Treatment of Aphasia
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NEUROLOGICAL REVIEW Treatment of Aphasia Martin L. Albert, MD, PhD pproximately 1 million people have aphasia in the United States today, yet with prop- erly targeted therapy in selected patients effective communication can be restored. Cur- rent approaches to treatment of aphasia include psycholinguistic theory-driven therapy, cognitive neurorehabilitation, computer-aided techniques, psychosocial manage- Ament, and (still on an experimental basis) pharmacotherapy. Arch Neurol. 1998;55:1417-1419 Languageisnotlocatedinautonomousmod- For some individuals with aphasia, ules strategically implanted within the left loss of the ability to communicate is tan- hemisphere (a comprehension module in tamount to loss of personhood, and any Wernicke’s area, an output module in Bro- help they can receive to recover function ca’s area, the 2 connected by a single, hard- in this cognitive domain is treasured. Neu- wired cable). Neuroimaging studies of the rologists should know that current ap- last 15 years and contemporary analyses by proaches to aphasia therapy, carefully tai- cognitive neuroscientists have shown that lored to treatment of specific signs and multiple, complex, and overlapping cerebral symptoms, actually help selected individu- systems underlie the elements of language.1,2 als with aphasia communicate more effec- Each system seems to consist of a widely dis- tively. Contemporary research in basic neu- tributed network of cortical and subcorti- roscience, cognitive neuroscience, and cal components, both within and beyond the neuroimaging is expanding our therapeu- classic left hemispheric zone of language. tic options for treatment of aphasia in ways Linguistic and nonlinguistic cogni- that might not have been considered pos- tive functions, such as attention, memory, sible just a few years ago. Consequently, and executive system functions, are inter- neurologists should work more closely and dependent and may be affected to differ- consistently with speech/language patholo- ent degrees in patients with aphasia. gists to help their patients with aphasia. Knowledge of how language can be influ- enced by nonlinguistic cognitive func- CURRENT APPROACHES tions (traditionally assigned to the right TO APHASIA THERAPY hemisphere or considered to be linked to frontosubcortical systems) has been use- Efficacy ful in developing new approaches to the treatment of aphasia. One reason, I suspect, that many neurolo- This review addresses 3 issues: rel- gists have been skeptical about the value evance of aphasia therapy to neurologists, of aphasia therapy was the relative dearth current state of the art, and future trends. of statistically valid and reliable studies documenting benefit of aphasia therapy IMPORTANCE OF APHASIA over spontaneous recovery. Research in the THERAPY TO NEUROLOGISTS last 10 years has changed that picture. In a meticulously detailed study on The number of people with aphasia in the the efficacy of treatment for individuals United States today, primarily as a conse- with aphasia, Robey5 carried out a meta- quence of stroke and traumatic brain in- analysis of 21 studies that provided suffi- jury, is estimated at about 1 million.3 cient information for inclusion. He evalu- Eighty thousand new patients with apha- ated 3 classes of effect size: untreated sia are added to the pool each year from recovery, treated recovery, and treated vs stroke alone.4 untreated recoveries. He excluded from his analysis all case studies, all studies using From the Harold Goodglass Aphasia Research Center, Department of Neurology, single-subject designs, all studies for which Boston University School of Medicine, and the Medical Research Service, Department of the report contained insufficient quanti- Veterans Affairs Medical Center, Boston, Mass. tative information to allow the calcula- ARCH NEUROL / VOL 55, NOV 1998 1417 ©1998 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 tion of an effect size, and all studies reporting uninter- Treating Linguistic Deficits—Psycholinguistic Approach. pretable effects. His conclusions document the clear The psycholinguistic approach to aphasia therapy applies superiority in performance of individuals receiving treat- information-processing models of normal cognition to an ment. The effect of treatment beginning in the acute stage understandingoflanguagedisorders.10,11 Anattemptismade of recovery was nearly twice as large as the effect of spon- to identify the locus of the language deficit within the taneous recovery alone, while treatment initiated after cognitive/linguistic structure of normal language. An anal- the acute period achieved a smaller, but nevertheless ap- ogy might be the search for a missing or defective enzyme preciable, effect. within a complex metabolic system. The premise under- Holland and colleagues6 provided another com- lying this approach is that a specific aphasic sign or symp- pelling review of treatment efficacy studies in aphasia. tom may be the surface clinical manifestation of different Disregarding case reports in which only anecdotal tes- underlying deficits within the cognitive structure of lan- timonial data were presented, they noted that nearly guage. Only by uncovering the precise underlying psycho- 200 studies pertaining to aphasia treatment have been linguistic deficit can therapy be properly targeted. To date, published in the English language alone. Included in the clinical phenomena of anomia and agrammatism have these reports were large and small group investiga- been most responsive to this approach. tions, single-subject experiments, and single-case studies. Holland et al conclude that individuals with Treating Related Neurobehavioral Deficits— aphasia meeting specific selection criteria who are Cognitive Neurorehabilitation. A newer approach to treated improve more than those who do not receive aphasia therapy is based on the idea that the ability to treatment. Improvement was documented in both the communicate is dependent not only on linguistic com- quantity and quality of language. petence but also on related neurobehavioral functions, such as attention and memory. The assumption is that Treatment Approaches brain damage that produces aphasia also produces dis- turbance in other, language-related cognitive functions, The critical clinical issue in current approaches to apha- and that treatment of these other cognitive deficits can sia therapy is the necessity to individualize the thera- facilitate communication. Holland12 outlines the strengths peutic modality for the specific aphasic sign or symp- and limitations of this approach. tom being targeted and the specific person being treated. For example, virtually all individuals with aphasia de- Traditional methods of aphasia therapy have been im- velop perseveration, which interferes with communica- proved by careful selection of timing and frequency of tive capability. In 1988 Helm-Estabrooks and colleagues13 treatment delivery, more precise delineation of which introduced Treatment for Aphasic Perseveration,9 and aphasic deficit to focus on, more reasoned matching of demonstrated that cognitive therapy focused on related therapy technique to deficit, and modification of treat- neurobehavioral deficits, in this case perseveration, can ment modality as the syndrome evolves. For each of these improve language function in individuals with aphasia. clinical elements, an informed neurologist, working in McNeil and colleagues14 have long argued that in- therapeutic partnership with the speech/language pa- dividuals with aphasia suffer a deficit in allocation of at- thologist, can manifestly aid the patient. tentional resources and proposed an “integrated atten- tion theory of aphasia,” asserting a relation among Output-Focused Therapy. Most speech/language pa- attention, arousal, and language processing. This argu- thologists still use the technique known as stimulation- ment receives support from contemporary research in cog- response or direct retraining of deficit, as one aspect of nitive neuroscience, in which a left hemisphere atten- their therapy program. First, the aphasic deficit is iden- tional system linked to language has been described by tified and, then, repetitive drill through several modali- Posner.15 Indirect evidence exists that attempts to treat ties (eg, reading or repetition) is encouraged. An end- attentional dysfunction in individuals with aphasia may less array of sophisticated modifications of this traditional ameliorate the language disorder; and experimental stud- approach has been developed.7 ies are just beginning to test this hypothesis. A newer technique, called melodic intonation therapy (MIT), is neurobehaviorally based. Through its Thera- Computer-Aided Therapy. Of the many attempts to ben- peutics and Technology Assessment Subcommittee, the efit individuals with aphasia by means of computer- American Academy of Neurology has identified MIT, cur- aided therapy, perhaps the most creative was intro- rently in use worldwide, as an effective form of output- duced by Baker and colleagues16 in the middle of focused language therapy.8,9 Melodic intonation therapy the 1970s17 and further developed by them and by is a formal, hierarchically structured treatment program Weinrich and colleagues18 over the next 20 years. Com- based on the assumption that the stress, intonation, and puterized visual communication (or C-VIC) was de- melodic patterns of language output are controlled pri- signed as an alternative communication