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2.
JACC Basic Transl Sci ; 9(8): 939-953, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39297140

RESUMEN

Postural hyperventilation has been implicated as a cause of postural orthostatic tachycardia syndrome (POTS), yet the precise mechanisms underlying the heightened breathing response remain unclear. This study challenges current hypotheses by revealing that exaggerated peripheral chemoreceptor activity is not the primary driver of postural hyperventilation. Instead, significant contributions from reduced stroke volume and compromised brain perfusion during orthostatic stress were identified. These findings shed light on our understanding of POTS pathophysiology, emphasizing the critical roles of systemic hemodynamic status. Further research should explore interventions targeting stroke volume and brain perfusion for more effective clinical management of POTS.

3.
J Neurosurg ; : 1-8, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39126727

RESUMEN

OBJECTIVE: In 10% of patients undergoing carotid endarterectomy (CEA), the cognitive function declines postoperatively, primarily in association with postoperative cerebral hyperperfusion. In contrast, in the majority of patients undergoing CEA, long-term cognitive outcomes remain unclear. Furthermore, it is not known whether the decline in cognition due to cerebral hyperperfusion recovers on a long-term basis. This study aimed to understand how postoperative cerebral hyperperfusion affects the cognitive outcomes of patients who undergo CEA. METHODS: The participants in this prospective observational study were patients with internal carotid artery stenosis who underwent CEA. Cerebral hyperperfusion syndrome or asymptomatic cerebral hyperperfusion following CEA was determined based on brain perfusion SPECT scans and symptomatology before and after surgery. Neuropsychological testing was performed preoperatively, at 1-2 months postoperatively, and at 2 years postoperatively to investigate cognitive decline. RESULTS: A logistic regression analysis revealed that asymptomatic cerebral hyperperfusion (95% CI 13.0-84.5, p < 0.0001) and cerebral hyperperfusion syndrome (95% CI 449.7-14,237.4, p < 0.0001) were significantly associated with cognitive decline at 1-2 months postoperatively. The incidence of cognitive decline was significantly decreased at 2 years postoperatively (7%) in comparison to 1-2 months postoperatively (11%) (p = 0.0461). A logistic regression analysis also revealed that asymptomatic cerebral hyperperfusion (95% CI 3.7-36.7, p < 0.0001), cerebral hyperperfusion syndrome (95% CI 128.0-6183.6, p < 0.0001), and further strokes during the 2-year follow-up period (95% CI 1.5-78.7, p = 0.0167) were significantly associated with cognitive decline at 2 years postoperatively. The incidence of cognitive decline at 1-2 months postoperatively was significantly higher in patients with cerebral hyperperfusion syndrome (100%) than in those with asymptomatic cerebral hyperperfusion (44%) (p < 0.0001). No significant difference in incidence was observed in the former patients at 2 years postoperatively (88%), but significant reduction was found in patients with asymptomatic cerebral hyperperfusion and cognitive decline between the timepoints of 1-2 months postoperatively (100%) and 2 years postoperatively (39%) (p = 0.0001). CONCLUSIONS: Postoperative cerebral hyperperfusion causes prolonged cognitive decline at 2 years postoperatively in patients undergoing CEA.

5.
Am J Physiol Heart Circ Physiol ; 327(4): H847-H858, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39120466

RESUMEN

Cerebrovascular and neurological diseases exhibit sex-specific patterns in prevalence, severity, and regional specificity, some of which are associated with altered cerebral blood flow (CBF). Females often exhibit higher resting CBF, but understanding the impact of sex per se on CBF is hampered by study variability in age, comorbidities, medications, and control for menstrual cycle or hormone therapies. A majority of studies report whole brain CBF without differentiating between gray and white matter or without assessing regional CBF. Thus fundamental sex differences in regional or whole brain CBF remain unclarified. While controlling for the above confounders, we tested the hypothesis that females will exhibit higher total gray and white matter perfusion as well as regional gray matter perfusion. Adults 18-30 yr old (females = 22 and males = 26) were studied using arterial spin labeling (ASL) magnetic resonance imaging (MRI) scans followed by computational anatomy toolbox (CAT12) analysis in statistical parametric mapping (SPM12) to quantify CBF relative to brain volume. Females displayed 40% higher perfusion globally (females = 62 ± 9 and males = 45 ± 10 mL/100 g/min, P < 0.001), gray matter (females = 75 ± 11 and males = 54 ± 12 mL/100 g/min, P < 0.001), and white matter (females = 44 ± 6 and males = 32 ± 7 mL/100 g/min, P < 0.001). Females exhibited greater perfusion than males in 67 of the 68 regions tested, ranging from 14% to 66% higher. A second MRI approach (4-dimensional flow) focused on large arteries confirmed the sex difference in global CBF. These data indicate strikingly higher basal CBF in females at global, gray, and white matter levels and across dozens of brain regions and offer new clarity into fundamental sex differences in global and regional CBF regulation before aging or pathology.NEW & NOTEWORTHY MRI used to measure cerebral blood flow (CBF) in gray matter, white matter, and 68 regions in healthy men and women. This study demonstrated that CBF is 40% higher in women, the highest sex difference reported, when controlling for numerous important clinical confounders like age, smoking, menstrual cycle, comorbidities, and medications.


Asunto(s)
Circulación Cerebrovascular , Sustancia Gris , Imagen por Resonancia Magnética , Sustancia Blanca , Humanos , Femenino , Masculino , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/irrigación sanguínea , Adulto , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/irrigación sanguínea , Adulto Joven , Adolescente , Factores Sexuales , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Voluntarios Sanos
6.
J Cereb Blood Flow Metab ; : 271678X241260526, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38867576

RESUMEN

Intra-vital visualization of deep cerebrovascular structures and blood flow in the aging brain has been a difficult challenge in the field of neurovascular research, especially when considering the key role played by the cerebrovasculature in the pathogenesis of both vascular cognitive impairment and dementia (VCID) and Alzheimer's disease (AD). Traditional imaging methods face difficulties with the thicker skull of older brains, making high-resolution imaging and cerebral blood flow (CBF) assessment challenging. However, functional ultrasound (fUS) imaging, an emerging non-invasive technique, provides real-time CBF insights with notable spatial-temporal resolution. This study introduces an enhanced longitudinal fUS method for aging brains. Using elderly (24-month C57BL/6) mice, we detail replacing the skull with a polymethylpentene window for consistent fUS imaging over extended periods. Ultrasound localization mapping (ULM), involving the injection of a microbubble (<<10 µm) suspension allows for recording of high-resolution microvascular vessels and flows. ULM relies on the localization and tracking of single circulating microbubbles in the blood flow. A FIJI-based analysis interprets these high-quality ULM visuals. Testing on older mouse brains, our method successfully unveils intricate vascular specifics even in-depth, showcasing its utility for longitudinal studies that require ongoing evaluations of CBF and vascular aspects in aging-focused research.

7.
Jpn J Radiol ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38888851

RESUMEN

The findings of brain perfusion single-photon emission computed tomography (SPECT), which detects abnormalities often before changes manifest in morphological imaging, mainly reflect neurodegeneration and contribute to dementia evaluation. A major shift is about to occur in dementia practice to the approach of diagnosing based on biomarkers and treating with disease-modifying drugs. Accordingly, brain perfusion SPECT will be required to serve as a biomarker of neurodegeneration. Hypoperfusion in Alzheimer's disease (AD) is typically seen in the posterior cingulate cortex and precuneus early in the disease, followed by the temporoparietal cortices. On the other hand, atypical presentations of AD such as the posterior variant, logopenic variant, frontal variant, and corticobasal syndrome exhibit hypoperfusion in areas related to symptoms. Additionally, hypoperfusion especially in the precuneus and parietal association cortex can serve as a predictor of progression from mild cognitive impairment to AD. In dementia with Lewy bodies (DLB), the differentiating feature is the presence of hypoperfusion in the occipital lobes in addition to that observed in AD. Hypoperfusion of the occipital lobe is not a remarkable finding, as it is assumed to reflect functional loss due to impairment of the cholinergic and dopaminergic systems rather than degeneration per se. Moreover, the cingulate island sign reflects the degree of AD pathology comorbid in DLB. Frontotemporal dementia is characterized by regional hypoperfusion according to the three clinical types, and the background pathology is diverse. Idiopathic normal pressure hydrocephalus shows apparent hypoperfusion around the Sylvian fissure and corpus callosum and apparent hyperperfusion in high-convexity areas. The cortex or striatum with diffusion restriction on magnetic resonance imaging in prion diseases reflects spongiform degeneration and brain perfusion SPECT reveals hypoperfusion in the same areas. Brain perfusion SPECT findings in dementia should be carefully interpreted considering background pathology.

8.
J Arrhythm ; 40(3): 411-422, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38939785

RESUMEN

Background: Recent evidence suggests an elevated risk of cognitive impairment and dementia in individuals with atrial fibrillation (AF), irrespective of stroke occurrence. AF, known to reduce brain perfusion, particularly through silent cerebral ischemia, underscores the intricate relationship between cardiac and cerebral health. The heart plays a crucial role in supporting normal brain function, and rhythm control, a standard AF treatment, has demonstrated enhancements in brain perfusion. This systematic review aimed to examine published data concerning the influence of rhythm control on brain perfusion in patients with atrial fibrillation. Methods: A systematic search for relevant studies was carried out in Scopus, PubMed, Cochrane Reviews, ProQuest, and EBSCOhost, spanning from their inception until April 30, 2023. Studies that specifically examined brain perfusion following any form of rhythm control in atrial fibrillation were included in the review. Results: The review encompassed 10 studies involving 436 participants. Among these, six utilized electrical cardioversion for rhythm control. The majority (8 out of 10) demonstrated that restoring sinus rhythm markedly enhances brain perfusion. In one of the two remaining studies, notable improvement was observed specifically in a region closely linked to cognition. Additionally, both studies reporting data on the Mini-Mental State Examination (MMSE) showed a consistent and significant increase in scores following rhythm control. Conclusion: Successful rhythm control in AF emerges as a significant contributor to enhanced brain perfusion, suggesting a potential therapeutic avenue for reducing cognitive impairment incidence. However, further validation through larger prospective studies and randomized trials is warranted.

9.
J Pediatr ; 271: 114086, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38705232

RESUMEN

OBJECTIVE: To evaluate associations between neurologic outcomes and early measurements of basal ganglia (BG) and thalamic (Th) perfusion using color Doppler ultrasonography (CDUS) in infants with hypoxic-ischemic encephalopathy (HIE). STUDY DESIGN: Prospective study of infants with mild (n = 18), moderate (n = 17), and severe HIE (n = 14) and controls (n = 17). Infants with moderate-severe HIE received therapeutic hypothermia (TH). CDUS was performed at 24-36 hours and brain magnetic resonance imaging (MRI) at a median of 10 days. Development was followed through 2.5-5 years. The primary outcome was the association between BG and Th perfusion and brain MRI injury. Secondary analyses focused on associations between perfusion measurements and admission neurologic examinations, MRI scores in infants treated with TH, and motor and sensory disability, or death. An exploratory analysis assessed the accuracy of BG and Th perfusion to predict brain MRI injury in infants treated with TH. RESULTS: Increased BG and Th perfusion on CDUS was observed in infants with severe MRI scores and those with significant motor and neurosensory disability or death through 2.5-5 years (P < .05). Infants with severe HIE showed increased BG and Th perfusion (P < .005) compared with infants with moderate HIE. No differences were identified between the between the control and mild HIE groups. Th perfusion ≥0.237 cm/second (Area under the curve of 0.824) correctly classified 80% of infants with severe MRI scores. CONCLUSIONS: Early dynamic CDUS of the BG and Th is a potential biomarker of severe brain injury in infants with HIE and may be a useful adjunct to currently used assessments.


Asunto(s)
Ganglios Basales , Hipotermia Inducida , Hipoxia-Isquemia Encefálica , Imagen por Resonancia Magnética , Tálamo , Ultrasonografía Doppler en Color , Humanos , Ganglios Basales/diagnóstico por imagen , Hipoxia-Isquemia Encefálica/diagnóstico por imagen , Hipoxia-Isquemia Encefálica/terapia , Estudios Prospectivos , Masculino , Femenino , Ultrasonografía Doppler en Color/métodos , Recién Nacido , Imagen por Resonancia Magnética/métodos , Tálamo/diagnóstico por imagen , Lactante , Lesiones Encefálicas/diagnóstico por imagen
10.
J Biomed Sci ; 31(1): 37, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627751

RESUMEN

BACKGROUND: Huntington's disease (HD) is marked by a CAG-repeat expansion in the huntingtin gene that causes neuronal dysfunction and loss, affecting mainly the striatum and the cortex. Alterations in the neurovascular coupling system have been shown to lead to dysregulated energy supply to brain regions in several neurological diseases, including HD, which could potentially trigger the process of neurodegeneration. In particular, it has been observed in cross-sectional human HD studies that vascular alterations are associated to impaired cerebral blood flow (CBF). To assess whether whole-brain changes in CBF are present and follow a pattern of progression, we investigated both resting-state brain perfusion and vascular reactivity longitudinally in the zQ175DN mouse model of HD. METHODS: Using pseudo-continuous arterial spin labelling (pCASL) MRI in the zQ175DN model of HD and age-matched wild-type (WT) mice, we assessed whole-brain, resting-state perfusion at 3, 6 and 9 and 13 months of age, and assessed hypercapnia-induced cerebrovascular reactivity (CVR), at 4.5, 6, 9 and 15 months of age. RESULTS: We found increased perfusion in cortical regions of zQ175DN HET mice at 3 months of age, and a reduction of this anomaly at 6 and 9 months, ages at which behavioural deficits have been reported. On the other hand, under hypercapnia, CBF was reduced in zQ175DN HET mice as compared to the WT: for multiple brain regions at 6 months of age, for only somatosensory and retrosplenial cortices at 9 months of age, and brain-wide by 15 months. CVR impairments in cortical regions, the thalamus and globus pallidus were observed in zQ175DN HET mice at 9 months, with whole brain reactivity diminished at 15 months of age. Interestingly, blood vessel density was increased in the motor cortex at 3 months, while average vessel length was reduced in the lateral portion of the caudate putamen at 6 months of age. CONCLUSION: Our findings reveal early cortical resting-state hyperperfusion and impaired CVR at ages that present motor anomalies in this HD model, suggesting that further characterization of brain perfusion alterations in animal models is warranted as a potential therapeutic target in HD.


Asunto(s)
Enfermedad de Huntington , Humanos , Ratones , Animales , Lactante , Enfermedad de Huntington/genética , Estudios Transversales , Hipercapnia , Encéfalo , Modelos Animales de Enfermedad , Perfusión
11.
J Cardiothorac Surg ; 19(1): 217, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627813

RESUMEN

BACKGROUND: Cerebral protection strategies have been investigated since the introduction of aortic arch surgery and have been modified over the centuries. However, the cerebral protective effects of unilateral and bilateral antegrade cerebral perfusion are similar, with opportunities for further improvement. METHODS: A total of 30 patients who underwent total arch surgery were enrolled in this study. Patients were assigned to the novel continuous whole-brain or unilateral antegrade cerebral perfusion group according to the cerebral perfusion technique used. Preoperative clinical data and 1-year postoperative follow-up data were collected and analyzed. RESULTS: There were no significant differences between the two groups in terms of the incidence of permanent neurological deficit, mortality, or therapeutic efficacy. However, the incidence of temporary neurological dysfunction in the novel whole-brain perfusion group was significantly lower than that in the unilateral antegrade cerebral perfusion group. CONCLUSIONS: In this study, the branch-first approach with a novel whole-brain perfusion strategy had no obvious disadvantages compared with unilateral antegrade cerebral perfusion in terms of cerebral protection and surgical safety. These findings suggest that this new technique is feasible and has application value for total arch surgery.


Asunto(s)
Aorta Torácica , Circulación Cerebrovascular , Humanos , Aorta Torácica/cirugía , Encéfalo , Perfusión/métodos , Paro Circulatorio Inducido por Hipotermia Profunda , Resultado del Tratamiento , Complicaciones Posoperatorias/prevención & control
12.
Cureus ; 16(3): e56236, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38618338

RESUMEN

The efficacy of extracranial-intracranial (EC-IC) bypass in preventing ischemic stroke progression and recurrence is controversial. As per the current hypothesis, EC-IC bypass is most beneficial for patients with persistent hemodynamic insufficiency. Hence, various approaches have been used to evaluate hemodynamic insufficiency, including repeated single photon emission CT (SPECT) imaging or continuous monitoring of cerebral flow with transcranial Doppler ultrasound (TCD). However, both modalities are time- and resource-intensive. In this report, we discuss how EC-IC bypass turned out to be beneficial for a patient presenting with blood pressure-dependent severe aphasia and right hemiparesis due to middle cerebral artery (MCA) occlusion that failed thrombectomy. CT perfusion (CTP) scan at admission demonstrated a persistent volume of delayed perfusion without core infarct. Following the superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass, the patient's National Institute of Health Stroke Scale (NIHSS) score improved from 12 to 1. Ischemic penumbra, as seen on CTP imaging, also improved after the STA-MCA bypass. Our case suggests that persistent volume of delayed perfusion and blood pressure-dependent neurological deficits can be used in tandem as selection criteria for EC-IC bypass.

13.
Radiol Phys Technol ; 17(1): 322-328, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38332240

RESUMEN

Head holder attenuation affects brain perfusion single-photon emission computed tomography (SPECT) image quality. Here, we proposed a head holder-attenuation correction (AC) method using attenuation coefficient maps calculated by Chang's method from CT images. Then, we evaluated the effectiveness of the head holder-AC method by numerical phantom and clinical cerebral perfusion SPECT studies. In the numerical phantom, the posterior counts were 10.7% lower than the anterior counts without head holder-AC method. However, by performing head holder-AC, the posterior count recovered by approximately 6.8%, approaching the true value. In the clinical study, the normalized count ratio was significantly increased by performing the head holder-AC method in the posterior-middle cerebral artery, posterior cerebral artery and cerebellum regions. There were no significant increases in other regions. The head holder-AC method can correct the counts attenuated by the head holder.


Asunto(s)
Encéfalo , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada de Emisión de Fotón Único/métodos , Fantasmas de Imagen , Perfusión , Encéfalo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador
14.
Am J Physiol Heart Circ Physiol ; 326(4): H923-H928, 2024 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-38334969

RESUMEN

It is known that electrical muscle stimulation (EMS) can enhance physical function, but its impact on cognition and cerebral hemodynamics is not well understood. Thus, the purpose of this study was to investigate the effects of one EMS session on cerebrovascular function and cognitive performance. The 17 recruited young healthy participants undertook a 25-min session of EMS and a resting control session (Ctrl group) in a random order. Cerebral blood flow velocity (CBFv) in the middle and posterior cerebral arteries (right MCAv and left PCAv, respectively), cerebral oxygenation, cardiac output, and heart rate were measured throughout the sessions, whereas cognitive function was assessed before and after each experimental condition. MCAv, cardiac output, heart rate, and cerebral oxygenation were increased throughout the EMS session, whereas PCAv remained unchanged. In addition, EMS led to improved scores at the Rey auditory verbal learning test-part B and congruent Stroop task versus Ctrl. The present study demonstrates that a single session of EMS may improve cognitive performance and concomitantly increase CBFv and cerebral oxygenation. Therefore, EMS appears to be a valuable surrogate for voluntary exercise and could therefore be advantageously used in populations with severe physical limitations who would not be able to perform physical exercise otherwise.NEW & NOTEWORTHY This study is the first to demonstrate that one session of EMS applied to the quadriceps increases cerebral blood flow velocity and cerebral oxygenation, which are pivotal factors for brain health. Thus, EMS has the potential to be used as an interesting option in rehabilitation to increase cerebral perfusion and defend if not improve cognitive function sustainably for people with severe physical limitations who would not be able to perform physical exercise voluntarily.


Asunto(s)
Circulación Cerebrovascular , Hemodinámica , Humanos , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular/fisiología , Cognición , Hemodinámica/fisiología , Músculo Cuádriceps
15.
Artif Organs ; 48(7): 743-752, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38391014

RESUMEN

BACKGROUND: The major concern in patients who have suffered from cardiac arrest (CA) and undergone successful extracorporeal cardiopulmonary resuscitation (E-CPR) is poor neurological outcomes. In this study, we aimed to introduce a rat model of selective brain perfusion (SBP) during E-CPR to improve the neurological outcome after CA. METHODS: The rats underwent 7 min of untreated asphyxial CA and then were resuscitated with E-CPR for 30 min. The right external jugular vein and right femoral artery were separately cannulated to the E-CPR outflow and inflow. The right common carotid artery was cannulated from the proximal to the distal side for SBP. Subsequently, rats were removed from E-CPR, wounds were closed, and 90 min of intensive care were provided. Neurological deficit scores were tested after 4 h of recovery when the rats were mechanical ventilation-free. S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP) were detected through immunohistochemistry (IHC) of brain tissue. RESULTS: The rats that received SBP while resuscitated by E-CPR showed markedly better neurological performances after 4-h recovery than those resuscitated by E-CPR only. The IHC staining of GFAP and S100B in the hippocampus was low in the rats receiving SBP during E-CPR, but only GFAP showed significant differences. CONCLUSIONS: We successfully developed a novel and reproducible rat model of SBP while resuscitated by E-CPR to ameliorate the neurological performances after CA. This achievement might have opportunities for studying how to improve the neurological outcome in the clinical condition.


Asunto(s)
Encéfalo , Reanimación Cardiopulmonar , Modelos Animales de Enfermedad , Oxigenación por Membrana Extracorpórea , Paro Cardíaco , Ratas Sprague-Dawley , Animales , Reanimación Cardiopulmonar/métodos , Paro Cardíaco/terapia , Paro Cardíaco/fisiopatología , Ratas , Masculino , Encéfalo/patología , Encéfalo/irrigación sanguínea , Oxigenación por Membrana Extracorpórea/métodos , Subunidad beta de la Proteína de Unión al Calcio S100/metabolismo , Perfusión/métodos , Proteína Ácida Fibrilar de la Glía/metabolismo , Circulación Cerebrovascular
16.
Res Vet Sci ; 165: 105070, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37925817

RESUMEN

Previous studies both in humans and dogs with chronic liver diseases have shown that regional cerebral brain flow (rCBF) is altered. The current study aimed to assess abnormalities in rCBF in dogs with congenital extrahepatic portosystemic shunts (cEHPSS), both at diagnosis and after successful surgical attenuation. Furthermore, the influence of age at diagnosis, severity of hepatic encephalopathy (HE) and type of cEHPSS on rCBF were explored as a base for future research. Single photon emission computed tomography (SPECT) with 99mtechnetium-hexamethylpropylene amine oxime tracer was performed before surgical attenuation and six months postoperatively. Twenty-four dogs with cEHPSS had SPECT at time of diagnosis and 13 dogs with a confirmed closed cEHPSS had a second SPECT six months postoperatively. At diagnosis, dogs with cEHPSS had an altered rCBF distribution compared to healthy dogs. This altered rCBF distribution seemed to be most apparent in dogs ≥ one year and in dogs with overt HE at diagnosis. Six months postoperatively, only the rCBF distribution in the subcortical region decreased compared to pre-operatively. In conclusion, all dogs with cEHPSS had altered rCBF which did not seem to normalize completely six months after successful surgical attenuation. Dogs diagnosed at an older age seemed to have more distinct abnormalities in rCBF compared to younger dogs.


Asunto(s)
Derivación Portosistémica Intrahepática Transyugular , Humanos , Perros , Animales , Derivación Portosistémica Intrahepática Transyugular/veterinaria , Encéfalo , Tomografía Computarizada de Emisión de Fotón Único/veterinaria , Circulación Cerebrovascular
17.
Int J Neurosci ; : 1-7, 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37812028

RESUMEN

BACKGROUND: There is limited information on brain perfusion single-photon emission computed tomography (SPECT) findings related to motor outcomes in patients with stroke. We aimed to investigate whether brain SPECT can be used to determine motor outcomes after corona radiata infarction. METHODS: Eighty-nine patients were recruited in this study. Brain SPECT and diffusion tensor tractography (DTT) were conducted to evaluate the state of the corticospinal tract (CST) within 7-30 days of corona radiata infarct. Motor outcome was measured 6 months after infarct onset and was evaluated using the modified Brunnstrom classification (MBC) and functional ambulation category (FAC) for motor function of the upper and lower extremities, respectively. The presence of hypoperfusion on brain SPECT was evaluated in the frontal lobe, temporal lobe, parietal lobe, basal ganglia, thalamus, and cerebellum on both the ipsilesional and contralesional sides. Statistical analysis was performed using multivariate logistic regression, comparing patients in which CST was spared versus interrupted. RESULTS: Hypoperfusion in the contralesional cerebellum was indicative of poor recovery in both the upper and lower extremities after corona radiata infarction when the CST was interrupted. Additionally, when the CST was preserved, hypoperfusion in the ipsilesional thalamus was indicative of poor recovery of the lower extremities. CONCLUSION: Brain SPECT evaluation was shown to be a useful tool for predicting motor outcomes in patients with corona radiata infarcts.

18.
Cureus ; 15(9): e44846, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809118

RESUMEN

This case highlights a patient presenting with a stroke code in the emergency department with decreased consciousness. The patient was later found to have bilateral thalamic strokes due to ischemia of the artery of Percheron. Initial head computed tomography (CT) and CT angiogram (CTA) of the head and neck showed no abnormalities. CT perfusion (CTP) showed a perfusion deficit of 169 mL with a T-max greater than 4 s and 4 mL with a T-max greater than 6 s in the posterior circulation. The patient received IV alteplase. This case report emphasizes the importance of perfusion neuroimaging in the evaluation of acute ischemic stroke.

19.
Acta Radiol ; 64(12): 3042-3051, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37872652

RESUMEN

BACKGROUND: The middle cerebral artery occlusion model (MCAo) is a commonly used animal model for cerebral ischemia studies but lacks accessible imaging techniques for the assessment of hemodynamic changes of the model. PURPOSE: The study aims to explore the value of contrast-enhanced ultrasound (CEUS) in evaluating brain perfusion in the early stages after MCAo surgery. MATERIAL AND METHODS: In total, 18 adult male Sprague-Dawley rats were subjected to right MCAo using an intraluminal filament model, and CEUS was performed at the three following timepoints: before (T0), immediately after (T1), and 6 h after permanent MCAo (T2). Twelve rats successfully completed the study, and their brains were removed and stained using 2, 3, 5-triphenyltetrazolium chloride (TTC). CEUS video images were visualized offline, and the time-intensity curves (TICs) were analyzed. Different cerebrovascular patterns and manifestations of the contrast enhancement in rat ischemic hemispheres were observed. Semi-quantitative parameters of TICs in ischemic areas (ROIi) and the surrounding normal- or hypo-perfused areas (ROIn) were calculated and compared between T0, T1, and T2, and also between ROIi and ROIn. RESULTS: A significant correlation was found between the lesion volume (%) determined by TTC and CEUS parameters (r = -0.691, P = 0.013 for peak intensity; r = -0.742, P = 0.006 for area under the curve) at T2. After the same occlusion, there were differences in contrast perfusion in each group. CONCLUSION: This study suggests that CEUS could be an effective imaging tool for studying cerebral ischemia and perfusion in small animals as long as the transcranial acoustic window allows it.


Asunto(s)
Isquemia Encefálica , Infarto de la Arteria Cerebral Media , Ratas , Masculino , Animales , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Ratas Sprague-Dawley , Proyectos Piloto , Isquemia Encefálica/patología , Encéfalo/patología , Perfusión , Isquemia , Modelos Animales de Enfermedad
20.
BMC Med ; 21(1): 238, 2023 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-37400817

RESUMEN

BACKGROUND: It is unclear whether dobutamine, commonly used clinically in echocardiography and short-term congestive heart failure treatment for promoting increased myocardial contractility, affects brain microcirculatory behavior. Cerebral microcirculation plays an important role in ensuring adequate oxygen transport. Therefore, we investigated the effects of dobutamine on cerebral hemodynamics. METHODS: Forty-eight healthy volunteers without cardiovascular or cerebrovascular disease underwent MRI to obtain cerebral blood flow (CBF) maps using 3D pseudocontinuous arterial spin labeling before and during the dobutamine stress test. Additionally, cerebrovascular morphology was obtained based on 3D-time-off-light (3D-TOF) magnetic resonance angiography (MRA). Electrocardiogram, heart rate (HR), respiration rate (RR), blood pressure, and blood oxygen were simultaneously recorded before and during dobutamine injection and during recovery (not during MRI). The anatomic features of the circle of Willis and the basilar artery (BA) diameter were assessed on MRA images by two radiologists with extensive neuroimaging experience. Binary logistic regression was used to test for the independent determinants of CBF changes. RESULTS: HR, RR, systolic (SBP), and diastolic blood pressure (DBP) significantly increased after dobutamine infusion. Blood oxygen levels remained similar. Compared to the CBF in the resting state, the CBF values exhibited significantly lower CBF levels in both grey matter and white matter. Furthermore, compared with the CBF in the resting state, that in the stress state was decreased in the anterior circulation, mainly in the frontal lobe (voxel level P < 0.001, pixel level P < 0.05). Logistic regression showed that body mass index (BMI; odds ratio [OR] 5.80, 95% confidence interval [CI] 1.60-21.01, P = 0.008], resting SBP (OR 0.64, 95% CI 0.45-0.92, P = 0.014), and BA diameter (OR 11.04, 95% CI 1.05-116.53, P = 0.046) were significantly associated with frontal lobe CBF changes. CONCLUSIONS: Dobutamine-induced stress significantly decreased CBF in the frontal lobe anterior circulation. Individuals with a high BMI and low SBP during the dobutamine stress test are more likely to have a stress-induced CBF decrease. Thus, attention should be paid to blood pressure, BMI, and cerebrovascular morphology of patients undergoing dobutamine stress echocardiography or those receiving intensive care or anesthesia.


Asunto(s)
Dobutamina , Imagen por Resonancia Magnética , Humanos , Adulto , Marcadores de Spin , Microcirculación , Imagen por Resonancia Magnética/métodos , Circulación Cerebrovascular/fisiología , Oxígeno
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