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7 results

  • Motor Band Sign in Motor Neuron Disease: A Marker for Upper Motor Neuron Involvement

  • Hee Sahng Chung, Gerd Melkus, Pierre Bourque, Santanu Chakraborty
  • Journal:
    Canadian Journal of Neurological Sciences / Volume 50 / Issue 3 / May 2023
    Published online by Cambridge University Press:
    28 April 2022, pp. 373-379
    • Article
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  • Background and Objective:

    The prevalence and role of the motor band sign (MBS) remain unclear in motor neuron disease. We report the frequency of MBS in amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS), its correlation with clinical upper motor neuron (UMN) signs, and prognostic value in ALS.

    Methods:

    We conducted a retrospective study of ALS, PLS, and controls with retrievable MRI between 2010 and 2018. We compared the frequencies of MBS across the three groups, and studied correlation between susceptibility-weighted MRI measurements in primary motor cortices and contralateral UMN features. Clinical outcomes were compared between ALS with and without MBS.

    Results:

    Thirteen ALS, 5 PLS, and 10 controls were included (median age 60 years, IQR 54–66 years; 14/28 males). MBS was present in 9/13 (69.2%, 95% CI 38.9–89.6%) and 4/5 (80.0%, 95% CI 29.9–99.0%) of ALS and PLS, respectively, and none in controls. 2/13 (15.4%, 95% CI 2.7–46.3%) ALS and 3/5 (60.0%, 95% CI 17.0–92.7%) PLS had MBS in the absence of corticospinal T2/FLAIR hyperintensity sign. Susceptibility measurements in left motor cortices had a significantly positive correlation with contralateral UMN signs in ALS (τ b = 0.628, p = 0.03). Similar but nonsignificant trends was observed for right motor cortices in ALS (τ b = 0.516, p = 0.07). There were no significant differences in mRS at last follow-up, mortality, or time from symptom onset to last follow-up between ALS patients with and without MBS.

    Conclusions:

    We provide limited evidence that MBS and susceptibility quantification measurements in motor cortices may serve as surrogate markers of UMN involvement in motor neuron disease.

  • An Important Pediatric Stroke Mimic: Hemiplegic Migraine

  • Michael T. Jurkiewicz, Arastoo Vossough, Avrum N. Pollock
  • Journal:
    Canadian Journal of Neurological Sciences / Volume 47 / Issue 2 / March 2020
    Published online by Cambridge University Press:
    10 January 2020, pp. 235-236
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  • Stroke is relatively rare in children but has become increasingly recognized clinically. Hemiplegic migraine (HM) is a rare subtype of migraine, with attacks typically beginning in childhood or adolescence. Attacks are characterized by migraine headaches and motor weakness, which develop over several minutes. HM may therefore mimic acute stroke; however, symptoms last less than an hour and resolve spontaneously, often without sequela.1–4 Distinction between these entities is important due to their different urgency and management. Neuroimaging is indispensible in working up patients presenting to the Emergency Department with stroke-like symptoms and can be used to distinguish between infarction and HM.

  • Chapter 8 - MRI for targeting in surgical treatment of movement disorders

  • Edited by Paul Tuite, University of Minnesota, Alain Dagher
  • Book:
    Magnetic Resonance Imaging in Movement Disorders
    Published online:
    05 October 2013
    Print publication:
    10 October 2013, pp 94-105

  • Summary

    This chapter provides an overview of magnetic resonance imaging (MRI) methods. The focus on iron in Parkinson's disease (PD) imaging has remained an important topic and researchers have often utilized T2*, or its reciprocal R2*, in nigral imaging protocols. Some iron-sensitive methods have been recently developed. These include adiabatic T2ρ, magnetization transfer (MT) imaging, and susceptibility-weighted imaging (SWI). The authors have developed a novel rotating frame relaxation experiment called relaxation along a fictitious field (RAFF). There has been greater refinement with the utilization of methods that do not employ a-priori regions of interest (ROIs). One such method is voxel-based morphometry (VBM), in which there is standardization of data and then voxel-by-voxel comparison between group data to determine if there are differences in signal intensity. Diffusion tensor imaging (DTI) provides structural data based on the directionally restrained diffusion of water within fiber tracts.

  • Chapter 9 - Magnetic resonance imaging and spectroscopy in Huntington’s disease

  • Edited by Paul Tuite, University of Minnesota, Alain Dagher
  • Book:
    Magnetic Resonance Imaging in Movement Disorders
    Published online:
    05 October 2013
    Print publication:
    10 October 2013, pp 106-120

  • Summary

    Iron content is one of the physiological variables that can be estimated with magnetic resonance imaging (MRI) in the basal ganglia of patients with Parkinson's disease (PD). Brain iron is relatively independent from total body iron content since it is excluded by the blood-brain barrier. The microstructural and physiological organization of tissue plays an important role in determining the local magnetic field behavior of a given region in the brain. Recent work has extended previous observations by using a multimodal approach that combines MRI techniques for imaging iron content with other MRI sequences. MR-based measurements that are directly related to magnetic susceptibility changes should be closely related to iron content and less dependent on its microscopic spatial distribution. Susceptibility-weighted imaging (SWI) is a technique that uses magnetic susceptibility differences between different regions to generate image contrast. Deep brain stimulation (DBS) plays an important role in the treatment of PD.

  • Chapter 9 - Cerebral microbleeds in healthypopulations

  • from Section 3 - Microbleeds in relation to specific populations, diseases and neurological symptoms
  • Edited by David J. Werring, Institute of Neurology, London
  • Book:
    Cerebral Microbleeds
    Published online:
    05 July 2011
    Print publication:
    26 May 2011, pp 79-86

  • Summary

    Susceptibility-weighted imaging (SWI) has proven to be a very sensitive technique for the identification of cerebral microbleeds (CMBs). Increased sensitivity to CMBs may allow assessment of the rate of microhemorrhage development or regression, allowing more precise analysis of the natural history of disease, or better assessment of response to therapy. Early recognition may be advantageous to patients treated with anticoagulant or aspirin therapy in that they are at increased risk for subsequent and possibly fatal hemorrhage. There are in the order of 1.4 million people a year affected by traumatic brain injury (TBI). For these patients, computed tomography (CT) is the mainstay of imaging in the emergency setting and does a good job detecting major bleeds. Radiation damage to blood vessels and radiation necrosis can result from treating tumors and disease with potentially damaging doses of radiation. Future semiautomated methods hold promise for evaluating large numbers of patients using SWI.

  • Chapter 11 - Cerebral microbleeds in relation to hypertensivearteriopathy

  • from Section 3 - Microbleeds in relation to specific populations, diseases and neurological symptoms
  • Edited by David J. Werring, Institute of Neurology, London
  • Book:
    Cerebral Microbleeds
    Published online:
    05 July 2011
    Print publication:
    26 May 2011, pp 99-108

  • Summary

    The cerebral microbleed (CMB) mimics form two types: those that contain blood products and those that do not (resembling CMBs because of shared signal intensity and morphology on gradient-recalled echo (GRE) MRI). This chapter describes both types, and outlines how these can be differentiated from true CMBs. It suggests a topographical approach to the recognition of CMB mimics on brain imaging. The GRE sequences used in the detection of CMBs are sensitive not only to blood breakdown products (deoxyhemoglobin, methemoglobin, hemosiderin and ferritin) but also to other paramagnetic substances such as calcium, manganese and iron, all of which may appear as foci of low signal. In lobar regions of the brain, common CMB mimics include vascular flow voids and hypointensities arising from partial volume artefact. The development of susceptibility-weighted imaging (SWI) has improved the detection of structures containing extravascular blood products, as well as those containing venous deoxygenated blood.