The impact of utilizing different optical coherence tomography devices for clinical purposes and in multiple sclerosis trials

Optical coherence tomography (OCT) derived retinal measures, particularly peri-papillary retinal nerve fiber layer (RNFL) thickness, have been proposed as outcome measures in remyelinating and neuroprotective trials in multiple sclerosis (MS). With increasing utilization of multiple centers to improve power, elucidation of the impact of different OCT technologies is crucial to the design and interpretation of such studies. In this study, we assessed relation and agreement between RNFL thickness and total macular volume (in MS and healthy controls) derived from three commonly used OCT devices: Stratus time-domain OCT, and Cirrus HD-OCT and Spectralis, two spectral-domain (SD) OCT devices. OCT was performed on both Cirrus HD-OCT and Stratus in 229 participants and on both Cirrus HD-OCT and Spectralis in a separate cohort of 102 participants. Pearson correlation and Bland-Altman analyses were used to assess correlation and agreement between devices. All OCT retinal measures correlated highly between devices. The mean RNFL thickness was 7.4 µm lower on Cirrus HD-OCT than Stratus, indicating overall poor agreement for this measurement between these machines. Further, the limits of agreement (LOA) between Cirrus HD-OCT and Stratus were wide (−4.1 to 18.9 µm), indicating poor agreement at an individual subject level. The mean RNFL thickness was 1.94 µm (LOA: −5.74 to 9.62 µm) higher on Spectralis compared to Cirrus HD-OCT, indicating excellent agreement for this measurement across this cohort. Although these data indicate that these three devices agree poorly at an individual subject level (evidenced by wide LOA in both study cohorts) precluding their co-utilization in everyday practice, the small difference for mean measurements between Cirrus HD-OCT and Spectralis indicate pooled results from these two SD-devices could be used as outcome measures in clinical trials, provided patients are scanned on the same machine throughout the trial, similar to the utilization of multiple different MRI platforms in MS clinical trials.

Weight gain and recurrence in idiopathic intracranial hypertension: a case-control study

OBJECTIVE

To determine whether weight gain is associated with recurrence in idiopathic intracranial hypertension (IIH).

METHODS

Medical records of adult patients with IIH seen between 1993 and 2009 at 2 university hospitals were reviewed to identify those with and without recurrence. Patients with documented height and weight at presentation and at subsequent visits were studied. The Wilcoxon rank sum test was used to compare mean body mass index (BMI) and percent weight change between the groups of patients with recurrence and without recurrence. The signed-rank test was used for comparing BMI within groups at the various time points.

RESULTS

Fifty women with IIH were included in the analyses: 26 had IIH recurrence and 24 did not. Patients with recurrence had greater BMI at the time of recurrence compared to BMI at diagnosis (p = 0.02, signed-rank test). They also demonstrated a greater degree of weight gain between initial resolution and recurrence (BMI change +2.0 kg/m(2) [-1.5 to 10.8]) compared to patients without recurrence (-0.75 kg/m(2) [-35 to 3.6], p = 0.0009, Wilcoxon rank sum test). Patients without recurrence demonstrated stable weights (0%[95% CI -9.6 to 10.1%]), while patients with recurrence demonstrated a 6% weight gain ([-3.5 to 40.2%], p = 0.005), with an average rate of BMI gain of 1.3 kg/m(2)/year vs -0.96 kg/m(2)/year in those without recurrence.

CONCLUSION

Patients with IIH recurrence had significant increases in BMI compared to patients without recurrence in this cohort. Patients with resolved IIH should be advised that weight gain may be a risk factor for IIH recurrence.

One eye or two: a comparison of binocular and monocular low-contrast acuity testing in multiple sclerosis

PURPOSE

To determine the magnitudes of binocular summation for low- and high-contrast letter acuity in a multiple sclerosis (MS) cohort, and to characterize the roles that MS disease, age, interocular difference in acuity, and a history of optic neuritis have on binocular summation. The relation between binocular summation and monocular acuities and vision-specific quality of life (QoL) was also examined.

DESIGN

Cross-sectional observational study.

METHODS

Low-contrast acuity (2.5% and 1.25% contrast) and high-contrast visual acuity (VA) were assessed binocularly and monocularly in patients and disease-free controls at 3 academic centers. Binocular summation was calculated as the difference between the binocular and better eye scores. QoL was measured using the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and the 10-item neuro-ophthalmic supplement. The relation of the degree of binocular summation to monocular acuity, clinical history of acute optic neuritis, age, interocular acuity difference, and QoL was determined.

RESULTS

Binocular summation was demonstrated at all contrast levels, and was greatest at the lowest level (1.25%). Increasing age (P < .0001), greater interocular differences in acuity (P < .0001), and prior history of optic neuritis (P = .015) were associated with lower magnitudes of binocular summation; binocular inhibition was seen in some of these patients. Higher magnitudes of summation for 2.5% low-contrast acuity were associated with better scores for the NEI VFQ-25 (P = .02) and neuro-ophthalmic supplement (P = .03).

CONCLUSION

Binocular summation of acuity occurs in MS but is reduced by optic neuritis, which may lead to binocular inhibition. Binocular summation and inhibition are important factors in the QoL and visual experience of MS patients, and may explain why some prefer to patch or close 1 eye in the absence of diplopia or ocular misalignment.

Stratus OCT Quality Control in Two Multi-Centre Multiple Sclerosis Clinical Trials

The University of California (UC) Davis Reading Center evaluated 19,961 scans from 981 subjects in two multiple sclerosis therapeutic trials with the aim of determining the influence of optical coherence tomography quality control procedures on error rates. There was no optical coherence tomography technician certification in Trial 1, and technicians had very limited monitoring and feedback during the trial in view of the fact that data were received retrospectively. However, technicians were certified in Trial 2 and submitted data in accordance with the protocol. Trial 2 scans had higher signal strengths, fewer errors, and more useable data than the scans in Trial 1. Thus, certified technicians and prompt transmission of data for ongoing quality control monitoring provided higher quality data in multiple sclerosis trials.

Retinal nerve fiber layer thickness in children with optic pathway gliomas

PURPOSE

To determine the relationship of high-contrast visual acuity (VA) and low-contrast letter acuity with retinal nerve fiber layer (RNFL) thickness in children with optic pathway gliomas.

DESIGN

Cross-sectional convenience sample, with prospective data collection, from a tertiary care children's hospital of patients with optic pathway gliomas associated with neurofibromatosis type 1, sporadic optic pathway gliomas, and neurofibromatosis type 1 without optic pathway gliomas.

METHODS

Patients underwent best-corrected VA testing using surrounded H, O, T, V optotypes and low-contrast letter acuity (5%, 2.5%, and 1.25% low-contrast Sloan letter charts). Mean RNFL thickness (micrometers) was measured by a Stratus optical coherence tomography device (Carl Zeiss Meditec) using the fast RNFL thickness protocol. Eyes were classified as having abnormal vision if they had high-contrast VA of more than 0.1 logarithm of the minimal angle of resolution units or visual field loss. The association of subject age, glioma location, and RNFL thickness with both VA and low-contrast letter acuity scores was evaluated by 1-way analysis of variance and linear regression, using the generalized estimating equation approach to account for within-patient intereye correlations.

RESULTS

Eighty-nine eyes of patients with optic pathway gliomas were included, and 41 were classified as having abnormal VA or visual field loss. Reduced RNFL thickness was associated significantly with higher logarithm of the minimal angle of resolution scores for both VA (P < .001) and all low-contrast letter acuity charts (P < .001) when accounting for age and glioma location.

CONCLUSIONS

Eyes of most children with optic pathway gliomas and decreased RNFL thickness had abnormal VA or visual field loss.

The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters

OBJECTIVE

Sports-related concussion has received increasing attention as a cause of short- and long-term neurologic symptoms among athletes. The King-Devick (K-D) test is based on measurement of the speed of rapid number naming (reading aloud single-digit numbers from 3 test cards), and captures impairment of eye movements, attention, language, and other correlates of suboptimal brain function. We investigated the K-D test as a potential rapid sideline screening for concussion in a cohort of boxers and mixed martial arts fighters.

METHODS

The K-D test was administered prefight and postfight. The Military Acute Concussion Evaluation (MACE) was administered as a more comprehensive but longer test for concussion. Differences in postfight K-D scores and changes in scores from prefight to postfight were compared for athletes with head trauma during the fight vs those without.

RESULTS

Postfight K-D scores (n = 39 participants) were significantly higher (worse) for those with head trauma during the match (59.1 ± 7.4 vs 41.0 ± 6.7 seconds, p < 0.0001, Wilcoxon rank sum test). Those with loss of consciousness showed the greatest worsening from prefight to postfight. Worse postfight K-D scores (r(s) = -0.79, p = 0.0001) and greater worsening of scores (r(s) = 0.90, p < 0.0001) correlated well with postfight MACE scores. Worsening of K-D scores by ≥5 seconds was a distinguishing characteristic noted only among participants with head trauma. High levels of test-retest reliability were observed (intraclass correlation coefficient 0.97 [95% confidence interval 0.90-1.0]).

CONCLUSIONS

The K-D test is an accurate and reliable method for identifying athletes with head trauma, and is a strong candidate rapid sideline screening test for concussion.

Primary retinal pathology in multiple sclerosis as detected by optical coherence tomography

Optical coherence tomography studies in multiple sclerosis have primarily focused on evaluation of the retinal nerve fibre layer. The aetiology of retinal changes in multiple sclerosis is thought to be secondary to optic nerve demyelination. The objective of this study was to use optical coherence tomography to determine if a subset of patients with multiple sclerosis exhibit primary retinal neuronopathy, in the absence of retrograde degeneration of the retinal nerve fibre layer and to ascertain if such patients may have any distinguishing clinical characteristics. We identified 50 patients with multiple sclerosis with predominantly macular thinning (normal retinal nerve fibre-layer thickness with average macular thickness < 5th percentile), a previously undescribed optical coherence tomography defined phenotype in multiple sclerosis, and compared them with 48 patients with multiple sclerosis with normal optical coherence tomography findings, 48 patients with multiple sclerosis with abnormal optical coherence tomography findings (typical for multiple sclerosis) and 86 healthy controls. Utilizing a novel retinal segmentation protocol, we found that those with predominant macular thinning had significant thinning of both the inner and outer nuclear layers, when compared with other patients with multiple sclerosis (P < 0.001 for both), with relative sparing of the ganglion cell layer. Inner and outer nuclear layer thicknesses in patients with non-macular thinning predominant multiple sclerosis were not different from healthy controls. Segmentation analyses thereby demonstrated extensive deeper disruption of retinal architecture in this subtype than may be expected due to retrograde degeneration from either typical clinical or sub-clinical optic neuropathy. Functional corroboration of retinal dysfunction was provided through multi-focal electroretinography in a subset of such patients. These findings support the possibility of primary retinal pathology in a subset of patients with multiple sclerosis. Multiple sclerosis-severity scores were also significantly increased in patients with the macular thinning predominant phenotype, compared with those without this phenotype (n = 96, P=0.006). We have identified a unique subset of patients with multiple sclerosis in whom there appears to be disproportionate thinning of the inner and outer nuclear layers, which may be occurring as a primary process independent of optic nerve pathology. In vivo analyses of retinal layers in multiple sclerosis have not been previously performed, and structural demonstration of pathology in the deeper retinal layers, such as the outer nuclear layer, has not been previously described in multiple sclerosis. Patients with inner and outer nuclear layer pathology have more rapid disability progression and thus retinal neuronal pathology may be a harbinger of a more aggressive form of multiple sclerosis.

Cup to disc ratio by optical coherence tomography is abnormal in multiple sclerosis

OBJECTIVE

To identify and characterize cup to disc ratio (CDR) and related optic nerve head abnormalities in multiple sclerosis (MS) using spectral domain optical coherence tomography (OCT).

BACKGROUND

While CDR is routinely assessed by ophthalmologists in the evaluation of glaucoma, CDR and related optic nerve head metrics remain largely unexplored in MS.

DESIGN/METHODS

Cirrus-HD (high density) OCT was used to evaluate average CDR, vertical CDR, optic disc area, optic cup volume, and neuro-retinal rim area in 105 MS patients and 88 age-matched healthy individuals. High-contrast (100%) visual acuity, 2.5% low-contrast letter acuity and 1.25% low-contrast letter acuity were assessed in 77 MS patients. Two-sample t-tests were used in the analysis of OCT-derived optic nerve head measures between healthy controls and MS patients. Multivariate regression (accounting for age and gender) was used to assess relationships between optic nerve head measures and visual function.

RESULTS

Average CDR (p=0.007) and vertical CDR (p=0.005) were greater in MS patients compared to healthy controls, while neuro-retinal rim area was decreased in MS patients (p=0.001). CDR increased with retinal nerve fiber layer (RNFL) thinning (r=-0.29, p=0.001). 2.5% low-contrast (p=0.005) and 1.25% low-contrast letter acuity (p=0.03) were lower in MS patients with higher vertical CDR.

CONCLUSIONS/RELEVANCE

CDR (as determined by spectral domain OCT) is abnormal in MS and correlates with visual function. OCT-derived CDR and related optic nerve head metrics may represent an objective measure by which to monitor disease progression, and potentially neuroprotection, in therapeutic MS trials.

Optical coherence tomography (OCT): imaging the visual pathway as a model for neurodegeneration

Axonal and neuronal degeneration are important features of multiple sclerosis (MS) and other neurologic disorders that affect the anterior visual pathway. Optical coherence tomography (OCT) is a non-invasive technique that allows imaging of the retinal nerve fiber layer (RNFL), a structure which is principally composed of ganglion cell axons that form the optic nerves, chiasm, and optic tracts. Since retinal axons are nonmyelinated until they penetrate the lamina cribrosa, the RNFL is an ideal structure (no other central nervous system tract has this unique arrangement) for visualizing the processes of neurodegeneration, neuroprotection and, potentially, even neuro-repair. OCT is capable of providing high-resolution reconstructions of retinal anatomy in a rapid and reproducible fashion and permits objective analysis of the RNFL (axons) as well as ganglion cells and other neurons in the macula. In a systematic OCT examination of multiple sclerosis (MS) patients, RNFL thickness and macular volumes are reduced when compared to disease-free controls. Conspicuously, these changes, which signify disorganization of retinal structural architecture, occur over time even in the absence of a history of acute demyelinating optic neuritis. RNFL axonal loss in MS is most severe in those eyes with a corresponding reduction in low-contrast letter acuity (a sensitive vision test involving the perception of gray letters on a white background) and in those patients who exhibit the greatest magnitude of brain atrophy, as measured by validated magnetic resonance imaging techniques. These unique structure-function correlations make the anterior visual pathway an ideal model for investigating the effects of standard and novel therapies that target axonal and neuronal degeneration. We provide an overview of the physics of OCT, its unique properties as a non-invasive imaging technique, and its potential applications toward understanding mechanisms of brain tissue injury in MS, other optic neuropathies, and neurologic disorders.

Eye disorders in patients with multiple sclerosis: natural history and management

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system and leading cause of disability in young adults. Vision impairment is a common component of disability for this population of patients. Injury to the optic nerve, brainstem, and cerebellum leads to characteristic syndromes affecting both the afferent and efferent visual pathways. The objective of this review is to summarize the spectrum of eye disorders in patients with MS, their natural history, and current strategies for diagnosis and management. We emphasize the most common disorders including optic neuritis and internuclear ophthalmoparesis and include new techniques, such as optical coherence tomography, which promise to better our understanding of MS and its effects on the visual system.

Associations between retinal nerve fiber layer abnormalities and optic nerve examination

OBJECTIVE

Retinal nerve fiber layer (RNFL) abnormalities detected by optical coherence tomography (OCT) are useful markers for axonal loss and visual dysfunction in multiple sclerosis (MS), but their role in routine clinical management is not well-studied.

METHODS

Clinical and OCT examinations were performed on 240 patients attending a neurology clinic. Using OCT 5th percentile to define abnormal RNFL thickness, we compared eyes classified by neurologists as having optic atrophy to RNFL thickness, and afferent pupillary defect (APD) to RNFL thickness ratios of eye pairs.

RESULTS

Mean RNFL thickness was less in eyes classified by neurologists as having optic atrophy (79.4 ± 21 μm; n=63) vs those without (97.0 ± 15 μm; n=417; p < 0.001, t test) and in eyes with an APD (84.1 ± 16 μm; n=44) than without an APD (95.8 ± 17 μm; n=436; p < 0.001). Physicians' diagnostic accuracy for detecting pallor in eyes with an abnormal RNFL thickness was 79% (sensitivity=0.56; specificity=0.82). Accuracy for detecting a RAPD in patients with mean RNFL ratio (affected eye to unaffected eye) <0.90 was 73% (sensitivity=0.30; specificity=0.86). Ability to detect visual pathway injury via assessment of atrophy and APD differed between neurologists.

CONCLUSIONS

OCT reveals RNFL abnormality in many patients in whom eyes are not classified by neurologic examiners as having optic atrophy. Further study is needed to define the role of OCT measures in the context of examinations for optic atrophy and APD by neuroophthalmologists. OCT-measured RNFL thickness is likely to have an important future role in the clinical setting.

Longitudinal study of vision and retinal nerve fiber layer thickness in multiple sclerosis

OBJECTIVE

Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes in RNFL thickness relate to visual loss. We also examined patterns of RNFL thinning over time in MS eyes with and without a prior history of acute optic neuritis (ON).

METHODS

Patients underwent OCT measurement of RNFL thickness at baseline and at 6-month intervals during a mean follow-up of 18 months at 3 centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed.

RESULTS

Among 299 patients (593 eyes) with >or=6 months follow-up, eyes with visual loss showed greater RNFL thinning compared to eyes with stable vision (low-contrast acuity, 2.5%: p < 0.001; VA: p = 0.005). RNFL thinning increased over time, with average losses of 2.9microm at 2 to 3 years and 6.1microm at 3 to 4.5 years (p < 0.001 vs 0.5-1-year follow-up interval). These patterns were observed for eyes with or without prior history of ON. Proportions of eyes with RNFL loss greater than test-retest variability (>or=6.6microm) increased from 11% at 0 to 1 year to 44% at 3 to 4.5 years (p < 0.001).

INTERPRETATION

Progressive RNFL thinning occurs as a function of time in some patients with MS, even in the absence of ON, and is associated with clinically significant visual loss. These findings are consistent with subclinical axonal loss in the anterior visual pathway in MS, and support the use of OCT and low-contrast acuity as methods to evaluate the effectiveness of putative neuroprotection protocols.

Reproducibility of high-resolution optical coherence tomography in multiple sclerosis

Optical coherence tomography (OCT) is a non-invasive method to quantify neurodegeneration as an outcome in multiple sclerosis clinical trials; however, no data exist on Cirrus spectral domain optical coherence tomography (SD-OCT) reproducibility in patients with multiple sclerosis. The objective of this study was to determine the protocol for achieving optimal inter-visit, inter-rater, and intra-rater reproducibility for studies performed on healthy controls and multiple sclerosis patients utilizing novel high-definition SD-OCT. This is a prospective study of inter-visit, inter-rater, and intra-rater reproducibility in multiple sclerosis patients (n = 58) and healthy controls (n = 32) on Cirrus-HD SD-OCT. Excellent reproducibility of average and quadrantic retinal nerve fiber layer (RNFL) thickness values, average macular thickness (AMT), and total macular volume (TMV) [measured by intraclass correlation coefficient (ICC)] was found for inter-visit (healthy controls: mean RNFL = 0.97, quadrant range = 0.92-0.97, AMT = 0.97, TMV = 0.92), inter-rater (MS: mean RNFL = 0.97, quadrant = 0.94-0.98, AMT = 0.99, TMV = 0.96; healthy controls: mean RNFL = 0.97, quadrant = 0.94-0.97, AMT = 0.98, TMV = 0.99), and intra-rater (MS patients: mean RNFL = 0.99, quadrant = 0.83-0.99, AMT = 0.97, TMV = 0.98) reproducibility. The reproducibility of retinal measures derived by Cirrus HD-OCT, especially quadrantic values, is excellent. Specific procedures for OCT acquisition and analysis of retinal imaging metrics using SD-OCT technology may improve the application of this novel technology in multiple sclerosis.

Education research: a new system for reducing patient nonattendance in residents' clinic

BACKGROUND

Patient nonattendance in neurology and other subspecialty clinics is closely linked to longer waiting times for appointments. We developed a new scheduling system for residents' clinic that reduced average waiting times from >4 months to < or =3 weeks. The purpose of this study was to compare nonattendance for clinics scheduled using the new model (termed "rapid access") vs those scheduled using the traditional system.

METHODS

In the rapid access system, nonestablished (new) patients are scheduled on a first-come, first-served basis for appointments that must occur within 2 weeks of their telephone request. Nonattendance for new patient appointments (cancellations plus no-shows) was compared for patients scheduled under the traditional vs the rapid access scheduling systems. Nonattendance was compared for periods of 6, 12, and 18 months following change in scheduling system using the chi2 test and logistic regression.

RESULTS

Compared to the traditional scheduling system, the rapid access system was associated with a 50% reduction in nonattendance over 18 months (64% [812/1,261 scheduled visits] vs 31% [326/1,059 scheduled visits], p < 0.0001). In logistic regression models, appointment waiting time was a major factor in the relation between rapid access scheduling and nonattendance. Demographics, diagnoses, and likelihood of scheduling follow-up visits were similar between the 2 systems.

CONCLUSIONS

A new scheduling system that minimizes waiting times for new patient appointments has been effective in substantially reducing nonattendance in our neurology residents' clinic. This rapid access system should be considered for implementation and will likely enhance the outpatient educational experience for trainees in neurology.

Measuring the rate of progression in Friedreich ataxia: implications for clinical trial design

Friedreich ataxia is an autosomal recessive neurodegenerative disorder characterized by ataxia of all four limbs, dysarthria, and arreflexia. A variety of measures are currently used to quantify disease progression, including the Friedreich Ataxia Rating Scale, examiner-rated functional disability scales, self-reported activities of daily living and performance measures such as the timed 25-foot walk, 9-hole pegboard test, PATA speech test, and low-contrast letter acuity vision charts. This study examines the rate of disease progression over one and two years in a cohort of 236 Friedreich ataxia patients using these scales and performance measure composites. The Friedreich Ataxia Rating Scale and performance-measure composites captured disease progression, with a greater sensitivity to change over 2 years than over 1 year. The measures differed in their sensitivity to change and in possible bias. These results help to establish norms for progression in FRDA that can be useful in measuring the long-term success of therapeutic agents and defining sample-size calculations for double-blind clinical trials.

Macular volume determined by optical coherence tomography as a measure of neuronal loss in multiple sclerosis

BACKGROUND

Inner (area adjacent to the fovea) and outer regions of the macula differ with respect to relative thicknesses of the ganglion cell layer (neurons) vs retinal nerve fiber layer (RNFL; axons).

OBJECTIVE

To determine how inner vs outer macular volumes relate to peripapillary RNFL thickness and visual function in multiple sclerosis (MS) and to examine how these patterns differ among eyes with vs without a history of acute optic neuritis (ON).

DESIGN

Study using cross-sectional optical coherence tomography.

SETTING

Three academic tertiary care MS centers.

PARTICIPANTS

Patients with MS, diagnosed by standard criteria, and disease-free control participants.

MAIN OUTCOME MEASURES

Optical coherence tomography was used to measure macular volumes and RNFL thickness. Visual function was assessed using low-contrast letter acuity and high-contrast visual acuity (Early Treatment Diabetic Retinopathy Study charts).

RESULTS

Among eyes of patients with MS (n = 1058 eyes of 530 patients), reduced macular volumes were associated with peripapillary RNFL thinning; 10-microm differences in RNFL thickness (9.6% of thickness in control participants without disease) corresponded to 0.20-mm(3) reductions in total macular volume (2.9% of volume in control participants without disease, P < .001). This relation was similar for eyes of MS patients with and without a history of ON. Although peripapillary RNFL thinning was more strongly associated with decrements in outer compared with inner macular volumes, correlations with inner macular volume were significant (r = 0.58, P < .001) and of slightly greater magnitude for eyes of MS patients with a history of ON vs eyes of MS patients without a history of ON (r = 0.61 vs r = 0.50). Lower (worse) visual function scores were associated with reduced total, inner, and outer macular volumes. However, accounting for peripapillary RNFL thickness, the relation between vision and inner macular volume remained significant and unchanged in magnitude, suggesting that this region contains retinal structures separate from RNFL axons that are important to vision.

CONCLUSIONS

Analogous to studies of gray matter in MS, these data provide evidence that reductions of volume in the macula (approximately 34% neuronal cells by average thickness) accompany RNFL axonal loss. Peripapillary RNFL thinning and inner macular volume loss are less strongly linked in eyes of MS patients without a history of ON than in eyes of MS patients with a history of ON, suggesting alternative mechanisms for neuronal cell loss. Longitudinal studies with segmentation of retinal layers will further explore the relation and timing of ganglion cell degeneration and RNFL thinning in MS.

Assessing disability progression with the Multiple Sclerosis Functional Composite

BACKGROUND

The initial Multiple Sclerosis Functional Composite (MSFC) proposal was a three-part composite of quantitative measures of ambulation, upper extremity function, and cognitive function expressed as a single composite Z-score. However, the clinical meaning of an MSFC Z-score change is not obvious. This study instead used MSFC component data to define a patient-specific disease progression event.

OBJECTIVE

Evaluate a new method for analyzing disability progression using the MSFC.

METHODS

MSFC progression was defined as worsening from baseline on scores of at least one MSFC component by 20% (MSFC Progression-20) or 15% (MSFC Progression-15), sustained for >or=3 months. Progression rates were determined using data from natalizumab clinical studies (Natalizumab Safety and Efficacy in Relapsing Remitting Multiple Sclerosis [AFFIRM] and Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing Remitting Multiple Sclerosis [SENTINEL]). Correlations between MSFC progression and other clinical measures were determined, as was sensitivity to treatment effects.

RESULTS

Substantial numbers of patients met MSFC progression criteria, with MSFC Progression-15 being more sensitive than MSFC Progression-20, at both 1 and 2 years. MSFC Progression-20 and MSFC Progression-15 were related significantly to Expanded Disability Status Scale (EDSS) score change, relapse rate, and the SF-36 Physical Component Summary (PCS) score change. MSFC Progression-20 and MSFC Progression-15 at 1 year were predictive of EDSS progression at 2 years. Both MSFC progression end points demonstrated treatment effects in AFFIRM, and results were replicated in SENTINEL.

CONCLUSION

MSFC Progression-20 and MSFC Progression-15 are sensitive measures of disability progression; correlate with EDSS, relapse rates, and SF-36 PCS; and are capable of demonstrating therapeutic effects in randomized, controlled clinical studies.

Optical coherence tomography helps differentiate neuromyelitis optica and MS optic neuropathies

OBJECTIVE

To evaluate the retinal nerve fiber layer (RNFL) thickness and macular volume in neuromyelitis optica (NMO) spectrum patients using optical coherence tomography (OCT).

BACKGROUND

OCT can quantify damage to retinal ganglion cell axons and can identify abnormalities in multiple sclerosis and optic neuritis (ON) eyes. OCT may also be useful in the evaluation of patients with NMO.

METHODS

OCT and visual function testing were performed in 26 NMO spectrum patients with a history of ON, 17 patients with isolated longitudinally extensive transverse myelitis (LETM) without ON, 378 patients with relapsing-remitting multiple sclerosis (RRMS), and 77 healthy controls at 2 centers.

RESULTS

Substantial RNFL thinning was seen in NMO ON eyes (63.6 microm) relative to both RRMS ON eyes (88.3 microm, p < 0.0001) and control eyes (102.4 microm, p < 0.0001). A first episode of ON was estimated to cause 24 microm more loss of RNFL thickness in NMO than RRMS. Similar results were seen for macular volume. ON also was associated with more severe visual impairment in NMO spectrum patients than in RRMS patients. Eyes in the LETM group and unaffected NMO eyes were not significantly different from controls, though conclusions about these subgroups were limited by small sample sizes.

CONCLUSIONS

Optical coherence tomography (OCT) shows more severe retinal damage after optic neuritis (ON) episodes in neuromyelitis optica (NMO) than in relapsing-remitting multiple sclerosis. Identification of substantial retinal nerve fiber layer loss (>15 microm) after ON in a non-multiple sclerosis patient should prompt consideration of an NMO spectrum condition. OCT may be a useful tool for the evaluation of patients with NMO.

Damage to the optic radiation in multiple sclerosis is associated with retinal injury and visual disability

OBJECTIVE

To determine whether damage to the optic radiation (OR) in multiple sclerosis (MS) is associated with optic nerve injury and visual dysfunction.

DESIGN

Case-control study.

SETTING

Referral center.

PARTICIPANTS

Ninety referred patients with MS and 29 healthy volunteers.

MAIN OUTCOME MEASURES

Magnetic resonance imaging indices along the OR were reconstructed with diffusion tensor tractography. Retinal nerve fiber layer thickness and visual acuity at high and low contrast were measured in a subset of the MS group (n = 36).

RESULTS

All tested magnetic resonance imaging indices (fractional anisotropy [FA]; mean, parallel, and perpendicular [lambda( perpendicular)] diffusivity; T2 relaxation time; and magnetization transfer ratio) were significantly abnormal in patients with MS. Mean retinal nerve fiber layer thickness was significantly correlated with FA (r = 0.55; P < .001) and lambda( perpendicular) (r = -0.37; P = .001). The retinal nerve fiber layer thickness in the nasal retinal quadrant was also specifically correlated with FA and lambda( perpendicular) in the synaptically connected contralateral OR. In individuals with less severely damaged optic nerves (mean retinal nerve fiber layer thickness >80 mum), letter acuity scores at 2.5% contrast were correlated with OR-specific FA (r = 0.55; P = .004), lambda( perpendicular) (r = -0.40; P = .04), and magnetization transfer ratio (r = 0.54; P = .01), as well as the fraction of OR volume made up of lesions (r = -0.69; P < .001).

CONCLUSIONS

Fractional anisotropy and lambda( perpendicular) are potentially useful quantitative magnetic resonance imaging biomarkers of OR-specific damage in MS. Such damage is associated with retinal injury and visual disability.

Proof of concept studies for tissue-protective agents in multiple sclerosis

BACKGROUND

There is considerable interest in tissue-protective treatments for multiple sclerosis (MS).

METHODS AND OBJECTIVES

We convened a group of MS clinical trialists and related researchers to discuss designs for proof of concept studies utilizing currently available data and assessment methods.

RESULTS

Our favored design was a randomized, double-blind, parallel-group study of active treatment versus placebo focusing on changes in brain volume from a post-baseline scan (3-6 months after starting treatment) to the final visit 1 year later. Study designs aimed at reducing residual deficits following acute exacerbations are less straightforward, depending greatly on the anticipated rapidity of treatment effect onset.

CONCLUSIONS

The next step would be to perform one or more studies of potential tissue-protective agents with these designs in mind, creating the longitudinal data necessary to refine endpoint selection, eligibility criteria, and sample size estimates for future trials.

Treatment of acute demyelinating optic neuritis

Patients with typical acute monosymptomatic demyelinating optic neuritis should receive gadolinium-enhanced magnetic resonance imaging (MRI) of the brain and orbits to determine if they are at high risk for the subsequent development of clinically definite multiple sclerosis (CDMS). The presence of >or=2 white matter lesions (>or=3 mm in diameter, at least 1 lesion periventricular or ovoid) indicates high risk for CDMS; the following treatment should be considered for such patients: 1. Intravenous methylprednisolone sodium succinate (1 gram IV/day for 3 days) followed by oral prednisone (1 mg/kg/day for 11 days) with 4-day taper (20 mg on day 1, 10 mg on days 2 and 4); 2. Interferon beta 1-a (Avonex 30microg intramuscularly [IM] weekly, or Rebif 22 microg subcutaneously [SQ] weekly). These two drugs have been shown to reduce the short-term risk of CDMS in high risk monosymptomatic patients. In monosymptomatic patients with <2 white matter lesions, and in patients for whom CDMS has been established, IV methylprednisolone treatment followed by oral prednisone should be considered on an individual basis. Treatment in these patients may hasten visual recovery, but does not affect long-term visual outcome. Oral prednisone alone, without prior treatment with IV methylprednisolone, may increase the risk for recurrent optic neuritis and should be avoided.

Vision related quality of life in multiple sclerosis: correlation with new measures of low and high contrast letter acuity

OBJECTIVE

To examine the relation between low contrast letter acuity, a new visual function test for multiple sclerosis (MS) trials, and vision targeted health related quality of life (HRQOL).

METHODS

Patients in this cross sectional study were part of an ongoing investigation of visual function in MS. Patients were tested binocularly using low contrast letter acuity and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) charts. The 25 Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25, Impact of Visual Impairment Scale and Short Form 36 Health Survey (SF-36) were administered.

RESULTS

Among 167 patients, mean age was 48 (10) years, with median Expanded Disability Status Scale (EDSS) 2.0 (range 1.0-7.5), and median binocular Snellen acuity equivalent (ETDRS charts) 20/16 (range 20/12.5 to 20/100). Reductions in vision specific HRQOL were associated with lower (worse) scores for low contrast letter acuity and VA (p<0.001, linear regression, accounting for age). Two line differences in visual function were associated, on average, with >4 point (6.7-10.9 point) worsening in the NEI-VFQ-25 composite score, reductions that are considered clinically meaningful. Scores for the 10 Item Neuro-Ophthalmic Supplement to the NEI-VFQ-25 also correlated well with visual function. Associations between reduced low contrast acuity and worse vision targeted HRQOL remained significant in models accounting for high contrast VA, EDSS and history of acute optic neuritis.

CONCLUSIONS

Low contrast letter acuity scores correlate well with HRQOL in MS. Two line differences in scores for low contrast acuity and VA reflect clinically meaningful differences in vision targeted HRQOL. Low contrast acuity testing provides information on patient reported aspects of vision, supporting use of these measures in MS clinical trials.

Relationship of optic nerve and brain conventional and non-conventional MRI measures and retinal nerve fiber layer thickness, as assessed by OCT and GDx: a pilot study

BACKGROUND

Measurement of retinal nerve fiber layer (RNFL) thickness in multiple sclerosis (MS) is gaining increasing attention.

OBJECTIVES

To explore the relationship between RNFL thickness as measured by optical coherence tomography (OCT) and scanning laser polarimetry with variable corneal compensation (GDx), and conventional and non-conventional optic nerve and brain MRI measures.

METHODS

Twelve relapsing-remitting (RR) MS patients (12 affected and 12 unaffected eyes) and 4 age- and sex-matched normal controls (NC) (8 unaffected eyes) were enrolled. Four MS patients had a history of bilateral optic neuritis (ON), four had a history of unilateral ON, and 4 had no history of ON. Optic nerve MRI measurements included the length of T2 lesions, measurement of optic nerve atrophy, magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI) measures. Optic nerve atrophy was measured by a novel method with high reproducibility. Brain MRI measurements included T1 and T2 lesion volumes (LVs) and their relative MTRs, and tissue class specific atrophy, MTR and DTI measures. Measures of RNFL were evaluated with OCT and GDx. We also evaluated both high and low contrast letter acuities (LCLA) in order to determine the relationship between vision, MRI metrics, and retinal structural architecture.

RESULTS

LCLA, RNFL-OCT and optic nerve radius measures showed more robust differences between NC and MS patients, and between MS patients with affected and unaffected eyes. T2-LV and T1-LV, as well as gray matter atrophy, DTI and MTR measures were related to LCLA and RNFL thickness. Unique additive variance regression models showed that both brain and optic nerve MRI measures independently accounted for about 50% of the variance in LCLA and RNFL thickness. In reverse models, about 20% of the additional independent variance was explained by optic nerve or brain MRI metrics.

CONCLUSIONS

Measurement of RNFL thickness and radius of the optic nerve should be preferred to the other optic nerve MRI measures in clinical studies. Whole brain lesion and GM measures are predictive of impaired visual function with corresponding structural concomitants.

Pediatric optic neuritis: brain MRI abnormalities and risk of multiple sclerosis

BACKGROUND

Optic neuritis is often the initial presentation of multiple sclerosis (MS). As established by the Optic Neuritis Treatment Trial, an abnormal baseline brain MRI is a strong predictor of MS after isolated optic neuritis in adults. However, the rate of conversion to MS after optic neuritis in children based upon brain MRI findings is unknown.

METHODS

We reviewed the medical records of children (<18 years) presenting with optic neuritis between 1993 and 2004 at the Children's Hospital of Philadelphia. Children with a history of demyelinating disease or prior optic neuritis were excluded. Symptoms, ophthalmologic findings, MRI findings, and clinical outcomes were recorded.

RESULTS

We identified 29 consecutive children with idiopathic optic neuritis. Eleven patients (38%) had white matter T2/FLAIR lesions in the brain (not including the optic nerves). Eighteen patients were followed for more than 24 months, and 3 of the 18 (17%) developed MS. All 3 patients had an abnormal brain MRI scan at their initial presentation of optic neuritis. None of the patients with a normal brain MRI scan at presentation developed MS over an average follow-up of 88.5 months. Patients with one or more white matter lesions on MRI were more likely to develop MS (3/7 vs 0/11, p = 0.04, Fisher exact test).

CONCLUSIONS

Children with brain MRI abnormalities at the time of the diagnosis of optic neuritis have an increased risk of multiple sclerosis. Larger collaborative studies are needed to further define the prognosis for childhood optic neuritis.

Reproducibility of optical coherence tomography in multiple sclerosis

BACKGROUND

Optical coherence tomography (OCT) is a promising new method of quantifying axon thickness in the retinal nerve fiber layer (RNFL) that has been used predominantly by ophthalmologists to monitor glaucoma. Optical coherence tomography is being considered as a potential outcome measure in multiple sclerosis (MS) clinical trials, but no data exist on the reproducibility of this technique in MS centers.

OBJECTIVE

To determine the reproducibility of OCT measurement of mean RNFL thickness in the undilated eyes of healthy control subjects and patients with MS.

DESIGN

Prospective analysis of 4 healthy controls to determine interrater, intrarater, and longitudinal reproducibility. Cross-sectional analysis of 3 cohorts of patients with MS (n = 396) and healthy controls (n = 153).

SETTING

Multiple sclerosis clinics at 3 academic medical centers.

PATIENTS OR OTHER PARTICIPANTS

Healthy controls and patients with MS. Main Outcome Measure Thickness of RNFL.

RESULTS

We found excellent agreement with respect to interrater (intraclass correlation [ICC], 0.89), intrarater (ICC, 0.98), and intervisit (ICC, 0.91) results. Mean RNFL thickness did not vary significantly among research centers for patients with MS (93, 92, and 90 microm) or among healthy controls (103, 105, and 104 microm) by site.

CONCLUSIONS

We demonstrate that mean RNFL thickness can be reproducibly measured by trained technicians in an MS center using the OCT-3 model. The RNFL measures from cohorts of age-matched controls and patients with MS from 3 different research centers were remarkably similar.

Tension Pneumocephalus after Endoscopic Sinus Surgery: Case Report of Repair and Management in Absence of Obvious Skull Base Defect

Tension pneumocephalus is a rare complication of functional endoscopic sinus surgery that may lead to rapid neurologic deterioration. Patients typically display symptoms within hours after the operation, and computed tomography reveals the presence of a skull base defect. We report a unique case of subacute tension pneumocephalus with no obvious skull base defect, which was associated with a pupil-involving third-nerve palsy. Wediscuss management of this complication and preventive measures for avoiding pneumocephalus after functional endoscopic sinus surgery.

Tension pneumocephalus after endoscopic sinus surgery: case report of repair and management in absence of obvious skull base defect

Tension pneumocephalus is a rare complication of functional endoscopic sinus surgery that may lead to rapid neurologic deterioration. Patients typically display symptoms within hours after the operation, and computed tomography reveals the presence of a skull base defect. We report a unique case of subacute tension pneumocephalus with no obvious skull base defect, which was associated with a pupil-involving third-nerve palsy. We discuss management of this complication and preventive measures for avoiding pneumocephalus after functional endoscopic sinus surgery.

Optical coherence tomography and disease subtype in multiple sclerosis

OBJECTIVE

To examine retinal nerve fiber layer (RNFL) thickness, macular volumes (MV), and visual acuity in multiple sclerosis (MS) eyes, with and without history of acute optic neuritis (ON).

METHODS

RNFL thickness was measured in 326 MS and 94 control eyes using optical coherence tomography (OCT). MV and vision testing were done in a subset of the cohort. MS subtype was classified as relapsing-remitting (RRMS, n = 135), primary progressive (PPMS, n = 12), and secondary progressive (SPMS, n = 16).

RESULTS

MS ON eyes had decreased RNFL thickness (84.2 microm) compared to controls (102.7 microm) (p < 0.0001). Unaffected fellow eyes of MS ON eyes (93.9 microm) (p < 0.01) and patients with MS with no history of ON (95.9 microm) (p < 0.05) also had decreased RNFL. RRMS (94.4 microm) (p < 0.001), PPMS (88.9 microm) (p < 0.01), and SPMS (81.8 microm) (p < 0.0001) (adjusted for age and duration of disease) had decreased RNFL compared to controls. There were significant differences in RNFL thickness within quadrants of peripapillary retina comparing relapsing to progressive MS subtypes. MV was decreased in MS ON eyes (6.2 mm(3)) (p < 0.0001) and SPMS subjects (6.2 mm(3)) (p < 0.05) compared to controls (6.8 mm(3)).

CONCLUSION

Retinal nerve fiber layer (RNFL) is significantly decreased in multiple sclerosis (MS) optic neuritis (ON) eyes, unaffected fellow eyes of patients with MS ON, and MS eyes not affected by ON in our cohort. Macular volumes (MV) showed a significant decrease in MS ON eyes. Progressive MS cases showed more marked decreases in RNFL and MV than relapsing-remitting MS. OCT is a promising tool to detect subclinical changes in RNFL and MV in patients with MS and should be examined in longitudinal studies as a potential biomarker of retinal pathology in MS.

Retinal nerve fiber layer is associated with brain atrophy in multiple sclerosis

OBJECTIVE

Optical coherence tomography (OCT) noninvasively quantifies retinal nerve fiber layer (RNFL) thickness. Studies show RNFL thinning in multiple sclerosis (MS), and we assessed its association with brain atrophy.

METHODS

RNFL thickness was measured in 40 patients with MS and 15 controls. Brain parenchymal fraction (BPF) and partial brain volumes were estimated from cranial MRI scans using SIENA-X. Multiple linear regression modeling assessed the association between OCT and MRI measures of atrophy.

RESULTS

Minimum RNFL thickness and subject age together predict 21% (p = 0.005) of the variance in BPF in all patients with MS and 43% (p = 0.003) of the variance in BPF in the subgroup with relapsing remitting MS (RRMS; n = 20). The partial correlation coefficient between BPF and minimum RNFL thickness, controlling for age, is 0.46 (p = 0.003) in all patients with MS and 0.69 (p = 0.001) in patients with RRMS. These associations are driven by CSF volume but not by gray or white matter volume. There is no significant association of these variables among controls.

CONCLUSIONS

In multiple sclerosis (MS), retinal nerve fiber layer thickness is associated with brain parenchymal fraction and CSF volume. These data suggest that quantification of axonal thickness in the retina by optical coherence tomography (OCT) provides concurrent information about MRI brain abnormality in MS. OCT should be examined in longitudinal studies to determine if it could be used as an outcome measure in clinical trials of neuroprotective drugs.

Antioxidant use in Friedreich ataxia

Many antioxidants have been suggested as potential treatments for Friedreich ataxia, but have not been tested in clinical trials. We found that a majority of patients in our cohort already use such antioxidants, including idebenone, which is not available at a pharmaceutical grade in the United States. Younger age, cardiomyopathy and shorter GAA repeat length were independent predictors of idebenone use, but no factors predicted use of other antioxidants. This confirms that non-prescription antioxidant use represents a major confounder to formal trials of existing and novel agents for Friedreich ataxia.

Relation of vision to global and regional brain MRI in multiple sclerosis

OBJECTIVE

To examine the relation between low-contrast letter acuity, an emerging visual outcome for multiple sclerosis (MS) clinical trials, and brain MRI abnormalities in an MS cohort.

METHODS

T2 lesion volume and brain parenchymal fraction were determined for whole brain and within visual pathway regions of interest. Magnetization transfer ratio histograms were examined. Vision testing was performed binocularly using low-contrast letter acuity (2.5%, 1.25% contrast) and high-contrast visual acuity (VA). Linear regression, accounting for age and disease duration, was used to assess the relation between vision and MRI measures.

RESULTS

Patients (n = 45) were aged 44 +/- 11 years, with disease duration of 5 years (range <1 to 21), Expanded Disability Status Scale score of 2.0 (0 to 6.0), and binocular Snellen acuity of 20/16 (20/12.5 to 20/25). The average T2 lesion volume was 18.5 mm(3). Patients with lower (worse) low-contrast letter acuity and high-contrast VA scores had greater T2 lesion volumes in whole brain (2.5% contrast: p = 0.004; 1.25%: p = 0.002; VA: p = 0.04), Area 17 white matter (2.5%: p < 0.001; 1.25%: p = 0.02; VA: p = 0.01), and optic radiations (2.5%: p = 0.001; 1.25%: p = 0.02; VA: p = 0.007). Within whole brain, a 3-mm(3) increase in lesion volume corresponded, on average, to a 1-line worsening of low-contrast acuity, whereas 1-line worsening of high-contrast acuity corresponded to a 5.5-mm(3) increase.

CONCLUSIONS

Low-contrast letter acuity scores correlate well with brain MRI lesion burden in multiple sclerosis (MS), supporting validity for this vision test as a candidate for clinical trials. Disease in the postgeniculate white matter is a likely contributor to visual dysfunction in MS that may be independent of acute optic neuritis history.

Seizure-Free Outcome in Randomized Add-on Trials of the New Antiepileptic Drugs

PURPOSE

The goal of this study is to (1) provide clinically useful, previously unpublished comparative analyses of seizure-freedom rates for newer antiepileptic drugs (AEDs), and (2) recommend a standard for data presentation and analysis.

METHODS

Data were reviewed from placebo-controlled adjunctive trials in refractory patients of gabapentin (GPN), lamotrigine (LTG), topiramate (TOP), tiagabine (TGB), oxcarbazepine (OXC), levetiracetam (LEV), zonisamide (ZNS), and pregabalin (PGB). Seizure-freedom analyses in these publications, if included at all, consistently included both patients who completed the trial, and those who dropped out prior to completion (last observation carried forward, LOCF). This has the potential to increase reported seizure-free outcomes. Pharmaceutical companies were contacted for the provision of unpublished seizure-free data in the patients who completed the entire study.

RESULTS

In most cases, LOCF analysis produced a higher rate of seizure freedom compared to complete analysis. A total of 0%-1.1% of the LOCF population was seizure-free in the GPN trials (complete data not available). For the remaining AEDs, seizure-freedom results in the LOCF versus complete populations were: 0.7% versus 0.8% (LTG trial); 12% versus 2.6% (OXC trial); 3.6%-6.4% versus 3.9%-7.1% (LEV trial); 3.7%-7.9% versus 1.3%-1.4% (PGB trial); and 6.0% versus 3.0% (ZNS trial, minus titration period).

CONCLUSIONS

By employing LOCF, a clinically unrealistic picture of seizure-free rates may be reported. Access to complete data is informative, as it includes only those patients who were able to tolerate the drug at doses that produced seizure freedom. Ideally, data from both ITT and complete analyses should be made available.

Natalizumab reduces visual loss in patients with relapsing multiple sclerosis

OBJECTIVE

To examine the effects of natalizumab on low-contrast letter acuity as a prespecified tertiary endpoint in two randomized clinical trials and to evaluate the usefulness of low-contrast letter acuity testing as a candidate test of visual function in multiple sclerosis (MS).

METHODS

AFFIRM and SENTINEL were randomized, double-blind, placebo-controlled, multicenter, phase 3 clinical trials of natalizumab in relapsing MS. Natalizumab was evaluated as monotherapy in AFFIRM and as add-on to interferon beta-1a in SENTINEL. Vision testing was performed at 100% contrast (visual acuity) and low-contrast (2.5% and 1.25%).

RESULTS

The risk of clinically significant visual loss (predefined as a two-line worsening of acuity sustained over 12 weeks) at the lowest contrast level (1.25%) was reduced in the natalizumab treatment arms by 35% in AFFIRM (hazard ratio = 0.65; 95% CI: 0.47 to 0.90; p = 0.008) and by 28% in SENTINEL (hazard ratio = 0.72; 95% CI: 0.54 to 0.98; p = 0.038, Cox proportional hazards models). Mean changes in vision scores from baseline were also significantly different, reflecting worsening in non-natalizumab groups.

CONCLUSIONS

Natalizumab reduces visual loss in patients with relapsing multiple sclerosis. Low-contrast acuity testing has the capacity to demonstrate treatment effects and is a strong candidate for assessment of visual outcomes in future multiple sclerosis trials.

Profiles of obesity, weight gain, and quality of life in idiopathic intracranial hypertension (pseudotumor cerebri)

PURPOSE

Obesity and weight gain are known risk factors for idiopathic intracranial hypertension (IIH; or pseudotumor cerebri). The authors examined profiles of body mass index (BMI) and patterns of weight gain associated with IIH. They also examined vision-specific health-related quality of life (HRQOL) in newly diagnosed IIH patients and explored the relative contribution of obesity and weight gain to overall HRQOL in this disorder.

DESIGN

Matched case-control study.

METHODS

Female patients with newly diagnosed IIH (n = 34) and other neuro-ophthalmologic disorders (n = 41) were enrolled in a case-control study to assess patterns of self-reported weight gain. The HRQOL was examined using the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and the SF-36 Health Survey (Physical Components Summary and Mental Components Summary [MCS]).

RESULTS

Higher BMIs were associated with greater risk of IIH (P = .003, logistic regression analysis adjusting for case-control matching), as were higher percentages of weight gain during the year before symptom onset (P = .004). Moderate weight gain (5% to 15%) was associated with a greater risk of IIH among both obese and nonobese patients. Obesity and weight gain influenced the relation between HRQOL and IIH only for subscale scores reflecting mental health (SF-36 MCS). The NEI-VFQ-25 and SF-36 subscale scores were lower in IIH compared with other neuro-ophthalmologic disorders and published norms.

CONCLUSIONS

Higher levels of weight gain and BMI are associated with greater risk of IIH. Even nonobese patients (BMI <30) are at greater risk for IIH in the setting of moderate weight gain. Vision-specific and overall HRQOL are affected to a greater extent in IIH than in other neuro-ophthalmologic disorders.

Multiple sclerosis and the ophthalmologist

Multiple sclerosis is a common demyelinating disorder of the central nervous system, and neuro-ophthalmologic manifestations occur in the majority of patients. This article provides a review of the pathogenesis, epidemiology, and classification of multiple sclerosis. Neuro-ophthalmologic abnormalities associated with multiple sclerosis, including acute demyelinating optic neuritis and internuclear ophthalmoplegia, are described in detail. Current and emerging technologies designed to assess visual function in multiple sclerosis are discussed. A summary presents the appropriate evaluation and management of patients with optic neuritis and other first demyelinating events (also referred to as clinically isolated syndromes).

Fear sensitivity and the psychological profile of patients with psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) remain a poorly understood phenomenon for both patients and their physicians. Recent work has begun to focus on the possible psychological underpinnings of this diagnosis, but few studies have focused on specific emotional pathologies. This study sought to investigate the impact of a specific emotional measure: self-reported fear sensitivity. Three patient groups (patients with PNES, patients with epilepsy, and healthy volunteers) were administered the Modified Fear Survey Schedule, along with other neuropsychological batteries. As expected, the PNES and epilepsy cohorts demonstrated elevated levels of depression, anxiety, and comorbid psychiatric conditions. The PNES group independently exhibited a statistically significant higher level of fear sensitivity compared with both patients with epilepsy and healthy volunteers. This fear-specific trait was independent of other comorbid psychological factors or psychiatric conditions. These results suggest that patients with PNES exhibit disproportionately elevated fear sensitivity on self-report measures when compared with patients with epilepsy. This finding may reflect an elevated internal "setpoint" for appraising the intensity of emotional settings.

Validation and test characteristics of a 10-item neuro-ophthalmic supplement to the NEI-VFQ-25

PURPOSE

To determine whether a 10-Item Neuro-Ophthalmic Supplement increases the capacity of the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) to capture self-reported visual dysfunction in patients with neuro-ophthalmologic disorders.

DESIGN

A cross-sectional survey to examine the characteristics of a 10-Item Neuro-Ophthalmic Supplement to the 25-Item NEI-VFQ-25 in a cohort of patients with neuro-ophthalmologic disorders.

METHODS

The 10-Item Neuro-Ophthalmic Supplement was designed previously by our research group by survey and focus-group methods. In the present study, the NEI-VFQ-25 and 10-Item Supplement were administered concurrently to patients and disease-free control subjects. High-contrast visual acuities with patient usual distance correction were measured with the use of Early Treatment Diabetic Retinopathy Study (ETDRS) charts.

RESULTS

Diagnoses for patients (n = 215) included optic neuritis, multiple sclerosis, idiopathic intracranial hypertension, ischemic optic neuropathy, stroke, ocular myasthenia gravis, ocular motor palsies, and thyroid eye disease. Scores for the 10-Item Supplement had a significant capacity to distinguish patients vs disease-free control subjects that was independent of the NEI-VFQ-25 composite score (odds ratio in favor of patient vs control status for 10-point worsening in Supplement scores: 2.7 [95% confidence interval [CI], 1.6, 4.6]; P < .001, logistic regression models that account for NEI-VFQ-25 composite score, age, and gender). Patients with visual dysfunction (binocular Snellen equivalents worse than 20/20) had significantly lower mean scores (9-21 points lower); these differences remained significant after accounting for age and gender (P >or= .001, linear regression). Supplement items and composite scores demonstrated appropriate degrees of internal consistency reliability.

CONCLUSION

The 10-Item Neuro-Ophthalmic Supplement demonstrates a capacity to capture self-reported visual dysfunction beyond that of the NEI-VFQ-25 alone, which supports validity for this new scale. The use of the 10-Item Supplement in clinical trials and epidemiologic studies will examine its capacity to demonstrate treatment effects in longitudinal cohorts.

Predictors of future publication record and academic rank in a cohort of neurology residents

We identified characteristics associated with future publication record and academic rank in a cohort of neurology residents from a single institution. Seventy-six percent of women and 94% of men currently hold academic positions (p = 0.10). Early publications may lay the foundation for future academic investigation as publishing before (p = 0.01) and during (p < 0.001) residency was associated with higher post-residency publication rates. Publication differences between women and men (1.5 vs 2.4 publications/year; p = 0.03) warrant further investigation.

Occult thyroid eye disease in patients with unexplained ocular misalignment identified by standardized orbital echography

PURPOSE

To describe the clinical presentation, orbital echography (OE) findings, and neuroimaging results of patients with chronic unexplained ocular misalignment, which includes patients with clinically occult thyroid eye disease (TED) that is identifiable through a characteristic OE appearance.

DESIGN

Retrospective observational case series.

METHODS

Seventy-eight patients with chronic ocular misalignment suspected of TED because of a history of systemic thyroid disease, proptosis, dysmotility, positive forced ductions, or eyelid retraction or lag were categorized as TED positive, negative, and indeterminate with the use of standardized OE. Demographic, clinical, OE, computed tomography, and magnetic resonance imaging information was collected. Analyses determined the prevalence of TED and differences between TED positive, negative, and indeterminate groups.

RESULTS

Fifty-five percent of the findings were suspicious for and most consistent with TED (TED positive); 26% of the findings were TED negative, and 19% of the findings were TED indeterminate. Of 30 patients with newly diagnosed TED by OE, 70% had no lid retraction, and 20% had no other findings of TED. The inferior rectus followed by the superior rectus/levator complex, medial rectus, and lateral rectus muscles were the most frequently involved muscles. Neuroimaging that was performed in only 26 of 78 patients (33%) did not appear to yield additional diagnostic information.

CONCLUSION

TED is a potential cause of chronic unexplained ocular misalignment in a substantial proportion of patients. These patients frequently present in an occult fashion without other clinical findings that are typical of TED. In these patients, a diagnosis of TED by OE can reduce further costly evaluation. OE appears to have significant clinical usefulness in the diagnosis of TED in patients with unexplained ocular misalignment.

Measuring Friedreich ataxia: complementary features of examination and performance measures

OBJECTIVE

To examine the potential validity of performance measures and examination-based scales in Friedreich ataxia (FA) by examining their correlation with disease characteristics.

METHODS

The authors assessed the properties of a candidate clinical outcome measure, the Friedreich Ataxia Rating Scale (FARS), and simple performance measures (9-hole peg test, the timed 25-foot walk, PATA test, and low-contrast letter acuity) in 155 patients with FA from six institutions, and correlated the scores with disease duration, functional disability, activity of daily living scores, age, and shorter GAA repeat length to assess whether these measures capture the severity of neurologic dysfunction in FA.

RESULTS

Scores for the FARS and performance measures correlated significantly with functional disability, activities of daily living scores, and disease duration, showing that these measures meet essential criteria for construct validity for measuring the progressive nature of FA. In addition, the FARS and transformed performance measures scores were predicted by age and shorter GAA repeat length in linear regression models accounting for sex and testing site. Correlations between performance measures were moderate in magnitude, suggesting that each test captures separate yet related dimensions of neurologic function in FA and that a composite measure might better predict disease status. Composite measures created using cohort means and standard deviations predicted disease status better than or equal to single performance measures or examination-based measures.

CONCLUSIONS

The Friedreich Ataxia Rating Scale, performance measures, and performance measure composites provide valid assessments of disease progression in Friedreich ataxia.

Low-contrast letter acuity testing captures visual dysfunction in patients with multiple sclerosis

OBJECTIVE

To evaluate concurrent and predictive validity for low-contrast letter acuity (L-CLA) testing as a candidate visual component for the Multiple Sclerosis Functional Composite (MSFC).

METHODS

L-CLA testing was conducted in two MS patient cohorts. In the MSFC Validation Study, 137 participants from a Phase III trial of inteferon beta-1a (Avonex) for relapsing-remitting MS were followed. A second cohort included 65 patients with secondary progressive MS who participated in a substudy of the International MS Secondary Progressive Avonex Controlled Trial (IMPACT). The total number of letters read correctly at four contrast levels (100, 5, 1.25, and 0.6%) was correlated with Expanded Disability Status Scale (EDSS), MSFC, Sickness Impact Profile, Multiple Sclerosis Quality of Life Inventory, and brain parenchymal fraction (BPF), as determined by MRI.

RESULTS

Low- and high-contrast letter acuity scores correlated with BPF at follow-up in the MSFC Validation Study (5%: r = 0.40, p < 0.0001; 100%: r = 0.31, p = 0.0002). L-CLA also correlated with EDSS (5%: r = -0.35, p < 0.0001; 1.25%: r = -0.26, p = 0.0003) and MSFC (5%: r = 0.47, p < 0.0001; 1.25%: r = 0.45, p < 0.0001). In the IMPACT Substudy, change in L-CLA scores from baseline to year 1 predicted subsequent change in the EDSS from year 1 to 2 at the 5% (p = 0.0142) and the 1.25% (p = 0.0038) contrast levels, after adjusting for change in MSFC scores from baseline to year 1.

CONCLUSIONS

Low-contrast letter acuity (L-CLA) scores demonstrate concurrent and predictive validity in patients with relapsing-remitting and secondary progressive multiple sclerosis (MS). L-CLA testing provides additional information relevant to the MS disease process that is not entirely captured by the Multiple Sclerosis Functional Composite.

Relation of visual function to retinal nerve fiber layer thickness in multiple sclerosis

PURPOSE

To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes.

DESIGN

Cross-sectional study.

PARTICIPANTS

Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes).

METHODS

Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed.

MAIN OUTCOME MEASURES

Retinal nerve fiber layer thickness measured by OCT, and visual function test results.

RESULTS

Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum.

CONCLUSIONS

Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.