Parkinson's disease-associated camptocormia: biopsy-confirmed focal myositis and treatment options.

BACKGROUND

The etiology of the disabling symptom camptocormia/dropped head in Parkinson's disease (PD) is still debated. Many PD patients develop involuntary flexion of the spine in an upright position that does not respond to dopaminergic treatment.

OBJECTIVES

To study the histopathology of paraspinal muscles in PD-associated camptocormia with potential consequences for therapy.

METHODS

We report a cohort of 66 patients with PD (mean age 68.4 ± 8.1 years) and associated camptocormia according to consensus criteria. Paravertebral muscle biopsy was performed in all patients with consecutive histopathological analysis.

RESULTS

Forty-two patients (64%) showed inflammatory myositis in the paravertebral muscles with features of T-cell dominant myositis with additional necrosis, in addition to moderate myopathic changes. Thirty-four of these 42 patients with myositis received immunosuppression according to general clinical guidelines for myositis (i.e., prednisolone, often followed by azathioprine) in addition to PD medication. Twenty-three/34 patients (68%) on prednisolone showed a partial or complete improvement of the muscle weakness. This effect persisted after switching from prednisolone to the long-term immunosuppressant. Three/34 patients were lost to follow-up, and 8/34 did not improve.

CONCLUSIONS

In this cohort of PD patients with camptocormia, muscle biopsy demonstrated local myositis in addition to myopathic changes in 64% of the cases. About two-thirds of these patients benefited from prednisolone therapy, as a symptomatic therapeutic option for muscle weakness. We recommend a histological work-up of the clinical diagnosis PD-associated camptocormia given that effective therapeutic options are available.