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April2010 Vol.47 Issue:      2 Table of Contents
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Ischemic Stroke of Anterior Circulation: Sensitivity and Prognostic Value of Early Ultrasound and Imaging Studies

Amr Kamel1, Sawsan Abdel Aziz1, Mahmoud M. El-Ebyary1,

Doriya A El-Fattah1, Khaled M. Shawky2

 

Departments of Neurology1, Radiology2, Zagazig University; Egypt

 



ABSTRACT

Background: Neurovascular imaging is essential to the development of acute stroke therapies. Objective: To evaluate the sensitivity of MRI, MRA, TCD and ECCD in the early diagnosis of ischemic stroke in the anterior circulation as well as to assess the prognostic value of such tools. Methods: This study was conducted in the intensive care unit of neurology department, Zagazig university Hospitals. It included 30 patients with stroke in the carotid domain. All patients were evaluated by CANS, MRI, MRA, ECCD and TCD within the first 24 hours of stroke onset. After 48 hours they were reevaluated with CANS and TCD. Results: Eleven (36.7%) out of 30 stoke patients deteriorated in the first 48 hours and the deteriorating patients were significantly older, had more diabetes mellitus and hypertension than non deteriorating patients. Within the first 24 hours, MCA occlusion was detected in 20% patients, whereas asymmetry was present in 50% patients. After 48 hours 20% patients showed recanalizaton. Regarding ECCD, we found significant stenosis and occlusion ipsilateraly in 33.3% & 10% of patients and contralateraly in 26.7% & 3.3% of patients respectively. We found significant relations between MRI and MRA results and between TCD and MRA results. High sensitivity was detected in TCD and ECCD 90.9% for each one, whereas sensitivity of MRI and MRA was 81.8%. Conclusion: The combination of investigations; MRI, MRA, TCD, and ECCD; would provide the clinician with a powerful tool for early comprehensive assessment of stroke patients with high sensitivity and in follow up, ultrasound may be technique of choice. (Egypt J Neurol Psychiat Neurosurg.  2010; 47(2): 303-310)

 

Key Words: Ischemic stroke, ECCD, TCD, MRI, MRA

 

Correspondence to Sawsan Abdel Aziz, Department of Neurology, Zagazig University; Egypt. Tel.: +20100089860. Email: sawsan_abdelaziz@hotmail.com.





INTRODUCTION

 

Neurovascular imaging is essential to the development of acute stroke therapies. With the introduction over the last 20 years of various diagnostic imaging techniques, especially the functional neuroimaging which allows imaging of brain physiology, stroke has been redefined as a dynamic and evolving process with potential openings for acute therapy and longer-term rehabilitation1. The most common etiology of stroke is the obstruction of cerebral vessels due to either thrombosis or emboli. The source of the emboli in 66% of these patents is atheromatous disease of middle cerebral, basilar, vertebral, carotid; either intracranial or extracranial; arteries. Investigators indicated that the severity and distribution of cerebral vessel involvement are different among various races and areas, e.g. it has been reported that small intracranial vessels are more involved in Asian and Chins races than in western and white races2.

Imaging, therefore, has become extremely important in the management of individual patients, as an accurate diagnosis is essential for safe, rapid and appropriate management. Also importantly, the newer functional imaging techniques allow individual patients to be classified according to pathophysiology rather than clinical or structural imaging alone. Thus, an understanding of the neuroimaging techniques and what they tell us about pathophysiology is required for all professionals who hope to provide optimal management of acute stroke patients and of patients in the rehabilitation phase1.

In practical terms, CT is likely to remain the imaging technique of first choice for stroke worldwide because of its ease of use and accessibility.  However, in the first 24-48 hours following stroke the CT often fails to reveal any detectable abnormality, since it is negative in 25-50% of cases. Angiography during this period carries a 1.2% complication rate and may be of limited availability. Magnetic resonance angiography (MRA) is a non-invasive method of visualizing the cerebrovascular anatomy and preliminary studies of patients with cerebrovascular disease have been performed. Carotid ultrasound has been used worldwide as a non invasive diagnostic test for evaluating extracranial carotid artery disease with higher accuracy and efficiency and is fundamental to decrease the disease burden from hospitals with moving towards more community based approach of disease prevention3. Transcranial Doppler ultrasonography (TCD) is another non-invasive, non-ionizing and inexpensive method of assessing cerebral blood flow velocities (CBFV) and sequential monitoring of potency of cerebral arteries in stroke4.

We now have the opportunity to witness clinical courses that in the past had already begun or even been completed by the time patients were hospitalized. Hence it would theoretically be possible to prevent or to counteract a neurological deterioration, or to plan a non intensive treatment of patients who are likely to improve spontaneously5.

This study is an attempt to evaluate the sensitivity of MRI, MRA, extracranial duplex and transcranial Doppler (TCD) in the early diagnosis of vascular disease in patients presenting with acute ischemic stroke in the distribution of middle cerebral artery as well as to assess the prognostic value of such tools in acute ischemic stroke patients.

SUBJECTS AND METHODS

 

This study was conducted in the intensive care unit of Neurology Department, Zagazig university Hospitals, during the period from October 2006 to July 2007. Fifty subjects (30 stroke patients and 20 healthy control), were included in our study.  The patients were diagnosed as stroke confined to carotid system according to diagnostic criteria6 and confirmed radiologically to be ischemic by using CT scan showing hypodense areas of infarction. All patients were fulfilled the following inclusion criteria: (1) Admission within 24 hours after symptom onset.(2) Adequate ultrasound of window in temporal bone for TCD examination available after admission.(3) Patient's CT scan of the brain was showing evidence of cerebral ischemia at carotid system.(4) Exactly defined time of onset of stroke.  The exclusion criteria include: (1) Cerebral hemorrhage on initial or repeated CT. (2) Induced thrombolysis. (3) Concurrent severe systemic disease. (4) In determined time of onset of stroke. (5) Subarachnoid hemorrhage.

 

All patients were subjected to the following:

Clinical assessment, including: (I) Detailed history taking with paying special attention to past medical history obtained from the patients or their relatives to establish the presence of any stroke risk factor. (II) Full general examination. (III) ECG and Echocardiography. (IV) Thorough neurological examination within the first 24 hours of stroke onset using Canadian Neurological Scale (CANS)7 and repeated after 48 hours (an increase in the global score of l or more points within the first 48 hours of stroke was considered early improvement, whereas a decrease in the global score of 1 or more points was considered early deterioration, the remaining patients were defined as stable). Laboratory investigations: the laboratory work - up looked for identification of risk factors as well as exploring any asymptomatic general medical disease.

 

Magnetic resonance imaging (MRI)

Each participant was subjected to MRI of the brain in the MRI unit at Zagazig University Hospitals, using MR-machine. 5T Signa Contour. The section thickness was 7 mm. The used protocol included: T1-weighted, T2 –weighted, and FLAIR, all were done in axial, coronal, and sagittal projections, except FLAIR that was only done in axial projections.

 

Magnetic Resonance Angiography (MRA):

To differentiate ischemic from hemorrhagic stroke and to exclude other causes of acute neurological deficit; CT scan of the brain was taken at the same time of MRI and MRA. Magnetic resonance angiography (MRA) was performed on 0.5 T GE system, with the use of a circularly polarized transmit-receive head coil with 26-cm inner diameter. Three-dimensional time of flight images was obtained. We use magnetization transfer and tilted optimized non random excitation to improve contrast between flowing blood and background tissue. The signal from flow in each common carotid artery (CCA), internal carotid artery (ICA), middle cerebral artery (MCA) and anterior cerebral artery(ACA), were graded as normal, partially occluded (reduced signal intensity i.e. narrowed lumen of slowed flow); or occluded (absent signal)8.

 

Duplex extracranial sonography 

The patients were examined with Toshiba (diagnostic ultrasound system), model (SSA 270 A), B-mode with pulsed Doppler flow imaging system. The patients were examined in the supine position with the head hyperextended and the neck rotated o the contralateral direction from the side being examined, this places the vessels more perpendicular to the transducer for maximum reflection. A 7.5 MHZ linear and 5 MHZ sector probes were used to visualize vessel anatomy and vascular pathology in both longitudinal and transverse view. The vessels were evaluated for the presence of atherosclerotic plaque. The plaque was characterized as homogenous when uniform echoes dominated, or as heterogeneous when mixed high-medium or low echoes were evident. The Doppler portion of the duplex examination is a complement to imaging and is used to assess luminal narrowing and to determine the presence and the degree of flow restriction. According to criteria proposed by Carroll (9), our patients were classified into; patients with non significant stenosis (0-40%), patients with significant stenosis (41-99), and patients with total carotid artery occlusion (100%).

 

Transcranial Doppler Scanning (TCD):

Bilateral TCD monitoring was performed at admission using pulsed wave range-gated directional 2MHZ Doppler instrument (Promelec s.a. France), pluri Dop program with acoustical focusing and real-time spectrum analysis. The patients underwent TCD examination within 24 hours of stroke followed by another one at 48 hours. The ACA and MCA, and PCA were explored through the temporal window, and the mean flow velocity of each artery was recorded. The side to side difference in blood flow velocity (asymmetry index AI) was calculated according to the formula proposed by Zanette et al (4): AI = (MV1-MV2)/{MVl+MV2/2} x 100%, where MV1 and MV2 represent the mean velocities in the symptomatic MCA and contralateral MCA, respectively. A negative AI indicates a reduction in the mean flow velocity in the symptomatic MCA. TCD findings were classified according to Ringelstein et al.10, as follows: (1) MCA no-flow, when the flow signal from the symptomatic MCA was absent, while those from the ipsilateral ACA and PCA were detected through the same acoustic window; (2) MCA asymmetry, when the flow velocity in the symptomatic MCA was reduced by 21 % or more when compared with the contralateral MCA; and (3) normal MCA, when flow velocities were the same or MCA asymmetry was less than 21%. TCD was then repeated after 48 hours, and after comparing these data with those at entry, according to Toni et al.5, we considered the modification of TCD findings from no-flow to asymmetry or normal and from asymmetry to normal as arterial recanalization.

 

Statistical Analysis

The collected data were statistically analyzed using EPI-INFO software version 6.1(11). Comparison between group means was done using student’s t-test; while, Chi-squared test was used for qualitative data. The significance level was considered at P value < 0.05.

 

RESULTS

 

Eleven (36.7%) out of 30 patients with ischemic stroke in the carotid domain deteriorated in the first 48 hours, whereas 19 (63.3%) were non deteriorated, 12 (40%) remained stable and the remaining 7 (23.3%) had an improving course. The deteriorating patients were significantly older, had more diabetes mellitus and more hypertension than non deteriorating patients, otherwise no significant differences between both groups were detected. Regarding the ultrasound examination, the deteriorating patients had significantly abnormal TCD and EED than the non deteriorating (Table 1).

Regarding TCD results, Table (2) shows that within the first 4 hours, MCA occlusion was detected in 6 (20%) patients, whereas asymmetry was present in 15 (50%) patients and the remaining 9 (30%) showed no abnormality in TCD examination. After 48 hours, among 21 patients with abnormal TCD at the first 24 hours, 6 (20%) patients showed recanalization within the next 48 hours.

As regards ECCD, we found significant stenosis ipsilateraly in 10 (33.3%) patients and contralateraly in 8 (26.7%) patients, whereas total occlusion was detected in 3 (10%) in the same side and in only one (3.3%) patient in the contralateral side (Table 3).

Findings of cerebral ischemia in MRI were detected in 26 (86.7%) patients, whereas, partial or complete occlusion were present in 21 (70%) patients. We found a significant relation between MRI results and that of MRA (p=0.017) (Table 4).

Table 5 demonstrates the relation between TCD results and both MRI and MRA, we found a significant relation between TCD and MRA results, whereas non significant relation was detected between TCD and MRI.

Sensitivity, specificity, positive and negative predictive values, with respect to deterioration of first 24 hours of all tools, are shown in Table (6). High sensitivity was detected in TCD and ECCD 90.9% for each one, whereas sensitivity of MRI and MRA was 81.8%. The specificity for all tools were 42.1%, 36.8%, 10.5%, and 36.8% for TCD, ECC, MRI, and MRA respectively.


 

Table 1. Demographic data, baseline clinical characteristic, risk factors, ultrasound and imaging studies of stroke patients in relation to clinical course.

No (%)

Deteriorating

Number=11

Non deteriorating

Number=19

X2

P-value

Demographic data

 

 

 

 

 Age (Mean±SD)

60±10.5

53.5±10.0

2.07

0.04*

 Sex (Male/Female)

8/3

12/8

0.1

0.75

Clinical

       (CANS)

 

5.3±2.1

 

6.8±2.5

 

1.75

 

0.1

Risk factors:

 

 

 

 

      Hypertension

10 (90.9)

10 (52.6)

4.59

0.03*

      Diabetes

10 (90.9)

8 (42.1)

6.91

0.008*

      Previous TIA

4 (36.4)

9 (47.4)

0.04

0.83

     Cardiac diseases

4 (36.4)

8 (42.1)

0.01

0.93

     Smoking

7 (63.6)

11 (57.9)

0.01

0.93

     Hyperlipidaemia

8 (72.7)

11 (57.9)

0.18

0.64

TCD abnormalities

 

 

 

 

Normal

Asymmetry

1 (9.0)

5 (45.5)

8 (42.1)

10 (52.6)

 

8.23

 

0.016*

No flow

5 (45.5)

1 (5.3)

 

 

ECCD (Ipsilateral)

       Non-significant stenosis

      Significant stenosis

      Total occlusion

 

1 (9.1)

7 (63.6)

3 (27.3)

 

16 (84.3)

3 (15.8)

0 (0)

 

 

7.19

 

 

0.027*

MRI abnormalities

      Present

     Absent

 

9 (81.8)

2 (18.2)

 

17 (89.5)

2 (10.5)

 

0.88

 

0.34

 

MRA abnormalities

      Present

 

9 (81.8)

 

12 (63.2)

 

0.44

 

0.5

      Absent

2 (18.2)

7 (36.8)

 

 

CANS Canadian neurological scale, ECCD extracranial carotid duplex, MRA magnetic resonance arteriography, MRI magnetic resonance imaging, TCD transcranial duplex, TIA transient ischemic attacks, X2 chi square

*Significant at p<0.05

Table 2. TCD findings of stroke patients at the first 24 hours and after 48 hours.

 

TCD

TCD findings

Normal

Asymmetry

No flow

Percentage of abnormal  TCD

MCA

 

       At 24 hour

9

15

6

70.0%

       After 48 hours

15

14

1

50.0%

                           X2

5.11

                           p

0.07*

MCA middle cerebral artery, TCD transcranial duplex, X2 chi square

*Significant at p<0.05

 

Table 3. Extracranial carotid duplex findings of stroke patients in relations to TCD results.

 

 

ECCD

TCD (MCA)

Normal

Number= 9

Asymmetry

Number= 15

No flow

Number=6

Ipsilateral

 

        Non significant stenosis (17)

7 (77.8)

10 (66.6)

0 (0)

        Significant stenosis (10)

2 (22.2)

4 (26.7)

4 (66.7)

        Total occlusion (3)

0 (0)

1 (6.7)

2 (33.3)

                                  p

<0.05*

Contralateral

 

        Non significant stenosis (21)

8 (88.9)

11 (73.3)

2  (33.3)

        Significant stenosis (8)

1 (11.1)

4 (26.7)

3 (50)

        Total occlusion (1)

0 (0)

0 (0)

1 (16.7)

                                 p

>0.05

ECCD extracranial carotid duplex, MCA middle cerebral artery, TCD transcranial duplex

Data are expressed as number (percentage)

*Significant at p<0.05

 

 

Table 4. MRI results in comparison to MRA findings in stroke patients

 

MRI lesion

Cranial MRA

Positive

Negative

Abnormal (26)

20

6

Normal (4)

1

3

Total (30)

21

9

                Kappa coefficient

0.33 ± 0.16

                                p

0.017*

MRA magnetic resonance arteriography

*Significant at p<0.05

 

 

Table 5. TCD results in relation to MRI and MRA results in stroke patients.

 

TCD

MRI results

MRA results

Abnormal

Normal

Abnormal

Normal

MCA

 

    Normal (9)

8

1

2

7

    Asymmetry (15)

13

2

14

1

    No flow (6)

5

1

5

1

                         p

>0.05

<0.05*

MRA magnetic resonance arteriography, MRI magnetic resonance imaging, TCD transcranial duplex

*Significant at p<0.05

 

 

Table 6. Sensitivity and specificity of TCD results and MRA results with respect to deterioration in stroke patients.

 

 

TCD

ECCD

MRI

MRA

Sensitivity

90.9

90.9

81.8

81.8

Specificity

42.1

36.8

10.5

36.8

Positive predictive

47.6

45.5

34.6

42.8

Negative predictive

88.6

87.5

50

77.8


ECCD extracranial carotid duplex, MRA magnetic resonance arteriography, MRI magnetic resonance imaging, TCD transcranial duplex

 


DISCUSSION

 

Evaluation   of the   cerebral   arteries   in   patients   with   acute cerebrovascular disease by efficient, accurate noninvasive tests has now achieved .What is more important is that the combination of theses safe noninvasive   tests   may   substitute   the   dangerous   invasive   tests8. This study was conducted upon 30 patients with cerebral infarction as evidenced by CT scan. Transcranial Doppler (TCD) and extracranial carotid duplex together with magnetic resonance  imaging  (MRI)  and  Magnetic  Resonance  Angiography (MRA) were chosen as the noninvasive tools in the present study. 

Our study confirms that early spontaneous improvement is a frequent occurrence in the clinical course of ischemic stroke patients and this is parallel to the results of Biller et al.12, Wityk et al.13 and Felberg et al.14. Toni et al.15 and Toni et al.16. Among the clinical data obtained at hospital entry in our patients, older age group, severe neurological deficit, hypertension, and diabetes were more frequent in patients of early deteriorating course. This is in good accordance with Davalos et al.17, who found that high systolic blood pressure, elevated blood sugar concentration at admission are independently related to deterioration in the logistic regression analysis during the first 48 hours. Toni et al(5)found that non-deteriorating patients were younger and showed trend towards lower blood pressure, decreased frequency of diabetes and less severe neurological deficits. Our results agree also with Wojczal et al(18) who studied the indicators of the prognosis of the MCA occlusion, and found that poor prognosis seemed to be related to a history of hypertension, age greater than 40 years and the presence of coma.

Normal TCD in the first 24 hours was an indicator of early improvement , while abnormal TCD was an indicator of early deterioration. Our data suggest that early spontaneous recanalization is associated with a better prognosis, underscoring the relevance and the individual variability of the window of opportunity .i.e. the time within which a therapeutic or a spontaneous recanalization can save ischemic brain tissue This is in agreement with Ringelstein et al(10) who found that early recanalization of embolic MCA occlusion has favorable impaction infarct size. Two patients who had normal 24 hrs TCD and had infarcts on MRI could be explained by presuming an occlusion of a few MCA branches undetected by TCD because it was insufficient to markedly modify the MCA velocity. This was, in fact, what we observed in 38% of normal TCD findings in a study of Zanette et al.4. In contrast, two patients with abnormal TCD and normal MRI, there remain, however, subsequent territorial infarct, for whom very early recanalization before the first TCD can be hypothesized and this in accordance with Toni et al.5 and Alexandrov et al.19.

In our patients with MCA asymmetry or no flow at 24 hrs examination ,TCD documented recanalization in (30%) between 24 hours and 48 hrs after stroke onset. This indicates that in a minority of patients delayed  recanalization  may  be  related  to improvement suggesting a more prolonged survival of the ischemic penumbra and this is in agreement to Marchal et al.20. Thus TCD performed a few hours after stroke onset may help to predict the clinical course in the subsequent 48 hours. On the other hand, serial TCD examinations showed a recanalization within 48 hours of stroke onset in (50%) of patients. Because we did not perform TCD examinations at shorter time intervals, we don't know the exact time of recanalization, but we may argue that it was too delayed to save brain tissue. This agrees with results of study done by Halsey et al.21 and contradict with Toni et al.5. The remaining (30%) of patients with normal TCD at entry and at 48 hours, they may had adequate collateral blood supply or reperfusion might occur. While those with MCA no flow (20%), they had an arterial occlusion, probably without adequate collateral blood supply. In our study we found about 50 % of stroke patients had cerebral blood flow velocities (CBFVs) asymmetries of MCA that was the basis of abnormal TCD diagnosis. This is in accordance with Razumovesky et al(8) and   Baracchinin et  al.22, who found that 34% and 41.1% respectively of their stroke patients had anterior circulation CBFVs asymmetries.

Our study suggests that in the first 24 hours after acute stroke, TCD sensitivity of  deterioration was 90.9%, whereas, specificity for detecting low CBFVs due to obstruction of intracranial vessels was 42.1%. Toni et al.5 found that the sensitivity of TCD in acute ischemic stroke in deteriorating patients was 70%, whereas, the specificity in deterioration was (84%). Camerlingo et al.23 found a specificity of TCD of about 92%, and Andrew et al.24 showed that TCD had a specificity of 94% with a sensitivity of 83% to identify the presence of any proximal extracranial or intracranial arterial occlusion compared with angiography. Lien et al.25, found that MCA peak systolic velocity ≥120cm/sec correlated with intracranial stenosis on MRA with high specificity (90.5%) but relatively low specificity (66.7%). Felberg et al.14 revealed in their study that TCD had a sensitivity of 93.9% and specificity of 91.2%. However, among the reasons that can contribute to different figures of specificity, is a collaterization, anterior-to-anterior, posterior-to anterior or vice versa4. Serial TCD examinations suggest that early deterioration is rarely, if ever, related to a propagating arterial occlusion. The occurrence of early recanalization (within 24 hours) in patients with a deteriorating course and that of both early and late recanalization (after 48 hours) in patients with an improving course confirm that there is not a fixed and universal time frame for tissue recovery but rather an individual therapeutic window and this agree with the study Andrew et al.24.

Ultrasonic duplex scanning of the extracranial portion of the carotid arteries is by far the most useful, non invasive and widely available method of detecting carotid artery disease26. We found ipsilateraly non significant stenosis (0-40%) in 17 (56.7%) patients, whereas significant stenosis was detected in 10 (33.3%) patients. Only three (10%) of our patients had ipsilateral total carotid artery occlusion. These results are keeping with Wityk et al.27, who found that more than half of patients with carotid ischemia have non significant stenosis. Other studies highlight the relationship between race and pattern of vascular involvement. Extracranial and intracranial vessels involvement (especially middle cerebral artery) have been cited as the main etiologies of ischemia in the white race and Asians, respectively2. In our study, we found that intracranial vessels involvement were more common than the extracranial involvement. However, this topics need further studies.

Nonetheless, it is worth mentioning that the use of TCD in conjunction with extracranial carotid duplex sonography may permit more comprehensive assessment of the cerebral circulation(28). In a study of 200 cases with carotid stroke and TIA, Markus and Markus(29) concluded that in patients with symptomatic carotid stenosis ≥ 50%, TCD embolic monitoring allows for distinction between groups at high and low risk for stroke. Lastly, Chernyshev et al(30) performed an urgent bedside neurovascular ultrasound examination with carotid/vertebral duplex and TCD in patients with acute cerebral ischemia to identify lesions amenable for interventional treatments and digital subtraction angiography (DSA), they concluded that bedside neurovascular ultrasound examination, combining carotid/vertebral duplex with TCD yields a substantial proportion of lesions amenable for interventional treatments in excellent agreement with urgent DSA in patients with acute cerebral ischemia.  The sensitivity of ECCD in our study for detecting carotid stenosis was 90.9% and specificity was 36.8%. In good accordance with our results, Fortea-Cabo et al(3), reported that sensitivity and specificity for Doppler sonography of the extracranial carotid artery to be 91.4% and 92.3% respectively. Furthermore, Aboyans et al(31) explored the fast-track  method of screening carotid stenosis in patients with atherosclerotic disease, found that the hand held scanner detected carotid stenosis of 60% of cases with relative 100% sensitivity and 6% specificity. 

MRA is completely non invasive technique for imaging of cerebrovascular tree, so it allows imaging of vascular occlusion related to stroke. MRA is more liable to demonstrate the anatomy of circle of Willis, thus it can demonstrate large vessel occlusion with different sensitivity and specificity. In our study, the sensitivity of MRA for deteriorating was 81.8%, whereas, specificity was 36.8%. Regarding MRI, the sensitivity of deterioration was 81.8%, whereas the specificity was 10.5%. Razumovsky et al(4) studied MRI and MRA in patients with acute cerebral ischemia and found that found that MRI revealed a sensitivity of 84% and a specificity of 90% for evaluation of ischemic parenchymal changes, whereas MRA had a sensitivity of 92% and specificity of 74%. They concluded that the high specificity and sensitivity of the ultrasound means high precision in predicting the presence of disease and has been equivalently effective when evaluated against gold standard procedures including angiography which is considerably more invasive and more accurate.

In conclusion, the combination of investigations; MRI, MRA, TCD, and ECCD; would provide the clinician with a powerful tool for the comprehensive assessment of the stroke patients. If follow up is required, ultrasound may be the technique of choice since it can be performed as a bedside test, is relatively inexpensive and may be more accessible.

 

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الملخص العربى

 

الاحتشاء المخى في الشرايين الأمامية: حساسية وقيمة التصوير  والأشعة التليفزيونية المبكرة

 

تهدف هذه الدراسة إلى تقييم حساسية أجهزة الرنين المغناطيسي على المخ وشرايين المخ والدوبلر عبر الدماغ وخارج الدماغ في التشخيص المبكر لجلطة المخ في الشرايين الأمامية وقيمة هذه الأجهزة في التكهن بمصير الجلطة.

وقد أجريت هذه الدراسة على 30 مريضا بالسكتة الدماغية الحادة نتيجة انسداد الشريان المخى الأوسط تم اختيارهم من العناية المركزة بقسم أمراض المخ والأعصاب, جامعة الزقازيق. وقد تم إخضاع هؤلاء المرضى في أول 24 ساعة للفحص الأكلينيكى بالمقياس الكندي وأشعة الرنين المغناطيسى على المخ وعلى شرايين المخ والدوبلر عبر الدماغ وخارج الدماغ. وتم إعادة الفحص الأكلينيى والدوبلر عبر الدماغ بعد 48 ساعة أخرى.

وقد وجد أن 11 مريضا بنسبة 36,7% قد تدهورت حالتهم الصحية في الفحص الأكلينيكى الثاني وهؤلاء كانوا أكبر سنا بدرجة إحصائية كما كانت فيهم  نسبة الإصابة بمرض البول السكري ومرض ضغط الدم المرتفع أعلى أيضا بصورة إحصائية.

وقد أظهر الدوبلر عبر الدماغ خلال ال24 ساعة الأولى انسداد كامل في الشريان المخى الأوسط فدى 20% من المرضى وانسداد جزئي في 50% من المرضى. كما أظهر الدوبلر عبر الدماغ بعد 48 ساعة إعادة سريان الدم في 20% من المرضى. 

أما الدوبلر خارج المخ فقد أظهر انسداد كامل وجزئي في 10% ,33,3% في الشريان السباتى على نفس ناحية الإصابة وفى 3,3% ,26,7% على الناحية الأخرى.

وقد كانت حساسية الأشعة التلفزيونية للمخ لإظهار انسداد شرايين المخ  بنسبة 90,9% وكانت للرنين المغناطيسي 81,1%.

مما سبق نستخلص أن استخدام هذه الأجهزة مجتمعة تفيد في التقييم الشامل لمرضى الاحتشاء المخى الحاد بدرجة حساسية عالية. كما يفيد الدوبلر عبر الدماغ في متابعة الحالة الصحية للمرضى.



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