Impairments after stroke: Challenges for diagnostics- and rehabilitation-research

Jour Fixe talk by Jennifer Randerath on January 13, 2016

Around 200.000 to 300.000 people in Germany suffer from a stroke each year. In case of a stroke, the blood supply of the human brain is deficient. This is caused by a blockage of the arteries or an internal bleeding. After a stroke the patient may lose control of several bodily functions, depending on the damage in the brain area which controls these functions.

In her research as a clinical neuropsychologist, Jennifer Randerath studies the human behaviour and (ab-)normal bodily and cognitive functions of patients after a stroke. Some of the most frequent major neuropsychological disorders are deficits in loss of motor functions, as well as visual-spatial or language deficits. In certain cases, the patient might not even be able to realize his own impairment(s).

Neuropsychologists use a wide range of tests to identify a disorder. For example, to check the ability of a patient to realize his loss of functions, he takes part in a self-assessment test and is asked several questions, e.g. if he is able to clap or wash his hands, and also check-questions, whether he is able to jump over a truck. At the reasonable suspicion of having lost the visual-spatial abilities, patients are asked to mark the centre of a line or cross signs on a paper. Marking the wrong centre or signs indicates visuo-spatial deficits. Language deficits are divided into two classical types. Firstly, the loss of the ability to produce language in general, like chuntering or mumbling, or second the loss of comprehension and production of meaningful speech. To check the patient´s motor cognitions, he is asked to use everyday tools like scissors or ladles in their normal context, e.g. for cutting paper or serving soup from a pot to a bowl. Using the wrong tool, like a bottle opener for serving soup indicates motor cognition deficits. To be able to predict the loss of function after brain damage, researchers analyse MR or CT-scans of the brain to localise the damaged brain area and relate this information to the lost functions.

A special challenge, both for patients, clinical staff and researchers, is the co-occurrence of deficits. For Example, large damages in the brain´s left hemisphere might affect the right-side motor function and in addition language and motor cognition abilities. Damages on the right hemisphere can affect the left motor function and the visuo-spatial abilities. When testing it is important to pay attention to other deficits which might be undetected yet.