The measuring of substantia nigra hyperechogenicity in an Italian cohort of Parkinson disease patients: a case/control study (NOBIS Study).

Transcranial sonography (TCS) shows an increased echogenic area of the substantia nigra (SN) in patients with Parkinson disease (PD). It has been increasingly used in the diagnosis of PD and its differentiation from atypical parkinsonian syndromes. Here, we studied the diagnostic accuracy of SN TCS in Italian patients. In this blinded cross-sectional study (NOBIS study), two expert neuro-sonologists performed TCS in 25 PD patients and 29 age- and sex-matched controls. The study participants were completely hidden to the TCS investigators using large drapery. One month later, the SN TCS recordings were re-read by the initial investigator, and cross-read by the second reader. Diagnostic accuracy was estimated on the first reading, intra-reader reliability on re-reading, and inter-reader reliability on cross-readings. The mean SN echogenic area was larger in the patients (0.24 cm2) than in the controls (0.15 cm2; Mann-Whitney test, p < 0.001). SN measures did not differ between right and left, or between ipsilateral and contralateral to the clinically more affected side. There was no correlation between SN echogenicity and PD severity or duration. High intra-reader (concordance correlation coefficient 0.93) and inter-reader (0.98) agreement of SN measurements was found. The diagnostic accuracy for the detection of PD was high (area under receiver-operating characteristic curve 0.91; 95% CI 0.83-1.00) with an optimum cut-off value for SN echogenic area of 0.18 cm2 with the device used here (specificity 0.83-0.90; sensitivity 0.72-0.92). This study supports the use of SN TCS in the diagnostic workup of PD if performed by trained readers.

Uric acid does not affect the prevalence and extent of coronary artery disease. Results from a prospective study.

BACKGROUND: Hyperuricemia may be involved in the atherosclerotic process due to endothelial dysfunction and facilitation of smooth muscle cell proliferation. However, debates still exist on the independent role of hyperuricemia, due to its association with several cardiovascular risk factors, such as hypertension, hyperlipidemia, obesity and insulin resistance. Thus, the aim of the current study was to investigate in a consecutive cohort of patients undergoing coronary angiography whether hyperuricemia is associated with the extent of coronary artery disease. METHODS AND RESULTS: Our population is represented by a total of 1901 consecutive patients undergoing coronary angiography between May 2007 and January 2010 at the Azienda Ospedaliera "Maggiore della Carità", Novara, Italy. We additionally evaluated platelet aggregation by PFA-100 (Collagen/Epinefrine) and Multiplate. Quantitative coronary angiography and analysis of IMT were performed by experienced cardiologists who had no knowledge of the patients' clinical information. Higher uric acid was associated with advanced age, larger prevalence of male gender, diabetes, renal insufficiency, hypertension, previous CABG and MI, but with a lower prevalence of family history of CAD. Patients with high uric acid were more often on calcium antagonists, ace-inhibitors, angiotensin receptor antagonists, and, as expected, on diuretics. A significant relationship was observed between uric acid and the prevalence (OR [95% CI] = 1.18 [1.04-1.32], p = 0.01) and severity of CAD (OR [95% CI] = 1.17 [1.03-1.33], p = 0.014). However, the relationship disappeared after correction for baseline confounding factors for both prevalence (OR [95% CI] = 1.06 [0.93-1.21], p = 0.35) and extent of CAD (OR [95% CI] = 1.0 [0.87-1.15], p = 0.96). No relationship was observed between acid uric and IMT (p = 0.73) analyzed in 359 consecutive patients. Finally, there was no relationship between uric acid and platelet aggregation in patients with or without aspirin therapy, as measured by PFA-100 and Multiplate. CONCLUSIONS: Our study showed that uric acid is not associated with platelet aggregation, the extent of coronary artery disease and IMT. Thus, waiting for the results of additional large studies, uric acid may not be considered as a risk factor for coronary artery disease, and its reduction by specific therapies may not be recommended to prevent coronary artery disease and atherosclerosis.

Transorbital sonography in acute optic neuritis: a case-control study.

BACKGROUND AND PURPOSE: Acute unilateral optic neuritis is associated with a thickening of the retrobulbar portion of the optic nerve as revealed by transorbital sonography, but no comparison has been made between nerve sheath diameter and optic nerve diameter in patients with acute optic neuritis versus healthy controls. We evaluated optic nerve sheath diameter and optic nerve diameter in patients with acute optic neuritis and healthy controls and compared optic nerve sheath diameter and optic nerve diameter with visual-evoked potentials in patients. MATERIALS AND METHODS: A case-control study was performed in 2 centers. Twenty-one consecutive patients with onset of visual loss during the prior 10 days and established acute noncompressive unilateral optic neuritis were compared with 21 healthy controls, matched for sex and age (±5 years). Two experienced vascular sonographers performed the study by using B-mode transorbital sonography. Visual-evoked potentials were performed on the same day as the transorbital sonography and were evaluated by an expert neurophysiologist. Sonographers and the neurophysiologist were blinded to the status of the patient or control and to clinical information, including the side of the affected eye. RESULTS: The median optic nerve sheath diameter was thicker on the affected side (6.3 mm; interquartile range, 5.9-7.2 mm) compared with the nonaffected side (5.5 mm; interquartile range, 5.1-6.2 mm; P < .0001) and controls (5.2 mm; interquartile range, 4.8-5.5 mm; P < .0001). The median optic nerve diameter was 3.0 mm (range, 2.8-3.1 mm) on the affected side and 2.9 mm (range, 2.8-3.1 mm) on the nonaffected side (P = not significant.). Both sides were thicker than those in controls (2.7 mm; interquartile range, 2.5-2.8 mm; P = .001 and .009). No correlation was found between optic nerve sheath diameter and optic nerve diameter and amplitude and latency of visual-evoked potentials in patients with optic neuritis. CONCLUSIONS: Transorbital sonography is a promising tool to support the clinical diagnosis of acute optic neuritis. Further studies are needed to define its specific role in the diagnosis and follow-up of optic neuritis.