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1.
Stroke ; 54(1): 78-86, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36321455

RESUMEN

BACKGROUND: Intracerebral hemorrhage (ICH) survivors are at high risk for recurrent stroke and cardiovascular events. Blood pressure (BP) control represents the most potent intervention to lower these risks, but optimal treatment targets in this patient population remain unknown. We sought to determine whether survivors of ICH achieving more intensive BP control than current guideline recommendations (systolic BP <130 mmHg and diastolic BP <80 mmHg) were at lower risk of major adverse cardiovascular and cerebrovascular events and mortality. METHODS: We analyzed data for 1828 survivors of spontaneous ICH from 2 cohort studies. Follow-up BP measurements were recorded 3 and 6 months after ICH, and every 6 months thereafter. Outcomes of interest were major adverse cardiovascular and cerebrovascular events (recurrent ICH, incident ischemic stroke, myocardial infarction), vascular mortality (defined as mortality attributed to recurrent ICH, ischemic stroke, or myocardial infarction), and all-cause mortality. RESULTS: During a median follow-up of 46.2 months, we observed 166 recurrent ICH, 68 ischemic strokes, 69 myocardial infarction, and 429 deaths. Compared with survivors of ICH with systolic BP 120 to 129 mmHg, participants who achieved systolic BP <120 mmHg displayed reduced risk of recurrent ICH (adjusted hazard ratio [AHR], 0.74 [95% CI, 0.59-0.94]) and major adverse cardiovascular and cerebrovascular events (AHR, 0.69 [95% CI, 0.53-0.92]). All-cause mortality (AHR, 0.76 [95% CI, 0.57-1.03]) and vascular mortality (AHR, 0.68 [95% CI, 0.45-1.01]) did not differ significantly. Among participants aged >75 years or with modified Rankin Scale score 4 to 5, systolic BP <120 mmHg was associated with increased all-cause mortality (AHR, 1.38 [95% CI, 1.02-1.85] and AHR, 1.36 [95% CI, 1.03-1.78], respectively), but not vascular mortality. We found no differences in outcome rates between survivors of ICH with diastolic BP <70 versus 70 to 79 mmHg. CONCLUSIONS: Targeting systolic BP <120 mmHg in select groups of survivors of ICH could result in decreased major adverse cardiovascular and cerebrovascular events risk without increasing mortality. Our findings warrant investigation in dedicated randomized controlled trials.


Asunto(s)
Accidente Cerebrovascular Isquémico , Infarto del Miocardio , Accidente Cerebrovascular , Humanos , Presión Sanguínea/fisiología , Hemorragia Cerebral/epidemiología , Infarto del Miocardio/complicaciones , Estudios de Cohortes , Accidente Cerebrovascular Isquémico/complicaciones , Accidente Cerebrovascular/complicaciones
2.
Stroke ; 54(6): 1548-1557, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37216445

RESUMEN

BACKGROUND: Major intracerebral hemorrhage (ICH) trials have largely been unable to demonstrate therapeutic benefit in improving functional outcomes. This may be partly due to the heterogeneity of ICH outcomes based on their location, where a small strategic ICH could be debilitating, thus confounding therapeutic effects. We aimed to determine the ideal hematoma volume cutoff for different ICH locations in predicting ICH outcomes. METHODS: We retrospectively analyzed consecutive ICH patients enrolled in the University of Hong Kong prospective stroke registry from January 2011 to December 2018. Patients with premorbid modified Rankin Scale score >2 or who underwent neurosurgical intervention were excluded. ICH volume cutoff, sensitivity, and specificity in predicting respective 6-month neurological outcomes (good [modified Rankin Scale score 0-2], poor [modified Rankin Scale score 4-6], and mortality) for specific ICH locations were determined using receiver operating characteristic curves. Separate multivariate logistic regression models were also conducted for each location-specific volume cutoff to determine whether these cutoffs were independently associated with respective outcomes. RESULTS: Among 533 ICHs, the volume cutoff for good outcome according to ICH location was 40.5 mL for lobar, 32.5 mL for putamen/external capsule, 5.5 mL for internal capsule/globus pallidus, 6.5 mL for thalamus, 17 mL for cerebellum, and 3 mL for brainstem. ICH smaller than the cutoff for all supratentorial sites had higher odds of good outcomes (all P<0.05). Volumes exceeding 48 mL for lobar, 41 mL for putamen/external capsule, 6 mL for internal capsule/globus pallidus, 9.5 mL for thalamus, 22 mL for cerebellum, and 7.5 mL for brainstem were at greater risk of poor outcomes (all P<0.05). Mortality risks were significantly higher for volumes that exceeded 89.5 mL for lobar, 42 mL for putamen/external capsule, and 21 mL for internal capsule/globus pallidus (all P<0.001). All receiver operating characteristic models for location-specific cutoffs had good discriminant values (area under the curve >0.8), except in predicting good outcome for cerebellum. CONCLUSIONS: ICH outcomes differed with location-specific hematoma size. Location-specific volume cutoff should be considered in patient selection for ICH trials.


Asunto(s)
Hemorragia Cerebral , Accidente Cerebrovascular , Humanos , Estudios Retrospectivos , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/cirugía , Globo Pálido , Hematoma/diagnóstico por imagen , Hematoma/cirugía
3.
Stroke ; 51(7): 2228-2231, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32432998

RESUMEN

BACKGROUND AND PURPOSE: The current coronavirus disease 2019 (COVID-19) pandemic represents a global public health crisis, disrupting emergency healthcare services. We determined whether COVID-19 has resulted in delays in stroke presentation and affected the delivery of acute stroke services in a comprehensive stroke center in Hong Kong. METHODS: We retrospectively reviewed all patients with transient ischemic attack and stroke admitted via the acute stroke pathway of Queen Mary Hospital, Hong Kong, during the first 60 days since the first diagnosed COVID-19 case in Hong Kong (COVID-19: January 23, 2020-March 24, 2020). We compared the stroke onset to hospital arrival (onset-to-door) time and timings of inpatient stroke pathways with patients admitted during the same period in 2019 (pre-COVID-19: January 23, 2019-March 24, 2019). RESULTS: Seventy-three patients in COVID-19 were compared with 89 patients in pre-COVID-19. There were no significant differences in age, sex, vascular risk factors, nor stroke severity between the 2 groups (P>0.05). The median stroke onset-to-door time was ≈1-hour longer in COVID-19 compared with pre-COVID-19 (154 versus 95 minutes, P=0.12), and the proportion of individuals with onset-to-door time within 4.5 hours was significantly lower (55% versus 72%, P=0.024). Significantly fewer cases of transient ischemic attack presented to the hospital during COVID-19 (4% versus 16%, P=0.016), despite no increase in referrals to the transient ischemic attack clinic. Inpatient stroke pathways and treatment time metrics nevertheless did not differ between the 2 groups (P>0.05 for all comparisons). CONCLUSIONS: During the early containment phase of COVID-19, we noted a prolongation in stroke onset to hospital arrival time and a significant reduction in individuals arriving at the hospital within 4.5 hours and presenting with transient ischemic attack. Public education about stroke should continue to be reinforced during the COVID-19 pandemic.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus , Ataque Isquémico Transitorio/epidemiología , Pandemias , Neumonía Viral , Accidente Cerebrovascular/epidemiología , Tiempo de Tratamiento/estadística & datos numéricos , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , COVID-19 , Atención a la Salud/estadística & datos numéricos , Servicios Médicos de Urgencia , Servicio de Urgencia en Hospital/estadística & datos numéricos , Femenino , Hong Kong/epidemiología , Hospitales Especializados/estadística & datos numéricos , Hospitales Urbanos/estadística & datos numéricos , Humanos , Ataque Isquémico Transitorio/terapia , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2 , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/terapia , Trombectomía/estadística & datos numéricos , Terapia Trombolítica/estadística & datos numéricos , Activador de Tejido Plasminógeno/uso terapéutico
4.
Int J Lang Commun Disord ; 50(3): 389-96, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25588767

RESUMEN

BACKGROUND: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. AIMS: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to the tongue region of the motor cortex on swallowing functions and the quality of life of post-stroke individuals with dysphagia. METHODS & PROCEDURES: Two male and two female participants were assigned randomly to active and sham groups. The participants in the active group received 10 sessions of active rTMS for 2 weeks, whereas the sham participants received 10 sessions of sham rTMS for 2 weeks. Each participant received a total of 3000 pulses of 5 Hz active or sham rTMS per day for 10 days. Outcome measures were taken at baseline, 1 week and 1 month post-rTMS. OUTCOMES & RESULTS: Participants who received active rTMS had improved swallowing functions and swallowing-related quality of life at 1 week and 1 month post-stimulation. CONCLUSIONS & IMPLICATIONS: The study showed that excitatory rTMS applied over the tongue motor cortex is a feasible approach in individuals with chronic post-stroke dysphagia. Further investigation with larger sample population is warranted to support the benefit of this stimulation protocol.


Asunto(s)
Trastornos de Deglución/terapia , Disartria/terapia , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Estimulación Magnética Transcraneal , Anciano , Enfermedad Crónica , Trastornos de Deglución/diagnóstico , Trastornos de Deglución/fisiopatología , Disartria/diagnóstico , Disartria/fisiopatología , Femenino , Humanos , Masculino , Corteza Motora/fisiopatología , Accidente Cerebrovascular/fisiopatología , Lengua/inervación
5.
Front Neurol ; 14: 1280015, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38152645

RESUMEN

The human vestibular system is crucial for motion perception, balance control, and various higher cognitive functions. Exploring how the cerebral cortex responds to vestibular signals is not only valuable for a better understanding of how the vestibular system participates in cognitive and motor functions but also clinically significant in diagnosing central vestibular disorders. Near-infrared spectroscopy (NIRS) provides a portable and non-invasive brain imaging technology to monitor cortical hemodynamics under physical motion. Objective: This study aimed to investigate the cerebral cortical response to naturalistic vestibular stimulation induced by real physical motion and to validate the vestibular cerebral cortex previously identified using alternative vestibular stimulation. Approach: Functional NIRS data were collected from 12 right-handed subjects when they were sitting in a motion platform that generated three types of whole-body passive translational motion (circular, lateral, and fore-and-aft). Main results: The study found that different cortical regions were activated by the three types of motion. The cortical response was more widespread under circular motion in two dimensions compared to lateral and fore-and-aft motions in one dimensions. Overall, the identified regions were consistent with the cortical areas found to be activated in previous brain imaging studies. Significance: The results provide new evidence of brain selectivity to different types of motion and validate previous findings on the vestibular cerebral cortex.

6.
J Am Heart Assoc ; 11(6): e024158, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35253479

RESUMEN

Background Survivors of intracranial hemorrhage (ICH) are at increased risk for major adverse cardiovascular and cerebrovascular events (MACCE), in the form of recurrent stroke and myocardial Infarction. We investigated whether long-term blood pressure (BP) variability represents a risk factor for MACCE after ICH, independent of average BP. Methods and Results We analyzed data from prospective ICH cohort studies at Massachusetts General Hospital and the University of Hong Kong. We captured long-term (ie, visit-to-visit) BP variability, quantified as individual participants' variation coefficient. We explored determinants of systolic and diastolic BP variability and generated survival analyses models to explore their association with MACCE. Among 1828 survivors of ICH followed for a median of 46.2 months we identified 166 with recurrent ICH, 68 with ischemic strokes, and 69 with myocardial infarction. Black (coefficient +3.8, SE 1.3) and Asian (coefficient +2.2, SE 0.4) participants displayed higher BP variability. Long-term systolic BP variability was independently associated with recurrent ICH (subhazard ratio [SHR], 1.82; 95% CI, 1.19-2.79), ischemic stroke (SHR, 1.62; 95% CI, 1.06-2.47), and myocardial infarction (SHR, 1.54; 95% CI, 1.05-2.24). Average BP during follow-up did not modify the association between long-term systolic BP variability and MACCE. Conclusions Long-term BP variability is a potent risk factor for recurrent hemorrhage, ischemic stroke, and myocardial infarction after ICH, even among survivors with well-controlled hypertension. Our findings support the hypothesis that combined control of average BP and its variability after ICH is required to minimize incidence of MACCE.


Asunto(s)
Hipertensión , Accidente Cerebrovascular Isquémico , Infarto del Miocardio , Accidente Cerebrovascular , Presión Sanguínea/fisiología , Hemorragia Cerebral/etiología , Humanos , Hipertensión/complicaciones , Hipertensión/epidemiología , Infarto del Miocardio/complicaciones , Infarto del Miocardio/epidemiología , Estudios Prospectivos , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología
7.
J Am Heart Assoc ; 10(11): e020392, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33998241

RESUMEN

Background Survivors of intracerebral hemorrhage (ICH) are at high risk for recurrent stroke, which is associated with blood pressure control. Because most recurrent stroke events occur within 12 to 18 months of the index ICH, rapid blood pressure control is likely to be crucial. We investigated the frequency and prognostic impact of uncontrolled short-term hypertension after ICH. Methods and Results We analyzed data from Massachusetts General Hospital (n=1305) and the University of Hong Kong (n=523). We classified hypertension as controlled, undertreated, or treatment resistant at 3 months after ICH and determined the following: (1) the risk factors for uncontrolled hypertension and (2) whether hypertension control at 3 months is associated with stroke recurrence and mortality. We followed 1828 survivors of ICH for a median of 46.2 months. Only 9 of 234 (4%) recurrent strokes occurred before 3 months after ICH. At 3 months, 713 participants (39%) had controlled hypertension, 755 (41%) had undertreated hypertension, and 360 (20%) had treatment-resistant hypertension. Black, Hispanic, and Asian race/ethnicity and higher blood pressure at time of ICH increased the risk of uncontrolled hypertension at 3 months (all P<0.05). Uncontrolled hypertension at 3 months was associated with recurrent stroke and mortality during long-term follow-up (all P<0.05). Conclusions Among survivors of ICH, >60% had uncontrolled hypertension at 3 months, with undertreatment accounting for the majority of cases. The 3-month blood pressure measurements were associated with higher recurrent stroke risk and mortality. Black, Hispanic, and Asian survivors of ICH and those presenting with severe acute hypertensive response were at highest risk for uncontrolled hypertension.


Asunto(s)
Presión Sanguínea/fisiología , Hemorragia Cerebral/etiología , Hipertensión/complicaciones , Anciano , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/fisiopatología , Femenino , Estudios de Seguimiento , Hong Kong/epidemiología , Humanos , Hipertensión/fisiopatología , Incidencia , Masculino , Recurrencia , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Factores de Tiempo
8.
J Peripher Nerv Syst ; 14(1): 14-21, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19335535

RESUMEN

Charcot-Marie-Tooth (CMT) neuropathy is inherited with genetic and clinical heterogeneity. The X-linked form (CMTX) is linked to mutations in the GJB1 gene. However, the genotype-phenotype correlation between variants in the non-coding region of GJB1 gene and CMTX is unclear. We found two structural variants (-459C>T and -713G>A) in the 5' non-coding region of a transcript (Ref seq ID: NM_000166) of the GJB1 gene and explored its association with CMTX in two Chinese families. All family members who carried the -459C>T variant either were symptomatic or had abnormal electrophysiological studies compatible with CMTX, whereas all the non-symptomatic family members who had normal electrophysiological studies and 10 healthy unrelated controls did not have this variant. The other variant in the 5'-flanking region of the gene was found to be a benign polymorphism, although it had been earlier reported to be associated with CMTX in a Taiwanese family. Secondary structure prediction analysis of mutant mRNA using M fold and RNA structure softwares indicates that the -459C>T mutation may reduce translation efficiency of the GJB1 gene by changing its 5'-untranslated region secondary structure and abolishing the internal ribosome entry site at the initialization of its translation in Schwann cells. Our study can help clarify the causal mutations of CMTX in the non-protein coding region of GJB1.


Asunto(s)
Regiones no Traducidas 5'/genética , Enfermedad de Charcot-Marie-Tooth/genética , Conexinas/genética , Salud de la Familia , Mutación Puntual/genética , Adolescente , Adulto , Anciano , Pueblo Asiatico/etnología , Enfermedad de Charcot-Marie-Tooth/patología , Enfermedad de Charcot-Marie-Tooth/fisiopatología , Niño , Análisis Mutacional de ADN , Electromiografía , Femenino , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Humanos , Masculino , Microscopía Electrónica de Transmisión , Persona de Mediana Edad , Conducción Nerviosa/genética , Conducción Nerviosa/fisiología , Nervios Periféricos/patología , Nervios Periféricos/fisiopatología , Nervios Periféricos/ultraestructura , Análisis de Secuencia , Adulto Joven , Proteína beta1 de Unión Comunicante
9.
Hong Kong Med J ; 13(4): 314-8, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17664536

RESUMEN

'Mah-jong epilepsy' is a rare reflex epilepsy syndrome, manifesting as recurrent epileptic seizures triggered by either playing or just watching mah-jong. We present three patients with this condition and review all the reported cases. Mah-jong-induced seizures can be considered a subtype of cognition-induced epilepsy. Nonetheless, these patients have distinctive clinical and electrophysiological features: late age of onset, different seizure patterns, single seizure-trigger, lack of spontaneous seizures, and electroencephalographic findings not supportive of idiopathic generalised epilepsy. The pathophysiological mechanism underlying mah-jong-induced seizures may be different from the other cognition-associated reflex epileptic phenomena.


Asunto(s)
Epilepsia Refleja/etiología , Recreación , Adulto , Femenino , Humanos , Masculino
10.
Appl Ergon ; 63: 1-8, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28502398

RESUMEN

This study examines the correlations between optokinetic after-nystagmus (OKAN) parameters and individual susceptibility to visually induced motion sickness (VIMS). Twenty-seven participants were exposed to vertical black-and-white stripes drifting along the yaw axis at 60° per second for 30 min to collect individual VIMS data (Phase 1). Two weeks after the exposure, OKANs were measured (Phase 2). 19 out of 27 participants (i.e., 70%) exhibited consistent OKAN patterns. Significant correlations between the time constants of OKAN and levels of VIMS experienced by the same viewers were found. Four months later, these 27 participants were invited back for a second OKAN measurement (Phase 3). Twenty-one participants came back. Their two OKAN measurements were significantly correlated (r = 0.69, p = 0.001). Rated levels of VIMS in phase 1 significantly correlated with the time constant of OKAN in both Phase 2 (r = 0.51, p = 0.044) and Phase 3 (r = 0.74, p = 0.006). The implications of the correlation results are discussed.


Asunto(s)
Mareo por Movimiento/fisiopatología , Nistagmo Optoquinético/fisiología , Estimulación Luminosa/efectos adversos , Adulto , Femenino , Humanos , Masculino , Mareo por Movimiento/etiología , Factores de Tiempo , Adulto Joven
11.
J Rehabil Med ; 49(6): 475-481, 2017 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-28612077

RESUMEN

OBJECTIVE: There are potential benefits of repetitive transcranial magnetic stimulation (rTMS) in improving swallowing functions after stroke; however, few studies have been performed in the chronic stroke population. This study aims to distil the key effects of rTMS on swallowing functions and swallowing-related quality of life. METHODS: Twenty-two participants with chronic post-stroke dysphagia were randomly assigned into active or sham rTMS groups. Seven participants withdrew from the study, thus data from 15 participants (mean age 64.6 years) were analysed. Participants received 3,000 pulses of 5 Hz rTMS (active: n = 11; sham: n = 4) on the tongue area of the motor cortex for 10 days over a period of 2 weeks. All participants were assessed 1 week before, and 2 months, 6 months and 12 months after stimulation. Outcomes were measured by a videofluoroscopic swallowing study, swallowing-related quality-of-life questionnaire and Iowa Oral Performance Instrument. RESULTS: No statistically significant effects were identified for any outcome measures. CONCLUSION: This study indicates that 5 Hz rTMS applied over the tongue area of the motor cortex is not effective for improving swallowing function in individuals with chronic post-stroke dysphagia. Possible explanations for these non-significant results are dis cussed. Future studies should explore the potential of the current protocol in conjunction with conventional dysphagia therapy.


Asunto(s)
Trastornos de Deglución/etiología , Calidad de Vida/psicología , Accidente Cerebrovascular/complicaciones , Estimulación Magnética Transcraneal/métodos , Enfermedad Crónica , Trastornos de Deglución/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Accidente Cerebrovascular/fisiopatología
12.
World Neurosurg ; 106: 85-91, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28606579

RESUMEN

BACKGROUND: Antiplatelet resumption in patients who developed intracerebral hemorrhage (ICH) while on antiplatelet therapy (antiplatelet-related ICH) represents an important medical dilemma. We aimed to study the long-term cardiovascular outcomes of antiplatelet-related ICH survivors, and the risk of recurrent ICH with antiplatelet resumption. METHODS: This was an observational study of 109 antiplatelet-related ICH survivors. The clinical end points were recurrent ICH, ischemic vascular events, and vascular death (fatal ICH or ischemic vascular events). Predictors of recurrent ICH and vascular death were derived using a multivariable Cox regression model. RESULTS: The median duration of follow-up was 3.5 years (interquartile range, 1.6-5.8 years). Ischemic vascular events were more common than recurrent ICHs (6.8 per 100 patient-years vs. 2.6 per 100 patient-years; P = 0.028). Antiplatelet use was not associated with an elevated risk of recurrent ICH (hazard ratio [HR], 1.11, 95% confidence interval [CI], 0.27-4.62). A mean follow-up systolic blood pressure of >140 mmHg increased the risk of both recurrent ICH (HR, 4.28; 95% CI, 1.01-18.11) and vascular death (HR, 11.14; 95% CI, 2.72-45.62). Cerebral amyloid angiopathy (CAA) was an independent predictor for recurrent ICH (HR, 24.34; 95% CI, 2.80-211.47). CONCLUSIONS: Antiplatelet resumption after antiplatelet-related ICH did not appear to carry a clinically significant risk of recurrent ICH, whereas inadequate blood pressure control and CAA contributed to a more robust risk. Antiplatelet resumption should be considered, especially in survivors with adequate blood pressure control and without CAA.


Asunto(s)
Hemorragia Cerebral/inducido químicamente , Inhibidores de Agregación Plaquetaria/efectos adversos , Anciano , Hemorragia Cerebral/mortalidad , Sustitución de Medicamentos , Femenino , Humanos , Isquemia/etiología , Isquemia/mortalidad , Masculino , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Sobrevivientes
13.
Brain Res ; 1076(1): 171-6, 2006 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-16476418

RESUMEN

This fMRI study studied age-related differences in neural activities during response regulation. Twenty-one male participants from two age groups, a younger group and an older group (mean ages: 29.9 and 65.2 years, respectively), were scanned while performing a task with response compatibility manipulation. They were presented with a sequence of arrowheads that pointed either upward or downward. In the "Response Compatible" condition, they were required to press an up or a down button consistent with the direction of the arrowhead. In the "Response Incompatible" condition, they were required to press the button opposite to the arrowhead direction so that an upward arrow should elicit a down response, and vice versa. Findings showed age-related differences in response regulation in several brain regions, including the right frontal, the right cingulate, and the left inferior parietal cortexes. The findings suggested a higher level of neural activity in the right prefrontal and left inferior parietal regions during response regulation for the older adults than for the younger adults.


Asunto(s)
Envejecimiento/fisiología , Encéfalo/irrigación sanguínea , Encéfalo/fisiología , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Adulto , Anciano , Análisis de Varianza , Mapeo Encefálico , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Oxígeno/sangre
15.
Stroke ; 34(8): 1847-51, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12829862

RESUMEN

BACKGROUND AND PURPOSE: We sought to report the occurrence and risk factors of intracranial hemorrhage during long-term follow-up of patients with internal carotid artery stenosis, with and without carotid endarterectomy. METHODS: From the prospective data of the North American Symptomatic Carotid Endarterectomy Trial, 3 types of intracranial hemorrhage were recognized: petechiae within infarction (PTI), intracerebral hematoma (ICH), and subarachnoid hemorrhage (SAH). The 30-day and 5-year risks of intracranial hemorrhage (PTI or ICH) were estimated from Kaplan-Meier event-free survival curves. Cox proportional-hazards regression modeling was used to identify risk factors. RESULTS: Of 1039 strokes that occurred in 749 of 2885 patients during an average follow-up of 5 years, there were 24 PTIs, 14 ICHs, and 1 SAH. The 5-year risk of intracranial hemorrhage was 1.7% in both medically and surgically treated patients, but the 30-day risk of 0.64% in surgically treated patients was 10 times higher than the risk of 0.07% in medically treated patients (P=0.01). Approximately 50% of all intracranial hemorrhages were either disabling or fatal, and ICHs were more likely to be fatal than PTIs. Old age, a history of hypertension, intermittent claudication and smoking, and infarct on brain images were risk factors for intracranial hemorrhage in medically treated patients, whereas diabetes mellitus was the sole risk factor in surgically treated patients. CONCLUSIONS: Intracranial hemorrhages are uncommon in patients with internal carotid artery stenosis but are associated with high mortality and morbidity. The risk factors for intracranial hemorrhage are different between medically and surgically treated patients.


Asunto(s)
Estenosis Carotídea/epidemiología , Hemorragias Intracraneales/epidemiología , Estenosis Carotídea/cirugía , Comorbilidad , Supervivencia sin Enfermedad , Endarterectomía Carotidea/estadística & datos numéricos , Estudios de Seguimiento , Humanos , Hemorragias Intracraneales/mortalidad , Estudios Multicéntricos como Asunto/estadística & datos numéricos , América del Norte/epidemiología , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Medición de Riesgo , Factores de Riesgo
16.
Free Radic Biol Med ; 32(8): 776-84, 2002 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-11937303

RESUMEN

In a rat endovascular middle cerebral artery occlusion (MCAO) stroke model, we previously showed that intracerebroventricular (ICV) injection of neuropeptide Y (NPY) or an Y1 receptor agonist, [Leu(31),Pro(34)]-NPY, increased the infarct volume, that an Y1 receptor antagonist, BIBP3226, reduced the infarct volume, and that an Y2 receptor agonist, NPY3-36, had no effect. In this study, we used electron paramagnetic resonance (EPR) spectroscopy to measure nitric oxide (NO) and examined how ICV administration of NPY or its receptor analogs would modulate the brain NO level between the bregma levels +2 and -4 mm during MCAO, since excessive NO mediates ischemic damage. The relative brain NO concentration was increased to 131.94 +/- 7.99% (mean +/- SEM; n = 8) at 15 min of MCAO. NPY treatment further increased the relative brain NO concentration to 250.94 +/- 50.48% (n = 8), whereas BIBP3226 significantly reduced the brain NO concentration to 69.63 +/- 8.84% (n = 8). [Leu(31),Pro(34)]-NPY (137.61 +/- 14.54%; n = 7) or NPY3-36 (129.23 +/- 21.77%; n = 8) did not affect the brain NO concentration at 15 min of MCAO. Our results suggest that the NPY-Y1 receptor activation mediates ischemic injury via NO overproduction and that inhibition of the Y1 receptor may confer protection via suppression of excessive NO production during ischemia.


Asunto(s)
Arginina/análogos & derivados , Encéfalo/efectos de los fármacos , Neuropéptido Y/farmacología , Óxido Nítrico/metabolismo , Receptores de Neuropéptido Y/metabolismo , Accidente Cerebrovascular/metabolismo , Animales , Arginina/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Inyecciones Intraarteriales , Inyecciones Intraventriculares , Masculino , Ratas , Ratas Sprague-Dawley , Receptores de Neuropéptido Y/antagonistas & inhibidores , Accidente Cerebrovascular/patología
18.
Neuroreport ; 14(5): 669-73, 2003 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-12692460

RESUMEN

We used fMRI to reveal the visual cortical activations during conventional or electro-acupuncture over four vision-implicated acupoints in 18 healthy volunteers and compared the results with those obtained during direct visual stimulation. Positive activations were seen over the visual cortex during visual stimulation in all subjects, and similar activations were observed in 10 subjects during conventional acupuncture as well as in eight and seven subjects during electro-acupuncture at 2 and 20 Hz, respectively. Negative activations were also seen over the occipital lobes, temporal gyri and frontal gyri bilaterally in 13 subjects during conventional acupuncture. Thus, acupuncture may modulate the activity of relevant brain sites. Our results also suggest that electro-acupuncture is useful in future studies.


Asunto(s)
Puntos de Acupuntura , Pie/fisiología , Corteza Visual/fisiología , Acupuntura , Adulto , Mapeo Encefálico , Electroacupuntura , Femenino , Pie/inervación , Lóbulo Frontal/anatomía & histología , Lóbulo Frontal/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Lóbulo Occipital/anatomía & histología , Lóbulo Occipital/fisiología , Estimulación Luminosa , Valores de Referencia , Lóbulo Temporal/anatomía & histología , Lóbulo Temporal/fisiología , Corteza Visual/anatomía & histología
19.
Brain Res ; 927(2): 138-43, 2002 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11821007

RESUMEN

Recent studies have shown increased immunoreactivity for neuropeptide Y (NPY) within the perilesional cortex following experimental middle cerebral artery occlusion (MCAO) or focal excitotoxic damage. Downregulation of the NPY Y1 receptor gene using an antisense oligodeoxynucleotide produced a doubling of the infarct volume, implying that NPY may mediate neuroprotection against focal ischemia. The effects of treatment with NPY on infarct volume and hemodynamic parameters were investigated in the present study. Adult male Sprague-Dawley rats were anesthetized with sodium pentobarbital to undergo right-sided endovascular MCAO for 2 h. A single dose of NPY was given via intracarotid injection (10 microg/kg) at the beginning of reperfusion, intracisternal injection (10 or 30 microg/kg) at 30 min of ischemia, or intracerebroventricular (i.c.v.) injection (10 or 70 microg/kg) at 30 min of ischemia. Control groups received the vehicle only via the same route. Body temperature was maintained constant, and hemodynamic parameters were monitored during anesthesia. Laser Doppler flowmetry was used to monitor the regional cerebral blood flow (rCBF) during ischemia and reperfusion in some rats. The rats were decapitated on day 3, and their brains were cut into 2-mm thick coronal slices before reaction with a 2% solution of 2,3,5-triphenyltetrazolium chloride to reveal the infarct. Compared to the respective control groups, NPY treatment via any method of administration increased the relative infarct volume. Suppression of rCBF was observed during reperfusion. These results indicate that peripheral or central administration of NPY impairs reperfusion following experimental MCAO and worsens the outcome of focal cerebral ischemia.


Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Infarto de la Arteria Cerebral Media/prevención & control , Neuropéptido Y/administración & dosificación , Animales , Infarto Cerebral/etiología , Infarto Cerebral/patología , Circulación Cerebrovascular/fisiología , Relación Dosis-Respuesta a Droga , Hemodinámica/efectos de los fármacos , Humanos , Infarto de la Arteria Cerebral Media/fisiopatología , Inyecciones Intraarteriales , Inyecciones Intraventriculares , Masculino , Microinyecciones , Neuropéptido Y/farmacología , Ratas , Ratas Sprague-Dawley
20.
Leuk Lymphoma ; 43(2): 455-7, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11999589

RESUMEN

Acute disseminated encephalomyelitis (ADEM) is a parainfectious or postvaccination demyelinating condition, characterized by rapid onset of multifocal neurological deficits, usually occurring in childhood or adolescence. We report case of ADEM in an allogeneic bone marrow transplant recipient, who presented with rapid onset of paraplegia and widespread neurological deficits 6 weeks after parainfluenza pneumonia. Magnetic resonance imaging (MRI) showed typical features of ADEM, involving the subcortical white matter, brain steam and spinal cord. There was a rapid and complete response to pulse high-dose corticosteriod and intravenous immunoglobulin. The importance of recognition and early treatment of this rare condition in transplantation practice is emphasized.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Encefalomielitis Aguda Diseminada/virología , Infecciones por Respirovirus/etiología , Adulto , Encefalomielitis Aguda Diseminada/diagnóstico , Encefalomielitis Aguda Diseminada/etiología , Enfermedad Injerto contra Huésped/virología , Humanos , Imagen por Resonancia Magnética , Masculino , Infecciones Oportunistas/etiología , Infecciones Oportunistas/virología , Virus de la Parainfluenza 3 Humana , Trasplante Homólogo/efectos adversos
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