An osteoporotic fracture mimicking cervical dystonia in idiopathic Parkinson's disease

We report on a case of a 65-year-old (CD) woman who sustained an atraumatic neck fracture. A combination of Parkinson's disease with motor fluctuations, chronic cervical dystonia and osteoporosis provided the basis for this interesting diagnosis. Mrs CD had progressed to complex phase idiopathic Parkinson's disease within 13 years of diagnosis. During this time she remained independent, only using a wheelchair when her motor fluctuations were bad. In 2011, she developed a sudden onset of neck spasm and occipital neuralgia, initially attributed to severe spasmodic cervical dystonia. Despite a titration regime of analgesics and weaning off of her Parkinson's disease medications, the pain persisted. An X-ray of her cervical spine showed degenerative discopathies from C4 to C7. Mrs CD underwent a trial of Botox injections to no avail and she was admitted acutely under the spinal team after an MRI of her spine showed abnormal oedema of the odontoid peg. Subsequent CT diagnosed a type II fracture of the odontoid peg on the background of severe osteoporotic bone (spinal T score -3.4 on subsequent DEXA scan) and she underwent a successful occipital cervical fusion of C1-C6. What makes this case interesting is the fact that this lady's profound powerful neck movements on a background of osteoporosis led to fracture of her neck. Post-operatively, she admitted to non-adherence to her bisphosphonates, prioritising levodopa in the morning with food rather than taking her alendronate on an empty stomach. She is now pain free and receives annual zolendronate infusions.