Imaging features inferring symptom onset due to spinal metastasis progression: a preliminary study.

Background: Spinal metastases can cause intractable pain and neurological deficits, which can markedly worsen both patients' activities of daily living (ADL) and their health-related quality of life (QOL). Early intervention is essential to prevent irreversible neurological deficits and pain associated with spinal metastases. We investigated the imaging features of spinal metastases that led to neurological deficits.

Methods: We analyzed axial cross-sectional computed tomography (CT) images of cervical and thoracic spinal metastases in patients with and without lower limb motor paralysis, neuropathic pain, and local nociceptive pain. We distinguished regions of the spine associated with these respective symptoms, and explored their inferable performance using images obtained before symptom onset. In addition, we analyzed the imaging features and type of bone metastasis (osteolytic and osteoblastic).

Results: Spinal lesions occupied the area in and around the spinal canal and around the pedicle in patients with motor paralysis. Lesions around the pedicle and in the most posterior vertebral body part before symptom onset were inferable. In patients with neuropathic pain, spinal metastases spread along the pedicle before symptom onset, and had surrounded the spinal canal circumferentially at symptom onset. Local nociceptive pain was more common near the center of the vertebral body either at or before symptom onset. There was no difference in the imaging features according to the type of bone metastasis.

Conclusions: Lesions in certain regions in the asymptomatic metastatic spine can indicate the onset of spinal metastasis-related symptoms in the next few months. Early therapeutic intervention might be applied to prevent neurological disorder.