The relationship between cognitive impairment and cerebral blood flow changes after transient ischaemic attack

Abstract

Objective: The associations between cognitive impairment following the initial onset of transient ischaemic attack (TIA) and the parameters of altered cerebral blood flow and high-sensitivity C-reactive protein (HsCRP) level are unclear.

Methods: A total of 97 first-time TIA patients aged 69·94±4·02 years (38–75 years; M:F, 50:47) hospitalized between March 2010 and July 2011 were compared to 100 healthy control patients aged 66·56±12·15 years (45–80 years; M:F, 60:40). Cognitive function was quantified by Montreal Cognitive Assessment (MoCA). Intracranial blood flow was measured using transcranial Doppler ultrasound, and HsCRP levels were assessed using the Spearman correlation coefficient. Relationships between both values and MoCA scores were examined.

Results: Transient ischaemic attack patients exhibited declined cognitive function manifested as impaired verbal fluency (97·93%), memory recall (91·75%), abstraction (84·53%), and visuospatial/executive abilities (79·38%). To a lesser degree, TIA patients also evidenced abnormalities in attention (50·52%), naming (20·62%), and orientation (20·62%). Furthermore, MoCA scores significantly correlated with high HsCRP levels and low vascular systolic peak velocities (P<0·001). Vascular systolic peak velocities were high in nine patients (9·23%) and low in 57 patients (58·76%). Thus, cognitive impairment was closely related to HsCRP levels and intracranial blood flow velocities.

Conclusion: Post-TIA cognitive impairment may result from atherosclerosis and reduced blood flow to the brain. Cognitive impairment, transcranial Doppler-visualized changes, and elevated HsCRP levels are important diagnostic indicators of TIA. Markers provided by cognitive evaluation of TIA patients following the initial onset of TIA may allow clinicians to better predict and prevent adverse vascular events.

Keywords:

• Transient ischaemic attack
• Montreal cognitive assessment
• Transcranial doppler
• High-sensitivity C-reactive protein