Abstract
A 17-year-old male with diffuse axonal injury (DAI) was referred to our psychiatric clinic with a diagnosis of depression. However, further investigation indicated that he had narcolepsy without cataplexy secondary to DAI. We assessed regional volume alterations in the patient; MRI analysis showed a significant decrease in the volume of the hypothalamus, left amygdala, and brainstem. Our findings add to further understanding of the structural basis of secondary narcolepsy, and may provide basis for future neuroimaging studies on sleep disturbances in traumatic brain injury (TBI).