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October2013 Vol.50 Issue:      4 Table of Contents
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Does the Disease Course or Treatment Type have Impact on Executive Functions and Cognition in Multiple Sclerosis Patients? A Clinical and 3 Tesla MRI study

Sherif Hamdy1, Hala A. Shaheen2, Ahmed M. Aboumousa1,

Marwa Farghaly1, Loai M. Ezzat3, Lamiaa Daker2

Departments of Neurology1, Radiology3, Cairo University; Neurology2, Fayoum University; Egypt



ABSTRACT

Background: Executive dysfunction in multiple sclerosis varies in relation to the course of the disease and therapy and could be correlated with 3- tesla MRI. Objective: Compare aspects of executive dysfunction and memory in RRMS and SPMS and interferon and non interferon treated patients correlating findings with 3 -tesla MRI brain images.  Methods: Thirty MS patients were included [25 RRMS and 5SPMS] 16 of them receive interferon were subjected to neurological, EDSS, fatigue severity scale, Beck depression Inventory assessment. In addition, neuropsychological assessment of memory, learning and executive dysfunctions.  A 3- tesla MRI brain imaging within 48 hours of the assessment. Ten healthy age, sex and educational level matched controls were selected for comparison of the psychometric results. Results: Patients with RRMS showed no significant change in memory tests while those with SPMS showed significant worse performance in the executive functions test .Patients on interferon therapy showed preserved good performance in verbal and visuospatial learning when compared with the non treated patients. The corpus callosum thickness was significantly correlated with processing speed, verbal learning and verbal fluency. The brain parenchyma was significantly correlated with ability to display flexibility in the face of changing schedules. The 3rd ventricle width was significantly negatively correlated with visuospatial learning. Conclusion: Patients with MS exhibit different patterns of affection of their executive functions and memory in different courses of the disease. Treatment with interferon was associated with preserved abilities in specific aspects of executive dysfunctions. [Egypt J Neurol Psychiat Neurosurg.  2013; 50(4): 389-396]

Key Words: multiple sclerosis; executive functions, course, treatment, 3-tesla MRI

Correspondence to Ahmed M. Aboumousa, Neurology department, Faculty of Medicine, Cairo University, Egypt.

Tel.: +201068884582    e-mail: Abomosaa1@hotmail.com





INTRODUCTION

 

Cognitive impairments have been demonstrated at all stages and in all subtypes of multiple sclerosis. This includes the clinically isolated syndrome, relapsing–remitting multiple sclerosis (RRMS), secondary progressive multiple sclerosis (SPMS), primary progressive multiple sclerosis and even benign multiple sclerosis.1

Executive dysfunction in MS could influence the patients' vocational and academic performance. A few studies have discussed the difference in patients’ performance in executive functions, memory and learning tests during relapsing remitting and secondary progressive stages of the disease.

Early treatment with disease-modifying therapies may reduce cognitive impairment or slow down the progression of cognitive deficits in MS patients. This parallels the beneficial effects of these therapies on physical and MRI parameters.2

High-field (typically 3.0 Tesla) MRI scanners have the potential to revolutionize research in MS. The data available showed that magnets operating at 3.0 Tesla detect a greater number and volume of T2 hyperintense and gadolinium-enhancing brain lesions than those operating at 1.5 T. In addition, their use might improve the early diagnosis of MS.3

In this study we compared different aspects of executive dysfunction and memory in patients with relapsing remitting and secondary progressive courses. Moreover we compared patients receiving interferon and non interferon treated patients. These were correlated with high field 3 tesla MRI brain images.

 

PATIENTS AND METHODS

 

This was a part of multi arm cross sectional study of the executive functions in 30 patients with MS. All were diagnosed with clinically definite MS according to revised McDonald’s criteria (2005).4 They were 8 males, 22 females. Their expanded disability status scale (EDSS) is ≤ 6. Twenty five patients presented with relapsing and remitting (RR) course and 5 patients presented with secondary progressive (SP).

The participants underwent the following battery of evaluation: a) full medical and neurological examination. b) Clinical evaluation by using different scales: Expanded disability status scale (EDSS), Fatigue evaluation using fatigue severity scale (FSS), Evaluation of depression using Beck depression Inventory (BDI).c) Neuropsychological Assessment: Evaluation of verbal memory& learning using: California Verbal Learning Test- 2nd edition (CVLT-II), Evaluation  of visuospatial memory & learning using: Brief Visuospatial Memory Test–Revised (BVMT-R), Evaluation of working memory using: Paced Auditory Serial Addition Task (PASAT) , Evaluation of sustained attention using: Symbol Digit Modalities Test (SDMT). Executive functions by using: Wisconsin Card Sorting test (WSCT), Verbal fluency by using: Controlled Oral Word Association Test (COWAT). Ten healthy age, sex and educational level matched controls were selected for comparison of the psychometric results.  

Magnetic resonance imaging of the brain was performed within 48 hours from neuropsychological assessment on 3.0 Tesla Phillips intera Scanner at the MRI unit. Different pulse sequences [T1, T2 and FLAIR] were used. We stressed the following measures: Brain Parenchymal Fraction (BPF) [the ratio of brain parenchymal volume (tissue compartment) to the total intracranial volume] at axial T1. Third ventricular width: was measured via a line drawn through the long axis of the third ventricle, parallel to the interhemispheric fissure. The width (in millimeters) was measured by drawing a second line perpendicular to the first line at its midpoint at axial FLAIR (Figure 1). Corpus callosum thickness at splenium (mm): was carried out from T1 weighted MRI.

The data was coded and entered, calculation and graphic presentation of important results were done by means of statistical software package namely "SPSS version 15". The data was summarized using descriptive statistics: mean, standard deviation, minimal and maximum values for quantitative variables   and number and percentage of qualitative variables.

 

RESULTS

 

The mean of the patients group's age was 24±6 years; the mean duration of illness of the MS patients was 3.54±2.13, the mean years of education of the patients was 13.73±2.38 years. The main systems involved were the motor (in 86.7%), sensory (in 86.7%), sphincters in (60%), brain stem in (56%), cerebellar in (43%) and optic neuritis in (36.7%) of the patients.  Mean EDSS was 2.22±1.29. The range of BDI score was from 3 to 42 and the mean was 17.10±10.86. The score of the FSS ranged from 3 to 6.0 and mean was 4.95±1.12. The mean duration of illness of the RRMS patients was 3.52±0.05 years. The mean duration of illness of the SRMS patients was 4.16±1.16 years. Sixteen (53.3%) patients were treated with interferon-B while the rest of the patients were not on interferon therapy.

The EDSS, FSS, BDI scores of the patients' groups is illustrated in Table (1). Comparing the neuropsychological data between the RRMS and SPMS patients and controls is shown in Tables (2) and (3). The RRMS patients showed worse performance than the controls in information processing speed, working memory, phenomic and semantic fluency. In addition they perform worse in concept formation and conceptual responses. Otherwise, there was no statistically significant difference found in other parameters of neuropsychological tests. The SPMS patients showed significant worse performance than the controls PASAT, SDMT, COWT-FAS, CVLT-DR and BVMT-TR. Otherwise, no statistically significant difference was found in other parameters of neuropsychological tests. Upon comparing the performance of the RRMS and SPMS patients to each other (Table 4), it was found that the SPMS patients perform significantly worse in CVLT- delayed recall while RRMS patients perform worse in WSCT scores 

Comparing the neuropsychological data between the interferon treated and non treated groups is shown in Tables (5) and (6). The interferon treated patients showed significant worse performance than controls in information processing speed, working memory, phenomic and semantic fluency. In addition they perform worse in concept formation and conceptual responses, concept formation and CVLT-DR. Otherwise, no statistically significant difference was found in the other neuropsychological parameters. The non treated patients showed worse performance than controls in verbal and visuospatial learning and memory. Upon comparing the interferon treated and non treated groups it was found that the interferon treated patients showed significant better performance than non treated patients in BVMT-DR, SDMT, percentage of conceptual responses, PASAT and number of trials to complete 1st set. Otherwise, no statistically significant difference was found in the other neuropsychological parameters.

Comparison between the MRI parameters in the RRMS and SPMS and treated and non treated patients is shown in Table (1). When correlating the neuropsychological data with the MRI finding it was noticed that: There was significant positive correlation between corpus callosum thickness and SDMT score, COWT-FAS, CVLT-TR, BVMT-TR, PASAT score, CVLT-SR and percentage of conceptual responses. There was negative significant correlation between the third ventricular with and BVMT-TR. There was positive significant correlation between the brain parenchymal fraction and number of categories completed. Otherwise, there was no statically significant difference between the other psychometric tests and the neuroradiological data.

There was a statistically significant difference in the three radiological parameters used when comparing RRMS and SPMS patients but this difference does not reach significant difference when comparing treated and non treated patients.


 

Table 1. Comparison between clinical scales and MRI findings in patients groups.

 

 

RRMS

patients

SPMS

patients

P-value

Interferon treated patients

Non treated patients

P-value

EDSS

1.85±0.96

4±1.22

0.01*

1.81±1.10

2.73±1.34

0.05*

FSS

5.18±1.05

3.80±0.67

0.005**

4.78±1.08

5.09±1.17

0.4

BDI

18.68±10.99

9.20±6.06

0.03*

11.31±5.71

23.71±11.71

0.003**

brain parenchymal fraction

0.7±0.13

0.6±0.06

0.01*

0.65±0.13

0.708±0.146

0.3

third ventricle width

4.44±1.193

5.6±0.548

0.05*

4.81±1.223

4.42±1.158

0.3

corpus callosum thickness

70±14.142

60±7.071

0.03*

70±14.142

66.42±13.36

0.4

BDI Beck depression inventory, EDSS expanded disability status scale, FSS fatigue severity scale, RRMS relapsing remitting multiple sclerosis, SPMS  secondary progressive multiple sclerosis

*Significant at p≤0.05. **Significant  at p≤0.01

 

Table 2. Comparison between RRMS and control performances in the neuropsychological tests.

 

Psychometric tests

RRMS patients

Controls

P-value of RRMS

CVLT-TR

54.12±10.54

58.80±13.37

0.26

CVLT-SR

14.32±1.93

15.40 ± 0.70

0.15

CVLT-DR

14.64±1.50

15.80 ± 0.42

0.09

CVLT-recognition

39.04±1.10

39.20± 0.78

0.25

BVMT-TR

25.20 ± 9.06

32.50 ± 5.62

0.05

BVMT-DR

8.60 ± 3.57

11.70 ± 0.48

0.06

BVMT-recognition

10.64 ± 0. 95

11.20 ± 1.03

0.41

Total errors

44.00 ± 19.66

18.80 ± 11.47

0.02*

Preservative errors

22.36 ± 12.75

8.40 ± 5.38

0.03*

Non preservative

2.80 ± 2.36

0.30 ± 0.94

0.02*

Total categories

4.40 ± 1.76

5.90 ± 0.32

0.06

Preservative responses

23.92 ± 12.55

8.70 ± 5.91

0.02*

%conceptual-level responses

51.37 ± 18.35

77.11± 10.72

0.01*

NO of trials to complete 1st set

25.08 ± 26.83

15.60 ± 11.83

0.13

%learning to learn

-23.58 ± 10.25

-18.18 ± 5.37

0.17

Failure to maintain set

7.12 ± 7.07

5.50 ± 5.54

1

PASAT

33.68 ± 12.86

54.70 ± 3.30

0.001**

SDMT

86.28 ± 31.44

116.60 ± 4.65

0.001**

COWT-FAS

25.44±8.21

42.90 ± 12.14

0.0001**

COWT- animal

12.32 ± 3.57

21.20 ± 5.07

0.001**

BVMT-R  Brief Visuospatial Memory Test–Revised, BVMT-R-TR   Total recall over all learning trials, BVMT-R-DR Recall after the delay interval, COWAT Controlled Oral Word Association Test, CVLT-II  California Verbal Learning Test- 2nd edition,  CVLT-II-TR Total recall over all learning trials , CVLT-II-SR Short term recall after interference, CVLT-II-DR Recall after the delay interval,  PASAT  Paced Auditory Serial Addition Task, RRMS relapsing remitting multiple sclerosis, SDMT Symbol Digit Modalities Test

*Significant at p≤0.05. **Significant at p≤0.01

Table 3. Comparison between SPMS and control performances in the neuropsychological tests.

 

Psychometric tests

SPMS patients

Controls

P-value

CVLT-TR

47.40±8.20

58.80±13.37

0.11

CVLT-SR

13.40±2.70

15.40 ± 0.70

0.15

CVLT-DR

13.40±2.07

15.80 ± 0.42

0.01*

CVLT-recognition

39.00±0.01

39.20± 0.78

0.25

BVMT-TR

23.40±4.51

32.50 ± 5.62

0.02*

BVMT-DR

10.40±3.05

11.70 ± 0.48

0.55

BVMT-recognition

11.20±1.10

11.20 ± 1.03

1

Total errors

23.50±3.42

18.80 ± 11.47

0.15

Preservative errors

12.50±3.51

8.40 ± 5.38

0.13

Non preservative

0.50±1.00

0.30 ± 0.94

0.65

Total categories

6.00±0.01

5.90 ± 0.32

0.52

Preservative responses

13.00±4.24

8.70 ± 5.91

0.13

%conceptual-level responses

70.64±3.18

77.11± 10.72

0.12

NO of trials to complete 1st set

15.25±5.32

15.60 ± 11.83

0.56

%learning to learn

-10.57±7.21

-18.18 ± 5.37

0.06

Failure to maintain set

13.00±12.83

5.50 ± 5.54

0.3

PASAT

27.40±7.67

54.70 ± 3.30

0.002**

SDMT

74.80±20.47

116.60 ± 4.65

0.002**

COWT-FAS

22.20±4.82

42.90 ± 12.14

0.001**

COWT- animal

14.00±3.32

21.20 ± 5.07

0.006**

BVMT-R  Brief Visuospatial Memory Test–Revised, BVMT-R-TR   Total recall over all learning trials, BVMT-R-DR Recall after the delay interval, COWAT Controlled Oral Word Association Test, CVLT-II  California Verbal Learning Test- 2nd edition,  CVLT-II-TR Total recall over all learning trials , CVLT-II-SR Short term recall after interference, CVLT-II-DR Recall after the delay interval,  PASAT  Paced Auditory Serial Addition Task, SPMS secondary progressive multiple sclerosis, SDMT Symbol Digit Modalities Test

*Significant  at P≤0.05 **Significant  at P≤0.005

 

Table 4. Comparison between RRMS and SPMS performance in the neuropsychological tests.

 

Psychometric tests

RRMS patients

SPMS patients

P-value

CVLT-TR

54.12 ± 10.54

47.40 ± 8.20

0.25

CVLT-SR

14.32±1.93

13.40 ± 2.70

0.35

CVLT-DR

14.64 ± 1.50

13.40 ± 2.07

0.03*

CVLT-recognition

39.04 ± 1.10

39.00 ± 0.01

0.6

BVMT-TR

25.20 ± 9.06

23.40 ± 4.51

0.27

BVMT-DR

8.60 ± 3.57

10.40 ± 3.05

0.14

BVMT-recognition

10.64 ± 0. 95

11.20 ± 1.10

0.82

Total errors

44.00 ± 19.66

23.50 ± 3.42

0.04*

Preservative errors

22.36 ± 12.75

12.50 ± 3.51

0.1

Non preservative errors

2.80 ± 2.36

0.50 ± 1.00

0.03*

Total categories

4.40 ± 1.76

6.00 ± 0.01

0.04*

Preservative responses

23.92 ± 12.55

13.00 ± 4.24

0.05

%conceptual-level responses

51.37 ± 18.35

70.64 ± 3.18

0.03*

NO of trials to complete 1st set

25.08 ± 26.83

15.25 ± 5.32

0.56

%learning to learn

-23.58 ± 10.25

-10.57 ± 7.21

0.03*

Failure to maintain set

7.12 ± 7.07

13.00 ± 12.83

0.41

PASAT

33.68 ± 12.86

27.40 ± 7.67

0.44

SDMT

86.28 ± 31.44

74.80 ± 20.47

0.17

COWT-FAS

25.44 ± 8.21

22.20 ± 4.82

0.32

COWT-animal

12.32 ± 3.57

14.00 ± 3.32

0.2

BVMT-R  Brief Visuospatial Memory Test–Revised, BVMT-R-TR   Total recall over all learning trials, BVMT-R-DR Recall after the delay interval, COWAT Controlled Oral Word Association Test, CVLT-II  California Verbal Learning Test- 2nd edition,  CVLT-II-TR Total recall over all learning trials , CVLT-II-SR Short term recall after interference, CVLT-II-DR Recall after the delay interval,  PASAT  Paced Auditory Serial Addition Task, RRMS relapsing remitting multiple sclerosis, SPMS secondary progressive multiple sclerosis

*Significant  at P≤0.05 **Significant  at P≤0.005

 

Table 5. Comparison between interferon treated and control  performances in the neuropsychological tests.

 

Psychometric tests

Interferon treated patients

Controls

P-value

CVLT-TR

56.25±8.82

58.80±13.37

0.56

CVLT-SR

14.88±1.67

15.40 ± 0.70

0.6

CVLT-DR

14.88±1.50

15.80 ± 0.42

0.02*

CVLT-recognition

38.94±0.68

39.20± 0.78

0.85

BVMT-TR

27.69±5.07

32.50±5.62

0.021

BVMT-DR

10.81±1.33

11.70 ± 0.48

0.06

BVMT-recognition

11.13±1.02

11.20± 1.03

0.95

Total errors

34.88±16.24

18.80±11.47

0.005**

Preservative errors

20.75±13.46

8.40±5.38

0.002**

Non preservative errors

2.38± 2.31

0.30±0.94

0.007**

Total categories

5.13±1.45

5.90±0.32

0.11

Preservative responses

21.19±11.74

8.70±5.91

0.002**

% conceptual-level responses

60.78±14.25

77.11±10.72

0.003**

NO of trials to complete 1st set

13.75±4.78

15.60±11.83

0.74

%learning to learn

-23.36±11.16

-18.18± 5.37

0.11

Failure to maintain set

10.44±8.50

5.50±5.54

0.12

PASAT

37.50±10.58

54.70±3.30

0.001**

SDMT

100.38±14.22

116.60± 4.65

0.001**

COWT-FAS

27.75±5.99

42.90±12.14

0.001**

COWT-animal

13.37±1.96

21.20 ± 5.07

0.001**

BVMT-R  Brief Visuospatial Memory Test–Revised, BVMT-R-TR   Total recall over all learning trials, BVMT-R-DR Recall after the delay interval, COWAT Controlled Oral Word Association Test, CVLT-II  California Verbal Learning Test- 2nd edition,  CVLT-II-TR Total recall over all learning trials , CVLT-II-SR Short term recall after interference, CVLT-II-DR Recall after the delay interval,  PASAT  Paced Auditory Serial Addition Task, SDMT Symbol Digit Modalities Test

*Significant  at P≤0.05 **Significant  at P≤0.005

 

Table 6. Comparison between non treated patients and control  performances in the neuropsychological tests.

 

Psychometric tests

Non treated patients

Controls

P-value

CVLT-TR

49.29 ± 11.08

58.80±13.37

0.04*

CVLT-SR

13.36 ± 2.21

15.40 ± 0.70

0.02*

CVLT-DR

13.93 ± 1.69

15.80 ± 0.42

0.005**

CVLT-recognition

39.14 ± 1.29

39.20± 0.78

0.2

BVMT-TR

21.71 ± 10.43

32.50±5.62

0.003**

BVMT-DR

6.71 ± 3.97

11.70 ± 0.48

0.001**

BVMT-recognition

10.29 ± 0.73

11.20± 1.03

0.06

Total errors

48.92 ± 21.19

18.80±11.47

0.002**

Preservative errors

21.31 ± 11.37

8.40±5.38

0.002**

Non preservative errors

2.62±2.50

0.30±0.94

0.002**

Total categories

4.00±1.87

5.90±0.32

0.004**

Preservative responses

23.92±13.31

8.70±5.91

0.001**

% conceptual-level responses

45.71±19.83

77.11±10.72

0.001**

NO of trials to complete 1st set

36.00±33.92

15.60±11.83

0.01**

%learning to learn

-19.18±10.30

-18.18± 5.37

0.57

Failure to maintain set

4.85±6.49

5.50±5.54

0.69

PASAT

27.07±12.02

54.70±3.30

0.001**

SDMT

66.07±32.97

116.60± 4.65

0.001**

COWT-FAS

21.64±8.48

42.90±12.14

0.001**

COWT-animal

11.71±4.66

21.20 ± 5.07

0.001**

BVMT-R  Brief Visuospatial Memory Test–Revised, BVMT-R-TR   Total recall over all learning trials, BVMT-R-DR Recall after the delay interval, COWAT Controlled Oral Word Association Test, CVLT-II  California Verbal Learning Test- 2nd edition,  CVLT-II-TR Total recall over all learning trials , CVLT-II-SR Short term recall after interference, CVLT-II-DR Recall after the delay interval,  PASAT  Paced Auditory Serial Addition Task, SDMT Symbol Digit Modalities Test

*Significant  at P≤0.05 **Significant  at P≤0.005

 

 


DISCUSSION

 

Multiple sclerosis affects patients in the main productive part of their lives. Cognitive abilities constitute a major influence in this productivity. This study was a part of multi-arm study designed in a trial to answer the question:  Does the course or the treatment of multiple sclerosis affect the executive dysfunctions? Studying a group of patients with a relatively young age with high years of education gave the study a power to avoid confound influence of aging and low education years on cognitive abilities. In addition we got the chance to compare nearly equal groups of patients treated and not treated with interferon therapy without a conflict of interest in assessing the results.

The present study showed that the RRMS patients compared to the healthy controls had poor performance in working memory, information processing speed, verbal fluency and executive function in particularly the concept formation. In agreement with these results, Schulz et al., (2006) reported that RRMS patients displayed significantly deficient working memory and reduced speed of information processing which may be a fundamental neuropsychological deficit in the earliest stages of the disease.5

The SPMS patients showed worse performance in working memory, information processing speed and verbal fluency but did not reach statistically significant difference. But the SPMS patients showed better performance in concept formation ability of executive function and they had better scores in the depression scale than RRMS patients. The better performance of SPMS patients in concept formation ability could be explained by that the SPMS patients could develop effective adaptive coping skills to overcome sense of depression that enable them to identify their problems and to help them for better planning and problem solving abilities. So this leads us to ask a question which influences the other, is the coping ability is essential for better performance of executive function or is the maintained concept formation ability is mandatory for effective cognitive coping strategy?

The current study showed that the SPMS patients had worse performance than RRMS patients in long term verbal memory recall. The SPMS patients demonstrated greater dysfunction than RRMS patients in the verbal new learning, it was clearly demonstrated that the primary difficulty in the initial acquisition of information and retrieval failure could be worsen with progression of the disease.6

The secondary progressive MS is associated with distinctive cognitive impairment in the form of diminished memory and learning abilities which could not be attributed to the longer duration of the illness as no statically significant difference was found in duration of illness between the groups. But in fact it could be secondary to the pathological changes of the progressive disease in the form of irreversible neurodegeneration and associated loss of ability of acquiring new information.

It was concluded that the influence of the MS disease course is evident, as the working memory, information processing speed and verbal fluency were present since the early stages of the disease and showed worsening with the progression of the disease. While, the verbal and visuospatial memory recall impairment could be present later with the progressive course.

The treatment of MS with disease-modifying therapy (DMT) is expected to bring great benefits in cognitive functioning.  Interestingly, it was shown in the current study that there was a significant effect of interferon on cognitive performance of the treated MS patients. Moreover, it had a selective effect on certain cognitive domains.  In this study, it was found that the treated patients showed better performance than the non treated patients in the visuospatial delayed memory recall, information processing speed, working memory and executive functions. it was concluded that the interferon-B could improve the performance of the visual memory and learning, working memory and executive functions. But, it has no influence on verbal memory and learning and verbal fluency.

The most likely cause of the increased sensitivity of 3.0T is the demonstration of small hyperintense lesions missed by the conventional MRI, particularly those in the periventricular white matter, cortical, or juxtacortical areas. These lesions could result in cortical–subcortical circuits disconnection involved in complex cognitive functions.7

In this study the corpus callosum thickness was significantly correlated with processing speed, verbal learning and verbal fluency. Llufriu et al. (2012) found that immediate, delayed verbal memory recall, delayed visual spatial memory recall and working memory were correlated with increased mean diffusivity of corpus callosum.8 Corpus callosum damage is likely to contribute to cognitive dysfunction in MS through a disconnection mechanism. The white matter atrophy like corpus callosum thinning accounted for significant impairment in the performance of mental processing speed, working memory and verbal memory tasks as temporary storage and manipulation of new information may require rapid communication between different brain regions via white matter tracts.9

Another measure of the grey matter atrophy is the third ventricular width which is increased secondary to thalamic atrophy. In this study, there was negative correlation between the visuospatial memory total recall and third ventricular width. The preferential loss of thalamic volume compared with the whole brain volume could be due to the fact that the thalamus has rich reciprocal connectivity with much of the brain and might be particularly susceptible to hypometabolism and Wallerian degeneration due to demyelination and axonal loss in cerebral white matter.10 The link between thalamic atrophy and memory & learning in MS could be attributed to that the thalamus is an integral component of the limbic system and Papez circuit which were crucial for memory and learning.10

The present study showed positive significant correlation between the brain parenchymal fraction and cognitive flexibility of the executive function. While, no statistically significant difference was found between the other psychometric tests and the brain parenchymal fraction. In comparison to Deloire et al. (2010) stated that the deterioration of verbal memory scores was significantly associated with diffuse brain atrophy in particularly with late stages of the disease. While the information processing speed and executive functions were correlated with parenchymal brain fraction, and central brain atrophy change which may occur in early stages of the disease.11

Patients with MS exhibit different patterns of affection of their executive functions and memory in different courses of the disease. Treatment with interferon was associated with preserved abilities in specific aspects of executive dysfunctions.

 

[Disclosure: Authors report no conflict of interest]

 

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الملخص العربى

 

هل يؤثر مسار المرض و العلاج على اداء الوظائف التنفيذيه فى مرضى التصلب المتعدد فى الجهاز العصبى؟ دراسه اكلينيكيه و باستخدام الرنين المغناطيسى.  استهدفت هذه الدراسة تقييم نمط الخلل في الذاكرة والقدرة على التعلم وأداء الوظائف التنفيذية في مرضى التصلب المتعدد واستكشاف العلاقة بين الأداء المعرفي والتغيرات المرضية للمخ بالتصوير الرنين المغناطيسي عالي الجودة 3 تسلا.

وقد اشتملت هذه الدراسة على 30 مريضا مصابين بمرض التصلب المتناثر25 يعانون من النوع الانتكاسي للمرض و 5 يعانون من النوع التقدمي من مسار المرض16 منهم يتلقون عقار الانترفيرون.  وقد تم تقييم الحالات تقييما إكلينيكيا عن طريق أخذ التاريخ المرضي والفحص الإكلينيكي. تقييم درجة الإعاقة باستخدام مقياس EDSS. تقييم الأداء المعرفي والقدرة على التعلم باستخدام كل من CVLT- II ,BVMT- R تقييم أداء الوظائف التنفيذية. تقييم درجة الوهن باستخدام مقياس شدة الوهن. تقييم الاكتئاب باستخدام مقياس بيك للاكتئاب. عمل الرنين المغناطيسي للمخ عالي الجودة 3 تسلا متضمنة الصور المحملة على الوقت الأول (T1) والمحملة على الوقت الثاني (T2) وصور FLAIR.

وقد لوحظ وجود علاقة ذات دلالة إحصائية بين مسار المرض والأداء المعرفي والقدرة على انجاز الوظائف التنفيذية .حيث تبين إصابة الذاكرة العاملة، وسرعة معالجة المعلومات والقدرات التنفيذية وكذلك ضعف الطلاقة اللفظية منذ المراحل المبكرة من النوع الانتكاسي للمرض، وقد أظهرت تفاقماً مع التقدم في المرض. في حين أن اصابة الذاكرة اللفظية والذاكرة البصرية ظهرت مع النوع التقدمي من مسار المرض.

ومن المثير للاهتمام أنه قد تبين أن هناك تأثير رائع لعقار الانترفيرون على الأداء التنفيذي والمعرفي لمرضى التصلب المتناثر . وعلاوة على ذلك تبين وجود تحسناً انتقائيا في المجالات المعرفية حيث يمكن لعقار الانترفيرون أن يحسن أداء الذاكرة البصرية والذاكرة العاملة والوظائف التنفيذية. ولكن ليس له تأثير على الذاكرة اللفظية والطلاقة اللفظية. وقد أظهرت الدراسة أن هناك علاقة سلبية بين سمك الجسم الثفني مع سرعة معالجة المعلومات والذاكرة العاملة واستدعاء الذاكرة اللفظية طويلة الأجل والإجمالية واستدعاء الذاكرة البصرية والطلاقة اللفظية وتشكيل مفهوم الوظائف التنفيذية. كما وجد أن هناك علاقة عكسية بين استدعاء الذاكرة البصرية الإجمالية وعرض البطين الثالث ناتجا عن ضمور المهاد.

 

 

 



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