Transcranial Doppler Findings Research Articles

Clinical Role of Microembolic Signals in Adult Moyamoya Disease With Ischemic Stroke.

Background and Purpose- Hemodynamic compromise has been implicated in moyamoya disease (MMD) with transient ischemic attacks or ischemic stroke. However, increasing evidence supports the notion that artery-to-artery embolism may also contribute to ischemic events based on microembolic signal (MES) monitoring. Methods- A total of 48 patients aged between 20 and 60 years with newly diagnosed MMD were enrolled and angiographically classified according to the Suzuki staging system. For detection of MESs, transcranial Doppler was performed at the middle cerebral artery bilaterally for a 30-minute period. Mean flow velocities in the middle cerebral artery were also evaluated and categorized into low (<40 cm/s), normal (40-80 cm/s), and high (>80 cm/s). Clinical characteristics, cerebral angiography findings, recent ischemic events within 3 months, and antiplatelet medication were correlated with transcranial Doppler findings. Results- MESs were detected in 11 of the 48 patients (23%), with a frequency of 11 of 89 (12%) examined hemispheres. The mean number of MESs was 2 (range, 1-6). Six of the 11 hemispheres (55%) presented with ischemic strokes or transient ischemic attacks, and 2 (18%) presented with hemorrhagic strokes. The presence of MESs was associated with recent ischemic events ( P=0.024) and high mean flow velocities ( P=0.016), which was usually observed in Suzuki stage I and II (early-stage MMD). After controlling for age, sex, and antiplatelet medication, both recent ischemic events (odds ratio, 6.294; 95% CI, 1.345-29.457; P=0.019) and high mean flow velocities (odds ratio, 6.172; 95% CI, 1.235-31.25; P=0.027) were found to be independent predictors of MESs. Conclusions- MESs were observed in patients with high mean flow velocities, particularly early-stage MMD, and clinically associated with recent ischemic events. A randomized controlled study is necessary to determine the efficacy of antiplatelet agents in the treatment of MES-positive MMD.

Transcranial Doppler findings in antiphospholipid syndrome.

Transcranial Doppler is a method that enables the assessment of different cerebral hemodynamic parameters. It also allows for the evaluation of the presence of right-to-left circulation shunts (RLS) and for the detection of microembolic signals (MESs), which might be associated with an increased risk of cerebrovascular events. For instance, the presence of MESs on transcranial Doppler in patients with systemic lupus erythematous (SLE) and antiphospholipid syndrome (APS) is associated with an increased risk of stroke. Therefore, transcranial Doppler could be a useful tool for stroke risk stratification in these patients. Our objective was to evaluate transcranial Doppler cerebral mean blood flow velocities as well as the presence of MESs and RLS in patients with antiphospholipid syndrome and SLE. Twenty-two patients with primary APS (PAPS), 24 patients with secondary APS (SAPS), 27 patients with SLE without APS and 21 healthy controls were evaluated. Clinical and epidemiological data were compiled from medical charts, and all subjects underwent transcranial Doppler examination with breath-holding index calculation. Both middle cerebral arteries were monitored for 60 min for the detection of MESs. RLS was investigated with agitated saline injected as a bolus. There were no significant differences in mean blood flow velocities among the groups. MESs were more frequently found in patients with SLE when compared with controls and patients with APS (SLE: 17.4%, SAPS: 4.3%, PAPS: 0%, controls: 0%, p = 0.03). Anticoagulant therapy was more frequently used in the APS group (PAPS: 81.8%, SAPS: 75.2%, SLE: 1.7%, p < 0.001). Patients with APS had a higher frequency of RLS when compared with volunteers (63.6% versus 38.1%, p = 0.05). Breath-holding index values tended to be lower in patients with SAPS than in control subjects and patients with PAPS and SLE ( p = 0.06). Patients with APS had a higher frequency of RLS than healthy controls. This finding alerts to the importance of cardiac investigation in patients with stroke and APS, because further therapies such as RLS occlusion might eventually add protection. The higher frequency of MES in patients with SLE could suggest an effect of anticoagulant therapy on MES prevention, more frequently used in patients with APS.

Portable gamma-camera for the diagnosis of brain death diagnosis.

To evaluate the feasibility of using the Sentinella® portable gamma-camera for the diagnosis of brain death (BD). A prospective, observational feasibility study was carried out. Intensive Care Unit of a third level hospital. Consecutive recording was made of the adults diagnosed with brain death based on clinical criteria following admission to the Intensive Care Unit in the period from January to December 2017. The procedure was performed at the patient bedside with the intravenous administration of technetium 99 metastable hexamethylpropylene amine oxime. The absence of perfusion in the cerebral hemispheres and brainstem was described as a pattern consistent with BD. The diagnosis was correlated to the transcranial Doppler and / or electroencephalographic findings. A total of 66.1% of the patients were men with an average age of 60 years [IQR: 51-72]. The most frequent causes resulting in BD were hemorrhagic stroke (48.2%, n=27), followed by traumatic brain injury (30.4%, n=17), ischemic stroke (10.7%, n=6) and post-cardiac arrest anoxic encephalopathy (7.1%, n=4). A clinical diagnosis of BD was made in all cases, and the portable gamma-camera confirmed the diagnosis in 100% of the patients with a pattern characterized by the absence of brain perfusion. In addition, the results were compared with the transcranial Doppler findings in 46 patients, confirming the presence of diastolic reverberation and / or systolic peaks. The electroencephalographic tracing was obtained in 10 cases, with the appearance of electrical silence, due to the absence of an acoustic window in the transcranial Doppler study. A portable gamma-camera could be a useful and feasible tool for the diagnosis of BD.

Cerebral Blood Flow Velocities and Functional Outcomes in Pediatric Mild Traumatic Brain Injury.

Outcomes can be challenging to predict in children with mild traumatic brain injury (TBI). Transcranial Doppler (TCD) ultrasound has become an increasingly useful modality in adult and pediatric TBI by measuring blood flow velocities within the circle of Willis. In children with moderate-to-severe TBI, multiple studies have correlated abnormal TCD measurements and poor outcomes. Additionally, TCD has shown value in assessing adults with mild brain injury. To date, there are no studies that correlate TCD findings and outcomes in children with mild TBI. We hypothesize that altered cerebral blood flow after mild TBI is associated with poor functional outcome using the Glasgow Outcome Scale-Extended, Pediatrics (GOS-E Peds). TCD was performed within 24 h of admission on 60 patients at a tertiary Level 1 children's hospital. A secondary analysis was performed on the subgroup of 28 mild TBI patients. GOS-E Peds was measured at the time of hospital discharge and 4-6 weeks post-discharge. Cerebral blood flow velocities did not show correlation with outcome. At discharge, the right-sided Spearman's correlation coefficient was 0.19 (p value = 0.33) and the left-sided was 0.36 (p = 0.06). At follow up the right-sided coefficient was -0.04 (p = 0.84), the left-sided was -0.25 (p = 0.24). Pulsatility index likewise showed no correlation. Right and left-sided correlation at discharge were -0.25 (p = 0.19) and 0.01 (p = 0.96), respectively. At follow up the right side showed 0.004 (p = 0.99), and the left showed 0.18 (p = 0.41). Although our data did not show correlation, it showed that the investigation could feasibly be done in pediatric patients with mild TBI. The study was limited by small sample size and infrequent outcome of interest. Future studies may help define the role of TCD in the large population of mild pediatric TBI patients.

Transcranial Doppler Ultrasound in Peninsular Arab Patients With Sickle Cell Disease.

Transcranial Doppler ultrasound is used to identify patients with sickle cell disease (SCD) at risk for stroke. We performed transcranial Doppler studies in patients from 4 countries in the Arabian Peninsula (Kuwait, Oman, Iraq, and United Arab Emirates) to document the prevalence of abnormal transcranial Doppler findings. The patients were recruited from outpatient clinics and studied in a steady state. Transcranial Doppler examinations were performed with standard equipment by experienced operators. The time-averaged maximum mean velocity (TAMMV) was documented in the arteries of the circle of Willis. The hemoglobin (Hb) genotype was confirmed, and the fetal Hb level and complete blood counts were determined. There were 415 patients in the study, aged 2 to 18 years (mean ± SD, 8.6 ± 3.5 years). None of the patients had an abnormal TAMMV (ie, > 200 cm/s), whereas only 13 (3.1%), all from Iraq, had conditional values (170-200 cm/s) in the right middle cerebral artery and 7 (1.7%) in the left middle cerebral artery. There were no consistent TAMMV differences among male and female patients or in patients with different Hb genotypes (sickle cell anemia, sickle cell β0- thalassemia, and sickle D). The use of hydroxyurea was associated with a lower TAMMV, whereas a blood transfusion history had no influence. Total hemoglobin, reticulocyte count, serum bilirubin, and fetal Hb values showed varying degrees of association with the TAMMV in the different vessels. This study has demonstrated the rarity of abnormal transcranial Doppler findings among Peninsular Arab patients with SCD. The guidelines for transcranial Doppler screening in this population need further studies and recommendations.

Lower Transcranial Doppler Flow Velocities in Sickle Cell Anemia Patients on Hydroxyurea: Myth or Fact.

Transcranial Doppler (TCD) detects stroke risk in patients with sickle cell anemia (SCA). Hydroxyurea therapy has the ability to induce increased levels of fetal hemoglobin in sickle cells thus decreasing tendency for red cell sickling. This study aimed to evaluate TCD findings in SCA patients on hydroxyurea and correlate the time-averaged mean velocity (TAMV) with their hematological parameters. Forty SCA patients of both sexes, aged 16-22years with no history of stroke were screened with TCD for an elevated TAMV, divided into: Group T (20 patients on blood transfusion); and Group H (20 patients on daily hydroxyurea). For all, full medical history, clinical examination, hemoglobin, hematocrit, leukocytes, platelets, fetal hemoglobin and sickling test, in addition TCD to describe the pattern of cerebral blood flow abnormalities were done. TAMV in all cerebral arteries were significantly higher in Group T than Group H, the highest TAMV (147.5±57.09cm/s) was found in the right middle cerebral artery and correlated negatively with hematocrit in Groups H (P<0.001). There were 2 (10%) abnormal TAMV results and 5 (25%) conditional in Group T, while all results were normal in Group H. Hydroxyurea therapy may lower TCD velocities and prevent the risk of primary stroke in SCA patients.

Carotid duplex ultrasound and transcranial Doppler findings in commercial divers and pilots.

The risky working environments of divers and pilots, and the possible role of extreme ambient pressure in carotid stenosis, make ischemic stroke an important occupational concern among these professionals. In this study, we aimed to evaluate the association of being exposed to hyperbaric or hypobaric conditions with carotid artery stenosis by comparing common carotid intima-media thickness (CCIMT) and blood flow velocities of cerebral arteries in divers and pilots using carotid duplex ultrasound (CDUS) and transcranial Doppler (TCD). CDUS and transtemporal TCD were performed in 29 divers, 36 pilots and 30 control participants. Medical history, blood pressure, lipid profile and blood sugar were recorded to control the previously well-known risk factors of atherosclerosis. Findings of the CDUS and TCD [including: CCIMT and blood flow velocities of internal carotid artery (ICA), common carotid artery (CCA), and middle cerebral artery (MCA)] of divers and pilots were compared with those of the control group using regression analysis models. Both right and left side CCIMT were significantly higher in divers (P<0.05) and pilots (P<0.05) in comparison with the control group. Carotid index [peak systolic velocity (PSV) of ICA/PSV of CCA) of divers and pilots were also higher than the control group. TCD findings were not significantly different between divers, pilots, and the control group. Increased CCIMT and carotid index in diver and pilot groups appear to be suggestive of accelerated atherosclerosis of carotid artery in these occupational groups.

Cerebral vasculitis as a major manifestation of rheumatoid arthritis

Objective and Importance:Cerebral vasculitis (CV) is a rare described complication of rheumatoid arthritis (RA). Although the most frequent neurological manifestations of RA are peripheral neuropathy and cervical spinal cord compression due to subluxation of the cervical vertebrae, CV can be seen especially in patients with seropositive and long-standing RA.Clinical presentation: We report two cases of CV associated with RA. Both patients had no extraarticular manifestations and RA clinics were under control. Our first case is a 30-years-old woman with seropositive RA for 15 years who had suddenly onset left facial and upper extremity weakness. In magnetic resonance imaging (MRI) DWI, hyperintensity in frontotemporal region due to acute ischaemia was detected. The new lacuner acute ischaemic lesions in right precentral gyrus, bilateral frontoparietal and corpus callosal region were detected in the control MRI. The cerebral MR angiography and transcranial doppler findings were consistent with CV. The patient responded favourably to pulse methylprednisolone and oral azathiopurine treatments. The second patient is a 52-year-old man who had been RA for 29 years. He admitted to our neurology clinic with speech difficulty and right upper extremity minimal weakness. Magnetic resonance imaging DWI showed left parietooccipital acute ischaemia which was progressed within a week and a new right parietooccipital ischaemia was added. His cerebral MR angiography and cerebral angiography were concordant with CV. The cyclophosphamide therapy was started since the cerebral ischaemia was progressed during pulse methylprednisolone and he responded well to this therapy.Conclusion: CV due to RA is an uncommon serious complication which can be life-threatening. Therefore clinicians should be aware of the possibility of CV especially in progressive strokes in RA.

Prognosis of spontaneous cervical artery dissection and transcranial Doppler findings associated with clinical outcomes.

We categorised spontaneous cervical artery dissection (sCAD) by radiological features and investigated factors associated with favourable outcomes. We retrospectively analysed 128 patients with sCAD with a median follow-up duration of 25months. Twenty-nine constituted the aneurysm group, 52 the stenotic group, and 47 the occlusive group. Various relevant factors, including National Institute of Health Stroke Scale (NIHSS) scores, type of antithrombotic therapy, stroke progression in the first week, and transcranial Doppler (TCD) flow-waveforms (in the occlusive subgroup) were analysed. Favourable outcomes were defined as a 1-year modified Rankin-Scale score of 0-1. Favourable anatomical outcomes were defined as a reversal of dissection-associated stenosis during follow-up. The aneurysm and stenotic groups showed favourable outcomes, while the occlusive group outcomes were less favourable. In the stenotic group, anticoagulation, an NIHSS score ≥4, and stroke progression were inversely associated with favourable long-term outcomes. Remarkably, in the occlusive group, flow abnormality more severe than minimal flow was associated with stroke progression, unfavourable long-term outcome, and arterial irreversibility. The outcome of sCAD depends on its radiological subtype. In the occlusive subtype, which is associated with the worst outcome, TCD flow analysis may predict acute stroke progression and long-term outcome. • Outcomes in cervical artery dissection may be determined by radiological subtypes. • The aneurysm and stenotic groups had favourable outcomes. • The occlusive group had less favourable functional outcomes. • Flow-waveform analysis by TCD could predict functional and anatomical outcomes.

How I manage cerebral vasculopathy in children with sickle cell disease.

Sickle cell disease induces specific brain alterations that involve both the macrocirculation and the microcirculation. The main overt neurovascular complications in children are infarctive stroke, transient ischaemic attack and cerebral haemorrhage. Silent cerebral infarction, cognitive dysfunction and recurrent headache are also common. Cerebrovascular disease selectively affects children with the HbSS or HbS-β(0) genotypes (i.e. sickle cell anaemia). The incidence of stroke peaks between 2 and 5years of age (1·02/100 patient-years) and increases with the severity of the anaemia. Most strokes can be prevented by annual transcranial Doppler screening from 2 to 16years of age and providing chronic blood transfusion when this investigation shows elevated blood-flow velocities. The role for hydroxycarbamide in children with abnormal transcranial Doppler findings is under investigation. After a stroke, chronic blood transfusion is very strongly recommended, unless haematopoietic stem cell transplantation can be performed. Routine magnetic resonance imaging shows that more than one-third of children have silent cerebral infarction, which is associated with cognitive impairments. Screening for silent infarcts seems legitimate, since their presence may lead to supportive treatments. The role for more aggressive interventions such as hydroxycarbamide or chronic blood transfusion is debated.

Unruptured intracranial aneurysms in children with sickle cell disease: analysis of 18 aneurysms in 5 patients.

Intracranial aneurysms (IAs) are rare in the general pediatric population and account for <2% of all cerebral aneurysms. Only 7 children with sickle hemoglobinopathy and IAs have been reported, the majority of which were discovered after rupture. To report the prevalence of unruptured IAs in a selected population of children with sickle cell disease (SCD) and to describe the aneurysm morphology, hematologic characteristics, and management in this patient population. A retrospective review of the electronic database for all children with SCD who underwent brain magnetic resonance imaging or angiography from January 2002 to August 2013 at a single institution was performed. Records were reviewed for IA, age, sex, sickle cell genotype, neurological symptoms, hematologic indexes, transcranial Doppler findings, and management. Five of 179 children (2.8%) with SCD imaged by brain magnetic resonance imaging or angiography were diagnosed with IAs. None presented with subarachnoid hemorrhage. Four patients (80%) had HbSS disease, and 1 patient had hemoglobin sickle cell HbSC disease. A total of 18 aneurysms were detected; the majority of patients had multiple aneurysms (80%) and bilateral involvement (60%). Children with SCD are at risk for developing multiple intracranial aneurysms, and a high index of suspicion must be maintained during the interpretation of routine magnetic resonance imaging or angiography of the brain.

Transcranial Doppler ultrasound in therapeutic hypothermia for children after resuscitation

Aim of the studyThe aim of the present study was to assess the cerebral flow in children receiving therapeutic hypothermia after resuscitation. The prognostic value of transcranial Doppler findings was correlated with the clinical outcomes in these children. MethodsA retrospective cohort study was conducted at the paediatric intensive care unit of Chang Gung Children's Hospital between January 2011 and December 2012. All children from 1 month to 18 years of age who received therapeutic hypothermia after resuscitation were eligible. Serial transcranial Doppler examinations were performed and the findings were reviewed. ResultsSeventeen children met the eligibility criteria for this study. Fourteen patients (82.3%) were asphyxial in aetiology, and 12 (70.5%) of these cases occurred outside of the hospital. Eight patients (47.1%) had a Paediatric Cerebral Performance Score of 1 or 2 at 3 months after the events. Reversal diastolic or undetectable flow patterns during therapeutic hypothermia were associated with unfavourable prognosis. Normal mean flow velocity in the rewarming phase and normal pulsatility index in the hypothermia and rewarming phases were associated with favourable outcome. ConclusionThe transcranial Doppler examinations provided additional information for cerebral perfusion during therapeutic hypothermia, which may in the future be used to guide changes to hypothermia management. Mean cerebral blood flow velocity and pulsatility index by transcranial Doppler sonography can serve as a prognostic factor for children who receive therapeutic hypothermia after resuscitation.

Cerebral vasospasm after selective amygdalohippocampectomy.

Symptomatic cerebral vasospasm (CV) is a frequently observed complication after aneurysmal subarachnoid haemorrhage (SAH).[1] Infrequently, it is known to occur after skull base surgeries and surgeries for medically intractable epilepsy (viz., temporal lobectomy and selective amygdalo-hippocampectomy (AHE).[2] Factors predicting the occurrence of CV after AHE have been described.[3] Transcranial Doppler (TCD) has been suggested as an invaluable modality for the detection of CV after epilepsy surgery.[3] We report a case of AHE where the patient developed symptoms of CV even in the absence of predictive factors and normal TCD findings.

Endothelial Function and Vascular Properties in Children with Sickle Cell Disease.

Sickle cell disease (SCD) is an inherited disorder characterized by recurrent painful crises with ischemia resulting from vascular occlusion. Adults with SCD have increased arterial stiffness and reduced flow-mediated dilation (FMD), due to impaired release of substances such as nitric oxide. We aimed to assess the vascular properties of carotid and brachial arteries in children with SCD compared with a control group without cardiovascular risk factors. Thirty patients with SCD, mean age 12.3±4.5years, were prospectively enrolled. A control group was made up of 30 age- and gender-matched healthy subjects. Carotid intima-media thickness (IMT), cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS), incremental elastic modulus (Einc), and FMD were determined in both groups. There was no significant difference in FMD between the two groups (8.2±5.0% in the SCD group vs. 9.3±4.2% in the control group, P=0.15). There was no significant correlation between FMD and age, hemoglobin, LDH level, or transcranial Doppler findings. CSD was significantly elevated in the SCD group (0.96±0.44 vs. 0.59±0.21, P=0.0002), whereas DWS and Einc were significantly lower in the SCD group. CSC did not differ significantly between the two groups. Children with SCD have no marked endothelial dysfunction or change in arterial stiffness. These manifestations may be related to disease severity and duration. Changes may become evident later in life as the disease progresses.

Adding computed tomography and transcranial Doppler findings to the ABCD2 score to predict long-term risk of stroke after transient ischaemic attack or minor stroke.

The ABCD(2) score can predict the early risk of stroke after transient ischaemic attack or minor stroke. However, there is no simple and practical assessment method for the long-term risks. Computed tomography (CT) and transcranial Doppler (TCD) findings were added to the ABCD(2) score to build an ABCD(2) L(2) score and whether the new scoring system could improve the predictive value of the ABCD(2) score for the long-term risk of stroke was determined. From January 2004 to December 2005, all patients with a definite diagnosis of transient ischaemic attack or minor stroke at the Prince of Wales Hospital were consecutively enrolled and followed up until August 2008. CT and TCD were performed. The areas under the curve were used to quantify the ABCD(2) and ABCD(2) L(2) scores and related items. All 481 patients completed the follow-up. The shortest follow-up time was 0.17months (until death), the longest follow-up time was 55.60months and the mean follow-up time was 40.3±11.0months. In total, 277 (57.6%) patients showed lesions on CT scans and 195 (40.6%) patients were found with intracranial large artery atherosclerosis. Further strokes occurred in 74 (15.4%) patients, including four (0.83%) patients who died of ischaemic stroke during the follow-up period. The area under the curve increased from 0.650 (0.586-0.715) for the ABCD(2) score to 0.700 (0.637-0.764) for the ABCD(2) L(2) score. Adding CT and TCD results to the ABCD(2) score to increase its predictability for long-term risk of stroke recurrence might be a meaningful exploration.

Transcranial Doppler to assess sepsis-associated encephalopathy in critically ill patients

BackgroundTranscranial Doppler can detect cerebral perfusion alteration in septic patients. We correlate static Transcranial Doppler findings with clinical signs of sepsis-associated encephalopathy.MethodsForty septic patients were examined with Transcranial Doppler on the first and third day of sepsis diagnosis. The pulsatility index (PI) and cerebral blood flow index (CBFi) were calculated by blood velocity in the middle cerebral artery (cm/sec). Patients underwent a daily cognitive assessment with the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) test.ResultsTwenty-one patients (55%) were found to present confusion. The majority of the patients presented a PI > 1.1 (76%). PI on the first day (but not the third day) could predict a positive CAM-ICU test in septic patients (PI cut-off: 1.3, AUC: 0.905, p < 0.01, sensitivity: 95%, specificity: 88%, AUC: 0.618, p = 0.24). Multivariable analysis showed that PI on the first day is related to a positive CAM-ICU test independent of age and APACHE II score (OR: 5.6, 95% CI: 1.1-29, p = 0.03). A decrease of the PI on the third day was observed in the group that presented initially high PI (>1.3) (2.2 ± 0.71 vs. 1.81 ± 0.64; p = 0.02). On the other hand, an increase in PI was observed in the other patients (1.01 ± 0.15 vs. 1.58 ± 0.57; p < 0.01). On only the first day, the mean blood velocity in the middle cerebral artery and CBFi were found to be lower in those patients with a high initial PI (36 ± 21 vs. 62 ± 28 cm/sec; p < 0.01, 328 ± 101 vs. 581 ± 108; p < 0.01, respectively).ConclusionsCerebral perfusion disturbance observed with Transcranial Doppler could explain clinical symptoms of sepsis-associated encephalopathy.

Does the sex of acute stroke patients influence the effectiveness of rt-PA?

BackgroundWomen have been reported to show more frequent recanalization and better recovery after intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment for acute stroke compared with men. To investigate this we studied a series of stroke patients receiving IV rt-PA and undergoing acute transcranial doppler (TCD) examination.MethodsAcute stroke patients received IV rt-PA and had acute TCD examination within 4 hours of symptom onset at 4 major stroke centers. TCD findings were interpreted using the Thrombolysis in Brain Ischemia (TIBI) flow grading system. The recanalization rates, and poor 3-month outcomes (modified Rankin scale >2) of men and women were compared using the chi-square test. Multiple regression analysis was used to assess sex as a predictor of recanalization and poor 3-month outcome after controlling for age, baseline NIH Stroke Scale (NIHSS), time to treatment, hypertension, and blood glucose.Results369 patients had TCD examinations before or during IV rt-PA treatment. The 199 (53.9%) men and 170 (46.1%) women had mean ages of 67 ± 13 and 70 ± 14 years, respectively. The sexes did not differ significantly in baseline stroke severity, time to TCD examination, or time to thrombolysis. Of the men, 68 (34.2%) had complete recanalization, 58 (29.1%) had partial recanalization, and 73 (36.6%) had no recanalization. Of the women, 53 (31.2%) had complete recanalization, 46 (27%) had partial recanalization, and 71 (41.8%) had no recanalization (p = 0.6). Multiple regression analyses showed no difference between the sexes in recanalization rate, time to recanalization, or clinical outcome at 3 months.ConclusionsIn our study; sex is not a significant predictor of recanalization rate, time to recanalization or 3-month outcome in stroke patients following IV rt-PA.Trial registrationData from CLOTBUST trial Clinicaltrails.gov Identifier: NCT01240356.

Transcranial doppler findings in a case of rabies encephalitis

Introduction Rabies in humans is a fatal illness characterized by severe encephalopathy and generalized paresis. When the disease is not treated, death typically occurs within five to seven days after the onset of symptoms. Rabies virus is not cytopathic and does not incite inflammatory response [1]. Several theories have been hypothesized

Can STOP Trial Velocity Criteria Be Applied to Iranian Children with Sickle Cell Disease?

Background and PurposeSickle cell disease (SCD) is strongly linked to stroke across all haplotypes in the pediatric population. Transcranial Doppler (TCD) ultrasound is known to identify the highest risk group in African-Americans who need to receive and stay on blood transfusions, but it is unclear if the same flow velocity cut-offs can be applied to the Iranian population. We aimed to evaluate baseline TCD findings in Iranian children with SCD and no prior strokes.MethodsChildren with genetically confirmed SCD (Arabian haplotype, homozygote) and without SCD (controls) were prospectively recruited from pediatric outpatient clinic over a period of 9 months. We performed TCD in both groups to determine flow velocities in the middle cerebral (MCA) and terminal internal carotid arteries (TICA).ResultsOf 74 screened children, 60 met the inclusion/exclusion criteria (62% female; mean age 10±4 years). Baseline characteristics did not differ between the cases and controls, except hemoglobin (Hb) which was significantly lower in the SCD group (P<0.001). The right MCA TAMM (Time Averaged Maximum Mean) was significantly higher than in controls (125+5.52 cm/s vs. 92.5+1.63 cm/s, P<0.001). Left MCA did not show differences. The TICA TAMM was also different between cases and controls (P<0.05).ConclusionsAmong Iranian children with asymptomatic SCD and without receiving recent transfusion TCD velocities are higher as compared to healthy controls but appear much lower than those observed in STOP (Stroke Prevention Trial in Sickle Cell Anemia) studies. We hypothesize that some children at high risk may be present with velocities lower than 170-200 cm/s thresholds. A prospective validation of ethnicity-specific prognostic criteria is warranted.

The diagnostic accuracy of TCD for intracranial arterial stenosis/occlusion in patients with acute ischemic stroke: the importance of time interval between detection of TCD and CTA

Objective: To evaluate prospectively the diagnostic accuracy of transcranial doppler (TCD) as an additional screening tool for intracranial arterial steno-occlusive disease against computed tomography angiography (CTA) in patients with acute ischemic stroke (AIS) if both are performed in a short time interval.Methods: Between July 2011 and May 2012, 128 patients who were hospitalized within 24 hours of symptom onset and fulfilled the criteria for the clinical diagnosis of AIS were enrolled. Bedside detection of TCD was accomplished immediately after admission. High-resolution brain CTA was performed within 3 hours after the completion of TCD and the images were interpreted by a neuroradiologist blinded to TCD findings. The accuracy parameters of TCD against CTA were calculated after computation of true-positive, false-positive, true negative, and false-negative values.Results: Among the 128 patients, there were 68 males and 60 females, aged 61·4±17·5 years. The mean time interval between the detection of TCD and CTA was 89·7 (77·8) minutes. In 65% of patients, both examinations were performed with less than a half-hour interval between them. The diagnostic accuracy of TCD for different arteries showed slight distinction. Transcranial doppler demonstrated the most accurate diagnosis for middle cerebral artery (MCA), where TCD showed 35 true-positive, 0 false-negative, 1 false-positive, and 92 true-negative studies compared with CTA. Furthermore, elevated MCA velocities on TCD correlated well with the severity of intracranial stenosis detected on CTA. Vertebral artery (VA) is one of the arteries with the lowest sensitivity for TCD diagnosis (sensitivity 63·4%, specificity 96·5%, positive predictive value (PPV) 89·6%, negative predictive value (NPV) 84·8%, and accuracy 85·9%). In 20 cases (15·6%), TCD showed findings complementary to CTA (real-time embolization, collateral flow patterns, and steal phenomenon).Conclusions: Transcranial doppler shows high diagnostic accuracy against CTA if both are performed in a short time interval in evaluating intracranial arterial stenosis/occlusion in patients with AIS, especially for MCA obstruction. Transcranial doppler can also provide additional real-time dynamic findings complementary to the information provided by CTA. This can result in changes in the management in some of these patients.