Stroke, Parkinson’s disease, and traumatic brain injury (TBI) affect millions of Americans each year, diminishing the quality of life for patients and rendering once simple tasks, such as performing household chores or carrying on a conversation, difficult or impossible.
Although brain research has made great strides in recent years and has brought about improved treatments, many aspects of brain and behavior remain poorly understood. The use of sophisticated brain imaging technology, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), has greatly enhanced research in this area.
Aiming to advance scientific knowledge of brain injuries and the most effective treatments, researchers at NYU Steinhardt are engaged in a variety of research projects that will ultimately benefit patients suffering from these debilitating injuries.
Sharon Antonucci, assistant professor in Steinhardt’s department of communicative sciences and disorders, is currently researching how word retrieval is affected among adults following stroke. For the majority of people, the primary linguistic seat is located in the brain’s left hemisphere. A stroke which causes lesions in the patient’s left hemisphere can adversely affect language ability such as word retrieval.
Using high resolution structural MRI technology, Antonucci is examining brain images of adult stroke patients. By having the patients perform word retrieval tests and comparing the test results with the location of the brain lesion, Antonucci is mapping which areas of the brain are essential for naming functions. Among her findings is that the inferior temporal lobe appears to affect retrieval of words for living things (such as “dog” or “apple”). A possible future clinical application of Antonucci’s work is development of treatment for word retrieval impairment that is informed by the location of the patient’s brain lesion.
For instance, she says, “a clinician may choose among types of cues to facilitate word retrieval depending on the specific location of the lesion in the stroke patient’s brain and how that affects processing of different types of semantic information.”
Problems with speech also affect patients with Parkinson’s disease, a degenerative brain disorder that is characterized by chronic tremors and difficulty with movement. Parkinson’s patients often have difficulty vocalizing, resulting in breathy, low-volume speech. Diana Van Lancker Sidtis, professor of communicative sciences and disorders, is currently engaged in a 5-year, $2 million study funded by the National Institutes of Health to study the effects of Deep Brain Stimulation (DBS) on the vocal quality of Parkinson’s patients. The work is administered through the Nathan Kline Institute of Psychiatric Research, where she and her husband, John J. Sidtis, are both research scientists.
DBS is a relatively new surgical treatment for Parkinson’s that involves inserting an electrode into the subthalamic nucleus of the patient’s brain. Much like a pacemaker is used to regularize a heartbeat, DBS is used to chronically stimulate the brain and significantly reduces tremors, resulting in a better quality of life for the patient. A side effect of DBS, however, may be reduced fluency of speech.
Sidtis’ research examines whether speech production and fluency of Parkinson’s patients are affected when the stimulator is turned on. Her results are encouraging: her findings suggest that there is only a subtle effect on speech production when the stimulator is turned on. “While some patients exhibit slight deterioration in motor output, there is generally an improvement in vocal quality among patients who undergo DBS,” she says.
Aside from verbal fluency, brain injury can affect an individual’s working memory and executive function. Gerald Voelbel, assistant professor of occupational therapy, researches the effects of mild traumatic brain injury (TBI) on these important brain functions. Each year, more than one million Americans suffer some form of mild TBI, such as concussions from athletic injuries or car accidents. While the majority of people return to normal brain functioning within six months, about twenty percent of patients exhibit more serious cognitive problems.
Using a technology that measures blood flow to the brain, functional Near Infrared Spectroscopy (fNIRS), Voelbel is currently working on an NIH-funded grant to detect changes to the brains of individuals with mild TBI. Unlike fMRI, which requires the patient be placed in an imaging machine, fNIRS requires only an array be fitted on the patient’s scalp. The patient can sit up and perform tasks while the fNIRS equipment monitors blood flow to the brain. Voelbel hopes his research will enable clinicians to better predict the twenty percent of TBI patients who will go on to develop serious cognitive problems, enabling them to design more appropriate treatments for this population.
(Pictured above: structural MRI scan of a healthy brain, courtesy of Dr. Sharon Antonucci)