Corpus callosum lesions are not inextricably linked to CNS symptoms in reported cases of susac syndrome.

OBJECTIVE: To evaluate whether corpus callosum (CC) lesions are inextricably linked to CNS symptoms of Susac Syndrome (SuS) by reviewing published cases to find instances where: 1) CC lesions occur without CNS symptoms, and 2) whether patients with CNS symptoms lack CC lesions. METHODS: 100 reported cases of SuS were identified in PubMed. Clinical symptoms, para-clinical testing and MRI data were collected both at presentation and for any available follow-up and analyzed. Cases were reviewed to evaluate how they met European diagnostic criteria for SuS (EuSaC) both at first presentation and at most recent evaluation after followup, if available. RESULTS: Limited disease is a common finding in the 100 recently published cases and 56/100 cases did not meet EuSaC probable or definite criteria at first evaluation. CC lesions were not inextricably linked with encephalopathy, as 8 cases presented with CC lesions without CNS symptoms and 6 cases had encephalopathy without CC lesions. In five patients with both eye and ear involvement, isolated CC lesions or CNS symptoms could enhance diagnostic certainty. This may reduce specificity, but would increase sensitivity, ultimately benefitting patient care. CONCLUSION: Patients with early SuS rarely meet diagnostic criteria at presentation. Future diagnostic criteria could make use of unlinked CC lesions or CNS symptoms.

The Hotel Study-Clinical and Health Service Effectiveness in a Cohort of Homeless or Marginally Housed Persons.

OBJECTIVE: The Hotel Study was initiated in Vancouver's Downtown East Side (DTES) neighborhood to investigate multimorbidity in homeless or marginally housed people. We evaluated the clinical effectiveness of existing, illness-specific treatment strategies and assessed the effectiveness of health care delivery for multimorbid illnesses. METHOD: For context, we mapped the housing locations of patients presenting for 552,062 visits to the catchment hospital emergency department (2005-2013). Aggregate data on 22,519 apprehensions of mentally ill people were provided by the Vancouver Police Department (2009-2015). The primary strategy was a longitudinal cohort study of 375 people living in the DTES (2008-2015). We analysed mortality and evaluated the clinical and health service delivery effectiveness for infection with human immunodeficiency virus or hepatitis C virus, opioid dependence, and psychosis. RESULTS: Mapping confirmed the association between poverty and greater number of emergency visits related to substance use and mental illness. The annual change in police apprehensions did not differ between the DTES and other policing districts. During 1581 person-years of cohort observation, the standardized mortality ratio was 8.43 (95% confidence interval, 6.19 to 11.50). Physician visits were common (84.3% of participants over 6 months). Clinical treatment effectiveness was highest for HIV/AIDS, intermediate for opioid dependence, and lowest for psychosis. Health service delivery mechanisms provided examples of poor access, poor treatment adherence, and little effect on multimorbid illnesses. CONCLUSIONS: Clinical effectiveness was variable, and illness-specific service delivery appeared to have little effect on multimorbidity. New models of care may need to be implemented.

Canadian Expert Panel Recommendations for MRI Use in MS Diagnosis and Monitoring.

BACKGROUND: A definitive diagnosis of multiple sclerosis (MS), as distinct from a clinically isolated syndrome, requires one of two conditions: a second clinical attack or particular magnetic resonance imaging (MRI) findings as defined by the McDonald criteria. MRI is also important after a diagnosis is made as a means of monitoring subclinical disease activity. While a standardized protocol for diagnostic and follow-up MRI has been developed by the Consortium of Multiple Sclerosis Centres, acceptance and implementation in Canada have been suboptimal. METHODS: To improve diagnosis, monitoring, and management of a clinically isolated syndrome and MS, a Canadian expert panel created consensus recommendations about the appropriate application of the 2010 McDonald criteria in routine practice, strategies to improve adherence to the standardized Consortium of Multiple Sclerosis Centres MRI protocol, and methods for ensuring effective communication among health care practitioners, in particular referring physicians, neurologists, and radiologists. RESULTS: This article presents eight consensus statements developed by the expert panel, along with the rationale underlying the recommendations and commentaries on how to prioritize resource use within the Canadian healthcare system. CONCLUSIONS: The expert panel calls on neurologists and radiologists in Canada to incorporate the McDonald criteria, the Consortium of Multiple Sclerosis Centres MRI protocol, and other guidance given in this consensus presentation into their practices. By improving communication and general awareness of best practices for MRI use in MS diagnosis and monitoring, we can improve patient care across Canada by providing timely diagnosis, informed management decisions, and better continuity of care.

Increased spinal cord movements in cervical spondylotic myelopathy.

BACKGROUND CONTEXT: Magnetic resonance imaging (MRI) is a very useful diagnostic test for cervical spondylotic myelopathy (CSM) because it can identify degenerative changes within the spinal cord (SC), disclose the extent, localization, and the kind of SC compression, and help rule out other SC disorders. However, the relationships between changes in cerebrospinal fluid (CSF) flow, cord motion, the extent and severity of spinal canal stenosis, and the development of CSM symptoms are not well understood. PURPOSE: To evaluate if changes in the velocity of CSF and SC movements provide additional insight into the pathophysiological mechanisms underlying CSM beyond MRI observations of cord compression. STUDY DESIGN: Prospective radiologic study of recruited patients. PATIENT SAMPLE: Thirteen CSM subjects and 15 age and gender matched controls. OUTCOME MEASURES: Magnetic resonance imaging measures included CSF and SC movement. Cervical cord condition was assessed by the Japanese Orthopaedic Association (JOA) score, compression ratio (CR), and somatosensory evoked potentials (SSEPs) of the tibial and ulnar nerves. METHODS: Phase-contrast imaging at the level of stenosis for patients and at C5 for controls and T2-weighted images were compared with clinical findings. RESULTS: Cerebrospinal fluid velocity was significantly reduced in CSM subjects as compared with controls and was related to cord CR. Changes in CSF velocity and cord compression were not correlated with clinical measures (JOA scores, SSEP) or the presence of T2 hyperintensities. Spinal cord movements, that is, cord displacement and velocity in the craniocaudal axis, were increased in CSM patients. Increased SC movements (ie, total cord displacement) both in the controls and CSM subjects were associated with altered spinal conduction as assessed by SSEP. CONCLUSIONS: This study revealed rather unexpected increased cord movements in the craniocaudal axis in CSM patients that may contribute to myelopathic deteriorations in combination with spinal canal compression. Understanding the relevance of cord movements with respect to supporting the clinical CSM diagnosis or disease monitoring requires further long-term follow-up studies.

The hotel study: multimorbidity in a community sample living in marginal housing.

OBJECTIVE: The health of people living in marginal housing is not well characterized, particularly from the perspective of multimorbid illness. The authors investigated this population in a community sample. METHOD: A prospective community sample (N=293) of adults living in single-room occupancy hotels was followed for a median of 23.7 months. Assessment included psychiatric and neurological evaluation, multimodal MRI, and viral testing. RESULTS: Previous homelessness was described in 66.6% of participants. Fifteen deaths occurred during 552 person-years of follow-up. The standardized mortality ratio was 4.83 (95% CI=2.91-8.01). Substance dependence was ubiquitous (95.2%), with 61.7% injection drug use. Psychosis was the most common mental illness (47.4%). A neurological disorder was present in 45.8% of participants, with definite MRI findings in 28.0%. HIV serology was positive in 18.4% of participants, and hepatitis C virus serology in 70.3%. The median number of multimorbid illnesses (from a list of 12) was three. Burden of multimorbidity was significantly correlated with lower role functioning score. Comorbid addiction or physical illness significantly decreased the likelihood of treatment for psychosis but not the likelihood of treatment for opioid dependence or HIV disease. Participants who died during follow-up appeared to have profiles of multimorbidity similar to those of the overall sample. CONCLUSIONS: This marginally housed cohort had greater than expected mortality and high levels of multimorbidity with adverse associations with role function and likelihood of treatment for psychosis. These findings may guide the development of effective health care delivery in the setting of marginal housing.

Diagnosis and management of calcified carotid artery atheroma: dental perspectives.

The calcification of cervical carotid artery atheroma (CCAA) represents maturation of a lumenal atherosclerotic plaque that has been associated with a high risk of cerebral stroke. The demonstration of CCAA on rotational panoramic images has received increasing attention in dentistry since it was first described in 1981. The purposes of this article are to provide a background to the mechanism of arterial calcification, to review the clinical diagnostic and management algorithms for dental practitioners when CCAA are identified radiologically, and to describe and illustrate current appropriate radiographic modalities and medical management strategies used to confirm and assess stenosis associated with CCAA.

MR imaging of the spinal bone marrow.

Adequate interpretation of a cervical, thoracic, or lumbar spine MR imaging examination includes a careful evaluation of the bone marrow. Detecting an abnormality in bone marrow may cause a diagnostic dilemma because the marrow in the spine can vary in appearance according to the patient's age, and can be affected by infectious, inflammatory, metabolic, and neoplastic processes. Its appearance can be affected as well by underlying degenerative disc disease, trauma, and numerous iatrogenic therapies, including vertebroplasty, radiation therapy, and medications. In addition to conventional MR imaging sequences, newer imaging techniques, such as diffusion weighting and opposedphase sequences, are being studied to help increase the diagnostic accuracy of spine and bone marrow evaluation and to help differentiate benign from malignant and infectious processes.

Prevalence of eye strain among radiologists: influence of viewing variables on symptoms.

OBJECTIVE: To determine the prevalence of and factors contributing to eye strain among radiologists, we examined the influence of the viewing method (PACS vs hard-copy film), age, case volume, technique, work habits, and workstation design on symptoms. MATERIALS AND METHODS: An Internet-based survey was sent to 2,700 radiologists randomly selected from the membership database of the Radiological Society of North America. Questions included demographic information, viewing method, work habits, and workstation design. Common eye strain symptoms were evaluated on a 5-point Likert scale. Chi-square analysis, analysis of variance, and step-wise and regression analyses were performed to evaluate codependence of the explanatory variables with eye strain. RESULTS: The adjusted response rate was 14% (380 respondents). The largest age cohort was 36-50 years. The prevalence of eye strain was 36% and was not affected by the viewing method (PACS vs film). Increased symptoms could be independently predicted in radiologists who were women (p <0.001), had longer work days (p=0.009), took fewer breaks (p=0.03), reported screen flicker (p=0.0003), and performed CT screening (p=0.04). Working hours had the strongest influence on eye strain. Eye strain was increased in those who reported studies for longer than 6 hr per day (p=0.01) and decreased in those who took breaks every hour (p=0.04). Symptoms were independent of the length of the break taken and of other workstation and technique factors. CONCLUSION: Eye strain was common among the radiologists in our study population, with no significant difference between PACS and hard-copy film users. Taking frequent short breaks, eliminating screen flicker, and limiting the number of CT screening studies interpreted may improve symptoms.

"Chasing the dragon"--imaging of heroin inhalation leukoencephalopathy.

"Chasing the dragon" refers to the inhalation of heroin pyrolysate vapors produced when the freebase form of heroin is heated. Inhalation of these vapors can result in a rare toxic spongiform leukoencephalopathy. The patients may progress through 3 defined clinical stages, with one-quarter reaching the terminal stage, which invariably leads to death. Imaging and, in particular, magnetic resonance imaging (MRI) demonstrates white matter findings that are felt to be specific for this entity and essential in its early diagnosis. We present the typical imaging findings in a pictorial essay format, using images taken from 9 patients who presented within an 18-month period at UBC-affiliated hospitals. These findings include low computed tomography (CT) attenuation and high T2 MRI signal most commonly in the posterior cerebral and cerebellar white matter, cerebellar peduncles, splenium of the corpus callosum, and posterior limb of the internal capsules. In addition, there is often selective, symmetric involvement of the corticospinal tract, the medial lemniscus, and the tractus solitarius. We also present the variable diffusion-weighted imaging and apparent diffusion coefficient findings from 4 of our patients, which to our knowledge, have not been described in the literature.