scholarly journals Optic Tract Shrinkage Limits Visual Restoration After Occipital Stroke

Stroke ◽  
2021 ◽  
Author(s):  
Berkeley K. Fahrenthold ◽  
Matthew R. Cavanaugh ◽  
Subin Jang ◽  
Allison J. Murphy ◽  
Sara Ajina ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Visual Field ◽  
Vision Loss ◽  
Optic Tract ◽  
Visual Recovery ◽  
Resonance Imaging ◽  
Chronic Patients ◽  
Visual Hemifield ◽  
The Impact

Background and Purpose: Damage to the adult primary visual cortex (V1) causes vision loss in the contralateral visual hemifield, initiating a process of trans-synaptic retrograde degeneration. The present study examined functional implications of this process, asking if degeneration impacted the amount of visual recovery attainable from visual restoration training in chronic patients, and if restoration training impacted optic tract (OT) shrinkage. Methods: Magnetic resonance imaging was used to measure OT volumes bilaterally in 36 patients with unilateral occipital stroke. From OT volumes, we computed laterality indices (LI), estimating the stroke-induced OT shrinkage in each case. A subset of these chronic patients (n=14, 13±6 months poststroke) underwent an average of nearly 1 year of daily visual restoration training, which repeatedly stimulated vision in their blind field. The amount of visual field recovery was quantified using Humphrey perimetry, and post training magnetic resonance imaging was used to assess the impact of training on OT shrinkage. Results: OT LI was correlated with time since stroke: it was close to 0 (no measurable OT shrinkage) in subacute participants (<6 months poststroke) while chronic participants (>6 months poststroke) exhibited LI >0, but with significant variability. Visual training did not systematically alter LI, but chronic patients with baseline LI≈0 (no OT shrinkage) exhibited greater visual field recovery than those with LI>0. Conclusions: Unilateral OT shrinkage becomes detectable with magnetic resonance imaging by ≈7 months poststroke, albeit with significant interindividual variability. Although visual restoration training did not alter the amount of degeneration already sustained, OT shrinkage appeared to serve as a biomarker of the potential for training-induced visual recovery in chronic cortically blind patients.

scholarly journals Impact of the COVID-19 pandemic on neuroimaging scan volumes at a teaching hospital

2021 ◽  
pp. 197140092098866
Author(s):  
Daniel Thomas Ginat ◽  
James Kenniff
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
The United States ◽  
Radiology Department ◽  
Magnetic Resonance Imaging Scan ◽  
Resonance Imaging ◽  
Academic Medical Centre ◽  
Academic Medical ◽  
The Impact

Background The COVID-19 pandemic led to a widespread socioeconomic shutdown, including medical facilities in many parts of the world. The purpose of this study was to assess the impact on neuroimaging utilisation at an academic medical centre in the United States caused by this shutdown. Methods Exam volumes from 1 February 2020 to 11 August 2020 were calculated based on patient location, including outpatient, inpatient and emergency, as well as modality type, including computed tomography and magnetic resonance imaging. 13 March 2020 was designated as the beginning of the shutdown period for the radiology department and 1 May 2020 was designated as the reopening date. The scan volumes during the pre-shutdown, shutdown and post-shutdown periods were compared using t-tests. Results Overall, neuroimaging scan volumes declined significantly by 41% during the shutdown period and returned to 98% of the pre-shutdown period levels after the shutdown, with an estimated 3231 missed scans. Outpatient scan volumes were more greatly affected than inpatient scan volumes, while emergency scan volumes declined the least during the shutdown. In addition, the magnetic resonance imaging scan volumes declined to a greater degree than the computed tomography scan volumes during the shutdown. Conclusion The shutdown from the COVID-19 pandemic had a substantial but transient impact on neuroimaging utilisation overall, with variable magnitude depending on patient location and modality type.

scholarly journals Neuroimaging at Term Equivalent Age: Is There Value for the Preterm Infant? A Narrative Summary

Children ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 227
Author(s):  
Rudaina Banihani ◽  
Judy Seesahai ◽  
Elizabeth Asztalos ◽  
Paige Terrien Church
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Preterm Infant ◽  
Resonance Imaging ◽  
Long Term Outcomes ◽  
Equivalent Age ◽  
Current State ◽  
Patterns Of Injury ◽  
The Impact

Advances in neuroimaging of the preterm infant have enhanced the ability to detect brain injury. This added information has been a blessing and a curse. Neuroimaging, particularly with magnetic resonance imaging, has provided greater insight into the patterns of injury and specific vulnerabilities. It has also provided a better understanding of the microscopic and functional impacts of subtle and significant injuries. While the ability to detect injury is important and irresistible, the evidence for how these injuries link to specific long-term outcomes is less clear. In addition, the impact on parents can be profound. This narrative summary will review the history and current state of brain imaging, focusing on magnetic resonance imaging in the preterm population and the current state of the evidence for how these patterns relate to long-term outcomes.

scholarly journals Effect of early sleep apnoea treatment with adaptive servo-ventilation in acute stroke patients on cerebral lesion evolution and neurological outcomes: study protocol for a multicentre, randomized controlled, rater-blinded, clinical trial (eSATIS: early Sleep Apnoea Treatment in Stroke)

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Simone B. Duss ◽  
Anne-Kathrin Brill ◽  
Sébastien Baillieul ◽  
Thomas Horvath ◽  
Frédéric Zubler ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Acute Stroke ◽  
Acute Ischaemic Stroke ◽  
Sleep Apnoea ◽  
Resonance Imaging ◽  
Stroke Patients ◽  
Adaptive Servo Ventilation ◽  
Randomized Controlled ◽  
The Impact

Abstract Background Sleep-disordered breathing (SDB) is highly prevalent in acute ischaemic stroke and is associated with worse functional outcome and increased risk of recurrence. Recent meta-analyses suggest the possibility of beneficial effects of nocturnal ventilatory treatments (continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV)) in stroke patients with SDB. The evidence for a favourable effect of early SDB treatment in acute stroke patients remains, however, uncertain. Methods eSATIS is an open-label, multicentre (6 centres in 4 countries), interventional, randomized controlled trial in patients with acute ischaemic stroke and significant SDB. Primary outcome of the study is the impact of immediate SDB treatment with non-invasive ASV on infarct progression measured with magnetic resonance imaging in the first 3 months after stroke. Secondary outcomes are the effects of immediate SDB treatment vs non-treatment on clinical outcome (independence in daily functioning, new cardio-/cerebrovascular events including death, cognition) and physiological parameters (blood pressure, endothelial functioning/arterial stiffness). After respiratory polygraphy in the first night after stroke, patients are classified as having significant SDB (apnoea-hypopnoea index (AHI) > 20/h) or no SDB (AHI < 5/h). Patients with significant SDB are randomized to treatment (ASV+ group) or no treatment (ASV− group) from the second night after stroke. In all patients, clinical, physiological and magnetic resonance imaging studies are performed between day 1 (visit 1) and days 4–7 (visit 4) and repeated at day 90 ± 7 (visit 6) after stroke. Discussion The trial will give information on the feasibility and efficacy of ASV treatment in patients with acute stroke and SDB and allows assessing the impact of SDB on stroke outcome. Diagnosing and treating SDB during the acute phase of stroke is not yet current medical practice. Evidence in favour of ASV treatment from a randomized multicentre trial may lead to a change in stroke care and to improved outcomes. Trial registration ClinicalTrials.gov NCT02554487, retrospectively registered on 16 September 2015 (actual study start date, 13 August 2015), and www.kofam.ch (SNCTP000001521).

scholarly journals Acute Visual Loss as a First Sign of Hyperhomocysteinaemia

1970 ◽  
Vol 12 (3) ◽  
pp. 172-174
Author(s):  
Aggeliki Kolea ◽  
Aggelos Baltatzidis ◽  
Vasileios Margaritis ◽  
Belal Almoghrabi ◽  
Irini Kaldi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Visual Field ◽  
Genetic Analysis ◽  
Visual Loss ◽  
Methylenetetrahydrofolate Reductase ◽  
Occipital Lobe ◽  
Field Testing ◽  
Resonance Imaging ◽  
Acute Visual Loss

A 38-year-old man presented with an acute right homonymous visual field defect due to occipital lobe infarct caused by hyperhomocysteinaemia. Visual field testing, magnetic resonance imaging, laboratory studies, and genetic analysis were carried out. On magnetic resonance imaging, a left occipital lesion with bright signal on the diffusion-weighted and fluid-attenuated inversion recovery images suggested a diagnosis of an acute infarct. Blood tests revealed raised homocysteine of 52.08 μmol/L (reference range, <15 μmol/L) and genetic analysis showed the patient to be homozygote to 5, 10-methylenetetrahydrofolate reductase deficiency. Hyperhomocysteinaemia is a rare causes of acute visual loss due to cerebral ischaemia and should always be suspected and investigated with the appropriate tests to diagnose the condition and limit further vision deterioration.

Radiation Necrosis of the Optic Chiasm, Optic Tract, Hypothalamus, and Upper Pons after Radiotherapy for Pituitary Adenoma, Detected by Gadolinium-Enhanced, T1-Weighted Magnetic Resonance Imaging: Case Report

Neurosurgery ◽  
1990 ◽  
Vol 27 (4) ◽  
pp. 640-643 ◽  
Author(s):  
Osamu Tachibana ◽  
Narihito Yamaguchi ◽  
Tetsumori Yamashima ◽  
Junkoh Yamashita
Keyword(s):  
Magnetic Resonance Imaging ◽  
Pituitary Adenoma ◽  
Magnetic Resonance ◽  
Radiation Necrosis ◽  
Optic Tract ◽  
Optic Chiasm ◽  
Magnetic Resonance Imaging Scan ◽  
Resonance Imaging ◽  
Weighted Magnetic Resonance Imaging ◽  
Resonance Imaging Scan

Abstract A 26-year-old woman was treated for a prolactin secreting pituitary adenoma by surgery and radiotherapy (5860 rads). Fourteen months later, she developed right hemiparesis and dysarthria. A T1-weighted magnetic resonance imaging scan using gadolinium contrast showed a small, enhanced lesion in the upper pons. Seven months later, she had a sudden onset of loss of vision, and radiation optic neuropathy was diagnosed. A T1-weighted magnetic resonance imaging scan showed widespread gadolinium-enhanced lesions in the optic chiasm, optic tract, and hypothalamus. Magnetic resonance imaging is indispensable for the early diagnosis of radiation necrosis, which is not visualized by radiography or computed tomography.

Severe Monocular Vision Loss Followed by Gait Difficulty

2021 ◽  
pp. 35-38
Author(s):  
Brian G. Weinshenker
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Immunoglobulin G ◽  
Vision Loss ◽  
Position Sense ◽  
Aquaporin 4 ◽  
Resonance Imaging ◽  
Gadolinium Enhancement ◽  
Fluid Analysis ◽  
Severe Impairment

A 56-year-old woman sought care for painless vision loss over 24 hours in the superior field of her right eye, which progressed to total vision loss. Intravenous corticosteroids were administered over 5 days, and she recovered well. Approximately 6 months later, paresthesias and sensory loss of her legs developed, which was sufficiently severe that she was unable to walk. She had severe impairment of vibration sense and lesser impairment of position sense, as well as proximal weakness of both legs. She recovered but had persistent burning dysesthesias of the legs. Magnetic resonance imaging of the orbits at the onset of symptoms showed gadolinium enhancement extending from the middle of the orbit posteriorly, almost to the level of the optic chiasm. Magnetic resonance imaging of the spine at the time of acute myelitis revealed a long spinal cord lesion extending from the lower cervical cord to the conus which was central and homogeneous on T2 images and exhibited patchy gadolinium enhancement. Cerebrospinal fluid analysis showed 37 leukocytes/µL with lymphocyte predominance and negative tests for oligoclonal bands. On serologic analysis, she was positive for aquaporin-4-immunoglobulin G antibodies by enzyme-linked immunosorbent assay. The patient was diagnosed with neuromyelitis optica spectrum disorder, aquaporin-4-immunoglobulin G seropositive. The patient was started on rituximab treatment. After 2 years, she decided to discontinue treatment because she was concerned about potential adverse effects. Six months after discontinuing rituximab, severe weakness of her right leg developed, which improved with intravenous corticosteroids. Rituximab therapy was restarted, 2 doses of 1 g each, but she had 1 further episode of myelitis 2 weeks after receiving rituximab. Six months later, her visual acuity in the right eye was only counting fingers, and she had a flaccid paraplegia with areflexia of the lower extremities and total loss of sensory function below T4.

scholarly journals The Impact of Preoperative Breast Magnetic Resonance Imaging on Surgical Management in Symptomatic Patients With Invasive Lobular Carcinoma

2020 ◽  
Vol 14 ◽  
pp. 117822342094847
Author(s):  
Brian M Moloney ◽  
Peter F McAnena ◽  
Éanna J Ryan ◽  
Ellen O Beirn ◽  
Ronan M Waldron ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Lobular Carcinoma ◽  
Multivariable Analysis ◽  
Breast Mri ◽  
Breast Conserving Surgery ◽  
Conventional Imaging ◽  
Resonance Imaging ◽  
Tertiary Centre ◽  
The Impact

Objective: Due to an insidious proliferative pattern, invasive lobular breast cancer (ILC) often fails to form a defined radiological or palpable lesion and accurate diagnosis remains challenging. This study aimed to determine the value of preoperative magnetic resonance imaging (MRI) for ILC and its impact on surgical outcomes. Methods: Consecutive symptomatic patients diagnosed with ILC in a tertiary centre over a 9-year period were reviewed. The time from diagnosis until surgery, initial type of surgery/index operation (breast-conserving surgery [BCS]/mastectomy) and the rates of reoperation (re-excision/completion mastectomy) were recorded. Patients were grouped into those who received conventional imaging and preoperative MRI (MR+) and those who received conventional imaging alone (MR–). Results: There were 218 cases of ILC, and 32.1% (n = 70) had preoperative MRI. Time from diagnosis to surgery was longer in the MR+ than the MR– group (32.5 vs 21.1 days, P < .001) even when adjusting for age and breast density. Initial BCS was performed on 71.4% (n = 50) of MR+ patients and 72.3% (n = 107) of the MR– group. While the rate of completion mastectomy following initial BCS was higher in the MR+ group (30.0%, n = 15 vs 14.0%, n = 15; χ2 = 5.63; P = .018), this association was not maintained in multivariable analysis. No difference was recorded in overall (initial and completion) mastectomy rate between the MR+ and MR– group (50.0%, n = 35 vs 37.8%, n = 56; χ2 = 2.89; P = .089). Margin re-excision following BCS was comparable between groups (8.0%, n =4, vs 9.3%, n = 10; χ2 = 0.076, P = .783) despite the selection bias for borderline conservable cases in the MR+ group. The rate of usage of MRI for ILC cases declined over the study period. Conclusion: While MRI was associated with minor delays in treatment and did not reduce overall rates of margin re-excision or completion mastectomy, it altered the choice of surgical procedure in almost a quarter of MR+ cases. The benefit of preoperative breast MRI appears to be confined to select (younger, dense breast, borderline conservable) cases in symptomatic ILC.

scholarly journals An Unusual Case of Unilateral Papilledema

2019 ◽  
Vol 3 (4) ◽  
pp. 444-445
Author(s):  
Daniel Quesada ◽  
Matthew Stapleton ◽  
Jadipak Heer ◽  
Phillip Aguìñiga-Navarrete ◽  
Luke Kim
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebrospinal Fluid ◽  
Magnetic Resonance ◽  
Frontal Lobe ◽  
Unusual Case ◽  
Vision Loss ◽  
Physical Exam ◽  
Fluid Density ◽  
Resonance Imaging

Neuroretinitis from neurosyphilis is an uncommon finding in previously healthy young individuals. A 37-year-old presented with three days of painless, unilateral vision loss with an associated diffuse erythematous non-pruritic truncal rash. Physical exam demonstrated vision loss in the left eye. Fundoscopic exam showed unilateral peripapillary hemorrhage, papilledema and venous engorgement. Labs showed positive syphilis antibody qualitative. Magnetic resonance imaging demonstrated 12 millimeters of high right frontal lobe cerebrospinal fluid density. The patient was treated with benzylpenicillin and within 18 hours had improvement of his vision.

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