Many Patients With TIA Have Long-term Cognitive Impairment

July 03, 2014

More than a third of patients have some cognitive impairment after suffering a transient ischemic attack (TIA), a new study suggests.

"Our findings confirm what we experience in daily practice: While motor and language disturbances recover within 24 hours after a TIA, long-lasting cognitive complaints are a problem for many patients. There needs to be more clinical awareness of this issue," lead investigator Ewoud J van Dijk, MD, from the Radboud University Nijmegen Medical Centre, the Netherlands, told Medscape Medical News.

He suggested that a TIA affects complex networks that are involved in cognitive functioning. "These networks are likely more vulnerable than those involved in motor and language function. Further study is needed to confirm this, but physicians should be aware of these cognitive dysfunctions because it potentially affects quality of professional and daily living," he said.

The study was published online June 24 in Stroke.

Younger Population

In their article, the researchers point out that only a few studies have been conducted investigating cognitive impairment after TIA, and those that have been done often include elderly patients, so the findings may be obscured by age-related or Alzheimer pathology–related cognitive decline.

They therefore conducted the current study to determine the cognitive performance of patients within 3 months of a TIA. To minimize the effects of aging and concomitant cognitive disorders, they included only patients between the ages of 45 to 65 years and excluded patients with a history of stroke or dementia.

The study involved 107 patients attending the stroke unit or TIA outpatient clinic of the Radboud University Medical Center after a TIA from 2004 to 2010.

A comprehensive neuropsychological assessment was performed within 3 months after the qualifying event, and patients underwent either computed tomography or a magnetic resonance imaging brain scan.

Performances on all individual cognitive tests were compared with a control group of 81 individuals recruited among spouses or relatives or from the social environment of patients attending the outpatient department.

Results showed that patients with TIA performed worse on all cognitive domains except episodic memory. More than 35% of patients with TIA had impairment of 1 or more cognitive domain.

Table. Mean Difference in Z Scores per Cognitive Domain Between Patients With TIA and Control Patients

Cognitive Domain Mean Difference in Z Score P Value Percentage of Patients Impaired
Executive function −0.59 <.001 10.3
Information processing speed −0.66 <.001 16.1
Working memory −0.87 <.001 24.5
Attention −0.51 .01 21.7
Episodic memory 0.01 .96 8.4

The presence of silent brain infarcts was related to worse executive functioning but did not explain the whole relationship between TIA and cognitive impairment.

Noting that subjective cognitive complaints were not more frequently reported by patients with TIA than by healthy individuals, Dr. van Dijk and colleagues suggest that the discrepancy between prevalence of objective and subjective cognitive dysfunction in TIA might mean that only relatively minor difficulties in everyday life are perceived.

"Still, because patients with TIA in our study were relatively young, a large proportion would still be working and be socially active. Even minor cognitive decline might, therefore, have impact," they say.

They point out that the causes of cognitive impairment after TIA are unknown. Future studies should include advanced brain imaging techniques to identify microstructural and functional cerebrovascular damage and longitudinal assessment of cognitive function after TIA to observe whether cognitive impairment is transient, stationary, or progresses over time, the researchers conclude.

Stroke. Published online June 24, 2014. Abstract


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