Recovery of cerebellar peduncle injury in a patient with a cerebellar tumor: validation by diffusion tensor tractography

The cerebellum has a complex network and relates to various clinical functions including ataxia, gait disturbance, hearing and vision, cognition and affective control. Cerebellar peduncles are the structure connecting the cerebellum to the brain stem and the cerebrum. There exist three cerebellar peduncles. The superior cerebellar peduncle (SCP) involves vestibular sense and proprioception connecting to the thalamocortical pathway. The middle cerebellar peduncle (MCP) is the largest structure among the three cerebellar peduncles conveying impulses from the cerebral cortex to the cerebellum through corticopontocerebellar tract. The main function of the inferior cerebellar peduncle (ICP) is to integrate proprioceptive sensory input and postural maintenance connecting the cerebellum with the spinal cord. Therefore, these three cerebellar peduncles were known as useful indicators of neurological ataxia in several kinds of diseases including cerebellar tumor, cerebellar infarct and traumatic brain injury (Kashimura et al., 2003; Ying et al., 2009; Hong and Jang, 2010). However, because conventional MRI is limited in delineating structural abnormalities of cerebellar peduncle, accurate estimation of the cerebellar peduncle is difficult (Lee et al., 2013). Recent development of diffusion tensor imaging (DTI) has enabled detailed assessment of the state of neural tracts in vivo using its ability to visualize characteristics of water diffusion (Lee et al., 2013).