Bradley N. Delman

Comparative Neuropathology of Brain Aging in Primates

aKastor Neurobiology of Aging Laboratories and Fishberg Research Center for Neurobiology, Departments of bGeriatrics and Adult Development, cRadiology, dOtolaryngology and ePathology, Mount Sinai School of Medicine, fDepartment of Anthropology, Columbia University, gNew York Consortium in Evolutionary Primatology, New York, N.Y., hDivision of Neurobiology, Behavior, and Genetics, Bioqual Inc., Rockville, Md., and iFoundation for Comparative and Conservation Biology, Rockville, Md., USA; jDepartment of Anatomical Sciences, University of the Witwatersrand, Parktown, South Africa

Imaging of Pediatric Pituitary Abnormalities

Evaluation of the sella and surrounding structures in pediatric endocrinopathies is best performed with high-resolution magnetic resonance imaging. Adequate assessment relies not only on determining the size and shape of the gland but also on confirming normal signal characteristics and homogeneous parenchymal enhancement. Surrounding structures, including the hypothalamus-infundibulum-stalk and the skull base and midline structures about the cerebral hemispheres, warrant careful attention to identify any associated abnormalities. Tumors, whether they arise in the gland or affect gland function through mass effect, are usually well resolved on todays scanners and imaging provides accurate characterization of these lesions.

MR microscopy of normal human brain

MR microscopy at 9.4T depicts the architecture of the brain in exquisite detail, including the individual laminae of the cortex, the individual nuclei of the basal ganglia, the thalami, subthalami and metathalami, and the orientations and relationship among the dominant nuclei and white matter tracts of the brain. The authors believe that these anatomic relations will ultimately be displayed in vivo as clinical MR scanners begin to operate at field strengths of 4.7T, 7T, and 8T. Then, those familiar with this anatomy will be able to interpret patient images with far greater sophistication.

Magnetic Resonance Imaging of Meningoradiculomyelitis in Early Disseminated Lyme Disease

Lyme disease, a multisystem illness caused by the spirochete Borrelia burgdorferi, is the most common vector‐borne disease in the United States. There are 3 clinical stages of Lyme disease: early localized, early disseminated, and late persistent disease. Neuroborreliosis, infection of the nervous system by B. burgdorferi, may occur during early disseminated or late persistent disease. Spinal cord involvement in early disseminated disease is extremely rare. In patients with early disseminated neuroborreliosis, treatment with antibiotics often leads to rapid recovery and may prevent further complications of Lyme disease. The authors present the clinical and radiographic findings, both before and after treatment, in a patient with meningoradiculomyelitis due to early disseminated Lyme disease.

Patient crossover and potentially avoidable repeat computed tomography exams across a health information exchange

Objective: The purpose of this study was to measure the number of repeat computed tomography (CT) scans performed across an established health information exchange (HIE) in New York City. The long-term objective is to build an HIE-based duplicate CT alerting system to reduce potentially avoidable duplicate CTs. Methods: This retrospective cohort analysis was based on HIE CT study records performed between March 2009 and July 2012. The number of CTs performed, the total number of patients receiving CTs, and the hospital locations where CTs were performed for each unique patient were calculated. Using a previously described process established by one of the authors, hospital-specific proprietary CT codes were mapped to the Logical Observation Identifiers Names and Codes (LOINC®) standard terminology for inter-site comparison. The number of locations where there was a repeated CT performed with the same LOINC code was then calculated for each unique patient. Results: There were 717 231 CTs performed on 349 321 patients. Of these patients, 339 821 had all of their imaging studies performed at a single location, accounting for 668 938 CTs. Of these, 9500 patients had 48 293 CTs performed at more than one location. Of these, 6284 patients had 24 978 CTs with the same LOINC code performed at multiple locations. The median time between studies with the same LOINC code was 232 days (range of 0 to 1227); however, 1327 were performed within 7 days and 5000 within 30 days. Conclusions: A small proportion (3%) of our cohort had CTs performed at more than one location, however this represents a large number of scans (48 293). A noteworthy portion of these CTs (51.7%) shared the same LOINC code and may represent potentially avoidable studies, especially those done within a short time frame. This represents an addressable issue, and future HIE-based alerts could be utilized to reduce potentially avoidable CT scans.

Toward Understanding the Mammalian Zygoma: Insights From Comparative Anatomy, Growth and Development, and Morphometric Analysis: MAMMALIAN ZYGOMA

The zygoma, or jugum, is a cranial element that was present in Mesozoic tetrapods, well before the appearance of mammals. Although as an entity the zygoma is a primitive retention among mammals, it has assumed myriad configurations as this group diversified. As the zygoma is located at the intersection of the visual, respiratory, and masticatory apparatuses, it is potentially of great importance in systematic, phylogenetic, and functional studies focused on this region. For example, the facial component of the zygoma and its contribution to a postorbital bar (POB) appear to be relevant to the systematics of a number of mammalian subclades, and the formation of a bony postorbital septum (POS) that separates the orbit from the infratemporal fossa is unique to, and thus potentially phylogenetically significant for uniting anthropoid primates, while the zygoma itself appears to serve to resist tension and bending forces during mastication. In order to better understand the zygoma in the context of its contributions to the circumorbital region, we documented its morphological expression in specimens representing 10 orders of mammals. Since the presence of a POB and of a POS has long been used to justify uniting extant primates and anthropoid primates as respective clades, and because postorbital closure (POC) is morphologically more complex than a POB, we provide detail necessary to address these claims. Our taxically broad overview also allowed us to provide for the first time definitions of configurations that can be applied to future studies. Using a different, but also taxically broad sample of mammals, and of primates in particular, we performed two geometric morphometric analyses that were geared toward testing long‐held interpretations of the functional role of the zygoma, especially with regard to mastication and in the context of orbital frontation (to which the zygoma contributes). Further, overall, zygomatic morphology tends not to scale with allometry, sexual dimorphism, or angle of orbital convergence, but it does contribute to unique patterns of intraspecies variation. Anat Rec, 300:76–151, 2017.

Intravascular lymphomatosis of the brain in a patient with myelodysplastic syndrome

Background. A 77-year-old retired research pharmacologist with a long-standing history of anemia and a recent pathologically confirmed diagnosis of myelodysplastic syndrome was referred to a stroke unit for evaluation of slowly progressive cognitive deterioration, confusion and paroxysmal stroke-like episodes. A previous neurological work-up had revealed no noteworthy abnormalities except for chronic bilateral caudate infarctions seen on MRI and CT examinations of the brain.Investigations. Physical examination, laboratory testing, brain MRI scanning, EEG, transesophageal echocardiography, cerebral angiography, CT scanning, and brain biopsy.Diagnosis. Intravascular lymphomatosis of the brain.Management. Combined chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) and rituximab.

Relationship between timed 25-foot walk and diffusion tensor imaging in multiple sclerosis

Objective/Background The majority of multiple sclerosis patients experience impaired walking ability, which impacts quality of life. Timed 25-foot walk is commonly used to gauge gait impairment but results can be broadly variable. Objective biological markers that correlate closely with patients’ disability are needed. Diffusion tensor imaging, quantifying fiber tract integrity, might provide such information. In this project we analyzed relationships between timed 25-foot walk, conventional and diffusion tensor imaging magnetic resonance imaging markers. Design/Methods A cohort of gait impaired multiple sclerosis patients underwent brain and cervical spinal cord magnetic resonance imaging. Diffusion tensor imaging mean diffusivity and fractional anisotropy were measured on the brain corticospinal tracts and spinal restricted field of vision at C2/3. We analyzed relationships between baseline timed 25-foot walk, conventional and diffusion tensor imaging magnetic resonance imaging markers. Results Multivariate linear regression analysis showed a statistically significant association between several magnetic resonance imaging and diffusion tensor imaging metrics and timed 25-foot walk: brain mean diffusivity corticospinal tracts (p = 0.004), brain corticospinal tracts axial and radial diffusivity (P = 0.004 and 0.02), grey matter volume (p = 0.05), white matter volume (p = 0.03) and normalized brain volume (P = 0.01). The linear regression model containing mean diffusivity corticospinal tracts and controlled for gait assistance was the best fit model (p = 0.004). Conclusions Our results suggest an association between diffusion tensor imaging metrics and gait impairment, evidenced by brain mean diffusivity corticospinal tracts and timed 25-foot walk.

Quantification of perivascular spaces at 7 T: A potential MRI biomarker for epilepsy

PURPOSE 7T (7T) magnetic resonance imaging (MRI) facilitates the visualization of the brain with resolution and contrast beyond what is available at conventional clinical field strengths, enabling improved detection and quantification of small structural features such as perivascular spaces (PVSs). The distribution of PVSs, detected in vivo at 7T, may act as a biomarker for the effects of epilepsy. In this work, we systematically quantify the PVSs in the brains of epilepsy patients and compare them to healthy controls. METHODS T2-weighted turbo spin echo images were obtained at 7T on 21 epilepsy patients and 17 healthy controls. For all subjects, PVSs were manually marked on Osirix image analysis software. Marked PVSs with diameter≥0.5mm were then mapped by hemisphere and lobe. The asymmetry index (AI) was calculated for each region and the maximum asymmetry index (|AImax|) was reported for each subject. The asymmetry in epilepsy subjects was compared to that of controls, and the region with highest asymmetry was compared to the suspected seizure onset zone. RESULTS There was a significant difference between the |AImax| in epilepsy subjects and in controls (p=0.016). In 72% of patients, the region or lobe of the brain showing maximum PVS asymmetry was the same as the region containing the suspected seizure onset zone. CONCLUSION These findings suggest that epilepsy may be associated with significantly asymmetric distribution of PVSs in the brain. Furthermore, the region of maximal asymmetry of the PVSs may help provide localization or confirmation of the seizure onset zone.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Imaging in the Diagnosis and Management of Patients With Vestibular Schwannomas

QUESTION 1 What sequences should be obtained on magnetic resonance imaging (MRI) to evaluate vestibular schwannomas before and after surgery? TARGET POPULATION Adults with vestibular schwannomas. RECOMMENDATIONS Initial Preoperative Evaluation Level 3: Imaging used to detect vestibular schwannomas should use high‐resolution T2‐weighted and contrast‐enhanced T1‐weighted MRI. Level 3: Standard T1, T2, fluid attenuated inversion recovery, and diffusion weighted imaging MR sequences obtained in axial, coronal, and sagittal plane may be used for detection of vestibular schwannomas. Preoperative Surveillance Level 3: Preoperative surveillance for growth of a vestibular schwannoma should be followed with either contrast‐enhanced 3‐dimensional (3‐D) T1 magnetization prepared rapid acquisition gradient echo (MPRAGE) or high‐resolution T2 (including constructive interference in steady state [CISS] or fast imaging employing steady‐state acquisition [FIESTA] sequences) MRI. Postoperative Evaluation Level 2: Postoperative evaluation should be performed with postcontrast 3‐D T1 MPRAGE, with nodular enhancement considered suspicious for recurrence. QUESTION 2 Is there a role for advanced imaging for facial nerve detection preoperatively (eg, CISS/FIESTA or diffusion tensor imaging)? TARGET POPULATION Adults with proven or suspected vestibular schwannomas by imaging. RECOMMENDATION Level 3: T2‐weighted MRI may be used to augment visualization of the facial nerve course as part of preoperative evaluation. QUESTION 3 What is the expected growth rate of vestibular schwannomas on MRI, and how often should they be imaged if a “watch and wait” philosophy is pursued? TARGET POPULATION Adults with suspected vestibular schwannomas by imaging. RECOMMENDATION Level 3: MRIs should be obtained annually for 5 yr, with interval lengthening thereafter with tumor stability. QUESTION 4 Do cystic vestibular schwannomas behave differently than their solid counterparts? TARGET POPULATION Adults with vestibular schwannomas with cystic components. RECOMMENDATION Level 3: Adults with cystic vestibular schwannomas should be counseled that their tumors may more often be associated with rapid growth, lower rates of complete resection, and facial nerve outcomes that may be inferior in the immediate postoperative period but similar to noncystic schwannomas over time. QUESTION 5 Should the extent of lateral internal auditory canal involvement be considered by treating physicians? TARGET POPULATION Adult patients with vestibular schwannomas. RECOMMENDATION Level 3: The degree of lateral internal auditory canal involvement by tumor adversely affects facial nerve and hearing outcomes and should be emphasized when interpreting imaging for preoperative planning. QUESTION 6 How should patients with neurofibromatosis type 2 (NF2) and vestibular schwannoma be imaged and over what follow‐up period? TARGET POPULATION Adult patients with NF2 and vestibular schwannomas. RECOMMENDATION Level 3: In general, vestibular schwannomas associated with NF2 should be imaged (similar to sporadic schwannomas) with the following caveats: 1. More frequent imaging may be adopted in NF2 patients because of a more variable growth rate for vestibular schwannomas, and annual imaging may ensue once the growth rate is established. 2. In NF2 patients with bilateral vestibular schwannomas, growth rate of a vestibular schwannoma may increase after resection of the contralateral tumor, and therefore, more frequent imaging may be indicated, based on the nonoperated tumors historical rate of growth. 3. Careful consideration should be given to whether contrast is necessary in follow‐up studies or if high‐resolution T2 (including CISS or FIESTA‐type sequences) MRI may adequately characterize changes in lesion size instead. QUESTION 7 How long should vestibular schwannomas be imaged after surgery, including after gross‐total, near‐total, and subtotal resection? TARGET POPULATION Adult patients with vestibular schwannomas followed after surgery. RECOMMENDATION Level 3: For patients receiving gross total resection, a postoperative MRI may be considered to document the surgical impression and may occur as late as 1 yr after surgery. For patients not receiving gross total resection, more frequent surveillance scans are suggested; annual MRI scans may be reasonable for 5 yr. Imaging follow‐up should be adjusted accordingly for continued surveillance if any change in nodular enhancement is demonstrated. The full guideline can be found at https://www.cns.org/guidelines/guidelines‐management‐patients‐vestibular‐schwannoma/chapter_5.