Subcortical structural abnormalities in juvenile myoclonic epilepsy (JME): MR volumetry and vertex based analysis.

PURPOSE: Imaging studies in juvenile myoclonic epilepsy (JME) have shown abnormalities of the thalamus and frontal cortex. The purpose of this study was to systematically investigate the morphological changes in the deep gray matter (GM) structures using techniques of voxel based morphometry (VBM), MR volumetry and shape analysis. METHODOLOGY: The study included 40 patients with JME (M:F=21:19; age 22.8±5.3 years) and 19 matched controls (M:F=13:6; age 24.5±4.2 years). All subjects underwent MRI using standard protocol that included T1-3D TFE (Turbo Field Echo) images with 1mm thickness. VBM analysis and MR volumetry were performed. The volumes of deep subcortical GM structures were extracted and vertex-wise shape analysis was performed using FSL-FIRST (FSL-Integrated Registration and Segmentation Toolbox) software. RESULTS: VBM analysis with a thalamic mask revealed focal thalamic alterations in the anteromedial aspect of the thalamus (p<0.05, false discovery rate (FDR) corrected) which remained significant after adjusting for age, gender and intracranial volume (ICV). Significant volume loss was noted in both the thalami. Vertex-wise shape analysis showed significant focal surface reductions in the thalami bilaterally in patients that were predominantly seen in the medial as well as lateral aspects of the thalamus (p<0.05, FDR corrected). The disease duration correlated with left hippocampus volume while age of onset correlated with right hippocampus volume. CONCLUSIONS: This study confirms the presence of thalamic alterations in patients with JME. Shape analysis technique provided complementary information and disclosed the presence of focal atrophic changes in patients' thalami. The striatum and hippocampus did not show any significant alterations.

Temporal resolution deficits in patients with refractory complex partial seizures and mesial temporal sclerosis (MTS).

We studied the temporal resolution ability in patients with refractory complex partial seizures and mesial temporal sclerosis (MTS) using Gaps-In-Noise (GIN) test in a prospective cross-sectional study. Thirteen patients with right MTS (age: 31±7.67 years; M:F=8:5) and 13 patients with left MTS (age: 25.76±8.26 years; M:F=9:4) having normal hearing and mini-mental state examination (MMSE) score of >23/30 were recruited. Fifty healthy volunteers (26.3±5.17 years; M:F=28:22) formed the control group. Gaps-In-Noise test demonstrated impaired temporal resolution: 69.2% of patients with right MTS (RMTS) and 76.9% of patients with left MTS (LMTS) had abnormal scores in the right ear for gap detection threshold (GDT) measure. Similarly, 53.8% of patients in the RMTS group and 76.9% of patients in the LMTS group had abnormal scores in the left ear. In percentage of correct identification (PCI), 46.1% of patients with RMTS and 69.2% of patients with LMTS had poorer scores in the right ear, whereas 46.1% of patients with RMTS and 61.5% of patients with LMTS had poorer scores in the left ear. Both patient groups, viz., RMTS and LMTS, demonstrated bilateral temporal resolution deficits.

Efficacy and timed sequence analyses of modified single-injection peribulbar anesthesia.

This study evaluated a modified single-injection technique of administering peribulbar anesthesia. All 150 eyes achieved complete lid anesthesia; 49 eyes (32.7%) demonstrating exophthalmos after injection achieved excellent (grade 1) instantaneous ocular akinesia. Sequence of timed events after injection included lid anesthesia (60.2 +/- 15.33 seconds), lid akinesia (75.18 +/- 15.33), lateral rectus akinesia (90.19 +/- 2.13), inferior rectus akinesia (140.44 +/- 17.51), superior rectus akinesia (229.60 +/- 15.23), and medial rectus akinesia (250.42 +/- 18.99). Peribulbar anesthesia, when successful, achieved complete akinesia in fewer than five minutes. In 12 eyes (8%), the peribulbar injection had to be repeated. For routine intraocular surgery, we recommend this efficacious, safe technique without the use of a separate facial block.