Objective: Magnetic resonance imaging (MRI) is useful in diagnosing spontaneous spinal epidural hematoma (SSEH). The purpose of the present study is to determine whether apparent diffusion coefficient (ADC) values could determine severity of spinal cord damage and predict functional recovery in SSEH.
Methods: The study involved four consecutive patients with SSEH (two men and two women: aged 21-76 years). Using axial slices, ADC values were determined in four separate regions of the spinal cord. These areas were classified into the following three groups based on findings in T2-weighted images: normal T2 intensity; persistent T2 abnormality; and temporary T2 abnormality. ADC values among different groups were compared. The relationship between preoperative ADC values and neurological grades were also evaluated.
Results: ADC values in normal T2 areas were 0.89 ± 0.10 × 10(-3) mm(2) s(-1), whereas those for the persistent T2 abnormality group were significantly lower (0.63 ± 0.14 × 10(-3)). In a patient who was Frankel A on admission and in the follow-up, the ADC value was as low as 0.41 × 10(-3). Functional recovery was also limited in the spinal cord segments with lower ADC values. In the temporary T2 abnormality group, ADC values were significantly higher (1.05 ± 0.10 × 10(-3)).
Conclusions: In SSEH, if MRI demonstrated T2-hyperintensity with lower ADC values, patients may suffer from irreversible spinal cord damages. ADC values of the spinal cord can be added as a new factor that reliably indicated the severity of spinal cord damage and predicted functional recovery.