Search results for "transcranial Doppler"

Image-guided transcranial Doppler sonography for monitoring of vasospasm after subarachnoid hemorrhage.

2016

Transcranial Doppler ultrasound (TCD) is a standard method for bedside vasospasm monitoring after subarachnoid hemorrhage (SAH). Image guidance has previously been shown to reduce intra- and interobserver variability of this method. The aim of the present study was to compare image-guided and conventional TCD in vasospasm monitoring after SAH.418 TCD exams of 24 consecutive SAH patients registered in a database were evaluated. Of these, 130 image-guided exams were identified which had been performed on the same day as conventional Doppler exams. These matched pairs were taken for statistical analysis. Data were tested statistically using the sign test applied at patient level to aggregated …

Transkranielle Dopplersonographie bei Kopf-Hals-Tumoren*

1991

Transcranial Doppler ultrasound (TCD) recording is a non-invasive diagnostic procedure for the evaluation of the cerebral collateral flow in patients, in whom therapeutic ligation or resection of the common and/or internal carotid artery is planned. Patients are first examined under resting conditions, and then under manual compression of the ipsilateral carotid artery. Since January 1989, 31 ENT and neurosurgical patients have been examined. In all patients an immediate decrease in flow velocity in the middle cerebral artery (mca) of about 25% to 90% was recorded. In 42.8% of the patients the mca flow velocity reached 90% or more of its value under normal conditions within a short period. …

Transcranial Doppler diagnosis of cerebral vasospasm following subarachnoid haemorrhage: correlation and analysis of results in relation to the age o…

1994

A retrospective analysis was undertaken to determine whether cerebral vasospasm following subarachnoid haemorrhage (SAH) correlates with the age of patients. For at least 3 weeks after bleeding 80 subjects underwent very close follow-up with clinical examination and transcranial Doppler records of the blood velocities within the basal cerebral arteries. Firstly a correlation between measured maximal mean blood flow velocities and age was made. Secondly, according to their age and the maximum of recorded mean velocities (v), the patients were divided into groups as follows: age 55 years or less, age more than 55 years; and maximum velocity v190 cm/s, 90 cm/sv2120 cm/s, 120 cm/sv3160 cm/s, v4…

A range of pulses commonly used for human transcranial ultrasound stimulation are clearly audible.

2021

Intraoperative monitoring of cerebral blood flow during ventricular shunting in hydrocephalic pediatric patients.

1995

Several studies have demonstrated lowered cerebral blood flow (CBF) in patients with hydrocephalus and symptoms of raised intracranial pressure. Ventricular shunting in such cases permits a sudden increase in CBF. The pathophysiology of functional brain deficit secondary to hydrocephalus is little understood. Improvement of the patient's clinical status after drainage of CSF suggests that cerebral dysfunction is not necessarily due to permanent brain damage. In fact, it improves rapidly after ventricular taps. In view of this it would be helpful to monitor cerebral perfusion. The transcranial Doppler (TCD) ultrasonography technique allows real-time monitoring of the intracranial circulation…

Impaired Cerebrovascular Autoregulation in Large Vessel Occlusive Stroke after Successful Mechanical Thrombectomy: A Prospective Cohort Study

2020

Abstract Introduction: Successful thrombectomy improves morbidity and mortality after stroke. The present prospective, observational cohort study investigated a potential correlation between the successful restoration of tissue perfusion by mechanical thrombectomy and intact cerebrovascular autoregulation (CA). Objective: Status of CA in patients with large vessel occlusive stroke after thrombectomy. Methods: After thrombectomy CA was measured using transcranial Doppler ultrasound. For this purpose a moving correlation index (Mxa) based on spontaneous arterial blood pressure fluctuations and corresponding cerebral blood flow velocity changes was calculated. CA impairment was defined by Mxa …

Cerebral lateralisation during signed and spoken language production in children born deaf

2019

Highlights • Children born deaf show typical left-hemisphere dominance during language production. • No evidence of an association between left-lateralisation and language proficiency. • Exposure to auditory speech via a cochlear implant is not a prerequisite for left hemisphere language dominance.

Cerebral blood flow velocities after subarachnoid haemorrhage in relation to the amount of blood clots in the initial computed tomography.

1998

In 72 patients with acute subarachnoid haemorrhage (SAH) the relationship between the amount of subarachnoid blood clots detected by initial cranial computed tomography (CCT) up to 48 hours after bleeding and the later development of vasospasm, established by blood flow velocity measurement with transcranial Doppler ultrasound (TCD) was investigated. The serial Doppler examinations started within the first 72 hours after SAH and were carried out every second day up to three weeks. Each Doppler recording was accompanied by a neurological examination. Patients classified as Hunt and Hess grade V were excluded from the study. All patients with remarkable brain oedema in CCT or with intracrania…

The percutaneous treatment of Patent Foramen Ovale, an effective and safe therapeutic choice

2013

Introduction: The aim of our study is to evaluate the feasibility, safety and efficacy of the percutaneous closure of PFO (abnormal communication between the right and left atrium). Methods: Between July 2009 and October 2012 percutaneous closure was performed in 37 patients. The presence of PFO was diagnosed through the use of ultrasound techniques: transcranial doppler with contrast (cTCD), transthoracic echocardiography(TTE) and transesophageal echocardiography (TEE). Follow-up was composed consisted of a Holter ECG 7 days after the closure with a 24 hour heart rhythm monitoring, to evaluate eventual arrhythmia cases and programmed controls which included a TTE at 1-3 months, TTE+ cTCD a…

Cerebrovascular and cardiovascular variability interactions investigated through conditional joint transfer entropy in subjects prone to postural syn…

2017

Objective: A model-based conditional transfer entropy approach was exploited to quantify the information transfer in cerebrovascular (CBV) and cardiovascular (CV) systems in subjects prone to develop postural syncope. Approach: Spontaneous beat-to-beat variations of mean cerebral blood flow velocity (MCBFV) derived from a transcranial Doppler device, heart period (HP) derived from surface electrocardiogram, mean arterial pressure (MAP) and systolic arterial pressure (SAP) derived from finger plethysmographic arterial pressure device were monitored at rest in supine position (REST) and during 60° head-up tilt (TILT) in 13 individuals (age mean ± standard deviation: 28 ± 9 years, min-max r…