Research & Current Literature
February 2011
List compiled by Robin Lindsay, M.D.
Bitter, T., B. Sorger, et al. (2011). "Cortical representation sites of mimic movements after facial nerve reconstruction: A functional magnetic resonance imaging study." Laryngoscope.
OBJECTIVES/HYPOTHESIS: To describe cortical reorganization after classic hypoglossal-facial nerve anastomosis (HFA) (four patients), hypoglossal-facial nerve jump anastomosis (HFJA) (three patients), and facial nerve interpositional graft (FNIG) (three patients). STUDY DESIGN: Prospective case series. METHODS: Functional magnetic resonance imaging (fMRI) was performed during lip and tongue movement using a block or an event-related design. RESULTS: Despite the presence of some intersubject variability, the following general brain activation patterns were revealed: As expected, lip movements after FNIG led to selective brain activation in the original facial motor cortex, and lip movements after HFA were associated with activation in the hypoglossal motor cortex. Following HFJA, lip movements resulted in overlapping activation encompassing both the original facial and the hypoglossal motor cortex, but tongue movements led solely to strong activation within the original hypoglossal motor cortex. In contrast, tongue movements after HFA were associated with strong activation in the original hypoglossal motor cortex and weaker activation in the facial motor cortex. CONCLUSIONS: Direct facial nerve repair (FNIG) leads to restoration of the original cortical activation. A cross nerve suture (HFA or HFJA) changes cortical activation and leads to different patterns of cortical activation during lip and tongue movements. Laryngoscope, 2011.
Emel, E., S. S. Ergun, et al. (2011). "Effects of insulin-like growth factor-I and platelet-rich plasma on sciatic nerve crush injury in a rat model." J Neurosurg 114(2): 522-528.
Object Local administration of insulin-like growth factor-I (IGF-I) has been shown to increase the rate of axon regeneration in crush-injured and freeze-injured rat sciatic nerves. Local administration of platelet-rich plasma (PRP) has been also shown to have a measurable effect on facial nerve regeneration after transection in a rat model. The objective of the study was to compare the effects of locally administered IGF-I and PRP on the parameters of the Sciatic Function Index (SFI), sensory function (SF), axon count, and myelin thickness/axon diameter ratio (G-ratio) in a rat model of crush-injured sciatic nerves. Methods The right sciatic nerve of Wistar albino rats (24 animals) was crushed using a Yasargil-Phynox aneurysm clip for 45 minutes. All animals were randomly divided into 3 groups: Group 1 (control group) was treated with saline, Group 2 was treated with IGF-I, and Group 3 was treated with PRP. Injections were performed using the tissue expander's injection port with a connecting tube directed at the crush-injured site. Functional recovery was assessed with improvement in the SFI. Recovery of sensory function was using the pinch test. Histopathological examination was performed 3 months after the injury. Results The SFI showed an improved functional recovery in the IGF-I-treated animals (Group 2) compared with the saline-treated animals (Group 1) 30 days after the injury. In IGF-I-treated rats, sensory function returned to the baseline level significantly faster than in saline-treated and PRP-treated rats as shown in values between SF-2 and SF-7. The G-ratios were found to be significantly higher in both experimental groups than in the control group. Conclusions This study suggests that the application of IGF-I to the crush-injured site may expedite the functional recovery of paralyzed muscle by increasing the rate of axon regeneration.
Fujita, Y., K. Watabe, et al. (2011). "Morphological changes of Golgi apparatus in adult
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