Doi: 10.1590/0004-282X20130176 Article (original) (raw)
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Neurosurgical Review
Syndrome of the trephined (SoT) is an underrecognized complication after decompressive craniectomy. We aimed to investigate SoT incidence, clinical spectrum, risk factors, and the impact of the cranioplasty on neurologic recovery. Patients undergoing a large craniectomy (> 80 cm2) and cranioplasty were prospectively evaluated using modified Rankin score (mRS), cognitive (attention/processing speed, executive function, language, visuospatial), motor (Motricity Index, Jamar dynamometer, postural score, gait assessment), and radiologic evaluation within four days before and after a cranioplasty. The primary outcome was SoT, diagnosed when a neurologic improvement was observed after the cranioplasty. The secondary outcome was a good neurologic outcome (mRS 0–3) 4 days and 90 days after the cranioplasty. Logistic regression models were used to evaluate the risk factors for SoT and the impact of cranioplasty timing on neurologic recovery. We enrolled 40 patients with a large craniectom...
2017
PURPOSE OF THE STUDY: To evaluate and compare the change in measurements of optic nerve sheath diameter (ONSD) between Trendelenburg position (30 degree head down), supine and reverse Trendelenburg position (30 degree head elevation) in normal subjects and to evaluate and compare the change in measurements of optic nerve sheath diameter (ONSD) between Trendelenburg position (30 degree head down), supine and reverse Trendelenburg position (30 degree head elevation) in patients before and after cranioplasty. METHODS: This study was approved by institutional review board. This study is done in 2 groups. Normal healthy subjects working in the Department of Neurological Sciences in CMC Vellore and willing to volunteer for the study were included in the first study group. Patients who had undergone a decompressive craniectomy following traumatic brain injury are routinely screened in the Brain Injury Clinic and readmitted for cranioplasty. These patients were included as the 2nd study gro...
Effect of Trabeculectomy on OCT Measurements of the Optic Nerve Head Neuroretinal Rim Tissue
Ophthalmology Glaucoma, 2019
Purpose: Ophthalmologists commonly perform glaucoma surgery to treat progressive glaucoma. Few studies have examined the stability of OCT neuroretinal rim parameters after glaucoma surgery for ongoing detection of glaucoma progression. Design: Longitudinal cohort study. Participants: 20 eyes (16 subjects) with primary open angle glaucoma who had undergone a trabeculectomy. Methods: We calculated the change in OCT parameters (minimum rim area (MRA), minimum rim width (MRW), Bruch's membrane opening (BMO) area, mean cup depth (MCD), anterior lamina cribrosa surface depth (ALCSD), prelaminar tissue thickness (PLTT), retinal nerve fiber layer thickness (RFNLT) during an interval from the visit before the surgery to the visit after the surgery, a span of approximately 6-months. We also calculated changes in the same eyes over two separate 6-month intervals that did not contain trabeculectomy to serve as control. We compared these intervals using a generalized linear model (with compound symmetry correlation structure), accounting for the correlation between time intervals for the same eye. Main outcomes measures: MRW, MRA, angle above the reference plane for MRW and MRA, BMO area, MCD, mean ALCSD, PLTT, RNFLT and visual field parameters (mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI)). Results: The intervals containing trabeculectomy showed a significant decrease in intraocular pressure (−9.2 mmHg, p<.001) when compared to control intervals. Likewise, the following neuroretinal rim parameters showed significant changes with trabeculectomy: increased MRW (+6.04μm, p=.001), increased MRA (+0.014mm 2 , p=.024), increased angle above reference plane of MRW (+2.64°, p<.001), decreased MCD (−11.6μm, p=.007), and decreased mean ALCSD (−18.91μm, p=.006).
Clinical spectrum and radiographic features of the syndrome of the trephined
Journal of Neurosciences in Rural Practice, 2015
Object: Craniectomy is a common neurosurgical procedure. Syndrome of the trephined (ST) occurring after craniectomy results in neurologic symptoms that are reversible with cranioplasty. While well-documented, previous literature consisted of case reports, symptom spectrum and risk factors have not been well characterized. Materials and Methods: A retrospective review of 29 consecutive cases who underwent decompressive craniectomy within a 30-month period was performed. Patients were considered affected by ST if a previously stable neurological deficit improved within 3 weeks after cranioplasty. Prevalence of ST was measured and association with demographic information, clinical symptoms patterns, indication for and size of craniectomy, as well as radiological signs were tested. Results: Seven patients (24%) developed ST. Chronic rehabilitation arrest was more common than acute neurologic decline. Factors such as craniectomy size and patient age did not reach statistical significance in development of ST. Radiographic factors were predictive, with a sunken skin flap contour being most sensitive, while ventricular effacement was most specific. Conclusion: ST may have a higher incidence than previously thought, with a chronic rehabilitation arrest being a more common presentation than an acute decline. Medical providers involved in the post surgical care and rehabilitation of these patients should maintain a high index of suspicion for ST.
Reappraisal of the ratio of disc to macula/disc diameter in optic nerve hypoplasia
British journal of ophthalmology, 1991
The ratio of disc to macula/disc diameter is characteristically increased in eyes with optic nerve hypoplasia. We present the largest reported series of patients with a definitive diagnosis of optic nerve hypoplasia for whom this ratio has been determined. Ali measurements were made by an independent masked observer. Our results are in accordance with previous reports. A ratio of 2*94 provides a one-tailed upper population limit of 95%. An attempt has been made to correlate optic disc size and visual acuity. In 75% of bilateral cases the eye with the relatively smaller optic disc was found to have a better Snelien visual acuity than the fellow eye. This suggests that additional pathogenic mechanism(s) may have determined the eventual visual outcome in such eyes. Such mechanisms include macular hypoplasia, high refractive error, refractive amblyopia, central scotoma, and optic atrophy.
Morphometric characteristics of the optic canal and the optic nerve
Folia Morphologica, 2015
Background: The optic nerve (ON), a major component of the visual system, is divided into four segments: the intrabulbar (IB), the intraorbital (IO), the intracanalicular (ICn) and the intracranial (ICr). The ICr ends with the two nerves partially decussating in the optic chiasm (OCh). The purpose of this study is to provide a detailed description of the dimensions of the OC (the diameter and the surface area of its foramina and the central segment, as well as the length of the OC and the thickness of its walls) as well as the ON (the length of the ON segments, the diameter of the ICn segment of the ON, the angle of decussation in the OCh, as well as the distance between the two ON at the cranial foramen of the OC). Materials and methods: The acquired data was then used to estimate the volume of the OC and the ICn segment of the ON. The morphometric research was performed on 25 cadavers (17 male and 8 female) and 30 skulls. Results: The surface area of the central segment of the OC was significantly smaller than the cranial foramen (p = 0.02) and the orbital foramen (p = 0.009). The inferior wall of the OC was significantly shorter than the other OC walls (p < 0.0001). The IO segment of the ON was the longest, where the difference to the ICn and ICr was statistically significant (p < 0.0001). The surface area of the ON at the cranial foramen was significantly larger than the surface area at the central segment of the OC (p = 0.02) and orbital foramen (p < 0.0001). The difference between the surface areas of the ON at the orbital foramen and the central segment of the OC was also statistically significant (p = 0.01). The estimated volume of the OC was calculated to be 190.72 mm 3 , and the volume of the ICn segment of the ON was estimated to be 50.25 mm 3. Conclusions: It is absolutely crucial to open the central segment of the OC when decompressing the ON, due to the narrowing of the OC in this segment.
Effect of Axial Length on Retinal Nerve Fiber Layer Thickness in Children
European Journal of Ophthalmology, 2014
To investigate the effect of axial length on peripapillary retinal nerve fiber layer (RNFL) thickness in myopic, hyperopic, and emmetropic eyes in children by Cirrus HD spectral-domain optical coherence tomography (OCT). Methods: Subjects were divided into 3 groups according to their refractive status: myopic (n = 36), emmetropic (n = 30), and hyperopic (n = 28) eyes. The RNFL thickness measurements were taken from the superior, inferior, nasal, and temporal quadrants in the peripapillary region by Cirrus HD OCT. Axial length was also determined for each patient. results: The myopic eyes had thinner average RNFL and RNFLs of temporal, superior, nasal, and inferior quadrants than the hyperopic eyes (p1<0.001, p2 = 0.004, p3 = 0.011, p4 = 0.006, p5 = 0.033, respectively). In addition, average peripapillary RNFL thickness and RNFL thicknesses of all quadrants had significant negative correlations with axial length. On the other hand, after applying modified Littmann formula for correction of magnification effect, the differences among the 3 groups disappeared (all p>0.05). conclusions: We have shown that axial length and accordingly refractive status influenced peripapillary RNFL thickness measurements by Cirrus HD OCT in children. Therefore, to make a correct diagnosis of glaucoma or other optic neuropathies in children, either axial length-induced magnification effect should be corrected by ophthalmologists or the current Cirrus HD OCT database should be revised taking axial length into consideration.