Pisa syndrome in Parkinson's disease: a mobile or fixed deformity?

Abstract

Background: Although Pisa syndrome and scoliosis are sometimes used interchangeably to describe a laterally flexed postural deviation in Parkinson's disease (PD), the imaging findings of Pisa syndrome in PD have not been previously studied in detail.

Methods: Patients with PD and Pisa syndrome (lateral flexion >10° in the standing position) were examined clinically and underwent radiological assessment using standing radiograph and supine CT scan of the whole spine.

Results: Fifteen patients were included in this observational study. All patients had scoliosis on standing radiographs, and 12 had scoliosis persisting in the supine position. Scoliotic curves improved by a mean of 44% when patients moved from standing to supine. Only a quarter of patients with structural scoliosis had evidence of bony fusion on the side of their lateral deviation rendering their deformity fixed.

Conclusions: Pisa syndrome describes a patient who lists to the side whereas scoliosis is defined by spinal curvature and rotation and may not be associated with lateral flexion. The finding of 'structural scoliosis' in Pisa syndrome should not preclude intervening to improve posture as most patients had little or no evidence of structural bony changes even when the deformity had been present for a number of years.

Keywords: PARKINSON'S DISEASE.

Figures

Figure 1

Mobile and fixed scoliosis in Pisa syndrome. Patient A had scoliosis on standing radiograph (A-2) but not when he was scanned supine (A-3, A-4 and A-5). There was evidence of osteophytic overgrowth below the apex of the scoliosis in the lumbar spine and above on the opposite side in the thoracic spine (A-4 and A-5), this pattern suggests the degenerative changes were working to stabilise his spine but stopped short at the apex of his curve leaving him mobile but tilted at that level when standing (A-1 and A-2). The reduction in curve with position, presence of interdiscal gas (red arrows A-5) and gaps between the osteophytes are evidence that despite attempts the deformity is not fixed. Patient B had only minor improvement of his scoliosis on supine positioning (9% reducibility) (B-2 and B-3). Fusion of vertebral segments due to complete osteophytic bridging at the apex of the curve was clearly seen (B-4 and B-5) resulting in a fixed and possibly stable spinal deformity. Key: 1=patient photographs of Pisa syndrome while walking; 2=standing full spine anterior–posterior radiograph; 3=supine CT scan two-dimensional composite image; 4=supine CT scan three-dimensional surface rendered image; 5=supine CT scan two-dimensional fine cut in coronal plane.