Recovery of an injured dentato-rubro-thalamic tract in a patient with traumatic brain injury

@#Several studies have reported on injury of the dentato-rubro-thalamic tract (DRTT) in patients with various brain pathologies. However, no study on recovery of an injured DRTT has been reported so far. We report on a patient who showed recovery of an injured DRTT during a period of approximately 4 years following traumatic brain injury (TBI), which was demonstrated by follow-up diffusion tensor tractography (DTT). A 24-year-old male patient suffered a car accident. The patient lost consciousness for approximately 4 months. At the beginning of rehabilitation, the patient showed mild quadriparesis, severe resting and intentional tremor on four extremities and severe truncal ataxia. He was not able to sit independently. With rehabilitation, he showed continuous improvement, and was able to walk independently at 45 months after onset of injury. On 5-month DTT, DRTTs in both hemispheres were not reconstructed. In contrast, on 13-month DTT, the lower portion of the left DRTT was reconstructed, although the right DRTT was still not reconstructed. On 32-month DTT, the whole left DRTT was reconstructed, however, only the lower portion of the right DRTT was reconstructed. Finally, both DRTTs were reconstructed on 45-month DTT.Conclusions: Recovery of an injured DRTT was demonstrated in a patient with TBI, using DTT. We believe that evaluation of the DRTT using DTT may be helpful to monitor the progress of rehabilitation in patients with movement symptoms following TBI.

Preoperative Identification of Facial Nerve in Vestibular Schwannomas Surgery Using Diffusion Tensor Tractography

OBJECTIVE: Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve. METHODS: We prospectively collected data from 11 patients with VS, who underwent preoperative DTT for facial nerve. Imaging results were correlated with intraoperative findings. Postoperative DTT was performed at postoperative 3 month. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) facial nerve grading system. RESULTS: Facial nerve courses on preoperative tractography were entirely correlated with intraoperative findings in all patients. Facial nerve was located on the anterior of the tumor surface in 5 cases, on anteroinferior in 3 cases, on anterosuperior in 2 cases, and on posteroinferior in 1 case. In postoperative facial nerve tractography, preservation of facial nerve was confirmed in all patients. No patient had severe facial paralysis at postoperative one year. CONCLUSION: This study shows that DTT for preoperative identification of facial nerve in VS surgery could be a very accurate and useful radiological method and could help to improve facial nerve preservation.