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J L Saver

Publications and source records attributed to J L Saver.

At least 37 records · Page 2Linked to original sources
PubMed2001

Diffusion-perfusion MR evaluation of perihematomal injury in hyperacute intracerebral hemorrhage.

BACKGROUND: It has been suggested that a zone of perihematomal ischemia analogous to an ischemic penumbra exists in patients with primary intracerebral hemorrhage (ICH). Diffusion-perfusion MRI provides a novel means of assessing injury in perihematomal regions in patients with ICH. OBJECTIVE: To characterize diffusion-perfusion MRI changes in the perihematomal region in patients with hyperacute intracerebral hemorrhage. METHOD: Twelve patients presenting with hyperacute, primary ICH undergoing CT scanning and diffusion-perfusion MRI within 6 hours of symptom onset were reviewed. An automated thresholding technique was used to identify decreased apparent diffusion coefficient (ADC) values in the perihematomal regions. Perfusion maps were examined for regions of relative hypo- or hyperperfusion. RESULTS: Median baseline NIH Stroke Scale score was 17 (range, 6 to 28). Median hematoma volume was 13.3 mL (range, 3.0 to 74.8 mL). MRI detected the hematoma in all patients on echo-planar susceptibility-weighted imaging and in all seven patients imaged with gradient echo sequences. In six patients who underwent perfusion imaging, no focal defects were visualized on perfusion maps in tissues adjacent to the hematoma; however, five of six patients demonstrated diffuse ipsilateral hemispheric hypoperfusion. On diffusion imaging, perihematomal regions of decreased ADC values were identified in three of 12 patients. All three subsequently showed clinical and radiologic deterioration. CONCLUSIONS: A rim of perihematomal decreased ADC values was visualized in the hyperacute period in a subset of patients with ICH. The presence of a rim of decreased ADC outside the hematoma correlated with poor clinical outcome. Although perfusion maps did not demonstrate a focal zone of perihematomal decreased blood flow in any patient, most patients had ipsilateral hemispheric hypoperfusion.

Acute Disease↗
PubMed2001

Transcranial Doppler pulsatility indices as a measure of diffuse small-vessel disease.

BACKGROUND AND PURPOSE: Elevation in pulsatility indices (PIs) as measured by transcranial Doppler (TCD) have been postulated to reflect downstream increased vascular resistance caused by small-vessel ischemic disease. METHODS: The authors retrospectively compared TCD PIs and magnetic resonance imaging (MRI) manifestations of small-vessel disease in 55 consecutive patients who underwent TCD studies and brain MRI within 6 months of each other during a 2-year period. RESULTS: Correlations between TCD middle cerebral artery PIs and MRI measures were as follows: periventricular hyperintensity (PVH) = 0.52 (P < .0001), deep white matter hyperintensity (DWMH) = 0.54 (P < .0001), lacunar disease = 0.31 (P = .02), and combined PVH/DWMH/lacunes = 0.54 (P < .0001). Correlation between pontine ischemia and vertebrobasilar PIs was 0.46 (P = .0004). Univariate analysis showed that age, elevated PI, and hypertension strongly correlated with white matter disease measures. After adjusting for these factors in a multivariate Poisson regression analysis, PI remained an independent predictor of white matter disease. Receiver operator curve analyses identified PI cut points that allowed discrimination of PVH with 89% sensitivity and 86% specificity and discrimination of DWMH with 70% sensitivity and 73% specificity. CONCLUSIONS: Elevation in PIs as measured by TCD shows strong correlation with MRI evidence of small-vessel disease. TCD may be a useful physiologic index of the presence and severity of diffuse small-vessel disease.

Adult↗
PubMed2001

Correlation of aphasia and/or neglect with cortical infarction in a subpopulation of RANTTAS.

Classically in neurology, aphasia and neglect were accepted as reliable markers of cortical lesions. The actual prognostic values of aphasia and neglect have yet to be formally tested. This analysis sought to determine the predictive accuracy of aphasia and/or neglect in acute stroke for cortical infarction. Data from the RANTTAS investigation of tirilazad mesylate in stroke patients were reanalyzed, comparing acute National Institutes of Health Stroke Scale (NIHSS) measures of aphasia and neglect to lesion location on day 7-10 CT scans. Correlations between the presence of aphasia and/or neglect and the presence of a cortical lesion were only in the moderate range, and positive predictive values were far from perfect, as would be expected. 'Subcortical' aphasia or neglect was more likely in large, subcortical lesions. Aphasia and neglect, as determined in the acute setting by the NIHSS, are only moderately associated with cortical infarct identified on follow-up CT scans. If selective neuroprotection is envisioned for acute stroke patients, more accurate markers of cortical infarction may be needed.

Aphasia↗
PubMed2001

Combination therapies and the theoretical limits of evidence-based medicine.

BACKGROUND: Advances in molecular pharmacology and surgical, endovascular, and radiation techniques have yielded multiple effective or promising, and potentially complementary, classes of treatments for virtually every major medical disorder. Consequently, determining the optimum combination of therapies for a condition is a burgeoning challenge to clinical trialists and practicing physicians. METHODS: General phase III trial strategies for testing combination regimens are described, and then applied to two illustrative conditions, Alzheimer disease and ischemic stroke. RESULTS: Strategies for testing combination regimens include: head to head trials of all combinations, which lead to unwieldy trial numbers; very large multi-arm trials, which impractically delay interval information on regimen utility; and hierarchical, serial clinical trials. Systematic literature review revealed seven classes of agents already approved or in late phase III testing for preventing the development or slowing the progression of Alzheimer disease and five for ischemic stroke prevention. Possible combination regimens number 128 (2(7)) for Alzheimer disease and 32 (2(5)) for ischemic stroke. Hierarchical, serial clinical trials would permit identification of the optimum combination of these agent classes for Alzheimer disease through 127 trials, enrolling 63,500 patients, requiring 286 years; for ischemic stroke through 31 trials, enrolling 186,000 patients, requiring 155 years. CONCLUSIONS: Marked limitations in the ability of clinical trials to interrogate varied treatment combinations to determine the most effective ensemble exist, and their scope is widely underappreciated. Steps that may attenuate, though not eliminate, the challenge of a surfeit of combination treatment regimens include preclinical testing to identify the most promising regimens, use of surrogate outcome measures in exploratory clinical trials, and use of hierarchical, serial and factorial phase III trials.

Aged↗
PubMed2001

Trends in acute ischemic stroke trials through the 20th century.

BACKGROUND AND PURPOSE: The advent of controlled clinical trials revolutionized clinical medicine over the course of the 20th century. The objective of this study was to quantitatively characterize developments in clinical trial methodology over time in the field of acute ischemic stroke. METHODS: All controlled trials targeting acute ischemic stroke with a final report in English were identified through MEDLINE and international trial registries. Data regarding trial design, implementation, and results were extracted. A formal 100-point scale was used to rate trial quality. RESULTS: A total of 178 controlled acute stroke trials were identified, encompassing 73 949 patients. Eighty-eight trials involved neuroprotective agents, 59 rheological/antithrombotic agents, 26 agents with both neuroprotective and rheological/antithrombotic effects, and 5 a nonpharmacological intervention. Only 3 trials met conventional criteria for a positive outcome. Between the 1950s and 1990s, the number of trials per decade increased from 3 to 99, and mean trial sample size increased from 38 (median, 26) to 661 (median, 113). During 1980-1999, median time window allowed for enrollment decreased per half decade from 48 to 12 hours. Reported pharmaceutical sponsorship increased substantially over time, from 38% before 1970 to 68% in the 1990s. Trial quality improved substantially from a median score of 12 in the 1950s to 72 in the 1990s. CONCLUSIONS: Accelerating trends in acute stroke controlled trials include growth in number, sample size, and quality, and reduction in entry time window. These changes reflect an increased understanding of the pathophysiology of acute stroke, the imperative for treatment initiation within a critical time window, and more sophisticated trial design.

Acute Disease↗
PubMed2001

Intra-arterial thrombolysis.

Intra-arterial (IA) thrombolysis is an emerging treatment strategy for acute ischemic stroke. In IA thrombolysis, the cervicocephalic arterial tree is traversed with an endovascular microcatheter delivery system, the catheter port is positioned immediately within and adjacent to the offending thrombus, and fibrinolytic agents are infused directly into the clot. This delivery technique permits high concentrations of lytic agent to be applied to the clot while minimizing systemic exposure. Early open series suggested that IA thrombolysis achieves higher recanalization rates than i.v. thrombolysis. The first randomized Phase III trial of IA thrombolysis, the Prolyse in Acute Cerebral Thromboembolism II (PROACT II) trial, confirmed this promise, showing that IA therapy begun up to 6 hours after symptom onset was associated with higher recanalization rates and better clinical outcomes, with acceptable hemorrhage rates. MRI studies have provided striking imaging evidence of the potential beneficial effects of IA therapy, showing not only rescue of regions of diffusion-perfusion mismatch but also normalization and salvage of some tissues with pretreatment bioenergetic failure evidenced by early diffusion abnormality. The Emergency Management of Stroke Bridging Trial demonstrated the feasibility of combined i.v. and intra-arterial thrombolysis. Intra-arterial thrombolysis is a promising treatment strategy for acute ischemic stroke. In coming years, IA thrombolysis, alone or in combination with endovascular mechanical reperfusion techniques, is likely to be increasingly refined and validated and to become a widely accepted therapy for acute ischemic stroke.

Clinical Trials, Phase III as Topic↗
PubMed2000

Advances in neuroimaging of acute stroke.

As therapeutic options for treating acute stroke evolve, neuroimaging strategies are assuming an increasingly important role in the initial evaluation and management of patients. There is a recognized need for objective neuroimaging methods to identify the best candidates for early intervention. Both acute and long-term treatment decisions for stroke patients should optimally incorporate information provided by neuroimaging studies regarding tissue viability (eg, size, location, vascular distribution, degree of reversibility of ischemic injury, presence of hemorrhage), vessel status (site and severity of stenoses and occlusions), and cerebral perfusion (size, location, and severity of hypoperfusion). The ability to acutely identify the ischemic penumbra and to use this information to make treatment decisions may be within reach, particularly with the multimodal data provided by magnetic resonance techniques. This article will review recent developments in the field of neuroimaging of acute stroke and discuss the clinical applications of specific techniques of magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission tomography, catheter angiography, and ultrasound imaging.

Cerebral Angiography↗
PubMed2000

A new pocket-sized transcranial ultrasound device (NeuroDop): comparison with standard TCD.

The NeuroDop is a new bedside assessment tool consisting of a continuous wave ultrasound probe attached to a stethoscope earpiece. This study was designed to compare middle cerebral artery (MCA) velocity assessment obtained with the NeuroDop versus standard transcranial Doppler (TCD). TCD technologists performed continuous wave NeuroDop studies followed by standard TCD studies on 60 subjects. Technologists recorded presence of MCA signal and estimated velocity based on NeuroDop auditory characteristics. Signal was obtained in 108 MCA vessels with the portable unit and in 112 vessels using standard TCD. For detection of patency, sensitivity was 96%, specificity 88%, positive predictive value 99%, and negative predictive value 58%. Auditorially estimated velocities from the NeuroDop strongly correlated with TCD velocity measures (r = 0.71). Categorical estimates of velocity as decreased (< 37 cm/sec), normal (37-81 cm/sec), or increased (> 81 cm/sec) demonstrated an accuracy rate of 85%. This novel stethoscope-continuous wave unit has excellent sensitivity in detecting presence of MCA patency. Moreover, MCA velocities can be characterized to a reasonable degree of accuracy based on NeuroDop auditory characteristics. The NeuroDop shows promise as a tool to rapidly assess and serially monitor presence and amplitude of MCA velocity and may help guide thrombolytic and other emergency management decisions in stroke patients.

Blood Flow Velocity↗
PubMed2000

Identifying stroke in the field. Prospective validation of the Los Angeles prehospital stroke screen (LAPSS).

BACKGROUND AND PURPOSE: Reliable identification of stroke patients in the field by prehospital personnel could expedite delivery of acute stroke therapy. The Los Angeles Prehospital Stroke Screen (LAPSS) is a 1-page instrument designed to allow prehospital personnel to rapidly identify acute stroke patients in the field. We performed a prospective, in-the-field validation study of the LAPSS. METHODS: Paramedics assigned to 3 University of California at Los Angeles-based advanced life support units were trained and certified in use of the LAPSS. Over 7 months, paramedics completed the LAPSS on noncomatose, nontrauma patients with complaints suggestive of neurological disease. LAPSS form stroke identification results were compared with emergency department and final hospital discharge diagnoses. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and likelihood ratios were calculated for LAPSS identification of ischemic stroke, currently symptomatic transient ischemic attack, and intracerebral hemorrhage. RESULTS: Of a total of 1298 runs, 34% were for nontraumatic, noncomatose neurologically relevant complaints. Thirty-six of these patients (3% of all transports) had a final diagnosis of acute symptomatic cerebrovascular disease (21 ischemic strokes, 7 transient ischemic attacks, and 8 intracerebral hemorrhages). LAPSS forms were completed on 206 patients. Paramedic performance when completing the LAPSS demonstrated sensitivity of 91% (95% CI, 76% to 98%), specificity of 97% (95% CI, 93% to 99%), positive predictive value of 86% (95% CI, 70% to 95%), and negative predictive value of 98% (95% CI, 95% to 99%). With correction for the 4 documentation errors, positive predictive value increased to 97% (95% CI, 84% to 99%). CONCLUSIONS: The LAPSS allows prehospital personnel to identify patients with acute cerebral ischemia and intracerebral hemorrhage with a high degree of sensitivity and specificity.

Aged↗
PubMed2000

Safety and cost of low-molecular-weight heparin as bridging anticoagulant therapy in subacute cerebral ischemia.

BACKGROUND AND PURPOSE: Anticoagulation with intravenous unfractionated heparin (IVUH) while awaiting therapeutic oral anticoagulant levels is a common practice in patients with acute and subacute cerebral ischemia. A promising alternative strategy is to use bridging subcutaneous low-molecular-weight heparin (LMWH), which may have a favorable risk-benefit profile compared with IVUH and may permit earlier discharge with completion of transition to warfarin therapy as an outpatient. METHODS: A LMWH, enoxaparin 1 mg/kg BID, was used as bridging anticoagulation therapy in 24 consecutive patients admitted to a university stroke center in whom the treatment plan included transition from acute to chronic anticoagulation. The LMWH group was contrasted with the preceding 24 patients transitioned to warfarin with IVUH at the same center. RESULTS: Fewer patients in the LMWH bridging therapy group experienced neurological worsening than in the IVUH bridging therapy group (2/24 versus 8/24; P:=0.033). Fewer total adverse events were noted in the LMWH group than in the IVUH cohort (3 versus 20; P:=0. 002). Fifteen of the 24 LMWH patients (62.5%) were discharged while still receiving LMWH and completed transition to warfarin as outpatients, receiving an average of 3.6 days of outpatient transitional therapy. In these 15 patients, use of LMWH was associated with a net savings of $2197 per patient. CONCLUSIONS: In this pilot cohort with subacute cerebral ischemia, bridging LMWH appeared to be safer than bridging IVUH and was associated with reduced hospital stay and reduced total cost of care.

Adult↗
PubMed2000

Impact on stroke subtype diagnosis of early diffusion-weighted magnetic resonance imaging and magnetic resonance angiography.

BACKGROUND AND PURPOSE: The purpose of the present study was to assess the diagnostic usefulness of early diffusion-weighted MRI (DWI) and MR angiography (MRA) in patients with ischemic stroke. Past approaches to stroke diagnosis required a series of diagnostic tests over several days of hospitalization. New magnetic resonance methodologies that include DWI and MRA may allow more rapid characterization of stroke pathophysiology. However, no previous study has assessed the impact on formal stroke subtype diagnosis of early imaging with DWI/MRA. METHODS: We analyzed 46 consecutive patients with acute ischemic stroke who underwent DWI/MRA within 24 hours of admission. Initial diagnoses were rendered with use of the 2 most widely used formal stroke subtype classification schemes, the TOAST and the Oxfordshire methods, which were applied to patients after CT/conventional MRI but before DWI/MRA. Modified TOAST and Oxfordshire diagnoses were then rendered based on the results of day 1 DWI, MRA, and DWI plus MRA. Final TOAST/Oxfordshire diagnoses at discharge were taken as the gold standard. RESULTS: Compared with final diagnoses, pre-MRI TOAST diagnoses matched final diagnoses in 48%, improving to 83% after DWI alone, 56% after MRA alone, and 94% after DWI plus MRA. For the TOAST diagnostic subtypes of large-vessel atherothromboembolism and small-vessel disease, pre-MRI diagnoses matched final diagnoses in 56% and 35% of patients, respectively, improving to 89% and 100% after DWI/MRA. Pre-MRI Oxfordshire diagnoses matched final diagnoses in 67% of patients, improving to 100% after DWI. CONCLUSIONS: The use of DWI/MRA within 24 hours of hospitalization substantially improves the accuracy of the diagnosis of early ischemic stroke subtype. When initial management and clinical trial eligibility decisions are influenced by stroke subtype, day 1 multimodal MRI is advantageous as a guide to therapy.

Female↗
PubMed2000

Detection of early CT signs of >1/3 middle cerebral artery infarctions : interrater reliability and sensitivity of CT interpretation by physicians involved in acute stroke care.

BACKGROUND AND PURPOSE: This study had 2 goals: (1) to assess interrater reliability of academic neuroradiologists when classifying acute infarction by CT scan as >1/3 middle cerebral artery (MCA) involvement, <1/3 MCA involvement, or no infarction and (2) to determine the sensitivity of physicians potentially involved in acute stroke treatment in detecting >1/3 MCA acute infarctions. Studies of tissue plasminogen activator show an association between early signs of major infarction and poor outcome. The American Academy of Neurology and the American Heart Association recommend avoiding thrombolysis if early signs of major infarction are present. METHODS: We presented 25 scans (normals, acute infarctions, and old infarctions) to 3 academic neuroradiologists. A scoring sheet based on Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS)/CT Summit criteria was used to determine >1/3 MCA territory involvement. Nine of the 25 scans were presented again to assess intrarater reliability. We recalculated results of our previous study in which physicians interpreted infarction scans, now designating the scans as >1/3 MCA, <1/3 MCA, or normal, as determined by the neuroradiologists. RESULTS: All 3 neuroradiologists agreed on no infarction, <1/3 MCA, and >1/3 MCA on 64% of the scans. Neuroradiologist test-retest agreement was 96% for >1/3 MCA territory. Overall sensitivity for emergency physicians, neurologists, and general radiologists for detecting the presence of infarction in scans rated as >1/3 MCA was 78%. CONCLUSIONS: Neuroradiologists can achieve moderate agreement in detecting >1/3 MCA infarction. The emergency physicians, neurologists, and general radiologists tested were reasonably skilled at detecting >1/3 MCA acute infarction. However, their performance did not reliably identify all patients who have early CT infarct signs that place them at increased risk for cerebral hemorrhage after thrombolytic therapy.

Acute Disease↗
PubMed2000

Thrombolytic reversal of acute human cerebral ischemic injury shown by diffusion/perfusion magnetic resonance imaging.

Diffusion magnetic resonance imaging provides an early marker of acute cerebral ischemic injury. Thrombolytic reversal of diffusion abnormalities has not previously been demonstrated in humans. Serial diffusion and perfusion imaging studies were acquired in patients experiencing acute hemispheric cerebral ischemia treated with intra-arterial thrombolytic therapy within 6 hours of symptom onset. Seven patients met inclusion criteria of prethrombolysis and postthrombolysis magnetic resonance studies, presence of large artery anterior circulation occlusion at angiography, and achievement of vessel recanalization. Mean diffusion-weighted imaging lesion volume at baseline was 23 cm3 (95% confidence interval [95% CI], 8-38 cm3) and decreased to 10 cm3 (95% CI, 3-17 cm3) 2.5 to 9.5 hours after thrombolysis. Mean apparent diffusion coefficient lesion volume decreased from 9 cm3 (95% CI, 2-16 cm3) at baseline to 1 cm3 (95% CI, 0.4-2 cm3) early after thrombolysis. A secondary increase in diffusion volumes was seen in 3 of 6 patients at day 7. In all 4 patients in whom perfusion imaging was obtained before and after treatment, complete resolution of the perfusion deficit was shown. Diffusion magnetic resonance signatures of early tissue ischemic injury can be reversed in humans by prompt thrombolytic vessel recanalization. The ischemic penumbra includes not only the region of diffusion/perfusion mismatch, but also portions of the region of initial diffusion abnormality.

Acute Disease↗
PubMed1999

Pseudo-occlusion and/or pseudo-stenosis of the intracranial internal carotid artery.

This report summarizes our recent experience with two patients who presented with symptoms ipsilateral to a severe carotid stenosis at the bifurcation, with one having a severe stenosis at the siphon and the other an occlusion of the internal carotid artery in its intracranial portion. These lesions were documented on preoperative angiography. In both instances, persistence of symptoms, despite maximal medical therapy, led us to proceed with carotid endarterectomy. In both cases, intraoperative angiography confirmed a normal intracranial internal carotid artery, contrary to what had been seen on preoperative angiography. Carotid endarterectomy was performed, with resolution of clinical symptoms in both cases. This experience suggests that the appearance of the intracranial portion of the carotid artery can be significantly affected by the presence of a proximal lesion at the bifurcation. Stenosis and/or occlusion of the intracranial portion of the carotid artery may appear on preoperative angiography secondary to flow alterations as a result of the more proximal lesion. This, in part, may explain why many patients with combined extracranial and intracranial arterial disease improve after carotid endarterectomy and suggests that, in the presence of a severe extracranial lesion, further evaluation be undertaken to exclude the possibility of pseudo-stenosis or pseudo-occlusion of the intracranial carotid artery.

Aged↗
PubMed1999

Infarct volume as a surrogate or auxiliary outcome measure in ischemic stroke clinical trials. The RANTTAS Investigators.

BACKGROUND AND PURPOSE: Reduction in infarct volume is the standard measure of therapeutic success in animal stroke models. Reduction in infarct volume has been advocated as a biological surrogate or auxiliary outcome measure for human stroke clinical trials to replace or supplement deficit, disability, and global clinical scales. However, few studies have investigated correlations between infarct volume and clinical end points in acute ischemic stroke patients. METHODS: CT scans at days 6 to 11 were acquired prospectively in 191 fully eligible patients enrolled in the Randomized Trial of Tirilazad Mesylate in Patients With Acute Stroke (RANTTAS). Patients were enrolled within 6 hours of onset of stroke in any vessel distribution. Infarct volume was measured by operator-assisted computerized planimetry. RESULTS: One hundred thirty-two patients had visible new supratentorial infarcts, with median infarct volume of 28.0 cm3 (interquartile range, 9.0 to 93.0 cm3). Fifty-nine patients had no visible new infarct. Correlations with standard 3-month outcome scales and mortality were as follows: Barthel Index, r=0.43; Glasgow Outcome Scale, r=0.53; National Institutes of Health Stroke Scale, r=0.54; mortality, r=0.31. For visible infarcts alone, correlations were as follows: BI, r=0.46; GOS, r=0.59; NIHSS, r=0.56; mortality, r=0.32. CONCLUSIONS: Subacute CT infarct volume correlates moderately with 3-month clinical outcome as assessed by widely used neurological and functional assessment scales. The modesty of this linkage constrains the use of infarct volume as a surrogate end point in ischemic stroke clinical trials.

Acute Disease↗
PubMed1999

Diffusion MRI in patients with transient ischemic attacks.

BACKGROUND AND PURPOSE: Diffusion MRI has established value in patients with ischemic stroke but has not been systematically investigated in patients with transient ischemic attack (TIA). METHODS: Clinical, conventional MRI, and diffusion MRI data were collected on 42 consecutive patients with symptoms of cerebral TIA. TIA imaging data were compared with those from a contemporaneous group of 23 completed stroke patients. RESULTS: Twenty of the 42 TIA patients (48%) demonstrated neuroanatomically relevant focal abnormalities on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) imaging. When present, DWI/ADC signal changes in TIA patients were less pronounced and smaller in volume than those in completed stroke patients. TIA symptom duration was significantly longer for DWI-positive than for DWI-negative patients, 7.3 versus 3.2 hours. Diffusion MRI information changed the suspected anatomic and vascular TIA localization and the suspected etiologic mechanism in over one third of patients with diffusion MRI abnormalities. Of the 20 TIA patients with identifiable lesions on diffusion MRI, 9 had follow-up imaging studies; of these, 4 did not show a relevant infarct on follow-up imaging. CONCLUSIONS: Diffusion MRI demonstrates ischemic abnormalities in nearly half of clinically defined TIA patients. The percentage of patients with a DWI lesion increases with increasing total symptom duration. In nearly half, the diffusion MRI changes may be fully reversible, while in the remainder the diffusion MRI findings herald the development of a parenchymal infarct despite transient clinical symptoms. Finally, diffusion imaging results have significant clinical utility, frequently changing the presumed localization and etiologic mechanism.

Adult↗