Brussels, 30 Jun 2004
A breakthrough technique of artificially vibrating muscles and measuring neuro-stimulation offers potential for the development of new stroke rehabilitation methods, say Belgian scientists.
Recovering mobility and function after a debilitating stroke is a long and frustrating process for the millions of people worldwide who have suffered one. Sometimes called a cerebral infarction, strokes occur when brain tissue is damaged following interrupted blood flow to any part of the brain. It is the third leading cause of death in most developed countries, and the leading cause of disability in adults.
Physicians in the USA call it a 'brain attack', stressing the importance of obtaining immediate treatment which can save lives and reduce eventual disability. Treatment varies depending on the severity and cause of the stroke. For virtually all types – whether caused by embolism or thrombus (both clots), atherosclerosis (like plaque in the blood), or haemorrhagic stroke from brain bleeding – hospitalisation is required, possibly including intensive care and life support.
For the survivors, the road to recovery is slow and, in many cases, because of physical immobility, certain areas of the brain begin to degrade. The flow of messages from the brain to our body parts is usually two-way. Cut the stimuli and the areas of the brain responsible for this movement literally start to shrink. But Maarten Steyvers of the Catholic University of Louvain's Kinesiology Department (Motor Control Laboratory) had an idea that has potential to keep stroke victims' brains in shape.
He says that – at least in healthy subjects – artificially vibrating certain muscle receptors can 'train' the areas of the brain and neuronal pathways responsible for that movement. These findings can potentially reduce brain degeneration, as the movement-related parts of the brain and spinal cord are kept active in the absence of movement itself.
High risk category
Steyvers, speaking about his PhD research, says that he initially tested his method on healthy subjects, applying vibrations to targeted muscles in the wrist region, since stroke victims often encounter problems performing hand movements. These vibrations are registered by the somatosensory cortex – part of the brain responsible for perception – and he worked out a way to measure the level of stimulation that reached neurons in the primary motor cortex and the descending neuronal pathways towards muscle extremities. The primary motor cortex is located next to the somatosensory cortex and directs conscious movement.
At a specific wave frequency, stimuli originating in the vibrating muscle masses had an effect not only on the sensory but also the motor regions and the descending motor pathways, he notes. This finding has been confirmed by comparable studies in other research centres. What's more, the effect continued after the stimulation ceased. If the same technique yields positive results in stroke victims – the next phase of his research – rehabilitation should move ahead, he explains.
Ultimately, it could one day provide a new way to rehabilitate stroke patients. "Coming from a physiotherapy background, I was interested in how newly developed types of sensory stimulation during rehabilitation – say, after a stroke or cerebral haemorrhage – could improve the long-term recovery prospects," the young scientist told Headlines.
High blood pressure is the main reason that someone might have a stroke. The risk increases with age, smoking, diabetes, high cholesterol, heart disease and where there is a family history of strokes. Women are apparently at risk during pregnancy and in the weeks immediately after giving birth. But men are generally more prone. Cocaine use, alcohol abuse, head injury and bleeding disorders increase the risk of brain haemorrhage.