Optimising multi-task performance: opportunities for motoric neurorehabilitation

In their study, Hyndman and Ashburn administered the stops walking while talking test (SWWT) to predict the occurrence of falls (see p 994, this issue).¹ Optimising multi-task cognitive and motor performance and targeting individuals who may benefit from therapeutic interventions to improve gait and reduce falls after stroke are important goals of neurorehabilitation. Dual task paradigms, such as walking while talking, can substantially alter motor and cognitive performance in younger and older adults with and without pathology.^2,3 The authors’ results are particularly interesting in the light of the possibilities of dual task therapies to prevent falls in persons with brain dysfunction. For example, one study showed that treatment with electromagnet fields improves dual task performance.⁴ Much time is spent during rehabilitation to improve a patient’s functional gait parameters and few therapies are evidence-based. Evidence-based techniques in motoric neurorehabilitation of gait following stroke often include treadmill training with partial body weight support (TTPBWS). Dramatic improvements in gait can be observed during a single TTPBWS session where patients practice up to several thousand gait cycles on a motorised treadmill, while their bodyweight is partially supported by a parachute harness. This is thought to maximise motor practice time because the treadmill “forces” patients to ambulate in a safe environment with minimal fear of falling. Future studies should address the complementary nature of SWWT during TTPBWS, by assessing the precise effect of a cognitive task on gait in older adults.⁵ Rather than asking simple questions and measuring if patients respond by stopping or not stopping, future studies should examine elements of speech itself, such as speech rate, grammatical complexity, sentence length and structure, and their effects on gait patterns. Gait velocity should be controlled and this can be done with a treadmill. Then we may begin to ask if gait (and speech) patterns differ between stopper and non-stoppers. Optimally, the effects on gait should be studied in greater detail using three dimensional computerised gait analysis systems. Lower extremity leg strength and activity level should also be assessed. Most importantly, does dual task therapy transfer to functional gains in a real world environment? Answers to these questions may give further insights into the wondrous potential of the brain to recover from injury.