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In JoVE (1)
Other Publications (6)
- Postgraduate Medicine
- Allergy and Asthma Proceedings : the Official Journal of Regional and State Allergy Societies
- Pain Physician
- Annals of Allergy, Asthma & Immunology : Official Publication of the American College of Allergy, Asthma, & Immunology
- Frontiers in Synaptic Neuroscience
- Neurosurgery Clinics of North America
Articles by Umer Najib in JoVE
JoVE Neuroscience
State-Dependency Effects on TMS: A Look at Motive Phosphene Behavior
1Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, 2Brain Research Unit, Low Temperature Laboratory and Advanced magnetic Imaging Center, Aalto University School of Science and Technology
In this article, we examine the effects of visually relevant state dependency on TMS induced motive phosphenic presentations.
Other articles by Umer Najib on PubMed
An Update on Acute and Chronic Urticaria for the Primary Care Provider
Urticaria is a common dermatologic condition seen by primary care physicians. Urticaria can result in significant morbidity and a dramatic decline in quality of life. Acute urticaria is mostly an allergic or IgE-mediated reaction and tends to be self-limited, while chronic urticaria generally does not exhibit any specific external cause and is therefore considered idiopathic. Evidence suggests that up to 30% to 50% of idiopathic cases may be autoimmune and/or related to mast cell/basophil abnormalities. There is further evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), specifically binding to the alpha-chain (FcepsilonRIalpha), which may be pathogenic. The treatment regimen for urticaria needs to be individualized as the severity and clinical pattern can vary considerably between patients. Histamine antagonists are the mainstays of therapy. For more severe or persistent cases, there are few Food and Drug Administration (FDA)-approved options, and there are limited data from controlled trials. Further research is required to develop safe and more effective agents for this disease.
The Spectrum of Chronic Urticaria
Chronic urticaria is a common heterogeneous condition that can be quite debilitating. There are a number of potential causes of urticaria, and the severity and clinical pattern can vary considerably from patient to patient. Eighty to 90% of patients with chronic urticaria have no specific external cause for their disease, which is therefore labeled "chronic idiopathic urticaria." We now know, however, that up to 30-50% of idiopathic cases may be autoimmune or related to mast cell and basophil abnormalities. There is evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), specifically binding to the alpha-chain (FcepsilonRIalpha), which may be pathogenic. At this point in time, the gold standard for detecting clinically relevant autoantibodies to FcepislonRI is the functional in-vitro donor basophil histamine release assay. The exact prevalence and role of these autoantibodies is still under investigation. Histamine antagonists are the mainstays of therapy. For patients whose symptoms are not controlled by antihistamines alone, there are a number of adjunct therapy options, but there is still a need to develop better agents for this disease.
Low and Therapeutic Doses of Antidepressants Are Associated with Similar Response in the Context of Multimodal Treatment of Pain
Antidepressants are prescribed in a wide range of doses to treat both depression and chronic pain, with optimal psychopharmacology individualized for each patient. In the past decade more antidepressants from different chemical classes have become available and are being used for the treatment of both chronic pain and depression.
A Retrospective Review of Clinical Presentation, Thyroid Autoimmunity, Laboratory Characteristics, and Therapies Used in Patients with Chronic Idiopathic Urticaria
Our knowledge of autoimmune characteristics of chronic idiopathic urticaria (CIU) is limited.
Transcranial Magnetic Stimulation Provides Means to Assess Cortical Plasticity and Excitability in Humans with Fragile X Syndrome and Autism Spectrum Disorder
Fragile X Syndrome (FXS) is the most common heritable cause of intellectual disability. In vitro electrophysiologic data from mouse models of FXS suggest that loss of fragile X mental retardation protein affects intracortical excitability and synaptic plasticity. Specifically, the cortex appears hyperexcitable, and use-dependent long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength are abnormal. Though animal models provide important information, FXS and other neurodevelopmental disorders are human diseases and as such translational research to evaluate cortical excitability and plasticity must be applied in the human. Transcranial magnetic stimulation paradigms have recently been developed to non-invasively investigate cortical excitability using paired pulse stimulation, as well as LTP- and LTD-like synaptic plasticity in response to theta burst stimulation (TBS) in vivo in the human. TBS applied on consecutive days can be used to measure metaplasticity (the ability of the synapse to undergo a second plastic change following a recent induction of plasticity). The current study investigated intracortical inhibition, plasticity and metaplasticity in full mutation females with FXS, participants with autism spectrum disorders (ASD), and neurotypical controls. Results suggest that intracortical inhibition is normal in participants with FXS, while plasticity and metaplasticity appear abnormal. ASD participants showed abnormalities in plasticity and metaplasticity, as well as heterogeneity in intracortical inhibition. Our findings highlight the utility of non-invasive neurophysiological measures to translate insights from animal models to humans with neurodevelopmental disorders, and thus provide direct confirmation of cortical dysfunction in patients with FXS and ASD.
Transcranial Brain Stimulation: Clinical Applications and Future Directions
Noninvasive brain stimulation is a valuable investigative tool and has potential therapeutic applications in cognitive neuroscience, neurophysiology, psychiatry, and neurology. Transcranial magnetic stimulation (TMS) is particularly useful to establish and map causal brain-behavior relations in motor and nonmotor cortical areas. Neuronavigated TMS is able to provide precise information related to the individual's functional anatomy that can be visualized and used during surgical interventions and critically aid in presurgical planning, reducing the need for riskier and more cumbersome intraoperative or invasive mapping procedures. This article reviews methodological aspects, clinical applications, and future directions of TMS-based mapping.
