to 
discuss hypoglossal nerve dysfunction as the first sign of MM progression 
secondary to severe pathophysiologic bone lysis. A PubMed-based literature 
search was completed on April 17, 2016 for the terms "multiple myeloma" and 
"hypoglossal nerve neuropathy". A 73-year-old woman with known MM who received 
little treatment for several years, presented secondary to dysarthria and at 
first was thought to have hyperviscosity syndrome. On further examination, it 
was found she had light chain disease and her symptoms were secondary to severe 
disease progression. Imaging revealed multiple lytic lesions in the skull on 
skeletal survey and brain MRI revealed boney lysis near the occipital condyle 
and clivus likely interfering with the coursing of the hypoglossal nerve. 
Advanced progressing MM can cause severe boney destruction which can interfere 
with cranial nerve canals and cause neuropathy as a presenting symptom.