High-resolution ultrasonography of peripheral nerves: measurements on 14 nerve segments in 56 healthy subjects and reliability assessments.

PURPOSE: The aim of this study was to assess different aspects of reliability in high-resolution ultrasonography (HRUS) of the peripheral nerves and to establish reference values for the most frequently examined nerve segments. MATERIALS AND METHODS: A nerve size parameter, the cross-sectional area (CSA) of the C5, C6 and C7 cervical roots, the median, ulnar, radial, superficial radial, peroneal, tibial, and the sural nerves was measured using HRUS at a total of 14 predefined anatomical sites in two different cohorts of healthy subjects (n = 56), and the inter-rater, intra-rater and inter-equipment reliability of measurements was assessed. RESULTS: The mean CSA of the 14 nerve segments ranged from 2 to 10 mm(2). The intra-rater, inter-rater and inter-equipment reliability was high with intraclass correlation coefficients of 0.93, 0.98, and 0.86, respectively. The CSA values showed no consistent correlation with age, height, and body weight, but males had significantly larger values than females for nerve segments on the arm after correcting for age, weight and height in multivariate analysis. CSA values did not differ when two independent cohorts were compared. CONCLUSION: Peripheral nerve ultrasonography is a reliable and reproducible diagnostic method in the hands of experienced examiners. Normal values for several upper and lower extremity nerves are provided by our study.

Reversible focal MRI abnormalities due to status epilepticus. An EEG, single photon emission computed tomography, transcranial Doppler follow-up study.

We demonstrate clinical data and findings of MRI, transcranial Doppler (TCD), single photon emission computed tomography (SPECT) and electroencephalography (EEG) in an 8 month follow-up study of a 15 year old girl who developed focal status epilepticus with sensory and visual illusions. EEG showed right temporal and occipital seizure activity and attenuation of the alpha activity with right predominance. MRI showed a right temporo-parietal hyper signal on the T2 weighted images involving the cortex with sulcal effacement. MRI-angiography suggested insufficient flow in the right transverse sinus. TCD detected an elevated flow velocity in the ipsilateral middle cerebral artery during status epilepticus, corresponding to an increased perfusion of the epileptic area revealed by SPECT. After normalization of the TCD finding, the MRI detected persistent cortical abnormality beyond the 70th day after admission. MRI normalized on the 103rd day of follow-up. Serial EEG frequency analysis demonstrated the recovery of alpha peak frequency on the left side, but the attenuation of rhythmic signals remained persistent on the right. In our case, the restitution of postictal EEG lag behind the consolidation of MRI signal abnormality.