Correlation Between Visual Acuity and Foveal Threshold by Automated Perimetry With Size V Stimulus.

BACKGROUND: Visual acuity has been shown to correlate with foveal threshold as determined by automated perimetry. Although automated perimetry with size V stimulus is commonly used in neuro-ophthalmology practice, the relationship between the visual acuity and the foveal threshold with this larger stimulus is not well known. METHODS: Retrospective study of patients who had undergone neuro-ophthalmology evaluation and visual field testing with automated perimetry using size V stimulus. Healthy controls were also recruited. Using visual acuity and foveal threshold, Pearson correlation coefficients were calculated, and basic foveal threshold statistics were stratified by visual acuity. Prediction intervals for visual acuities by various foveal threshold were also calculated. RESULTS: A total of 106 unique eyes were included. The final Pearson correlation coefficient between visual acuities was -0.795 for the right eye and -0.578 for the left eye, with a pooled correlation coefficient of -0.751 (P < 0.001). A foveal threshold of at least 34 dB was present in 94.4% of eyes with 20/20 visual acuity, and a foveal threshold of greater than 35 dB was not observed in eyes with visual acuity of 20/40 or worse. CONCLUSIONS: Foveal threshold as determined by automated perimetry using size V stimulus has moderate-to-strong correlation with visual acuity in patients undergoing neuro-ophthalmology evaluation.

Neuro-Ophthalmic Features of Autoimmune Encephalitides.

BACKGROUND: Over the past decade, there has been a remarkable advancement in the understanding of autoimmune etiologies of encephalitis. The first identified generation of paraneoplastic encephalitis tends to occur in older populations, responds poorly to immunotherapy, and is mediated by T-cell damage with antibodies directed toward intracellular antigens. A new generation of autoimmune encephalitides has been described, which are mediated by antibodies to cell-surface proteins, tend to occur in younger individuals, are less frequently associated with malignancy, and often respond better to treatment compared to their intracellular antigen-related paraneoplastic counterparts. This review will focus on several specific antibody-mediated autoimmune encephalitides with neuro-ophthalmic pertinence. EVIDENCE ACQUISITION: Literature review and personal clinical experience. RESULTS: Several of the antibody-mediated encephalitides, specifically N-methyl-D-aspartate receptor, dipeptidyl-peptidase-like protein 6, glial fibrillary acidic protein, metabotropic glutamate receptor 1 (mGluR1), gamma-aminobutyric acid receptor, glutamic acid decarboxylase 65 (GAD65), collapsing response mediator protein 5 (CRMP5), and kelch-like protein 11 (KLHL11), contain features of neuro-ophthalmic interest. CONCLUSIONS: The novel cell-surface protein-directed autoimmune encephalitis group can present with a wide range of afferent and efferent neuro-ophthalmic manifestations. Neuro-ophthalmologists should be familiar with these antibody-associated syndromes, which are treatable and often require a high index of suspicion for diagnosis.

Migraine Headache: Updates and Future Developments.

Migraine is a common disabling condition that is frequently managed by primary care providers. In recent years, the growing array of migraine therapies has added complexity to patient care. This article serves as a succinct review of pertinent updates and future directions regarding migraine. Our understanding of pathophysiology has progressed along with new advances in biomarkers and genetics. These discoveries have led to a wealth of new options for treatment, many of which are specifically targeted against molecules implicated in migraine headache such as calcitonin gene-related peptide. These treatments include several monoclonal antibodies, calcitonin-gene related peptide receptor antagonists, and 5-hydroxytryptamine 1F (5-HT1F) receptor agonists; new options such as these are important for the large population falling out of eligibility for triptans. Furthermore, various nonpharmacological options including noninvasive brain stimulation have joined the arsenal of therapies used for treating migraine.

Outcomes of Surgical Decompression in Patients With Very Severe Degenerative Cervical Myelopathy.

STUDY DESIGN: A prospective observational international study. OBJECTIVE: The aim of this study was to evaluate outcomes of decompressive surgery in patients with very severe degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: Although decompressive surgery has been evidenced as a safe and effective approach for patients with myelopathic deficiencies, studies have suggested residual disability following treatment in patients with more severe disease presentation. METHODS: Postoperative outcomes of 60 patients with very severe DCM (modified Japanese Orthopaedic Association [mJOA] score ≤8) were compared to outcomes of 188 patients with severe DCM (mJOA 9-11). Postimputation follow-up rate was 93.1%. Unadjusted and adjusted analyses were performed using two-way repeated measures of covariance. RESULTS: The two cohorts were similar in demographics, length of duration of myelopathy symptoms, source of stenosis, and surgical approaches used to decompress the spine. The very severe and severe cohorts differed in preoperative Nurick grades (4.97 vs. 3.91, respectively, P < 0.0001) and Neck Disability Index scores (45.20 vs. 56.21, respectively, P = 0.0006). There were no differences in Short Form 36 (SF-36v2) physical (PCS) and mental (MCS) component summary scores. Both cohorts improved in mJOA, Nurick, Neck Disability Index, and SF-36v2 PCS and MCS scores. Despite the substantial postoperative improvements, patients in both cohorts had considerable residual symptoms. Two-thirds of the patients in the very severe cohort had severe (mJOA ≤11) or moderate (mJOA ≤ 14) myelopathy symptoms at 24 months follow-up. Longer duration of disease was associated with poorer treatment response. CONCLUSION: Decompressive surgery is effective in patients with very severe DCM; however, patients have significant residual symptoms and disability. The very severe subgroup (mJOA ≤8) of patients with DCM represents a distinct group of patients and their different clinical trajectory is important for clinicians and patients to recognize. Duration of symptoms negatively affects chances for recovery. Whenever possible, patients with DCM should be treated before developing very severe symptomatology. LEVEL OF EVIDENCE: 2.

Psychometric properties of the 30-m walking test in patients with degenerative cervical myelopathy: results from two prospective multicenter cohort studies.

BACKGROUND CONTEXT: The timed 30-m walking test (30MWT) is used in clinical practice and in research to objectively quantify gait impairment. The psychometric properties of 30MWT have not yet been rigorously evaluated. PURPOSE: This study aimed to determine test-retest reliability, divergent and convergent validity, and responsiveness to change of the 30MWT in patients with degenerative cervical myelopathy (DCM). STUDY DESIGN/SETTING: A retrospective observational study was carried out. PATIENT SAMPLE: The sample consisted of patients with symptomatic DCM enrolled in the AOSpine North America or AOSpine International cervical spondylotic myelopathy studies at 26 sites. OUTCOME MEASURES: Modified Japanese Orthopaedic Association scale (mJOA), Nurick scale, 30MWT, Neck Disability Index (NDI), and Short-Form-36 (SF-36v2) physical component score (PCS) and mental component score (MCS) were the outcome measures. METHODS: Data from two prospective multicenter cohort myelopathy studies were merged. Each patient was evaluated at baseline and 6 months postoperatively. RESULTS: Of 757 total patients, 682 (90.09%) attempted to perform the 30MWT at baseline. Of these 682 patients, 602 (88.12%) performed the 30MWT at baseline. One patient was excluded, leaving601 in the analysis. At baseline, 81 of 682 (11.88%) patients were unable to perform the test, and their mJOA, NDI, and SF-36v2 PCS scores were lower compared with those who performed the test at baseline. In patients who performed the 30MWT at baseline, there was very high correlation among the three baseline 30MWT measurements (r=0.9569-0.9919). The 30MWT demonstrated good convergent and divergent validity. It was moderately correlated with the Nurick (r=0.4932), mJOA (r=-0.4424), and SF-36v2 PCS (r=-0.3537) (convergent validity) and poorly correlated with the NDI (r=0.2107) and SF-36v2 MCS (r=-0.1984) (divergent validity). Overall, the 30MWT was not responsive to change (standardized response mean [SRM]=0.30). However, for patients who had a baseline time above the median value of 29 seconds, the SRM was 0.45. CONCLUSIONS: The 30MWT shows high test-retest reliability and good divergent and convergent validity. It is responsive to change only in patients with more severe myelopathy. The 30MWT is a simple, quick, and affordable test, and should be used as an ancillary test to evaluate gait parameters in patients with DCM.

Grade 1 spondylolisthesis and interspinous device placement: removal in six patients and analysis of current data.

BACKGROUND: In the treatment of patients with Grade 1 spondylolisthesis, the use of interspinous devices has been controversial for nearly a decade. Several authors have suggested that Grade 1 spondylolisthesis be considered a contraindication for interspinous device placement. METHODS: We removed interspinous devices in six symptomatic Grade 1 spondylolisthesis patients and analyzed pertinent literature. RESULTS: All six patients reported an improvement in symptoms following device removal and subsequent instrumented fusion. One patient who had not been able to walk due to pain regained the ability to walk. Several articles were identified related to spondylolisthesis and interspinous devices. CONCLUSIONS: Regarding patients receiving interspinous devices for symptomatic lumbar spinal stenosis, several high-quality studies have failed to demonstrate a statistical difference in outcomes between patients with or without Grade 1 spondylolisthesis. Nevertheless, surgeons should have a high degree of suspicion when considering use of interspinous devices in this patient population.

Simulation and resident education in spinal neurosurgery.

BACKGROUND: A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery. METHODS: We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use. RESULTS: A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported. CONCLUSION: The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education.