Single Photon Emission Computed Tomography of the Brain in Patients with Chemical Sensitivities

1994 ◽  
Vol 10 (4-5) ◽  
pp. 573-577
Author(s):  
Theodore R. Simon ◽  
David C. Hickey ◽  
Cynthia E. Fincher ◽  
Alfred R. Johnson ◽  
Gerald H. Ross ◽  
...  
Keyword(s):  
Psychological Symptoms ◽  
Single Photon ◽  
Single Case ◽  
Photon Emission ◽  
Clinical Syndrome ◽  
Emission Computed Tomography ◽  
Desert Storm ◽  
Petroleum Distillates ◽  
Other Substances ◽  
The Brain

Chemical sensitivities display a recurrent pattern on scintigraphic examinations of the brain. The pattern can include mismatching between early and late imaging, multiple hot and cold foci distributed throughout the cortex without regard to lobar distribution (salt and pepper pattern), temporal asymmetries, and sometimes increased activity in the basal ganglia. This study used Desert Shield/Desert Storm veterans who present with abnormal neurological and psychological symptoms as a model to exhibit abnormalities by brain scintigraphy. These are typical of those seen in patients with documented exposure to neurotoxic compounds who develop a clinical syndrome that has been termed chemical sensitivity. Exposure to cocaine, alcohol, and other substances of abuse can result in abnormal scintigrams of the brain using tracers such as [technetium 99m]hexamethylpropyleneoxime. This study used techniques combining regional cerebral blood flow data with delayed distributional data after the intracellular conversion of the tracer into a hydrophilic molecule. In addition to delayed image abnormalities, a mismatch occurs in the regional activity between the two image sets of the veterans. This degree of mismatch was not seen in control subjects who were screened for avoidance of neurotoxic agents. Patterns identified from examinations performed on patients with known exposure to petroleum distillates, pesticides and other materials linked with neurotoxicity were identified in some veterans of the Desert Shield/Desert Storm operation. A single case of repeated examinations on a veteran showed a reversion of these patterns toward normal after therapy. This reversion followed independent assessments of clinical improvement.

scholarly journals Magnetic Resonace–Based Attenuation Correction for Micro–Single-Photon Emission Computed Tomography

2012 ◽  
Vol 11 (2) ◽  
pp. 7290.2011.00036 ◽  
Author(s):  
Vincent Keereman ◽  
Yves Fierens ◽  
Christian Vanhove ◽  
Tony Lahoutte ◽  
Stefaan Vandenberghe
Keyword(s):  
Attenuation Correction ◽  
Single Photon ◽  
Photon Emission ◽  
The Body ◽  
Emission Computed Tomography ◽  
Micro Ct ◽  
Mr Images ◽  
Brain Scans ◽  
The Brain ◽  
Photon Emission Computed Tomography

Attenuation correction is necessary for quantification in micro–single-photon emission computed tomography (micro-SPECT). In general, this is done based on micro–computed tomographic (micro-CT) images. Derivation of the attenuation map from magnetic resonance (MR) images is difficult because bone and lung are invisible in conventional MR images and hence indistinguishable from air. An ultrashort echo time (UTE) sequence yields signal in bone and lungs. Micro-SPECT, micro-CT, and MR images of 18 rats were acquired. Different tracers were used: hexamethylpropyleneamine oxime (brain), dimercaptosuccinic acid (kidney), colloids (liver and spleen), and macroaggregated albumin (lung). The micro-SPECT images were reconstructed without attenuation correction, with micro-CT-based attenuation maps, and with three MR-based attenuation maps: uniform, non-UTE-MR based (air, soft tissue), and UTE-MR based (air, lung, soft tissue, bone). The average difference with the micro-CT-based reconstruction was calculated. The UTE-MR-based attenuation correction performed best, with average errors ≤ 8% in the brain scans and ≤ 3% in the body scans. It yields nonsignificant differences for the body scans. The uniform map yields errors of ≤ 6% in the body scans. No attenuation correction yields errors ≥ 15% in the brain scans and ≥ 25% in the body scans. Attenuation correction should always be performed for quantification. The feasibility of MR-based attenuation correction was shown. When accurate quantification is necessary, a UTE-MR-based attenuation correction should be used.

scholarly journals Shifting of global aphasia to Wernicke’s aphasia in a patient with intact motor function: a case report

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ya-Chi Chuang ◽  
Chuan-Ching Liu ◽  
I-Ching Yu ◽  
Yu-Lin Tsai ◽  
Shin-Tsu Chang
Keyword(s):  
Computed Tomography ◽  
Right Hemisphere ◽  
Single Photon ◽  
Ct Perfusion ◽  
Single Case ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Speech Fluency ◽  
Language Functions ◽  
The Right

Abstract Background Global aphasia without hemiparesis (GAWH) is a rare stroke syndrome characterized by the dissociation of motor and language functions. Here, we present a case of GAWH with the patient later regaining speech fluency. Case presentation A 73-year-old man was admitted to our emergency department immediately after an episode of syncope. On arrival, we noted his global aphasia but without any focal neurologic signs. Computed tomography (CT) perfusion scans showed a large hypodense region over his left perisylvian area. Under the impression of acute ischaemic stroke, he received recombinant tissue plasminogen activator (rtPA) injection and was treated as an inpatient. The patient was later discharged with GAWH status and received regular speech rehabilitation. After 14 months of rehabilitation, the patient gradually recovered his language expression ability. The degree of aphasia was evaluated with the Concise Chinese Aphasia Test (CCAT), and we obtained brain single photon emission computed tomography (SPECT) scans to assess cerebral blood flow. Conclusion A patient with severe impairments of Broca’s and Wernicke’s areas was able to talk fluently despite being unintelligible. SPECT revealed relative high level of radioactivity uptake in the right frontal lobe, suggesting the deficits in speech fluency could have been compensated by the right hemisphere. Although this is a single case demonstration, the results may strengthen the role of the right hemisphere in GAWH patients and suggests additional study that examines the possible benefits of stimulating activity at right homologous regions for recovering language function after global aphasia.

Age-Dependent Changes in the Plasma and Brain Pharmacokinetics of Amyloid-β Peptides and Insulin

2021 ◽  
pp. 1-14
Author(s):  
Andrew L. Zhou ◽  
Nidhi Sharda ◽  
Vidur V. Sarma ◽  
Kristen M. Ahlschwede ◽  
Geoffry L. Curran ◽  
...  
Keyword(s):  
Neurodegenerative Disorder ◽  
Single Photon ◽  
Photon Emission ◽  
Amyloid Β ◽  
Emission Computed Tomography ◽  
Systemic Injection ◽  
Age Related ◽  
Age Dependent ◽  
Plasma Pharmacokinetics ◽  
The Brain

Background: Age is the most common risk factor for Alzheimer’s disease (AD), a neurodegenerative disorder characterized by the hallmarks of toxic amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles. Moreover, sub-physiological brain insulin levels have emerged as a pathological manifestation of AD. Objective: Identify age-related changes in the plasma disposition and blood-brain barrier (BBB) trafficking of Aβ peptides and insulin in mice. Methods: Upon systemic injection of 125I-Aβ 40, 125I-Aβ 42, or 125I-insulin, the plasma pharmacokinetics and brain influx were assessed in wild-type (WT) or AD transgenic (APP/PS1) mice at various ages. Additionally, publicly available single-cell RNA-Seq data [GSE129788] was employed to investigate pathways regulating BBB transport in WT mice at different ages. Results: The brain influx of 125I-Aβ 40, estimated as the permeability-surface area product, decreased with age, accompanied by an increase in plasma AUC. In contrast, the brain influx of 125I-Aβ 42 increased with age, accompanied by a decrease in plasma AUC. The age-dependent changes observed in WT mice were accelerated in APP/PS1 mice. As seen with 125I-Aβ 40, the brain influx of 125I-insulin decreased with age in WT mice, accompanied by an increase in plasma AUC. This finding was further supported by dynamic single-photon emission computed tomography (SPECT/CT) imaging studies. RAGE and PI3K/AKT signaling pathways at the BBB, which are implicated in Aβ and insulin transcytosis, respectively, were upregulated with age in WT mice, indicating BBB insulin resistance. Conclusion: Aging differentially affects the plasma pharmacokinetics and brain influx of Aβ isoforms and insulin in a manner that could potentially augment AD risk.

Neuroimaging in dementia and depression

2000 ◽  
Vol 6 (2) ◽  
pp. 109-119 ◽  
Author(s):  
John O'Brien ◽  
Bob Barber
Keyword(s):  
Computed Tomography ◽  
Brain Mapping ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Near Future ◽  
The Brain ◽  
Photon Emission Computed Tomography

Neuroimaging is traditionally divided into structural and functional imaging. Structural imaging looks at brain structure or anatomy and includes computed tomography (CT) and magnetic resonance imaging (MRI). Functional techniques seek to examine the physiological functioning of the brain, either at rest or during activation, and include single photon emission computed tomography (SPECT), positron emission tomography (PET), MRI spectroscopy, functional MRI (fMRI) and encephalographic brain mapping. Although fMRI, MRI spectroscopy and brain mapping are likely to have clinical applications in the near future, the main imaging modalities of current clinical relevance to psychiatrists are CT, MRI and SPECT, which will be the focus of this article.

scholarly journals Advances in the Management of Cerebral Vascular Disease

2015 ◽  
Vol 1 (2) ◽  
pp. 86
Author(s):  
Muhammad Imran Qadir ◽  
Hina Kanwal
Keyword(s):  
Vascular Disease ◽  
Single Photon ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Industrialized Countries ◽  
Cerebral Vascular Disease ◽  
Neurologic Disability ◽  
The Brain ◽  
Photon Emission Computed Tomography ◽  
Cerebral Vascular

A cerebral vascular disease occurred with the arteries of brain due to the less supply of blood.  Stroke is mostly caused by cerebral vascular disease and it is also a common cause of vascular dementia due to reduced oxygen supply and blood flow to the brain. In industrialized countries, neurologic disability is most frequently caused by cerebeovascular disease. Individuals with cardiovascular disease, diabetes and high blood pressure etc are at higher possibility for cerebral vascular disease. After malignancy and heart disease, cerebral vascular disease is the third leading of death and estimated that an average 500,000 new stroke occurred in each year. Advance techniques such as Carotid Endarterectomy, Magnetic resonance imaging, Angiography and Single photon emission computed tomography etc are used for management of cerebral vascular disease.

Neuroimaging technologies

2020 ◽  
pp. 101-112
Author(s):  
Mark Woolrich ◽  
Mark Jenkinson ◽  
Clare Mackay
Keyword(s):  
Brain Imaging ◽  
Single Photon ◽  
Photon Emission ◽  
Experimental Medicine ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Brain Structure And Function ◽  
Magnetic Resonance Imaging Mri ◽  
And Function ◽  
The Brain

The brain is a highly complex system that is inaccessible to biopsy, which puts human brain imaging at the heart of our attempts to understand psychiatric disorders. Imaging has the potential to uncover the pathophysiology, provide biomarkers for use in the development and monitoring of treatments, and stratify patients for studies and trials. This chapter introduces the three main brain imaging technologies that are used to assay brain structure and function: magnetic resonance imaging (MRI), molecular imaging positron emission tomography (PET), and single-photon emission computed tomography (SPECT); electrophysiology [electroencephoaography (EEG)]; and magnetoencephalograpy (MEG). The chapter outlines the principles behind their use and the nature of the information that can be extracted. Together, these brain imaging methods can provide complementary windows into the living brain as an increasingly essential suite of tools for experimental medicine in psychiatry.

Sign in / Sign up

Export Citation Format

Share Document