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October2012 Vol.49 Issue:      4 Table of Contents
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Prognostic significance of Cerebral Blood Flow volume in Vascular Aphasia by Duplex Sonography

 

Adel Hassanein El Sayed Gad1, Nirmeen A. Kishk1, Kamel H. Morsi1,

Noha T. Abokrysha1, Mina A. Gerges2

Department of Neurology, Cairo University1; Elsahel Teaching Hospital2; Egypt

 



ABSTRACT

Background: The prognosis for language recovery varies depending on the size and nature of the lesion, level of education and the age. Most patients, even elderly ones, experience some recovery in post stroke aphasia, and some recover completely. Objective: The aim of this work is to study the relation between extra cranial vasculature and the recovery rate in different types of vascular aphasia. Methods: Thirty right handed patients with post ischemic stroke aphasia were included in this study. All patients had CT brain confirming ischemic stroke diagnosis. The patients were assessed using Kasr Al-Aini Aphasia Test (KAAT) and Extracranial duplex ultrasonography twice at three months interval to find a correlation between cerebral hemodynamics and recovery from aphasia. Results: The present study found a significant positive correlation between aphasia improvement percent with the initial left hemispheric cerebral blood flow volume (CBFV). The size of cerebral infarcts by CT brain showed a significant negative correlation with mean aphasia score both initially and after three months and also with Left hemispheric CBFV improvement percent (after three months). Conclusions: Low cost, bed side availability and lack of invasiveness in particular, deserves consideration for extracranial duplex Ultrasonography in monitoring CBFV in recovery of aphasic patients. [Egypt J Neurol Psychiat Neurosurg.  2012; 49(4): 309-315]

 Key Words: Aphasia; cerebral blood flow volume (CBFV); Duplex ultrasonography

Correspondence to  Noha T. Abokrysha. Department of Neurology, Cairo University, Egypt.

Tel.: +966509321228      e-mail: nhtaha@yahoo.com




 

INTRODUCTION

 

Aphasia, the loss or impairment of language, caused by brain damage is one of the most devastating cognitive impairments of stroke. Aphasia is present in 21-38% of acute stroke patients and is associated with high short- and long-term morbidity, mortality1. Previous studies of the relationship between perfusion, diffusion and stroke suggest that the extent of cerebral hypoperfusion may be a better indicator of neurological status than lesion size in the early phases of recovery. It is not clear how these factors are related to aphasia severity2. The recovery of speech in patients with ischemic stroke in dominant hemisphere depends not only on the form of aphasia and intensity of speech impairments but also on compensatory reserves of cerebral hemodynamics and collateral brain blood circulation3.

Ultrasound tests are used in the cerebrovascular evaluation of stroke patients. However, the use of carotid duplex ultrasound (CD) within the first hours after stroke onset in the Emergency Service is not a common practice. CD is excellent diagnostic tools that might be used in all acute stroke patients for immediate evaluation of arterial patency4.

 

The aim of this work is to study the relation between extra cranial vasculature and the recovery rate in different types of vascular aphasia.

 

PATIENTS AND METHODS

 

Thirty right handed patients with post ischemic stroke aphasia who had duration of aphasia not exceeding four weeks, and were without history of recurrent cerebrovascular stroke, psychiatric disorder, impairment of consciousness, or learning problems.

They were recruited from the Neurology department, Kasr Al-Aini university hospital between June (2009) and June (2010) and a verbal informed consent regarding the use of patients' details in publication was obtained from all patients.

 

Methods

All patients were subjected to the following:

1.      Thorough history taking and full neurological examination using Kasr Al-Aini Neurology Department Sheet.

2.      Aphasia test using Kasr al Aini Aphasia Test (KAAT). KAAT is considered a simple, standardized, valid and reliable test for Egyptian patients with score 90points for literate & score 70 points for illiterates 5.

3.      Laboratory Investigations:

a.      Routine labs including (CBC, renal and liver functions, blood sugar).

b.      Lipid profile including total cholesterol, triglycerides.

4.      CT brain was done for all patients confirming ischemic stroke diagnosis, excluding hemorrhagic stroke, describing the infarction size, site, number of lesions.

5.      Extracranial carotid and vertebral arteries duplex was performed at Kasr al Aini Neurology department in neurovascular ultrasonographic laboratory, by a Phillips HDI 5000 ultrasound equipment. Extracranial vessels were evaluated by real-time imaging by a linear 10 MHz transducer, real time, Sagittal, coronal and axial views. With the following vessels were examined: common carotid arteries (CCA), internal carotid arteries (ICA), external carotid arteries (ECA), vertebral arteries (VA).

 

The examination started by a B- mode transverse scanning of the vessels so as to examine the arterial wall morphology, detect intima media changes and presence of athermanous plaques and detects the degree of stenosis6.

In addition, the Cerebral Blood Flow volume (CBFV) is measured in the internal carotid Artery (ICA) and vertebral artery (VA) bilaterally. The Total Cerebral Blood Flow volume (CBFV) is calculated by adding the CBFV of the bilateral ICAs and VAs.

 

After three months, all patients were subjected to:

1.      Aphasia scoring using Kasr al Aini Aphasia Test (KAAT).

2.      Measuring CBFV changes in both ICA, VA bilaterally using extracranial carotid and vertebral arteries duplex.

 

Statistical package for social science (SPSS) version 12 was used for data management and analysis. Descriptive analyses were conducted using frequencies and percentage for qualitative variables, and mean and standard deviation for quantitative variables. To test the significance of difference between quantitative variables not normally distributed, Mann Whitney test was used. Chi square test was used to compare qualitative variables. Spearman correlation was performed to study the relation between numerical variable.

 

RESULTS

 

The demographic and clinical results are given in (Table 1). The size of the infarction was classified according to Brott et al.7, small (lesion involving < 1/2 lobe) in 13 patients (43.3%), medium (lesion involving between 1/2 lobe and one lobe) in 6 patients (20%) and large (Lesion involving > one lobe) in 11 patients (36.7%).

The Intima Media complex thickness (IMT) was recorded from both (CCA) for each patient and showed that 24 patient out of 30 patients (80%) have thickened IMT (> 0.08 cm).

Twenty six atheromatous plaques were detected in 15 patients (50%) with nine patients (30%) had unilateral plaques while 6 patients (20%) had bilateral ones.

Among the thirty patients only 3patients of them show total occlusion of the left ICA; and one patient with critical stenosis (70%) of the left ICA (Table 2).

Mean and S.D of Peak Systolic volume (PSV), Resistivity index (RI), pulsatility index (PI) of Common Carotid, internal carotid, and vertebral arteries on both sides were measured, data of the ECA were excluded from our statistical work (Table 3).

Cerebral blood flow volume was measured in both ICA and VA, and both hemispheric CBFV were calculated by (summation of CBFV of both ICA and VA) for both sides. And global CBFV was calculated by (summation of both hemispheric CBFV); all were assessed initially and after three months.

CBFV improvement percent: CBFV improvement percent (calculated simply as follow: {(mean CBFV in the follow up study after three months – mean initial CBFV) / mean initial CBFV} x 100). For all patient global CBFV improvement percent mean value was (6±11.9 ml/min).

Comparison between both hemispheric CBFV showed significant lower left CBFV as compared with right CBFV in the initial study (p value= 0.029), but no significant difference was detected between both sides in the follow up study after 3 month. Also, comparison between patients with Broca’s aphasia versus those with global aphasia as regard initial CBFV, revealed significant lower left hemispheric CBFV (p value = 0.005) and global CBFV (p value=0.037) in patients with global aphasia compared with patients with Broca’s aphasia. However, Comparison between the initial mean (331.67±137.48 ml/min) and follow up (351.81±153.88 ml/min) mean global CBFV showed no significant difference. Additionally, comparison between initial and follow up CBFV on right side and on left side showed non-significant difference.

Initial and follow up aphasia score had a statistically significant negative correlation with the size of infarction in CT brain (p<0.001) & (p=0.005) respectively (Figures 1 and 2).

Initial and follow up aphasia score had a statistically significant positive correlation with initial left ICA (PSV) (p=0.023), (p=0.034) respectively. Otherwise, there was no significant correlation between aphasia score and other duplex parameters.

Aphasia improvement percent calculated simply as follow: {(mean aphasia score in the follow up study after three months – mean initial aphasia score) /mean initial aphasia score} x 100). For all Patients aphasia improvement percent mean value was (31.6±14.3)

Aphasia improvement percent had statistically significant positive correlations with the initial right VA (PSV) (p=0.022).And statistically negative correlations with the initial right VA (RI) (p=0.008) and VA (PI) (p=0.027) respectively.

Additionally Aphasia improvement percent had statistically significant positive correlations with the initial left CBFV (p=0.001).

Left hemispheric CBFV improvement percent had a statistically significant negative correlation with the size of infarction in brain CT (p= 0.045).

Global CBFV improvement percent had a statistically significant negative correlation with left ICA stenosis with different degrees (p= 0.036).

By univariant analysis, there was no single parameter as (lesion size, age, extracranial Duplex parameters) could show any predictive value of improvement in aphasic patients.


 

 

Table 1. Demographic and clinical data.

 

Age (mean ± SD; years)

Disease duration (mean ± SD; years)                                                  

57±8.95 years

14.5±9.19 days

Gender

Males

Females

 

20 (67%)

10 (33%)

Literacy

Illiterate

Literate

 

25 (83.3%)

5 (16.7%)

Clinical types of aphasia

Aphasia with repetitive disorders Broca`s

Aphasia

Global aphasia

Wernicke`s aphasia

Conduction aphasia

Aphasia without repetitive disorders

Striatal aphasia

TCM aphasia

TCS aphasia

 

24 (80%)

11 (36.7%)

9 (30 %)

3 (10 %)

1 (3.3 %)

6 (20%)

3 (10%)

2(6.7%)

1 (3.3%)

Aphasia scoring using Kasr Al-Aini Aphasia Test (KAAT):

Initial  study                                   

Follow up study

 

34.73 ±19.25

45.7±22

Risk factors

Hypertension

Diabetes Mellitus

Hypercholesterolemia

Smoking

A history of IHD

A history of RHD

 

22 (73.3%)

18 (60%)

22 (73.3%)

16 (53.3%)

14 (46.7%)

1 (3.3%)

IHD Ischemic heart disease, RHD Rheumatic heart disease, TCM Transcortical motor aphasia. TCS Transcortical sensory aphasia.

 

 

Table 2. Degree of stenosis caused by the extracranial carotid plaques in our study population.

 

Degree of stenosis

Right CCA

Left CCA

Total

Right ICA

Left ICA

Total

Normal

22

25

47

26

21

47

Mild (0-29%)

4

2

6

1

1

2

Moderate (30-49%)

 Severe (50-69%)

 Critical (70-99%)

 Occlusion

1

3

0

0

2

1

0

0

3

4

0

0

3

0

0

0

1

3

1

3

4

4

0

3

Total

30

30

60

30

30

60

CCA Common carotid artery, ICA Internal carotid artery.

Table 3. Parameters of extracranial duplex of both sides.

 

 

Right side

Left side

CCA

ICA

VA

CCA

ICA

VA

PSV

60.28±20.36

50.77±16

34.80±16.22

63.27±24.93

43.85±18.86

35.45±11.35

RI

0.76±0.20

0.69±.18

0.81±0.21

0.82±0.30

0.68±0.26

0.69±0.21

PI

2.23±1.60

1.69±1.71

2.50±2.64

2.73±2.14

1.86±3.30

2.30±3.18

PI pulsatility index, PSV Peak systolic velocity, RI Resistivity index. VA Vertebral artery

 

 



 

 


Figure 1. Correlation between initial aphasia score and the size of the lesion in CT brain.

 

 

 

 

Figure 2. Correlation between follow up aphasia score and the size of the lesion in CT brain.


DISCUSSION

 

The importance of predicting language recovery early in the course of stroke is highlighted by recent reports showing that brain reorganization occurs earlier than previously thought and that early targeted post-stroke rehabilitation therapy significantly improves outcome8.

Age, aphasia type, and infarction size have been associated with long term improvement of aphasia9 .

Studies of spontaneous recovery have shown that greatest improvement occurs in the first 2 or 3 months with the amount of improvement being less in the following months and most patients reaching a plateau after one year10.

Early improvement of stroke symptoms is mostly dependent on reperfusion of distressed but still viable brain tissue (penumbra). The decrease in CBF during stroke may result in cessation of neuronal activity without immediate cell death11.

Depending on perfusion hemodynamics, neurons in these areas may ultimately die, remain hypoperfused, or reperfused with restoration of normal neuronal function12.

Using Ultrasonography for measurement of cerebral flow volume is generally introduced because, with this method, the artery to be examined can be well delineated and chosen for interrogation.

The present study was carried out on 30 right handed Egyptian patients with ischemic cerebral infarction presented with aphasia; 20 of them (66.7%) were males and 10 (33.3%) were females with a mean age of 57±8.95 years and a mean duration of illness was 14.5±9.19 days.

In our study Comparison between patients with Broca’s aphasia and patients with global aphasia as regard CBFV; patients with global aphasia had significant low both; initial left hemispheric CBFV (p value = 0.005) and global CBFV (p value = 0.037) and that agree with Maly et al.13, who showed that the lowest regional blood flows are observed in global aphasia.

Left hemispheric CBFV improvement percent (after three months) had a statistically significant negative correlation with the size of brain infarction (p = 0.045), and that agree with the observation of Moustafa et al.14, who found that the means of CBF(by SPECT) were significantly better in the left frontal, parietal and temporal lobes in the small sized brain infarctions. Also, Vitali et al.15, who reported pretreatment and post treatment fMRI data for two patients; one with a small lesion and one with a large lesion encompassing the entire perisylvian region. Results showed left hemisphere perilesional increased activation for the patient with the small lesion compared with large lesion.

We found a significant positive correlation between both initial and follow up aphasia score with initial left ICA (PSV) (P-value = 0.032), (P-value = 0.034) respectively.

Besides we found a negative correlation between global cerebral blood flow improvement percent and the presence of stenosis of the left ICA (P value= 0.036); this confirmed by Payabvash et al.16, who found in their study that patients who had proximal cerebral artery occlusion at admission were significantly less likely to experience any improvement of language function by discharge. Mimura et al.17 suggested two mechanisms involved in language recovery. The use of left (ipsilateral) hemisphere language zones together with accessory language fields; and their homotopic counterparts in the right (contralateral) hemisphere.

In our study Comparison between both hemispheric CBFV show significant lower left CBFV as compared with Right CBFV in the initial study (p value= 0.029) and that agree Kobayashi et al.18, who concluded that hypoperfusion on the left cerebral cortex was greater than that in the right cerebral cortex in patients with aphasia compared to those without aphasia, and with Moustafa et al.14, who found left CBF was significantly lower than that of the right hemisphere in aphasic patients in his study.

Moreover we found a significant positive correlation between aphasia improvement percent with the initial left hemispheric CBFV (p value=0.001). In contrast, we didn’t find any correlation between the initial right hemispheric CBFV with aphasia improvement. And that confirm the previous finding by Heiss et al.19, who used PET and glucose metabolism as a predictor of recovery in aphasia associated with ischemic stroke and they found that only the left hemisphere glucose value 15 days after stroke had a significant effect on the residual variance of the 4 months follow up Token test regression, thereby suggesting the importance of the left hemisphere integrity in the recovery of functional language.

We found no significant difference between both; Initial hemispheric CBFV and global CBFV compared with their follow up study. So we suggest that recovery of aphasia during the first three months mainly dependent on the initial left hemispheric CBFV, and that agree with Demeurisse et al.20, who demonstrated that clinical improvement of aphasia cannot be attributed to an increase in CBF until more than 90 days post onset.

In our study, for all; an increase in mean aphasia score after three months was observed (initial mean aphasia score for all patients was (34.73±19.25), and after three months was (45.7±22.53) with highly significant difference (P-value <0.001).and that agree with Hassanein21 and Kauhanen et al.10, who stated that the greatest improvement in aphasia occurs in the first 2 or 3 months.

However, our pilot study may differ from other studies as regard small number of aphasic patients, short time of follow up and different scoring tool of aphasia. In our study we detect a significant relationship between post stroke recovery from aphasia and initial left CBFV; however initial CBFV can’t be a single predictor for future language recovery in either hemisphere.

Low cost, bed side availability and lack of invasiveness in particular, deserves consideration for extracranial duplex Ultrasonography in monitoring the evolution of aphasia and the influence on its recovery.

 

[Disclosure: Authors report no conflict of interest]

 

REFERENCES

 

1.      Berthier ML. Poststroke Aphasia Epidemiology, Pathophysiology and Treatment. Drugs Aging. 2005; 22 (2): 163-82.

2.      Fridriksson J, Holland AL, Coull BM, Plante E, Trouard TP, Beeson P. Aphasia severity. Association with cerebral perfusion and diffusion. Aphasiology. 2002, 16: 859-71.

3.      Dubenko YG, Dubenko OY, Korolenko OM. Correlations between cerebral hemodynamic and recovery of speech in patients with aphasia caused by ischemic stroke. Poster session 2: recovery of function. 5th world stroke congress; June 23-26, 2004, Vancouver B.G., Canada.

4.      Martínez-Sánchez P, Tsivgoulis G, Lao A, Sharma V, Alexandrov AV. Ultrasound in acute ischemic stroke. Neurologia. 2009; 24(1): 59-68.

5.      Hassanein A, El-Tamawy M, Sallam T, Hosny H, Abdel Naseer M, El-Fayoumy N, et al. Kasr El Aini Arabic Aphasia test (KAAT) simple, standardized, valid, reliable test for Egyptian patients, literate and illiterate. Egypt J Neurol Psychiat Neurosurg. 2002; 39 (2): 381-95.

6.      Sabeti S, Schillinger M, Mlekusch W, Willfort A, Haumer M, Nachtmann T, et al. Quantification of internal carotid artery stenosis with duplex US: comparative analysis of different flow velocity criteria. Radiology. 2004; 232:431-9.

7.      Brott T, Marler JR, Olinger CP, Adams HP Jr, Tomsick T, Barsan WG, et al. Measurements of acute cerebral infarction: lesion size by computed tomography. Stroke. 1989; 20(7): 871-5.

8.      Lazar RM, Speizer AE, Festa JR, Krakauer JW, Marshall RS. Variability in language recovery after first time stroke. J Neurol Neurosurg Psychiatry. 2008; 79: 530-34.

9.      Nakagawa T, Murata Y, Kojima T, Shinkai Y, Yamaya Y, Kato M, et al. Prognostic value of brain perfusion single photon emission computed tomography (SPECT) for language recovery in patients with aphasia. Nucl Med Commun. 2005; 26: 919-23.

10.    Kauhanen ML, Korpelainen JT, Hiltunen P, Määttä R, Mononen H, Brusin E, et al. Aphasia depression, and non-verbal cognitive impairment in ischemic stroke. Cerebrovasc Dis. 2000; 10 (6): 455-61.

11.    Hakimelahi R, Gonzalz RG. Neuroimaging of ischemic stroke with CT and MRI: Advancing towards physiology-based diagnosis and therapy. Expert Rev Cardiovasc Ther. 2009; 7:29-48.

12.    Newhart M, Ken L, Kleinman JT, Heidler-Gary J, Hillis AE. Neural networks essential for naming and word comprehension. Cogn Behav Neurol. 2007; 20: 25-30.

13.    Maly J, Turnheim M, Heiss WD, Gloning K. Brain perfusion and neuropsychological test scores: A correlation study in aphasia. Brain Lang 1977; 4: 78-94.

14.    Moustafa M, Moustafa H, Fahmy I, El-Kattan1 M, Mahmoud A, El-Faioumy  N, et al. Cerebral blood flow changes in vascular aphasia: A clinical and SPECT study . Egypt J Neurol Psychiat Neurosurg 2004; 41(1): 251-61.

15.    Vitali P, Abutalebi J, Tettamanti M, Danna, M, Perani, D, Ansaldo, AI, et al. Training-induced brain remapping in chronic aphasia: a pilot study. Neurorehabil Neural Repair. 2007; 21: 152–60.

16.    Payabvash S, Kamalian S, Fung S, Wang Y, Passanese J, Kamalian S, et al. Predicting language improvement in acute stroke patients presenting with aphasia: a multivariate logistic model using location-weighted atlas-based analysis of admission CT perfusion scans. AJNR Am J Neuroradiol 2010; 31: 1661-8.

17.    Mimura M, Kato M, Sano Y, Kojima T, Nae-ser M, Kashima H.  prospective and retrospective studies of recovery in aphasia. Changes in cerebral blood flow and language functions. Brain. 1998; 121, 2083-94.

18.    Kobayashi K, Kitamura S, Terashi A. Assessment of regional cerebral blood flow in subcortical infarction with aphasia. Nippon Ika Daigaku Zasshi. 1998; 65(3): 213-9. [Abstract]

19.    Heiss WD, Thiel A, Winhuisen L, Mühlberger B, Kessler J, Herholz K. Functional imaging in the assessment of capability for recovery after stroke. J Rehabil Med. 2003; Suppl. 41: 27-33.

20.    Demeurisse G, Verhas M, Capon A. Resting CBF sequential study during recovery from aphasia due to ischemic stroke. Neurophysiologia. 1984; 22: 241-6.

21.    Hassanein A. Clinical, Topographic and Therapeutic Study of Aphasia of Vascular Origin. MD Thesis, Department of Neurology, Cairo University; 1995.


 

 

الملخص العربي

 

القياس الكمي لحجم تدفق الدم الدماغي ممكن عن طريق الأساليب الآمنة المختلفة مثل الموجات فوق الصوتية خارج وداخل الجمجمة، والمسح الذري وحيد الفوتون. وقد ثبت أن هذه القياسات دقيقة وموثوق بها.

وقد أجريت هذه الدراسة على مرضى الحبسة الكلامية باستخدام الموجات فوق الصوتية خارج الجمجمة في محاولة لإلقاء الضوء علي العلاقة ما بين التحسن في مرضى الحبسة الكلامية وحجم تدفق الدم الدماغي (الارتواء الدماغي) ومحاولة لاستنباط العوامل التي تساعد المريض على التأهل مرة أخرى أو الشفاء. كذلك دراسة المرضى ومتابعتهم بعد ٣ أشهر من حيث الحبسة الكلامية وحجم تدفق الدم الدماغي.

هؤلاء المرضى تم فحصهم إكلينيكيا حسب النظام التقليدي في الفحص لمرضى الأعصاب (اختبار الحبسة عن طريق اختبار القصر العيني العربي للعام ٢٠٠٢)، فحص معملي، أشعة مقطعية على المخ.

وقد أجريت هذه الدراسة على (٣٠ مريض، ٢٠ ذكر و ١٠ إناث) تتراوح أعمارهم ما بين ٣٦ إلى ٧٢ سنة .

وجدنا ارتباطا سلبيا بين نسبة التحسن في حجم الارتواء الدماغي الكلي ودرجة الضيق في الشريان السباتي الداخلي الأيسر في مرضى الحبسة .

وقد لاحظنا وجود ارتباط ايجابيا بين درجة الحبسة في الدراسة الأولية وبعد ٣ شهور مع ذروة سرعة الانقباض الخاص بالشريان السباتي الداخلي الأيسر.

وعند مقارنة فصي المخ من حيث حجم الارتواء الدماغي، وجد أن هناك نقص ذات دلالة احصائيه في حجم الارتواء الدماغي في الفص الأيسر مقارنة بالفص الأيمن في الدراسة الأولية ومع ذلك الفرق لم يكن ذا دلالة إحصائية في دراسة المتابعة.

أيضا وجدنا ارتباط ايجابيا بين نسبة التحسن في درجة الحبسة وحجم الارتواء الدماغي بالفص الأيسر في الدراسة الأولية.

أن استخدام أشعة الموجات فوق الصوتية على شرايين خارج المخ.

تكون مفيدة جدا عندما يكون الموضوع قيد الدراسة تشير إلى أهمية التغيرات في النشاط الخاص بفصي المخ كلا على حدا .أيضا قلة التكلفة،عدم وجود خطورة في الاستخدام شيء يستحق النظر فيه لاستخدامها في رصد تطور ال


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