Application of the Trail Making Test in the assessment of cognitive flexibility in patients with speech disorders after ischaemic cerebral stroke
The main aim of this study was to evaluate the level of cognitive flexibility in patients with speech disorders after ischaemic cerebral stroke. The study was conducted in a group of 43 patients (18 women and 25 men) who had experienced cerebral ischaemic stroke. The patients under study were divided into groups based on the type of speech disorders, i.e.: aphasia, lack of speech disorders and dysarthria. A Mini-Mental State Examination (MMSE) and a Clock Drawing Test (CDT) were applied for the general evaluation of the efficiency of cognitive functions. Cognitive flexibility – a component of executive functions, was evaluated with the use of a Trail Making Test (TMT). The results obtained prove that patients with aphasia show the lowest level of cognitive flexibility. Disorders of executive functions can be related to the dysfunction of the prefrontal cortex which has been damaged as a result of ischaemic cerebral stroke. Presumably, there are common functional neuroanatomical circuits for both language skills and components of executive functions. In the case of damage to the structures that are of key importance for both skills, language and executive dysfunctions can therefore occur in parallel. The presence of executive dysfunctions in patients with aphasia can additionally impede the functioning of the patient, and also negatively influence the process of rehabilitation the aim of which is to improve the efficiency of communication.