الفهرس 
Review of literatureOnly 14 pages are availabe for public view
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Abstract
Stroke is a leading cause of long-term adult disability worldwide. Only a small proportion of stroke survivors (≈14%) achieve full recovery of activities of daily living, whereas 25% to 50% require some assistance and approximately half experience long-term dependency. Prediction of outcome after ischemic stroke, therefore, is important for setting realistic and attainable treatment goals, informing patients and their relatives properly, facilitating discharge planning, and anticipating possible consequences for home adjustments and community support.
Moreover, knowledge of the expected recovery pattern is necessary to assess the effectiveness of new therapeutic interventions and their contribution to recovery and should be applied to select comparable patient’s populations for treatment trials.
Several standardized measures assess various aspects of stroke outcome and recovery, including quantification of neurological deficits, functional outcome measures, and quality of life measures. Activities of daily living, including dressing, mobility, and bathing, are assessed most frequently by the Barthel Index and by the modified Rankin Scale (MRS) but also by the Glasgow Outcome Scale, the Functional Independence Measure, or other activities of daily living assessment tools. Frequently used measures of quality of life include the Stroke Impact Scale and European Quality of Life Scale (EQ-5D).
A considerable number of prognostic stroke studies used the Barthel Index and the MRS as the primary outcome measure reached after 3 to 6 months and found that scores on scales assessing severity of neurological deficits such as the National Institutes of Health and Stroke Scale (NIHSS) and Canadian Neurological Scale in acute stroke (i.e within 72 hours) are strongly associated with outcome beyond 3 months.
A systemic review of prognostic studies indicated that age and motor weakness were important predictive variables of outcome in addition to stroke severity; however, sex and presence of vascular risk factors were not. Using simple models, a modestly large percentage of patients could be correctly classified with respect to survival and functional recovery (70.4% and 72.9%) and to the severity of impairment on the Barthel Index (severe versus mild neurological deficits, area under the curve, 0.789–0.808 depending on time of assessment 2 days to 5 days).
The addition of more clinical variables and application of more complex models improved prediction accuracy only slightly (83.9%).Treatment with recanalization therapies such as intravenous tissue-type plasminogen activator is also an important predictor of improved outcome.
Advanced neuroimaging techniques are now widely available for the assessment of stroke. These studies have the potential to improve accuracy of stroke outcome predictive scales, provide valuable insights into the pathophysiology of stroke injury and recovery, and provide biomarkers to test the efficacy of putative therapies.
In the current study we aimed to study the role of imaging using diffusion tensor tractoghraphy technique as a prognostic tool to predict outcome following acute ischemic stroke.
The current study was non-randomized retrospective cohort study conducted on 40 cases; 22 males (55%) and 18 females (45%). Their ages ranged from 25 to 75 years (Mean age: 58.4 ±11.3). Another 40, age and sex matching persons were enrolled as a control group for FA values. Diabetes mellitus was the most prevalent risk factor (65%) followed by hypertension (62.5%), dyslipidemia (52.5%), current smoking (47.5%).
I- Initially at onset of acute ischemic stroke:
There was highly significant statistical relation between NIHSS on admission of patients group and corticospinal tract (CST) affection measured by fiber tractography. All patients with very severe NIHSS (4) had disrupted corticospinal tract (CST) detected by fiber tractography
There was highly significant statistical relation between NIHSS and fractional anisotropy (FA).among 4 patients with very severe NIHSS on admission, 3 patients had severe FA and 1 patient had moderate FA value.
There was highly significantly statistically association between size of infraction. The larger infraction was, the more reduction of fractional anisotropy (FA) became.
There was statistical highly significant association between size of infraction and pattern of CST affection detected by fiber tractograhy which means that the larger size of infraction was, the more affection of CST (corticospinal tract) became detected by fiber tractography.
II- Follow up after 3months
There was highly significant statistical relation between NIHSS and fractional anisotropy (FA).All patients (N=2) with very severe NIHSS found to have severe FA.
There was significant statistical (0.019) relation between NIHSS after 3months of patients group and corticospinal tract (CST) affection measured by fiber tractography. All patients with very severe NIHSS (2) had disrupted corticospinal tract (CST) detected by fiber tractography.
We found that the relation between modified rankin scale (MRS) after 3 months of patients group and degree of fractional anisotropy (FA) reduction at the site of the infraction (ROI) was significant .Most of patients with favorable MRS had mild and moderate FA.
The association between modified rankin scale (MRS) after 3 months of patients group and degree of corticospinal tract (CST) Affection measured by fiber tractography was shown in table (9)
Association between modified rankin scale (MRS) after 3 monthes of patients group and pattern of corticospinal tract (CST) affection measured by fiber tractography was significant. we noticed that most of patients with unfavorable MRS, had disrupted corticospinal tract .
In conclusion, DTI and DTT could help us in visualize orientation of corticospinal tract fibers at three dimensions, not found in conventional MRI which affected in acute ischemic stroke. We also noticed that most of patients with favorable outcome after three months had undisrubted corticospinal tract and mild to moderate reduction in fractional anisotropy.