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The Role of Neuroimaging in the Study of Aphasia Recovery and Rehabilitation
Research Needs and Opportunities: Summary and Recommendations
The NIDCD has had a longstanding commitment to research in treatment of adult aphasia. In 1991, the NIDCD sponsored a workshop on the topic, which resulted in a monograph, "Aphasia Treatment: Current Approaches and Research Opportunities" and an RFA "Treatment and Rehabilitation of Adult Aphasia". Despite these early efforts, as well as the identification of rehabilitation research as a priority in the NIDCD Strategic Plan, the number of NIDCD-supported research studies focused on the topic has remained limited. As a result, in 2001, NIDCD began to develop a workshop focused on rehabilitation of adult aphasia; soon thereafter, Senate Appropriations Committee language encouraged the various NIH institutes that had an interest in aphasia research to "expand and better coordinate their support of research into the cause, incidence, treatment and prevention of aphasia", and to delineate "those areas with the most potential for yielding significant advances in… treatments and rehabilitation methodology". Accordingly, the advice and direction of a number of researchers in the fields of neuroimaging, aphasia and rehabilitation were incorporated into the development of the workshop.
The NIDCD workshop, "The Role of Neuroimaging in the Study of Aphasia Recovery and Rehabilitation: Research Needs and Opportunities" was held on the NIH campus May 13, 2002. The purpose of the workshop was to 1) identify research opportunities for the application of neuroimaging methods to the study of aphasia recovery and rehabilitation; 2) to identify and address particular methodological challenges of imaging research focusing on the issue of aphasia recovery and rehabilitation; and 3) to develop strategies to encourage collaborative efforts among researchers with expertise in functional neuroimaging, language processing and aphasia rehabilitation.
Selected scientists whose research was relevant to the focus of the workshop were invited to attend. Presentations focused in three major areas: neuroplasticity and recovery of function; neuroanatomical and neurophysiological correlates of language processing in brain damaged individuals, using neuroimaging techniques; and recovery of language function and neuroimaging. Following presentations, lengthy discussion ensued and a number of recommendations and research needs were noted.
Following the workshop, the chairs and co-chairs assembled for summary discussions and identification of workshop themes and issues, regarding research needs and opportunities. The major discussion points are noted below. NIDCD encourages investigator-initiated research applications in all of the areas noted below. A focused solicitation is under development and will be released soon. For further information about funding opportunities, please contact Dr. Judith Cooper, Chief, Scientific Programs Branch, NIDCD at Judith_Cooper@NIH.GOV
Research Needs in Neuroimaging as It Relates to the Study of Aphasia and Aphasia Recovery
- Document reliability of imaging results over time in aphasic individuals
- Improve methods for analyzing activation patterns in patients (as compared to normals)
- Develop procedures for overcoming problems related to linguistic/cognitive task difficulty. Determine the effect of degrading tasks on activation patterns. Determine reliability of tasks within and across aphasic groups. Determine how to interpret imaging patterns when language performance is poor
- Develop approaches to pooling of patient data: lesion location, language abilities/disabilities
- Develop better means of comparing patient vs. normal performance, ie, determine the significance of differences in brain responses in aphasic individuals vs. normal speakers
- Identify responses which reflect abnormal strategies vs. abnormal rewired system
- Compare and contrast patterns/profiles found utilizing electrophysiological and neuroimaging techniques
- Develop new methods for imaging language production
- Document the natural history of recovery, including changes over time in patterns of performance and neurobiological processes
- Identify prognostic indicators, specifically subject variables related to neural recruitment patterns, for example, lesion site and extent, aphasic language impairment and severity
- Determine which brain areas are involved in language recovery, for example, right hemisphere (RH); left hemisphere (LH) perilesional areas; new LH areas
- Examine how patterns of language recovery address issues regarding brain plasticity
- Examine possible LH inhibition of RH in aphasic and normal speakers
- Determine the role of general regulatory factors on patterns of recovery (e.g., attention, motivation, mood, level of arousal)
- Examine changes in activation patterns correlated with recovery. Determine utility of neuroimaging studies for predicting potential for language recovery
Research Needs in Neuroimaging Related Aphasia Rehabilitation/Treatment
- Utilize neuroimaging techniques to document the neurobiological correlates of treatment effects
- Utilize imaging techniques to document the effect of particular treatment on brain functioning and/or to predict functional outcome/likelihood of retention of skills post-treatment
- Determine utility of using neuroimaging data to determine the potential benefit of particular treatments
- Examine the effects of timing of treatment on neural recruitment patterns, ie, early after a deficit, or after a delay (when acute changes have at least partially dissipated).
- Study the effectiveness of components of intervention as well as combinations of intervention (for example, behavioral and pharmacotherapeutic);
- Examine features of training: presence of feedback associated with each trial, context of stimulus use, the timing of stimulation, what the individual already has mastered in area to be trained
- Identify the "cost" of treatment, ie, the possible detrimental effects of treatment, on other (nontreated) cognitive/language processes. Does competence in another domain suffer as treatment results in improvement in targeted area?
- Develop approaches to documenting changes over time within the intervention setting
- Determine the reliability and stability of measurement
- Develop reliable, quantitative outcome measures
- Determine efficacy of treatment as a function of intensity of treatment (focused, intense intervention vs. more traditional, less intense treatment) and the relation between intensity of treatment and recruitment of neural tissue in recovery
- Identify responses which reflect restoration versus reorganization of function, that is, training to the deficit vs. teaching of compensatory strategies
- Identify strategies that facilitate generalization of behaviors learned in treatment
- Develop more effective intervention/therapy tools with detailed specification of training procedures, task difficulty/patient performance
- Determine specificity of training effects.
- Determine role of general regulatory factors (attention, motivation, mood, level of arousal) in efficacy of treatment.