Rehabilitation for Cognitive-Communication Disorders in Right ...

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SPECIAL COMMUNICATION

Rehabilitation for Cognitive-Communication Disorders in Right Hemisphere Brain Damage Connie A. Tompkins, PhD ABSTRACT. Tompkins CA. Rehabilitation for cognitivecommunication disorders in right hemisphere brain damage. Arch Phys Med Rehabil 2012;93(1 Suppl 1):S61-9. Although the left hemisphere of the brain has long been linked with language, the right cerebral hemisphere also contributes importantly to cognitive operations that underlie language processing and communicative performance. Adults with right hemisphere damage (RHD) typically do not have aphasia, but they often have communication disorders that may have a substantial impact on their social functioning. After a brief summary of communicative and cognitive characteristics of RHD in adults and of extant theoretical accounts of common communicative difficulties, this article discusses rehabilitation issues, approaches, evidence, and needs. Key Word: Cerebral infarction; Communication disorders; Delirium, dementia, amnestic, cognitive disorders; Language disorders; Rehabilitation. © 2012 by the American Congress of Rehabilitation Medicine ANGENTIAL, LITERAL, aprosodic, verbose, socially T inappropriate, anosognosic, with unilateral neglect: these are some of the communicative and cognitive characteristics that typically come to mind for adults with brain damage restricted to the right cerebral hemisphere (RHD). The primary goal of this article is to describe rehabilitation issues, approaches, evidence, and needs relevant to the communicative difficulties of this clinical population. The discussion incorporates nonlanguage cognition and its treatment (eg, aspects of attention, memory, and executive functioning), because nonlanguage cognitive performance has been hypothesized and demonstrated to underlie, covary with, or otherwise modulate communication in adults with RHD.1,2 As such, rehabilitation approaches can and do focus on nonlanguage cognition with the goal of effecting change in communication. In fact, in light of these close links between cognitive and communicative impairments, the constellations of communication deficits that emerge after RHD have been described as cognitive-communication disorders. To preface this discussion, the material below briefly defines communication and cognition, summarizes communicative and cognitive sequelae of RHD in adults, and reviews current

From the Department of Communication Science and Disorders and Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA. Portions of this material were presented at the 2010 Clinical Aphasiology Conference, May 23–27, 2010, Isle of Palms, SC. Supported in part by the National Institute on Deafness and Other Communication Disorders (grant no. DC010182). No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. Correspondence to Connie A. Tompkins, PhD, Communication Science and Disorders, University of Pittsburgh, 4033 Forbes Tower, Pittsburgh, PA 15260, e-mail: [email protected]. Reprints are not available from the author. 0003-9993/12/9301S-00703$36.00/0 doi:10.1016/j.apmr.2011.10.015

theoretical accounts of common cognitive-communication difficulties. COMMUNICATION AND COGNITION DEFINED The term communication refers to the interpersonal exchange of ideas, information, needs, mutual understanding, and the like. Communication can be intentional or unintentional, and does not need to involve language (eg, may occur via facial expression or tone of voice), though language is 1 form of communication. Cognition can be defined as the “collection of mental processes and activities used in perceiving, remembering, and thinking, and the act of using those processes.”3(p10) COGNITIVE-COMMUNICATION DISORDERS IN RHD This article opened with a list of characteristics that actually are stereotypes of cognitive-communication impairments in RHD. In fact, there is great diversity in this population’s presentation of cognitive-communication problems. Many individuals with RHD stay on track when they talk, are not overly literal, have good intonational variation, and so on. This diversity derives from many factors, no doubt including lesion site and premorbid individual differences. The stereotypical view of the patient with RHD probably results in part from sampling bias: patients in research studies often are, or have been, receiving rehabilitation services. As a result, these individuals are likely more impaired than the population as a whole. In addition, many of the studies use metalinguistic or metacognitive tasks, such as defining metaphors or idioms, matching pictured facial expressions with vocal intonations, or solving hypothetical, “what would you do if . . .” problems. Such tasks, which require participants to consciously reflect on or make judgments about communication or cognition, do not reflect natural language, communicative, or cognitive processing and may overestimate deficits. With this in mind, table 1 summarizes some commonly observed language, communication, and cognitive difficulties in adults with RHD (Tompkins et al1 provides a detailed discussion of these and other characteristics). There is very little information on the prevalence of most of these difficulties, in part because the research area is quite new. Estimates suggest impairment in at least 1 aspect of communication and social interaction in somewhere between 50%4 and 78%5 of adults with RHD. There are almost no good estimates for specific communication impairments. Aprosodia was recorded in about 25% of charts for a sizeable inpatient rehabilitation sample,6,7 but this estimate may be low, because many in the

List of Abbreviations MSI RHD ToM VST WMCL

metacognitive strategy instruction right hemisphere damage theory of mind visual scanning training working memory capacity for language

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REHABILITATION FOR RIGHT BRAIN DISORDERS, Tompkins Table 1: Some Commonly Observed Language, Communicative, and Cognitive Difficulties in Adults With RHD

Language Discourse production -Produce stories or explanations go off topic and/or end abruptly -Supply vague referents, or none at all (eg, “You look just like her, you know?”) Discourse comprehension -Draw incorrect inferences/conclusions from what they read or are told, especially when there is some ambiguity in the information Conveying or interpreting intent (pragmatics) -Have difficulty catching on to hints from others (eg, “I’m trying to concentrate here . . .”; or comments that signal an end to a conversation) -May not “soften” requests of others by, for example, providing a reason or an apologetic opening (eg, “I’m sorry to bother you, but do you have change for a dollar?”) General -Have difficulty determining or designating relevant information Communication Expressive aprosodia -Exhibit little modulation of vocal intonation Receptive aprosodia -Have difficulty interpreting emotions or intentions from other peoples’ voices Social communication -Exhibit communication that is inappropriate for the situation and/or communication partner (eg, telling off-color jokes in church) Cognition Attention -Look around during conversation or testing -Orient toward extraneous sights or sounds -Interrupt others -Appear to talk/act without thinking -Have difficulty following lengthy instructions or conversations -Exhibit uniliateral neglect (a constellation of disorders of spatial exploration and selective attention, that manifests primarily in a directional bias for perception, attention, and/or action, and that cannot be explained by sensory or motor impairments) -For example, bump into doorframes; have rightward gaze bias; crowd writing/drawing/copying onto right side of a page; lack left-sided detail in copying/drawing from memory; omit left side of words, or of lines of text, when reading aloud; rarely choose left-side response options, even with material placed rightward; leave food on left side of plate Visual processing -Have difficulty interpreting emotional facial expressions -Have difficulty reading signs in the environment -Have difficulty finding way to unfamiliar location Memory -Have difficulty recalling information recently heard or read -Have difficulty drawing a complex figure recently copied -Have difficulty following multiple directions -Have difficulty remembering to bring belongings (eg, memory notebook, hearing aids) -Have difficulty remembering to take medications -Do not use memory strategies Executive functioning -Exhibit anosognosia (impaired awareness of deficits and/or reduced insight into how those deficits affect daily functioning) -For example, statements appear to contradict physical/cognitive/emotional abilities, obvious changes in function are denied, little attempt is made to self-correct, appear to lack awareness of social consequences of behavior -Appear unmotivated -Exhibit discrepancy between knowing (or saying) and doing -For example, can explain steps in safe wheelchair transfer but do not apply them, and/or cannot describe a solution for a hypothetical problem but act appropriately when actually confronted with that problem -Have difficulty planning daily activities, organizing materials or activities, keeping records, adhering to checklists, organizing schedules, keeping track of belongings, managing time -Have difficulty monitoring behavior, sustaining appropriate behavior, adjusting behavior

sample were not referred for evaluation of cognitive-communicative difficulties. The same study reported, unsurprisingly, that speech-language pathologists more often diagnose difficulties in communication and interpersonal interaction than do neurologists, neuropsychologists, and occupational therapists. In terms of RHD cognitive deficits, estimates suggest a conArch Phys Med Rehabil Vol 93, Suppl 1, January 2012

siderable prevalence of difficulties in attention, neglect, perception, learning and memory, and reasoning and problemsolving (all affecting at least 50%8 and up to 68%6) of patients evaluated. Some of the problems in table 1 may have several roots. For example, difficulty following multiple directions (eg, “fold the

REHABILITATION FOR RIGHT BRAIN DISORDERS, Tompkins

paper in half and seal it in the envelope”) could be due to deficits in sustained attention rather than in memory or language comprehension, and difficulty interpreting emotions from voices may reflect problems with perceiving emotion rather than impairments in decoding intonational cues. One primary job of the clinician is to discern the underlying nature of observed behaviors, to help shape behavioral treatment. Given the vast range of normal in communication, another crucial diagnostic task is to determine whether observed behaviors are significantly different from premorbid functioning. Poor functional outcomes in the RHD population are clearly associated with unilateral neglect9 and anosognosia.10 Otherwise there is little literature linking RHD impairments to broader outcomes. Nonetheless, many of these impairments could be quite socially debilitating. For example, adults with RHD may alienate or embarrass friends and family; experience diminished participation in jobs or hobbies that require concentration or visual perception/construction; or lose independence due to other peoples’ concerns about awareness and safety. Patients with RHD have cognitive-communication strengths, as well (see, eg, Tompkins et al2). They have few if any problems in comprehending or expressing language syntax (grammar), morphology (eg, word endings), and/or phonology (speech sounds), and as such do not have a classical aphasia. Their lexical retrieval ability (eg, coming up with words they want to use in conversation) is like that of age-matched healthy individuals. If they have trouble naming pictures or objects it may be due to visual-perceptual or visuospatial difficulties rather than language problems. Among the other strengths of the RHD population is an ability to profit from semantically consistent information, as when an interaction sticks to a single theme or topic, and to benefit from redundant input. Adults with RHD also comprehend better when expressions that may be difficult for them, such as metaphors (eg, “the man is a mule”), are preceded by moderately-to-strongly biased linguistic context (“The man is stubborn. He never quits. The man is a mule”). Other cognitive-communication strengths are introduced in the material below. THEORETICAL ACCOUNTS OF COMMON RHD COGNITIVE-COMMUNICATION DIFFICULTIES This section briefly describes some current proposals about the nature of RHD cognitive-communication deficits. These proposals, which vary widely in scope, are not mutually exclusive. The more general accounts are addressed first, 3 focusing primarily on language comprehension and 2 that are more broadly based. This section ends with a brief discussion of current thinking about the bases of expressive aprosodia. Interactions and contrasts between accounts are also considered. Cognitive Resources Hypothesis Early accounts of RHD cognitive-communication disorders emphasized domain-specific difficulties. That is, these disorders were attributed to impairments in processing discrete aspects of communication, such as figurative language, jokes, prosody (intonation patterns), or inferential or emotional elements of incoming messages. The limited utility of this view has been well-documented over the past 20 years. Patients with RHD perform well in these problem domains when tested indirectly or implicitly, using priming or word-monitoring methods that require little or no meta-language or metacognition (see summary in Tompkins2). In addition, performance in cognitively-demanding discourse conditions is predicted by

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interindividual differences in working memory capacity for language (WMCL) (see summary in Tompkins2), a system engaged in the simultaneous processing and storage of incoming language information. Together, these results underpin the first domain-general account of typical language comprehension difficulties in adults with RHD (see Tompkins2 for summary), a view dubbed the cognitive resources hypothesis. More recent work from other labs continues to support this view.11 This account specifies that in domains historically considered problematic for the RHD population, comprehension varies substantially with the attentional or working memory demands of a language task. In addition, these results suggest that the right hemisphere contributes mental resources to perform demanding language tasks. Coarse Coding Deficit Hypothesis The right cerebral hemisphere is involved in mentally representing and accessing word meanings to a greater degree than originally thought. In a seminal study,12 young adults without brain damage were briefly presented with ambiguous words (eg, bank) that have more than 1 meaning. Visual targets, some real words and some nonwords, were subsequently projected to each visual field to assess how the brain hemispheres contribute to processing word meaning. Participants decided whether or not each target was a real word. The critical targets were either related to the most frequent meaning of the ambiguous word (money) or to a less frequent meaning (river). These same targets also occurred in an unrelated condition, after a semantically unrelated word. Measures of priming were calculated by subtracting target response times in the unrelated condition from those obtained for either related condition. These priming effects reflect how readily the word meanings are mentally activated in the brain. When critical targets very rapidly followed the ambiguous words, both frequent and less frequent meanings were primed in both visual fields/cerebral hemispheres.12 However, with a longer delay between ambiguous words and targets, the less frequent meanings were primed only in the left visual field/ right hemisphere. This suggested that the right hemisphere serves an important maintenance function for secondary meanings of words. More recently, this approach has been extended to examine more distant features or meanings of words (eg, “rotten” as a semantically distant feature of an “apple,”13 or more generally, the connotative meanings of ambiguous words, if those meanings are sufficiently distant from the dominant interpretation of the word). This and other work (summarized in Beeman,14 and Jung-Beeman15) highlights the role of the intact right hemisphere in mentally activating and maintaining activation of distant meanings or features of words, regardless of the larger linguistic context. Beeman14,15 called this activation process coarse semantic coding. He further proposed that figurative language interpretation, some kinds of inference generation, and other aspects of narrative (story) comprehension are supported by the overlapping mental activations that result from coarse semantic coding. For example, a scenario like “when Sue called the lifeguard for help, he saw the broken glass” can yield the inference “Sue cut her foot,” due to remote associations between lifeguard (swim, bare feet) and broken glass. Beeman14 (Jung-Beeman15) and others reasoned that RHD would yield a coarse semantic coding deficit. Several recent studies have documented this difficulty for some individuals with RHD,16 manifest in reduced speed or accuracy to activate or maintain particularly peripheral features or meanings of words. In addition, this coarse coding deficit has been linked Arch Phys Med Rehabil Vol 93, Suppl 1, January 2012

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with poor comprehension of implied information in narratives by adults with RHD, even after accounting for vocabulary knowledge and WMCL.17 A majority of the patients who displayed the coarse coding deficit had lesions that involved the posterior parietal lobe, though this result is based on a small sample. Suppression Deficit Hypothesis The suppression deficit hypothesis (see Tompkins1,2) is a proposal about the nature of narrative comprehension difficulties after RHD, extrapolated from work on normal language comprehension across input media and modalities.18 During an initial phase of normal comprehension, a wide range of interpretive possibilities is mentally activated—from coarse coding processes, linguistic knowledge, and knowledge of the world. Shortly afterwards, a suppression mechanism18 dampens activation that is incompatible with the broader context (eg, for “The farmer’s pigs were crowded. He built a pen,” the contextually-inappropriate “ink” meaning of “pen” is initially active but quickly suppressed). Suppression is often assessed in a relatedness judgment task, in which participants indicate whether a target word (ink) is related to its prior context. The example above illustrates an assessment of suppression in the case of lexical-level ambiguity (pen), but suppression function has been examined in a variety of language forms and functions, including ambiguous inferences and nonliteral language. The suppression deficit hypothesis has 2 premises: (1) when processing material that supports or induces competing interpretations, some adults with RHD who activate those interpretations will be delayed in suppressing whichever is contextually inappropriate, and (2) interindividual differences in suppression function for such interpretations will predict comprehension of narratives by adults with RHD. Both premises were borne out in a series of studies assessing lexical- and inference-level interpretations (see Tompkins19 for summary). In addition, the link between story comprehension and suppression function (which ranges from unaffected to quite delayed for individual patients) is significant even after controlling for vocabulary knowledge, WMCL, and age. These results implicate the right cerebral hemisphere in processes of timely selection from among competing interpretations. Theoretically, coarse coding and suppression deficits could co-occur in adults with RHD. The former would reduce or delay the activation of meanings and features that are particularly distant from the dominant meaning or image of encountered words (eg, “rotten” for apple). The latter would slow the comprehension mechanism that dampens contextually irrelevant mental activation, regardless of considerations like semantic distance. The suppression deficit hypothesis also intersects with the cognitive resources view, in that effective suppression requires attention (as summarized in Tompkins2). Although the suppression deficit hypothesis derives from the psycholinguistic realm, we20 have argued that ineffective suppression could underlie a variety of the other difficulties in table 1, such as incorrect inferences (eg, being led astray by the “ink” meaning of the word “pen” in the example above) or difficulty being relevant. Tompkins et al20 provides an extended discussion of the potential breadth of this account, including its possible relevance for language production tasks and other situations that engender multiple, competing mental activations (eg, when different people’s points-of-view must be considered and reconciled, to understand an action). Pragmatic Deficits Hypothesis The fourth, broader-based account centers on right brain contributions to pragmatics.21,22 Pragmatics refers to the conArch Phys Med Rehabil Vol 93, Suppl 1, January 2012

text-appropriate, social interpretation and use of language, and many of the communication difficulties exhibited by patients with RHD can be situated under this umbrella. Pragmatic deficits may be less apparent in natural situations than research suggests, because pragmatic difficulties usually have been documented with contrived, metalinguistic or metacognitive tasks. For example, Tompkins described a group of patients with RHD who failed on a task of talking about how they would initiate a conversation with someone they did not know, just after welcoming a newcomer with questions and conversation.23 Another example concerns the processing of indirect requests, which are questions that serve as requests for action (eg, “Can you pass the salt?”), but that when taken literally require a yes or no answer. Metacognitive measures have documented a deficit in this area, but adults with RHD responded appropriately when such requests were used as they would be in a clinical setting (eg, “Can you sign your name on this sheet?”24). The pragmatic deficits account intersects with those described above, in that behavior that is pragmatically deficient could be due to deficits in cognitive resource capacity or its allocation, in coarse semantic coding, or in the suppression mechanism. Social Cognition Deficit Hypothesis A related account emphasizes deficits in social cognition.25 According to this view, RHD can impair broad cortical networks involved in empathy, the understanding of social information, and the conduct of social relationships. This account focuses on, for example, difficulty using contextually appropriate politeness conventions, or shaping communication based on information about interpersonal relationships (eg, friends vs boss vs family). Impaired reasoning based on a theory of mind (ToM) also has been attributed to adults with RHD,26 though a study with improved stimulus controls and lower metalinguistic demand did not replicate a ToM deficit.27 ToM refers to an ability to understand and interpret thoughts, beliefs, feelings, and intentions— both our own and those of others—to predict and account for behavior. The social cognition account is most easily distinguished from the coarse coding deficit hypothesis, because the latter emphasizes consequences of impaired word-level processing. The cognitive resources or suppression deficit views, however, may intersect with the social cognition account. For example, reasoning based on ToM requires the activation and then reconciliation of multiple individuals’ knowledge and perspectives. Thus poor performance on the ToM assessment tasks may reflect a limitation in the availability of cognitive resources to handle so much processing. Alternatively, difficulty reconciling the competing mental activations in such tasks may reflect a deficit in suppressing activation that becomes less compatible with a final, integrated interpretation.2,20 Nonetheless, the broader view of potential social impacts of RHD is an important one that merits further investigation. Accounts of Expressive Aprosodia As summarized by Rosenbek et al,28 the 2 major theories of expressive aprosodia emphasize either a motor impairment or a deficit in a “modality-specific nonverbal affect lexicon.”28(p787) The motor deficit may reflect a difficulty programming the movements of the speech mechanism that are needed to produce gradations in pitch, loudness, and duration, or in the actual execution of those movements. The affect lexicon is conceptualized as a right hemisphere counterpart to the left hemisphere verbal lexicon, as a vocabulary


of affective indicators that is presumably crucial for interpreting social signals.29 With its emphasis on social signals, this theory may be at least partly subsumable under the social cognition account. REHABILITATION ISSUES, APPROACHES, EVIDENCE, AND NEEDS Rehabilitation Issues As previously noted, the area of RHD cognitive-communication disorders is quite new, with the earliest systematic research only about 30 years old. As such, there continue to be a variety of challenges to research and rehabilitation. One is the heterogeneity of symptom presentation. This problem interacts with the lack of a sound definition of the disorders, to make it difficult at times to know what characterizes the patients in research studies. Other difficulties include a dearth of explicit, testable models of the domains and systems that support interpersonal communication; the vast range of normal in these domains and systems, that can make it difficult to discern what is disordered; and the still preliminary understanding of the nature of these disorders, that creates a challenge for tailoring treatments with the best chance of extra-clinic generalization and important daily life outcomes. Rehabilitation Approaches In most clinical situations, the medical model still prevails: clinicians identify and try to fix impairments. Increasingly, however, skilled clinicians think beyond the level of the deficit. The International Classification of Functioning, Disability and Health30 reminds us to consider how health conditions limit everyday activities and restrict habitual roles, and to take into account relevant contextual factors. Similarly, a multidimensional applied cognitive rehabilitation approach points us away from the mere existence of deficits and toward the functional impact of those deficits.31 This approach conceptualizes treatment as a process of addressing obstacles to patients’ attainment of their own goals. In this view, deficits are appropriate for direct treatment only when they create meaningful obstacles to goal attainment. Other obstacles may be factors outside of the patients themselves. Behavioral rehabilitation often has a restorative bent, aiming to improve the underpinnings of deficient performance. A renewed emphasis on restorative treatments has stemmed from increasing evidence of brain plasticity, which seems to be potentiated by intensive rehabilitation, even long postonset of stroke (eg, Cornelissen,32 Meinzer,33 and colleagues). Treatment also can take a compensatory focus, to work around existing deficits. Evidence Evidence-based practice has been defined in various ways, but in general involves applying the best available evidence to solve clinical problems.34 Evidence-based practitioners select treatments by considering research evidence, clinical expertise, and patient preferences.34 There is extensive research evidence on treatments for unilateral neglect, but otherwise, the evidence base for the RHD population is just emerging. This section summarizes the best available research evidence for difficulties associated with cognitive-communication disorders in RHD. Treatments specifically tested on RHD samples are considered first in each subsection. Evidence also is discussed briefly, when applicable, for patients with behavioral similarities to the RHD population, but due to other etiologies, most notably traumatic brain inju-

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ries. Most of the treatments investigated thus far have a restorative orientation, aimed at alleviating deficits. In this work, expectations vary for generalization to untreated behaviors, domains, or situations. Expert clinical opinion is available in a number of sources (eg, Blake,21 Mackenzie and Brady,35 Tompkins and Gibbs Scott36). In a few of the subsections below, expert clinical opinion is integrated with research evidence. A preliminary exploration of patient preference is reported in a recent study of a treatment for self-awareness and self-regulation37; results of this exploration also are described briefly. Research on Treatment of Cognitive-Communication Disorders in RHD Evidence has begun to emerge for treatment of coarse coding and suppression deficits, spoken interpretation of metaphor, and expressive aprosodia (diminished vocal intonation). Reading and writing outcomes are included in some of the treatments for neglect, which are addressed under research for treatment of cognition, below. For inefficient coarse coding and suppression, preliminary effects have been reported for 2 versions of a contextual constraint treatment.38 The treatment addresses (the speed of) these general comprehension processes, that, as described above, may underlie many aspects of performance in adults with RHD (eg, drawing and revising inferences, interpreting figurative language, comprehending narratives). As such, the effects of treatment are proposed to generalize more broadly than treatments that target specific language forms, like metaphor. The treatment is novel in being applied implicitly, for coarse coding, or with little demand on cognitive resources, for suppression. As such, it builds on well-documented strengths of the RHD population.1,2 Treatment tasks replicate the research tasks used to document the deficits, and differ slightly in the 2 versions of treatment. In the coarse coding version, the task is simply to decide as quickly as possible whether a target string of phonemes (speech sounds) is a real word or not. In the suppression version, the task is to decide as quickly as possible whether a target word fits with the meaning of a prior sentence. There are 2 primary reasons to emphasize speed of response. The first is because coarse coding and suppression deficits in RHD typically reflect delays or inefficiencies, rather than outright failure of these processes. The second is to tap processing that is relatively unaffected by metalinguistic strategies. The treatment involves presenting simple context sentences before a target word occurs, to bias or constrain the intended meaning or feature of another word to the meaning or feature represented by the target. To illustrate for coarse coding treatment, consider the target “rotten.” To facilitate activation of this distant feature of the word “apple,” a strongly constraining context is first presented: “The fruit smelled awful. It had turned very soft.” After this, the patient hears the experimental stimulus “There was an apple—rotten,” and responds to indicate that “rotten” is indeed a real word. (The task also includes items with nonword targets). Similarly, for suppression treatment, the biasing context “He looked at his pigs. They were too crowded” is presented prior to the experimental stimulus “He built a pen—ink.” This context facilitates the context-appropriate interpretation of the ambiguous word “pen” and bolsters suppression of the context-inappropriate, “ink” meaning. This contextual prestimulation or priming sped target responses of 3 participants with RHD, a result proposed to reflect the facilitation of coarse semantic coding and suppression processes. While these initial data suggest that contextual constraint treatment may have promise, the true test of its value Arch Phys Med Rehabil Vol 93, Suppl 1, January 2012

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will come from data currently being collected on generalization of treatment effects38 to the previously noted comprehension consequences of coarse coding and suppression deficits (improvements in certain types of inferencing, interpreting nonliteral language, and comprehending narratives) and to functional reasoning tasks that involve competing options. A highly metalinguistic treatment for novel metaphor (eg, “A family is a cradle”) also has demonstrated preliminary effects.39 Treatment activities include judging connotations of the word-level concepts represented in the metaphors (Is a family protective? Comfortable?); judging associations between these concepts (Are both families and cradles protective?); and generating associations between concepts (What else do families and cradles have in common?). Spoken interpretation of novel metaphors improved in quality for all 5 participants with RHD, with 3 maintaining their gains for 3 months. Nonliteral language comprehension improved in 1 patient. Turning to expressive aprosodia, preliminary evidence is available for 2 treatments targeting production of emotional prosody. One is cognitive-linguistic in nature and the other has a motor-imitative focus.40 The cognitive-linguistic approach, derived from the affective nonverbal lexicon theory, involves associating representations of emotion with one another (written label, facial expression, prosody). The motor-imitative treatment moves from maximal to minimal support in producing prosodic patterns (from clinician modeling to independent production). Effects for 14 participants have ranged from slight to sizeable, with no generalization to untrained emotions. The same research group has combined the treatments and is evaluating the effects of adding knowledge of performance or knowledge of results.41 Knowledge of performance is provided by an auditory signal, a visual display, and discussion to compare the display of the patient’s production with a target. Knowledge of results involves telling the patient only whether the production is correct or incorrect. Research on Treatment of Cognition in RHD Relevant treatment evidence is available for the areas of attention, including neglect, memory, and executive functioning. A survey of this evidence base is highly pertinent to this review, because, as described above, these cognitive deficits have been demonstrated or hypothesized to predict, influence, or underlie many of the communicative difficulties in adults with RHD. As such, treatments for cognitive deficits hold promise for improving language and communication in this population. Communicative outcomes have been targeted in some of these cognitive treatments, and in the future, should be so targeted more often. In the attention domain, a systematic review endorsed early treatment of attention deficits as a practice guideline for stroke patients; this review also cautioned against computerized drills without a clinician.42 Unfortunately, this review and most other relevant literature do not address right hemisphere stroke specifically. An exception is a small, single-blind randomized trial43 investigating Attention Process Training44 in patients with RHD. Attention Process Training is a comprehensive, theoretically based treatment that targets sustained, selective, alternating, and divided attention. Five weeks after treatment ended, the experimental group performed better than a nontreatment control group on tests of subtle selective attention. Neglect, as noted previously, is the subject of many published reviews and treatment studies, including a number of controlled trials (for reviews, see Arene and Hillis,45 Bowen and Lincoln46). One problem is that extant neglect treatment studies likely mixed participants with various forms of neglect Arch Phys Med Rehabil Vol 93, Suppl 1, January 2012

(viewer-centered vs stimulus-centered spatial neglect, spatial vs motor neglect, combinations), necessitating cautious interpretation of results and recommendations. Visual scanning training (VST), targeting mainly viewercentered spatial neglect, has been endorsed as a practice standard.42 VST has many variants, but in general, requires patients to consciously distribute their attention broadly, to targets that appear in both visual fields. Improvement has been reported to generalize to functional reading, writing, and motor tasks, with long-lasting gains in some cases. Using more complex stimuli seems to improve generalization effects. The same systematic review42 recommended as a practice option VST with electronic adjuncts (eg, a buzzer) or combined with forced limb activation (typically provided for motor neglect). Limb activation treatments generally involve initiating movements of a left-sided limb, usually the arm, into left hemispace. This active form of limb activation appears to yield greater benefits than a passive version, in which the affected limb is moved, by the patient or the clinician, into left space. Substantial and durable gains have been reported even for a patient with severe neglect.47 A randomized controlled trial documented improvements from training that requires a patient to use the left arm to deactivate a loudly buzzing alerting device,48 though evidence of functional gains remains elusive. Other approaches to the treatment of neglect use bottom-up stimulation (eg, see Arene and Hillis,49 Luauté et al50) to target patients who cannot voluntarily engage attention to treatment tasks. Treatment effects are generally transitory, with prism adaptation the potential exception. In prism adaptation, a sensorimotor approach that induces procedural learning, the patient wears prism glasses or goggles that shift the left visual field to the right. One study reported gains that lasted out to 6 months postonset.51 As noted by Arene and Hillis,49 patients with right cerebellar damage may not be good candidates for this treatment. In a recent randomized controlled trial,52 a spatial exploration treatment was combined with either of 2 bottom-up approaches: transcutaneous electrical nerve stimulation to leftsided neck muscles, or optokinetic stimulation, using visual stimuli that slowly moved to the left without eliciting nystagmus. A control group did only the spatial exploration. Greater effects were reported for both combined treatments than for spatial exploration alone, with generalization to simple reading and writing tasks that maintained for a week posttreatment. Several aspects of this study make it difficult to interpret the results, however. For example, pretreatment reading and writing performance was significantly worse in the control group than the other 2 groups. The control group also was potentially more neurologically stable (mean, 44d) when treatment was initiated (transcutaneous electrical nerve stimulation group mean, 25d; optokinetic group mean, 36d), calling into question contributions of spontaneous recovery. Finally, the spatial exploration treatment did not include complex scanning tasks of the kind associated with better generalization in VST. Thus, the jury remains out on the relative effectiveness of these treatment approaches. Exciting developments in neglect treatment are proliferating, and initial evidence exists for constraint-induced movement therapy53 and treatment via transcranial direct current54 or repetitive transcranial magnetic stimulation.55,56 Dopamine and norepinephrine agonists are also being examined as adjuncts, to treat sustained attention, alerting, and arousal in patients with neglect.57 Turning to memory and learning, a systematic review42 endorsed the training of external memory aids as a practice standard for individuals with relatively mild impairments due


to stroke or traumatic brain injury. This approach probably works best when focused on patient-identified needs with a socially acceptable aid. One recent example is a text messaging system57; more traditional are various kinds of memory notebooks, which are often used to support communication. It must be emphasized that patients need to be trained to use these notebooks, sometimes extensively. The amount of training typically provided in clinics in the United States may be woefully inadequate, in part due to restrictions on insurance coverage for treatment and in part due to the uninformed opinion that little training is necessary. For patients with more severe memory and planning difficulties, treatment to achieve functional outcomes with external compensations has been recommended as a clinical practice guideline.42,58 Again, extensive training is required to use these compensations, and in the case of assistive devices, training may be needed first just to get the patient to bring the device to treatment sessions. Treatment to acquire particularized information or skills, such as touch typing59 or adapted email,60 is endorsed as a practice option.42 A recent systematic review of instructional methods61 recommended an errorless learning approach for memory deficits of diverse causes and severities, as well as for varying memory targets (eg, declarative information, procedural skills) and tasks. Errorless learning aims to minimize errors during acquisition. This approach often involves modeling before a patient attempts a response, with clinician support carefully faded while maintaining accuracy. If an error occurs, the clinician immediately provides the correct response and has the patient try again. Expanded rehearsal, or spaced retrieval practice, was recommended in the same review for declarative memory training. In this approach, patients practice recalling specific target information over systematically increasing time delays. Working memory has been addressed in a randomized pilot study of young, chronic stroke patients.62 Improvements in neuropsychologic test performance and self-rated cognitive function were reported after 5 weeks of computerized training on various working memory tasks. Unfortunately, the sample size was small, and the randomization resulted in some potentially important differences between the experimental group and the no-treatment control group, in terms of lesion location and etiology (hemorrhage vs infarct). Finally, some progress has been made in treatment of executive functioning. For example, substantial gains in self-awareness and self-regulation were reported for a young patient with a right thalamic hemorrhage, after 12 weeks of comprehensive training for self-knowledge, self-perception, self-evaluation, self-prediction, self-reflection, self-monitoring, self-correction, goal identification, and on-the-job training.37 The patient was also able to get and keep a job, something he had not been successful at before treatment. Generalization of these results is of course limited by the N of 1, and by characteristics of the patient. For example, he did not have neglect, and had good metacognition. More importantly, it is hard to discern the mechanism(s) of reported improvements. The patient was receiving concurrent counseling/psychotherapy, had access to a disability employment service that offered on-the-job support, and participated in a unique partnership with the clinician. Specifically, he was interviewed for 10 to 15 minutes after each session to provide his perspectives about the treatment. He articulated several recurring themes, related to the importance of understanding social performance standards, learning through meaningful experiences, and individuated examples and exercises. He also commented about the confidence-building aspects of the treatment experience.

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Many of the techniques used to treat this young man are part of metacognitive strategy instruction (MSI). A recent systematic review and meta-analysis has endorsed MSI as a practice standard for patients with traumatic brain injuries who have difficulties with daily life planning, organization, problemsolving, and multitasking63; these problems can characterize patients with RHD, as well.64 MSI also includes time pressure management (eg, planning ahead, adjusting environment when possible, practicing a few times) and strategic thinking training (eg, clinician models problem-solving strategies, explaining decisions). MSI often incorporates external organizers and prompts, such as charts, notebooks, checklists, and cue cards. It is important to note, particularly for patients who cannot engage in such highly metalinguistic activities, that behavior can be changed without the patient’s explicit acknowledgment of awareness (eg, Cicerone et al42). To accomplish this, treatment should tap implicit learning of a procedure, as described above for patients with severe memory and planning abilities. Rehabilitation professionals and family members alike may need to be counseled that it is not necessary for patients to admit their deficits in order to make progress in treatment. Expert clinical opinion on awareness training also recommends experiential exercises.31,65 Rather than contradicting patients’ clearly unrealistic goals, members of the rehabilitation team engage patients in supported exploration and experience of subgoals. The aim of this approach is to improve patients’ awareness of gaps between their conditions or experiences and their goals, and to help them discard those goals, implicitly or explicitly, for alternatives. This approach must be used with caution, in an empathetic and supportive manner, as it may yield strong emotional responses in patients who begin to realize the extent and implications of their difficulties. Rehabilitation Needs The rehabilitation needs in the area of RHD cognitivecommunication disorders are many and varied. Clearly, more treatment evidence is essential, of every kind. But in particular, evidence is lacking for approaches that focus on obstacles to goal attainment other than patients’ deficits. Among these obstacles might be the expectations or misattributions of others—the patient is rude, lazy, not suited for treatment—which could be addressed by demonstration and training. Communication partners could be trained to interact in ways that reduce obstacles (eg, provide contextual constraint; supply and guide use of cue cards and other prompts or organizers; learn to elicit appropriate responses, reduce and simplify input, identify triggers and reinforcers of desired and undesirable behaviors). It is both legitimate and necessary to target clinical interventions in these ways, but in the United States, at least, insurance coverage is limited or unavailable for work with people other than the patient. In addition, treatment research going forward needs to specify clearly the theoretical underpinnings of rehabilitation approaches, and to explicitly program for and assess generalization to daily life activities and participation. Finally, and fundamentally, progress in this area will require a good definition of RHD cognitive-communication disorders, which incorporates inclusion and exclusion criteria, potential bases of common patterns of impairments, and factors likely to affect the expression or nature of strengths and weaknesses in individual subsets of patients. References 1. Tompkins CA, Klepousniotou E, Gibbs Scott A. Nature and assessment of right hemisphere disorders. In: Papathanasiou I, Coppens P, Potagas C, editors. Aphasia and related neurogenic communication disorders. Sudbury: Jones and Bartlett; 297-343. Arch Phys Med Rehabil Vol 93, Suppl 1, January 2012

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