Hoxworth, Joseph M

Objective To determine the frequency and accuracy of diffusion restriction (DR) of the retina and/or optic nerve (ON) detection on standard brain magnetic resonance diffusion-weighted imaging (DWI-MRI) in patients presenting with acute non-arteritic central retinal artery occlusion (CRAO). Methods This is a retrospective case-control study that includes all consecutive patients presenting to our tertiary academic center from 2013-2021 with acute non-arteritic CRAO (cases) or acute ischemic stroke syndrome (controls, age and gender-matched) that had brain MRI performed within 14 days from symptom onset. Two neurology residents (junior and senior), a vascular neurologist, and two neuroradiologists, blinded to the site of CRAO, independently reviewed the brain MRIs to assess for the presence of retina and ON DR. The consensus agreement between the two neuroradiologists was used to perform sensitivity and specificity analyses and calculate inter-rater reliability (prevalence-adjusted bias-adjusted kappa coefficient). Results A total of 128 patients with acute non-arteritic CRAO (mean (SD) age 69 (14) years; 50% female; median time from CRAO to DW-MRI 2 days (IQR 1-5)) and 128 age and gender-matched controls with acute cerebral ischemia were included. After the neuroradiologist consensus, DR was correctly identified in the retina or ON in 51/128 (39.8%) CRAO cases, retina alone 27.3%, ON alone 24.2%, and both retina and ON 11.7%, with almost perfect neuroradiologists’ inter-rater reliability for retina (K = 0.91) and ON (K = 0.83). Among controls, the retina DR was identified in 1/128 (0.8%) and ON DR in 5/128 (3.9%). The sensitivity, specificity, positive predictive value, and negative predictive value were 28.1%, 99.2%, 97.3%, and 58.0% for retina DR, and 27.3%, 96.1%, 87.5%, and 56.9% for ON DR. Conclusions Though experienced neuroradiologists identified retina and ON DR with excellent inter-rater reliability, these are infrequent findings in real world CRAO practice, with excellent specificity but limited sensitivity. Prospective studies with larger cohort of patients, optimization of standardized orbit DWI-MRI protocols are needed to facilitate a more accurate and reliable identification of retina and ON DR in acute CRAO.

AbstractBackgroundMargins in transoral surgery for tonsil cancer can be limited by oropharyngeal wall thickness (OWT), but the normal range is not well established.MethodsIn 240 noncancer subjects, OWT was measured bilaterally in the vicinity of the tonsils with MRI. Statistical analysis was performed to assess for interaction of age, sex, location, and obesity.ResultsMean(SD) OWT measured 3.4(0.6) mm posteriorly, 3.7(2.0) mm between the styloglossus and stylopharyngeus, and 5.3(0.8) mm laterally. OWT was greater in men, correlated with obesity, decreased posteriorly and laterally in the 60–80 versus 40–59 year age groups, and increased when styloglossus/stylopharyngeus were closer. OWT was <5 mm in 36.7%–97.9% of locations, with the largest percentage below this threshold located posteriorly.ConclusionsOWT is frequently <5 mm, particularly in the posterior and intermuscular areas, suggesting that a smaller surgical margin may need to be accepted in transoral tonsil cancer surgery for anatomic reasons.

OBJECT Precise localization and understanding of the origin of spontaneous high-flow spinal CSF leaks is required prior to targeted treatment. This study demonstrates the utility of ultrafast dynamic CT myelography for the precise localization of high-flow CSF leaks caused by spiculated spinal osteophytes. METHODS This study reports a series of 14 patients with high-flow CSF leaks caused by spiculated spinal osteophytes who underwent ultrafast dynamic CT myelography between March 2009 and December 2010. There were 10 male and 4 female patients, with an average age of 49 years (range 37–74 years). The value of ultrafast dynamic CT myelography in depicting the CSF leak site was qualitatively assessed. RESULTS In all 14 patients, ultrafast dynamic CT myelography was technically successful at precisely demonstrating the site of the CSF leak, the causative spiculated osteophyte piercing the dura, and the relationship of the implicated osteophyte to adjacent structures. Leak sites included 3 cervical, 11 thoracic, and 0 lumbar levels, with 86% of the leaks occurring from C-5 to T-7. Information obtained from the ultrafast dynamic CT myelogram was considered useful in all treated CSF leaks. CONCLUSIONS Spinal osteophytes piercing the dura are a more frequent cause of high-flow CSF leaks than previously recognized. Ultrafast dynamic CT myelography adds value beyond standard dynamic myelography or digital subtraction myelography in the diagnosis and anatomical characterization of high-flow spinal CSF leaks caused by these osteophytes. This information allows for appropriate planning for percutaneous or surgical treatment.

Objectives/HypothesisTo study reports of abducens nerve palsy following dural puncture procedures and to discuss possible etiologic theories, treatment, and prognosis.Study DesignSystematic review of peer‐reviewed literature.MethodsA systematic literature review was conducted (PubMed, 1950 to September 2011) for cases of sixth cranial nerve palsy following dural puncture procedures.ResultsWe report a case of abducens nerve palsy following lumbar drain placement for endoscopic trans‐sphenoidal pituitary macroadenoma resection. Sixth nerve palsy was noted immediately after surgery. Postoperative computed tomography and magnetic resonance imaging revealed no injury to the nerve or surrounding structures. A systematic literature review conducted for cases of abducens nerve palsy following dural puncture procedures found 22 studies (17 case reports and five case series). Twenty‐eight patients with temporary or permanent abducens nerve palsy were reported. Procedures included diagnostic lumbar puncture, spinal anesthesia, intrathecal catheterization, and shunting. Traction and local ischemia due to intracranial hypotension at the petroclival junction were proposed as causes of palsy.ConclusionsLumbar puncture procedures carry a rare risk of abducens nerve palsy from ischemic or traction injury. Routine use of lumbar drain during endoscopic skull base surgery is not without risk, and need for its placement should be carefully determined. Knowledge of such rare complications is helpful in risk–benefit analysis as endoscopic skull base techniques gain popularity.Level of Evidence4. Laryngoscope, 123:2633–2638, 2013

Objectives/HypothesisTo evaluate the results of patients treated by transoral laser microsurgery and margin mapping with attention to deep margin dimensions in the lateral pharyngeal wall.Study DesignA microscopic margin analysis of multiblock surgical specimens applied to a prospectively accrued case series of squamous cell carcinoma of the palatine tonsils.MethodsThere were 128 tonsil cancers analyzed that were removed transorally, using microscopic margin mapping by surgeon and pathologist. The closest deep and peripheral margins were assessed. The results were then related to a study of the normal dimensions of the lateral pharyngeal wall in 20 healthy patients using magnetic resonance imaging. Outcome measures included number of positive margins, narrowest margin, local control, and disease‐free and overall survival.ResultsThe average closest margin was 1.98 mm (range, 0.30–6.50 mm) deep and 2.82 mm (range, 1.00–5.00 mm) peripheral. There was one positive margin encountered in the previously untreated group (1%), and one local recurrence ultimately developed. Radiographic measures revealed a mean minimal thickness of the lateral pharyngeal wall musculature of 2.4 mm. With mean follow‐up of 4.3 years (range, 2–14 years), the 5‐year estimate for local control is 99%, disease‐free survival is 94.5%, and overall survival is 76%.ConclusionsMargin mapping achieves a low rate of positive margins and is associated with good local control. Based on lateral pharyngeal wall anatomy, wide margins are often unobtainable and may be unnecessary so long as the final inked margin is clear.Level of Evidence4.

Background and Purpose— The American Stroke Association guidelines emphasized the need for further high-quality studies that assess agreement by radiologists and nonradiologists engaged in emergency telestroke assessments and decision-making. Therefore, the objective of this study was to determine the level of agreement of baseline brain CT scan interpretations of patients with acute stroke presenting to telestroke spoke hospitals between central reading committee neuroradiologists and each of 2 groups, spoke hospital radiologists and hub hospital vascular neurologists (telestrokologists). Methods— The Stroke Team Remote Evaluation Using a Digital Observation Camera Arizona trial was a prospective, urban single-hub, rural 2-spoke, randomized, blinded, controlled trial of a 2-way, site-independent, audiovisual telemedicine and teleradiology system designed for remote evaluation of adult patients with acute stroke versus telephone consultation to assess eligibility for treatment with intravenous thrombolysis. In the telemedicine arm, the subjects’ CT scans were interpreted by the hub telestrokologist and in the telephone arm by the spoke radiologist. All subjects’ CT scans were subsequently interpreted centrally, independently, and blindly by 2 hub neuroradiologists. The primary CT outcome was determination of a CT-based contraindication to thrombolytic treatment. Kappa statistics and exact agreement rates were used to analyze interobserver agreement. Results— Fifty-four subjects underwent random assignment. The overall agreement for the presence of radiological contraindications to thrombolysis was excellent (0.91) and did not differ substantially between the hub telestrokologist to neuroradiologist and spoke radiologist to neuroradiologist (0.92 and 0.89, respectively). Conclusions— In the context of a telestroke network designed to assess patients with acute stroke syndromes, agreement over the presence or absence of radiological contraindications to thrombolysis was excellent whether the comparisons were between a telestrokologist and neuroradiologist or between spoke radiologist and neuroradiologist. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00623350.