Vikas Pandey, MD
Assayag E, Shenhar-Tsarfaty S, Korczyn A, Kliper E, Hallevi H, Shopin L, et al. Gait Measures as Predictors of Poststroke Cognitive Function: Evidence From the TABASCO Study. Stroke. 2015
Cognitive impairment related to stroke is a hot topic for discussion given the fact that cognition, obviously, is something that is very important to patient themselves as well as their long-term functionality, however is something that is not as easily predictable given the poor true localization of cognitive pathways. Cognitive impairment is not something that is immediately addressed when dealing with stroke patients. An example of this would be how carotid stenosis may be asymptomatic given the usual definitions of the term that are lack of speech, motor, sensory or visual deficits related to the carotid stenosis, however may be truly “symptomatic” from the cognitive standpoint (i.e. slower processing ability, poor short term memory, impaired concentration, etc). There have been established links previously between motor and cognitive domains in stroke patients however the reason for these connections has not been illuminated. Rightfully, the group from Israel decided to address the issue of post-stroke cognitive decline and test whether the assessment of balance and gait has any impact on prediction of long-term cognitive outcome in stroke survivors.
The group took 298 patients with first-time mild to moderate stroke or TIA from the TABASCO cohort which followed patients for at least 2 years with neurologic, neuropsychological, and mobility examinations. They found that 15.4% of the patients suffered cognitive decline over the 2 years of follow-up, but that these patients did not differ in neurological deficits or infarct volume/location compared to the group that did not decline. A specific test (Timed Up and Go) assessing patient mobility showed that there was a difference in the cognitive decline group (performed the test slower) compared to the cognitively intact group (p < 0.001). Other measures that were different were that the cognitive decline patients had lower Berg Balance scores (non-vestibular balance test), slower gait (p<0.001) and fewer correct answers during dual-task walking (p = 0.006). They found that patients with a Timed Up and Go time of 12 seconds at 6 months post-stroke/TIA was a significant independent risk marker of cognitive decline 24 months post-stroke (OR= 6.07, 95% CI: 1.36-27.15).
The authors found a link between balance and gait measures and development of cognitive impairment. These are tests that are routine and are rather simple to perform and thus there is high utility in performing these tests to predict those who are at higher risk of developing cognitive impairment. Perhaps it is these patients who would benefit from early intervention such as with cholinesterase inhibitors to prevent the progression of their decline. The understanding of why this link is present would also be important to explore and so the authors should be applauded for opening the door to new possibilities of discovery in an area that is currently underdeveloped.
Posted by Vikas Pandey (@DrVikasNeuro)