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To conduct feasibility and cost analysis of portable MRI implementation in a remote setting where MRI access is otherwise unavailable.
Portable MRI (ultra-low field, 0.064T) was installed in Weeneebayko General Hospital, Moose Factory, Ontario. Adult patients, presenting with any indication for neuroimaging, were eligible for study inclusion. Scanning period was from November 14, 2021, to September 6, 2022. Images were sent via a secure PACS network for Neuroradiologist interpretation, available 24/7. Clinical indications, image quality, and report turnaround time were recorded. A cost analysis was conducted from a healthcare system’s perspective in 2022 Canadian dollars, comparing cost of portable MRI implementation to transporting patients to a center with fixed MRI.
Portable MRI was successfully implemented in a remote Canadian location. Twenty-five patients received a portable MRI scan. All studies were of diagnostic quality. No clinically significant pathologies were identified on any of the studies. However, based on clinical presentation and limitations of portable MRI resolution, it is estimated that 11 (44%) of patients would require transfer to a center with fixed MRI for further imaging workup. Cost savings were $854,841 based on 50 patients receiving portable MRI over 1 year. Five-year budget impact analysis showed nearly $8 million dollars saved.
Portable MRI implementation in a remote setting is feasible, with significant cost savings compared to fixed MRI. This study may serve as a model to democratize MRI access, offer timely care and improved triaging in remote areas where conventional MRI is unavailable.
The 2022 update of the Canadian Stroke Best Practice Recommendations (CSBPR) for Acute Stroke Management, 7th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by an interdisciplinary team of healthcare providers and system planners caring for persons with an acute stroke or transient ischemic attack. These recommendations are a timely opportunity to reassess current processes to ensure efficient access to acute stroke diagnostics, treatments, and management strategies, proven to reduce mortality and morbidity. The topics covered include prehospital care, emergency department care, intravenous thrombolysis and endovascular thrombectomy (EVT), prevention and management of inhospital complications, vascular risk factor reduction, early rehabilitation, and end-of-life care. These recommendations pertain primarily to an acute ischemic vascular event. Notable changes in the 7th edition include recommendations pertaining the use of tenecteplase, thrombolysis as a bridging therapy prior to mechanical thrombectomy, dual antiplatelet therapy for stroke prevention,1 the management of symptomatic intracerebral hemorrhage following thrombolysis, acute stroke imaging, care of patients undergoing EVT, medical assistance in dying, and virtual stroke care. An explicit effort was made to address sex and gender differences wherever possible. The theme of the 7th edition of the CSBPR is building connections to optimize individual outcomes, recognizing that many people who present with acute stroke often also have multiple comorbid conditions, are medically more complex, and require a coordinated interdisciplinary approach for optimal recovery. Additional materials to support timely implementation and quality monitoring of these recommendations are available at www.strokebestpractices.ca.
A previously healthy 48-year-old female presented to the emergency department with a 2-week history of low back pain, progressive lower extremities weakness, and right leg numbness. There were no bowel or bladder dysfunction symptoms. Spine magnetic resonance imaging (MRI) showed an intradural cystic lesion dorsal to the spinal cord at the level of L1 measuring 1.6 × 2.1 × 4.1 cm, which was T1 hypointense and T2 hyperintense, with a small soft tissue component and no gadolinium enhancement (Figure 1). A small lipomatous component was also noted. There were no associated vertebral anomalies. The patient underwent a T12-L2 laminectomy and cyst resection, which was subtotal due to the cyst adherence to the conus medullaris. Histopathology showed characteristic features of a neurenteric cyst, with respiratory-type epithelium in the cyst wall (Figure 2). Eight months later, follow-up MRI showed no evidence of recurrence. The patient reported improved sensation in the lower extremities; however, there was some residual weakness predominantly in the proximal hip flexors bilaterally.
Adjuvant nitrosourea chemotherapy fails to prolong survival significantly as many tumors demonstrate resistance to these drugs. It has been documented in cell lines that O6-methylguanine DNA methyltransferase (MGMT) plays an important role in chloroethylnitrosourea (CENU) drug resistance.
We evaluated MGMT expression in 22 glioma specimens by using an immunofluorescence assay and compared the results with clinical responses of the patients to CENU-based chemotherapy.
Eight tumor samples had no detectable MGMT, whereas other samples had from 9,989 to 982,401 molecules/nucleus. In one group (12 patients), the tumor decreased in size or was stable (effective group), whereas in the other group (10 patients), the tumor demonstrated continuous growth during chemotherapy (progressive group). The Mer- patients (MGMT < 60,000 molecules/nucleus) appeared to have more chance of stable disease or response to CENU therapy than the Mer+ patients (MGMT > 60,000 molecules/nucleus) (X2 = 4.791, p = 0.0286). In patients with glioblastomas multiforme (GBMs), the median time to progression (TTP) of Mer+ patient was shorter than that of Mer- patient (t = 2.04, p = 0.049). As a corollary, the MGMT levels were significantly higher in GBM tumors from the progressive group than those from the effective group (t = 2.26, p = 0.029). However, there was no significant correlation between MGMT levels and either the survival time (r = 0.04, p = 0.8595) or TTP (r = 0.107, p = 0.6444).
This study suggests that being MGMT positive is indicative of a more aggressive disease that progresses more rapidly with CENU therapy. However, MGMT negative tumors are not always sensitive to CENU agents, suggesting that other factors are also important.
After five positive randomized controlled trials showed benefit of mechanical thrombectomy in the management of acute ischemic stroke with emergent large-vessel occlusion, a multi-society meeting was organized during the 17th Congress of the World Federation of Interventional and Therapeutic Neuroradiology in October 2017 in Budapest, Hungary. This multi-society meeting was dedicated to establish standards of practice in acute ischemic stroke intervention aiming for a consensus on the minimum requirements for centers providing such treatment. In an ideal situation, all patients would be treated at a center offering a full spectrum of neuroendovascular care (a level 1 center). However, for geographical reasons, some patients are unable to reach such a center in a reasonable period of time. With this in mind, the group paid special attention to define recommendations on the prerequisites of organizing stroke centers providing medical thrombectomy for acute ischemic stroke, but not for other neurovascular diseases (level 2 centers). Finally, some centers will have a stroke unit and offer intravenous thrombolysis, but not any endovascular stroke therapy (level 3 centers). Together, these level 1, 2, and 3 centers form a complete stroke system of care. The multi-society group provides recommendations and a framework for the development of medical thrombectomy services worldwide.
Background: The acquisition of a new 320-row multidetector computed tomography
angiography (CTA) scanner at the Montreal Neurological Institute and
Hospital has provided higher quality imaging with less radiation exposure
and shorter time of acquisition. However, its reliability has not been fully
proven in critical vascular lesions when it comes to replacing a more
invasive examination such as cerebral angiography. We wished to validate the
accuracy of this equipment to investigate four common indications for
patients to undergo conventional digital subtraction angiography:
subarachnoid hemorrhage, vasospasm, unusual intracerebral hemorrhage, and
unruptured aneurysm. Methods: Radiological reports and relevant imaging from 82 consecutive
subjects who underwent a 320-row multidetector CTA followed by cerebral
angiography from February 2010 to February 2014 were retrospectively
analysed. A total of 102 cerebrovascular anomalies were found. Reports from
both imaging modalities were compared to determine the diagnostic accuracy
of CTA. Results: The overall sensitivity and specificity of 320-row multidetector CTA
for detecting cerebrovascular abnormalities were, respectively, 97.60% and
63.20%. Similar results were obtained for all four categories of clinical
indications. Conclusion: Results obtained from CTA were consistent with those obtained on
digital subtraction angiography regardless of the vascular pathology. To our
knowledge, this study is the first validating the accuracy of 320-row CTA in
diagnosing critical cerebrovascular lesions.
Computed tomography and magnetic resonance imaging enable the identification of neuronal migration disorders during life. Several specific syndromes have been identified and early diagnosis of previously unrecognized entities is now possible. We report 51 patients with imaging. Thirty-two had a single widespread cortical dysplastic lesion. Twenty-eight had focal corticectomies. From a pathological standpoint, these encompassed focal cortical dysplasia (14 cases) and forme fruste of tuberous sclerosis (10 cases). These two groups of patients were indistinguishable from the clinical and radiological standpoint. In only two was the MRI examination normal. In addition, there were 10 with bilateral perisylvian dysplasia, four with diffuse cortical dysplasia or the "double cortex" syndrome, three with hemimegalencephaly, one with megalencephaly, and one with nodular neuronal heterotopia. The electroclinical and imaging findings led to the development of specific surgical strategies for the alleviation of the intractable seizures in each of these radiologically-defined syndromes.
A patient with a remote infarct, seizures, mild hemiparesis, and dysphasia became obtunded over four months and died. Computerized tomography (CT) over 5 years showed a consistent, large, wedge-shaped left hemisphere hypodensity with a central calcification, but without signs of mass effect. This was interpreted as an infarct of the left middle cerebral artery territory. Post-mortem examination of the brain revealed the entire area appearing as infarct on CT was a gliosarcoma. We suspect that the unusual CT appearance of the lesion was likely caused by multiple pathologies: a low grade glioma transforming into a gliosarcoma that was able to spread throughout the area of infarct encephalomalacia without revealing a typical CT appearance of mass effect. The patient's brief period of deterioration probably coincided with transformation of the tumor into a gliosarcoma. The variable CT characteristics of gliosarcomas are reviewed.
Transient focal lesions in the splenium of the corpus callosum (SCC) have been previously described in patients with epilepsy or without epilepsy but receiving antiepileptic drugs (AED).
Two epileptic patients were admitted to our long-term monitoring unit. Antiepileptic drugs were completely discontinued a few days later. One patient had no seizures. The other had three attacks, the last of which occurred two days before a brain magnetic resonance imaging (MRI) was performed. In both cases brain MRI showed a lesion in the SCC characterized by high signal on T2-weighted images and no enhancement after Gadolinium infusion. The patients were discharged with their pre-admission medications. A follow-up MRI five weeks later showed resolution of the SCC lesions.
The pathogenesis of transient SCC lesions in epileptic patients is still unclear. In our patients, either the sudden AED withdrawal or the seizures activity may be presumed to be the cause, though an individual susceptibility must also be considered.
Neurological involvement occurs in 5-15% of patients with sarcoidosis and isolated “neurosarcoidosis” occurs in less than 1% of all cases. Classical clinical presentations have been described, such as bilateral facial palsy, but often the disease presents insidiously with varied signs and symptoms. We present a patient who required biopsy of a lumbar nerve root for diagnosis of chronic, progressive neurosarcoidosis and review the literature with an emphasis on diagnosis.
We have reviewed a patient who presented with signs and symptoms related to infiltration of her meninges and nerve roots by sarcoidosis. All pertinent history and physical information was taken from interviews with the patient and review of her chart. Laboratory, radiographic, and pathological investigations are presented.
Results and conclusions:
A high index of suspicion is required for the diagnosis of neurosarcoidosis. Gadolinium-enhanced MRI is useful but the findings are often nonspecific, and there should be a low threshold for biopsy whenever the diagnosis is considered.
The neurological determination of death (NDD, brain death) is principally a clinical evaluation. However, ancillary testing is required when there are factors confounding the clinical determination or when it is impossible to complete the minimum clinical criteria. At the time of the 2003 Canadian Forum clarifying the criteria for brain death, 4-vessel cerebral angiography or radionuclide angiography were the recommended tests and the electroencephalogram was no longer supported. At the request of practitioners in the field, the Canadian Council for Donation and Transplantation sponsored the assembly of neuroradiology and neurocritical care experts to make further recommendations regarding the use of ancillary testing. At minimum, patients referred for ancillary testing should be in a deep unresponsive coma with an established etiology, in the absence of reversible conditions accounting for the unresponsiveness and the clinical examination should be performed to the fullest extent possible. For newborns, children and adults, demonstration of the absence of brain blood flow by following recommended imaging techniques fulfill the criteria for ancillary testing: 1. radionuclide angiography or CT angiography 2. traditional 4-vessel angiography 3. Magnetic resonance angiography or Xenon CT. In the absence of neuroimaging, an established cardiac arrest, as defined by the permanent loss of circulation, fulfills the ancillary criteria for the absence of brain blood flow. Acknowledging the existing limitations in this field, further research validating current or evolving techniques of brain blood flow imaging are recommended.
Locked-in syndrome (LIS) is the combination of quadriplegia and anarthria (inability to speak), with the preservation of consciousness. The majority of cases are caused by basilar artery occlusion leading to brainstem infarction in the ventral pons, yet numerous other etiologies have been described. The diagnosis of LIS is completely dependent on the physician's ability to know that these manifestations originate in the brainstem and the posterior circulation that supplies it. This knowledge hinges on the ability of the examining physician to conduct a rapid, yet appropriately thorough neurologic examination. With recent advances in interventional neuroradiology leading to improved patient outcomes, LIS has evolved into a critical, time-dependent diagnosis. Herein, we present the case of a male patient who initially presented to the emergency department of a community hospital with coma of unknown cause. By presenting this case and focusing on the importance of the occulomotor exam, we hope to help in the rapid identification and treatment of patients with LIS in the emergency room and avoid outcomes similar to that of our patient.
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