Neuroimaging Indices Of Vascular Cognitive Impairment After Stroke In a Sample Of Egyptian Patients

INTRODUCTION

The second major reason of death worldwide is cerebrovascular stroke. It’s responsible for a great extent of disabilities than any other condition ¹. A large share of  this disability is related to poststroke neurocognitive disorders as cognitive impairment ². The burden of stroke is likely to increase over the next few year on society, due to occurring demographic changes as aging of the population ³.

In the success of most everyday tasks, cognitive abilities play a vital role, so assessing them is an essential part of stroke rehabilitation and treatment. One of the most serious problems affecting stroke survivors is cognitive dysfunction. Through their  recovery ,   approximately  80%  of   stroke   patients

undergo a degree of cognitive disability ⁴. Greater risk of impairment, poorer quality of life, symptoms of depression, and mortality are linked to it ⁵.

Cognitive impairment prevalence varies according to evaluation techniques, descriptions, or characteristics of the sample ⁶. The use of a suitable evidence-based method for early detection of cognitive impairment lessen the risk of cognitive impairment post stroke ⁷.

Vascular cognitive impairment (VCI) is a condition that encompasses all cognitive disabilities due to different types of cerebral vascular disease and related risk factors. It typically occurs to higher brain functions, particularly memory and executive functions ⁸.

Neuroimaging is crucial for detecting and treating vascular cognitive dysfunction, as it gives vital information on the neuroanatomical substrate of the disease and the diagnosis of white and gray matter with ischaemic or hemorrhagic injury ⁹.

This study aimed to evaluate the vascular cognitive Impairment in relation to neuroimaging  indices as regard site right or left hemisphere, strategic location, and size of stroke in a sample of Egyptian stroke patients.

PATIENTS AND METHODS

Ethical considerations:

-The study protocol was accepted by the ethics committee of Al-Azhar University's faculty of medicine.

 -An informed written consent was taken from all the participants in the study or their relative.

Patients: This descriptive study was conducted at neurology department, Sohag Teaching Hospital, Sohag, Egypt. The study included 70 patients diagnosed with ischemic or hemorrhagic stroke after 3 months from the onset, during the period from May 2019 to April 2020.

Inclusion criteria:

Patient diagnosed ischemic or hemorrhagic stroke after 3 months from the event and their age not above 65 years old with no history of cognitive impairment before stroke ¹⁰.

Exclusion criteria:

- Patients with transient ischemic attack.

- Aphasia patients (on the language component of the National Institute of Health Stroke Scale (NIHSS) score ≥ 1.

- Patients with cognitive impairment other than vascular insult (e.g., Parkinsonism ,…).

- Mental subnormality.

- Psychiatric diseases such as (depression).

All of the participants were be subjected to the following:

-Detailed medical and neurological history.

-Detailed medical and neurological examination.

-Laboratory investigation as Complete Blood Count, liver function tests, Lipogram, Renal function tests, Random blood sugar.

-Radiological investigations as Magnetic resonance imaging or Computed topography.

-Montreal Cognitive Assessment test (MoCA) 126 & II, adding extra point to patients with ≤12 years of education ^11.

-Hamilton depression rating scale.

Statistical analysis:

Data from this study were reported as percentage and number or mean ± standard deviation (SD). Categorical data were compared using Fisher’s exact test while numerical data were compared by T test. All statistical procedures were processed by SPSS, 26 and p value less than 0.05 was considered statistically significant.

RESULTS

This study included 70 patients diagnosed stroke. They comprised 29 men and 41 women with an age of 52.9 ± 10.4 years. According to MoCA score, cognitive impairment was detected in 22 patients (31.4%) while the remainder 48 patients had normal cognitive function. Comparison between cognitive impairment patients and patients with normal cognition regarding the clinical characteristics revealed that those with cognitive impairment are significantly older (59.6 ± 6.2 versus 49.9 ± 10.6 years; have significantly higher frequency of atherosclerotic disease (64 % versus 36 %, p<0.001), have significantly higher frequency of smoking (54.6% versus 25%,P value = 0.016), have significantly higher frequency of hyperlipidemia (68% versus 32%,P value = 0.006), have significantly higher frequency of multiple risk factors ( 86% versus 14%, p<0.001), and have significantly higher frequency of lower level of education (77% versus 23%, P value ₌ 0.042) (Table-1).

Regarding the neuroimaging findings, patients with cognitive impairment showed significantly higher frequency of left hemisphere strokes (68 % versus 42 %; p=0.039), both (cortical-subcortical) stroke (59 % versus 18.6 % and 23 %; p=0.046). Patients with cognitive impairment had significantly larger stroke lesions when compared with patients with normal cognition (12.8 ± 1.9 versus 3.9 ± 0.9 cm; p<0.001). Patients with cognitive impairment show significantly with multible risk factors ( 86 % versus 14 %; p<0.001) (Table-2).

DISCUSSION

Discussion

Based on Montreal Cognitive Assessment in this report there was 22 (31.4 %) patients with cognitive impairment. Earlier recorded result of cognitive impairment rates is consistent with this study, which based on follow-up period and subtype of stroke, can range from around 30 percent to 74 percent ¹². 

In this study, cognitive dysfuction patients were significantly older in line with previous reports. Kalaria et al.¹³ found that older age is a strong predictor for cognitive dysfunction after stroke. Also, Renjen et al.¹⁴. found thatcognitive impairment frequency was significantly elevated with increasing age.

This study revealed a highly statistically significance between atherosclerosis and cognitive impairment with (P value  <0.001).

Studies by Wang et al. ¹⁵, Zhong et al.⁸, and Arntzen et al.¹⁶ showed that there was statistically significance between atherosclerosis and cognitive impairment.

This study revealed a statistically significance between smoking and cognitive impairment with (P value  <0.016).

In the study by Filip et al.¹⁷ there was worse performance of memory and cognitive function after adjustment for age, , educational attainment, which support this study result. Rusanen et al.¹⁸ found that middle age heavy smoking doubled the possibility of older age cognitive impairment.

On the other hand a study by Sabia et al. ¹⁹ showed that smoking and cognitive impairment have not been linked, but the underlying causes remain uncertain.

In this study, there was a statistically significance between hyperlipidemia, and cognitive impairment (P value  <0.046).

In the studies by Reijmer et al. ²⁰, and Akinyemi et al.²¹ there was statistically significant difference between hyperlipidemia and cognitive impairment function.

On the other hand,  Yannick et al.²² study showed that post-stroke cognitive dysfunction incidence was lower in patients with hyperlipedemia than in patients without hyperlipedemia.

In this study, as regard to predisposing factors , there was no statistically significance between  hypertension, diabetes, and cognitive impairment.

A study by Renjen et al.¹⁴ showed that there was no cognitive disability correlation was found with the degree of  blood sugar levels regulation.  In the study of  Yannick et al.²² there were no relation between post stroke cognitive impairment and either ischemic heart disease or hypertension.

Table 1: Clinical characteristics in the studied patients (* significant results).

Table 2: Stroke lesion characteristics in the studied patients(* significant results).