Gastrointestinal abnormalities in Parkinson's disease (PD) have been known for almost two centuries, but many aspects concerning their pathophysiology have not been completely clarified. The aim of this study was to characterize the oropharyngeal dynamics in PD patients with and without levodopa-induced dyskinesia. Fifteen dyskinetic, 12 nondyskinetic patients, and a control group were included. Patients were asked about dysphagia and evaluated with the Unified Parkinson's Disease Rating Scale Parts II and III and the Hoehn and Yahr scale. Deglutition was assessed using modified barium swallow with videofluoroscopy. Nondyskinetic patients, but not the dyskinetic ones, showed less oropharyngeal swallowing efficiency (OPSE) for liquid food than controls (Dunnett, P = 0.02). Dyskinetic patients tended to have a greater OPSE than nondyskinetic (Dunnett, P = 0.06). Patients who were using a higher dose of levodopa had a greater OPSE and a trend toward a smaller oral transit time (Pearson's correlation, P = 0.01 and 0.08, respectively). Neither the report of dysphagia nor any of the PD severity parameters correlated to the videofluoroscopic variables. In the current study, dyskinetic patients performed better in swallowing function, which could be explained on the basis of a greater levodopa dose. Our results suggest a role for levodopa in the oral phase of deglutition and confirm that dysphagia is not a good predictor of deglutition alterations in PD.
3T MRI using 3D T2-weighted DRIVE in combination with 3D TOF-MRA and 3D T1-weighted gadolinium-enhanced sequences proved to be reliable in detecting NVC and in predicting the degree of root compression, the outcome being correlated with the latter.
Because diffusion tensor imaging (DTI) is able to assess tissue integrity, we used diffusion to detect abnormalities in trigeminal nerves (TGN) in patients with trigeminal neuralgia (TN) caused by neurovascular compression (NVC). We also studied anatomical TGN parameters (cross-sectional area [CSA] and volume [V]). Using DTI sequencing in a 3-T magnetic resonance imaging (MRI) scanner, we measured the fraction of anisotropy (FA) and the apparent diffusion coefficient (ADC) of TGN in 10 patients selected as candidates to have microvascular decompression (MVD) for TN, and 6 normal control subjects. We compared data between the affected nerves of TN (ipsilateral TN), unaffected nerves of TN (contralateral TN), and both nerves in normal subjects (controls), and correlated these data with CSA and V. The FA of the ipsilateral TN (0.37±0.08) was significantly lower (P<.05) compared with the contralateral TN (0.48±0.08) and control values (0.52±0.04). The ADC of ipsilateral TN (5.6±0.89 mm(2)/s) was significantly higher (P<.05) compared with the contralateral TN (4.26±0.59 mm(2)/s) and control values (3.84±0.43 mm(2)/s). Ipsilateral TN had less V and CSA compared with contralateral TN and control values (P<.05). The Spearman correlation coefficient showed a strong positive correlation between loss of FA and loss of V (r=0.7576) and loss of CSA (r=0.9273) of affected nerves. The Spearman correlation coefficient showed a strong negative correlation between increase in ADC and loss of V (r=-0.7173) and loss of CSA (r=-0.7416) in affected nerves. DTI revealed alteration in the FA and ADC values of the affected TGN. These alterations were correlated with atrophic changes in patients with TN caused by NVC.
3D T2 high-resolution in combination with 3D TOF-MRA and 3D T1-Gadolinium proved to be reliable in detecting NVC and in predicting the degree of the root compression.
S trong evidence suggests that in classic trigeminal neuralgia (TN) caused by neurovascular compression (NVC), the neuralgia is related to morphological and structural changes in the trigeminal nerve (TGN) that are probably the result of chronic vascular compression. Morphological changes in the nerve include nerve deviation, distortion, groove formation, and atrophy. 5 Atrophy of the nerve is seen in most cases of TN 20 and is probably attributable to structural abnormalities such as axonal loss and demyelination, 4,10,12,18 but these morphological changes are difficult to describe objectively. Object. The aim of this study was to prospectively evaluate atrophic changes in trigeminal nerves (TGNs) using measurements of volume (V) and cross-sectional area (CSA) from high-resolution 3-T MR images obtained in patients with unilateral trigeminal neuralgia (TN), and to correlate these data with patient and neurovascular compression (NVC) characteristics and with clinical outcomes.Methods. Anatomical TGN parameters (V and CSA) were obtained in 50 patients (30 women and 20 men; mean age 56.42 years, range 22-79 years) with classic TN before treatment with microvascular decompression (MVD). Parameters were compared between the symptomatic (ipsilateralTN) and asymptomatic (contralateralTN) sides of the face. Twenty normal control subjects were also included. Two independent observers blinded to the side of pain separately analyzed the images. Measurements of V (from the pons to the entrance of the nerve into Meckel's cave) and CSA (at 5 mm from the entry of the TGN into the pons) for each TGN were performed using imaging software and axial and coronal projections, respectively. These data were correlated with patient characteristics (age, duration of symptoms before MVD, side of pain, sex, and area of pain distribution), NVC characteristics (type of vessel involved in NVC, location of compression along the nerve, site of compression around the circumference of the root, and degree of compression), and clinical outcomes at the 2-year follow-up after surgery. Comparisons were made using Bonferroni's test. Interobserver variability was assessed using the Pearson correlation coefficient.Results. The mean V of the TGN on the ipsilateralTN (60.35 ± 21.74 mm 3 ) was significantly smaller (p < 0.05) than those for the contralateralTN and controls (78.62 ± 24.62 mm 3 and 89.09 ± 14.72 mm 3 , respectively). The mean CSA of the TGN on the ipsilateralTN (4.17 ± 1.74 mm 2 ) was significantly smaller than those for the contralateralTN and controls (5.41 ± 1.89 mm 2 and 5.64 ± 0.85 mm 2 , respectively). The ipsilateralTN with NVC Grade III (marked indentation) had a significantly smaller mean V than the ipsilateralTN with NVC Grade I (mere contact), although it was not significantly smaller than that of the ipsilateralTN with NVC Grade II (displacement or distortion of root). The ipsilateralTN with NVC Grade III had a significantly smaller mean CSA than the ipsilateralTN with NVC Grades I and II (p < 0.05). The TGN on the ipsilateralT...
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