A case report of thoracolumbar paraspinal myopathy as the cause of camptocormia in a patient with atypical parkinsonism

Camptocormia is severe flexion of the thoracolumbar spine, exaggerated during standing and walking but minimized in supine position. Even though camptocormia is a relatively common condition during the course of Parkinson’s disease, there is ongoing controversy concerning its mechanisms. The most widely accepted and yet still disputed one is dystonia. However, based on myopathic changes observed in the paraspinal muscle biopsies of some PD patients with camptocormia, the attempt to attribute camptocormia to myopathy has continued. This case presents evidence for paraspinal myopathy as the cause of camptocormia in a patient with atypical parkinsonism.

A patient presented with a relatively acute onset of camptocormia and new-onset back pain. Upon examination, she had asymmetric parkinsonism. Magnetic resonance imaging of the lumbar spine revealed alterations in muscle signal intensity in the right paraspinal muscles at the L1–2 level. In the presence of persistent back pain, repeat imaging done two months later showed diffuse enlargement and patchy enhancement of the paraspinal muscles on T1-weighted imaging from T4 through sacrum bilaterally. About fifteen months after the onset of camptocormia, she underwent ultrasound-guided gun biopsy of the paraspinal muscles for evaluation of focal atrophy of the back muscles on the right. The biopsy revealed unmistakable myopathic changes, marked endomysial and perimysial fibrosis of the muscles, and merely mild infiltration of inflammatory cells but no clues regarding the cause of myopathy. On account of persistent back pain and MRI results indicative of ongoing inflammation, she was prescribed glucocorticoid, which she refused to take. Now merely two and a half years after the onset of camptocormia, she is in Hoehn and Yahr stage 4.

The coincidence of back pain with the appearance of camptocormia and the imaging and pathology findings supportive of myopathy give strong evidence for paraspinal myopathy as the cause of the deformity in this patient. When a patient presents with a relatively acute onset of camptocormia accompanied by back pain, the clinician should not overlook the possibility of myopathy of paraspinal muscles, which may be one of the few treatable causes of camptocormia.