Can diffusion tensor imaging predict outcome in acute traumatic deterioration of degenerative cervical spine disease

Abstract

IntroductionPatients with degenerative diseases of cervical spine are likely to develop acute cord injury following trivial trauma. However many of them can have a poor functional outcome. Routine MRI may not be helpful in accurately predicting the recovery in these cases. DTI of spinal cord is a promising tool in prognostication of various neurological diseases. Materials and methodA prospective study was done to know the use of DTI in predicting outcome in acute deterioration of degenerative cervical spine disease. Cases presenting within 48 h of acute traumatic deterioration were included in the study. A screening MRI was done to know the extent of disease and cord damage. Using DTI, apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated at the level of injury. 3D tractography was done using Label map seeding technique. Clinical correlation was done with ASIA and FIM scores. ResultsFive cases of cervical cord injury with a mean age of 46 ± 11 years were studied. The diffusion parameters were compared with three age matched controls. The cases were followed up prospectively. All the cases had a decrease in ADC values and increase in FA at the level of injury compared to other levels (p = 0.02) and to normal controls (p = 0.001). It was extending beyond the level of cord contusion identified by routine MRI. DiscussionDTI is well suited for evaluating effects of spinal cord injury like cellular swelling and myelin membrane disruption which is not diagnosed using conventional MRI. ADC helps us to define the type and extent of spinal cord injury. 3D tractography delineates the fiber disruption. ConclusionADC is a sensitive marker of acute cervical cord injury, in degenerative spine disease.3D tractography can help us to select the cases for early surgical intervention and to predict clinical outcome.