Structural abnormalities of trigeminal root with neurovascular compression revealed by high resolution diffusion tensor imaging

Objective:To detect neurovascular compression-induced structural abnormalities of trigeminal nerves(TGN) by diffusion tensor imaging(DTI).Methods:The affected ipsilateral TGN(iTGN) and unaffected contralateral TGN(cTGN) of 20 trifacial neuralgia(TIM) patients as well as the bilateral TGN of 10 normal controls(nTGN) were examined by DTI and 3D high resolution MR] using a 3.0 T MRI scanner.The fractional anisotropy and apparent diffusion coefficieiil(ADC) were determined.Results:Compared with the cTGN and nTGN,the iTGN.had significantly lower fraction of anisotropy(FA),significantly higher ADC.and significantly smaller volume and crosssectional area(P【0.05).Conclusions:The increase in ADC and decrease in FA has a close relationship with morphological changes of TGN,and the DTI could provide valuable diagnostic information on TGN structure forTN patients.

Longitudinal follow-up of patients with mild traumatic brain injury by magnetic resonance spectroscopic technique

Objective:To explore the changes in the concentrations of neural markers immediately or several months after mild traumatic brain injury(mTBI).Methods:The metabolic markers of neurons in white matter tissues above the lateral ventricle were semi-quantitatively determined by employing 1H magnetic resonance spectroscopic technique(1-H-MRS) in 30 clinically diagnosed cases of mTBI.At the same time,the neurological functions of the subjects,including ability to pay attention,memory,working memory and operational capacity etc were also assessed. Results:The patients were followed up for,on average,13 days after mTB1 and the results showed that Cre,PCre and Glx in the white matter tissues were significantly elevated in mTBI patients.17 patients(57%) recovered from the injury during the follow-up(median was defined as the 40th post-trauma day).Comparison in terms of intelligence among groups revealed that the levels of neural markers of intelligence development was positively related with intelligence scores).Conclusions:Change in Clx concentrations is most sensitive during trauma or in ensuing repairing processes,and might be different from normal status in the following months and Clx level tends to be accompanied with change in Cre,another energy-related marker.