Pharmacotherapy of aphasia. A critical review

Are pharmacotherapeutics effective for treating aphasia?

INTRODUCTION

Aphasia is a communication disorder resulting from stroke and/or neurodegenerative conditions which involve the left cerebral hemisphere. It is a debilitating disorder affecting a person's ability to speak, understand, read, and write. Its impact on daily life necessitates therapeutic strategies to aid patients with aphasia.

AREAS COVERED

In this special report, the authors speculate whether current pharmacotherapeutic strategies are effective in treating aphasia. The authors look at aphasia caused by different conditions and how this could impact therapy before providing the reader with their expert perspectives. The aim of this paper is for the reader to gain a clearer understanding of the efficacy of the current pharmacotherapeutic treatment paradigms as well as potential future developments.

EXPERT OPINION

The exploration of pharmacotherapy for aphasia in vascular brain disorders and neurodegenerative diseases has received much attention in recent years with various therapeutic strategies having been put forward. In terms of whether pharmacotherapy is effective for the treatment of aphasia, there is still no clear-cut answer. Further research is needed with more studies requiring a greater emphasis on language and communication deficits. Biomarkers may also help clinicians provide their patients with a more personalized treatment plan.

Supporting Post-Stroke Language and Cognition with Pharmacotherapy: Tools for Each Phase of Care

PURPOSE OF REVIEW

There is enormous enthusiasm for the possibility of pharmacotherapies to treat language deficits that can arise after stroke. Speech language therapy remains the most frequently utilized and most strongly evidenced treatment, but the numerous barriers to patients receiving the therapy necessary to recover have motivated the creation of a relatively modest, yet highly cited, body of evidence to support the use of pharmacotherapy to treat post-stroke aphasia directly or to augment traditional post-stroke aphasia treatment. In this review, we survey the use of pharmacotherapy to preserve and support language and cognition in the context of stroke across phases of care, discuss key ongoing clinical trials, and identify targets that may become emerging interventions in the future.

RECENT FINDINGS

Recent trials have shifted focus from short periods of drug therapy supporting therapy in the chronic phase to longer terms approaching pharmacological maintenance beginning more acutely. Recent innovations in hyperacute stroke care, such as tenecteplase, and acute initiation of neuroprotective agents and serotonin reuptake inhibitors are important areas of ongoing research that complement the ongoing search for effective adjuvants to later therapy. Currently there are no drugs approved in the United States for the treatment of aphasia. Nevertheless, pharmacological intervention may provide a benefit to all phases of stroke care.

Reversing the Ruin: Rehabilitation, Recovery, and Restoration After Stroke

PURPOSE OF REVIEW

Stroke is a common cause of disability in aging adults. A given individual's needs after stroke vary as a function of the stroke extent and location. The purpose of this review was to discuss recent clinical investigations addressing rehabilitation of an array of overlapping functional domains.

RECENT FINDINGS

Research is ongoing in the domains of movement, cognition, attention, speech, language, swallowing, and mental health. To best assist patients' recovery, innovative research has sought to develop and evaluate behavioral approaches, identify and refine synergistic approaches that augment the response to behavioral therapy, and integrate technology where appropriate, particularly to introduce and titrate real-world complexity and improve the overall experience of therapy. Recent and ongoing trials have increasingly adopted a multidisciplinary nature - augmenting refined behavioral therapy approaches with methods for increasing their potency, such as pharmaceutical or electrical interventions. The integration of virtual reality, robotics, and other technological advancements has generated immense excitement, but has not resulted in consistent improvements over more universally accessible, lower technology therapy.

Effectiveness of Atomoxetine (Strattera) for the Treatment of Poststroke Aphasia Combined With Cognitive Impairment

OBJECTIVE

In this study, we aimed for the first time to evaluate the effectiveness of atomoxetine (Strattera) in the treatment of cognitive impairment and aphasia after stroke in a large sample.

METHODS

We reviewed the data of 106 patients with poststroke aphasia and cognitive impairment (atomoxetine treatment group = 55 patients vs control group = 51 patients), including scores of the Korean version of the Mini-Mental State Examination (K-MMSE) and the Korean version of the Western Aphasia Battery. Wilcoxon signed-rank tests were used to compare the initial and follow-up K-MMSE and Korean version of the Western Aphasia Battery scores. Mann-Whitney U tests were used to compare the degree of improvement in K-MMSE and Aphasia Quotient (AQ) scores between the atomoxetine and control groups.

RESULTS

Baseline characteristics including age, years of education, and scores of the initial Functional Independence Measure, Korean version of the Modified Barthel Index, Hamilton Depression Rating Scale, K-MMSE, and AQ did not differ significantly between the 2 groups. Follow-up K-MMSE and AQ scores were significantly better than the initial scores in both the treatment and control groups. However, improvements in K-MMSE scores were significantly greater in the treatment group than in the control group. In addition, the atomoxetine group had significantly higher AQ scores than the control group, especially for auditory verbal comprehension and naming.

CONCLUSIONS

Atomoxetine has been shown to significantly improve cognitive function and language in patients with poststroke aphasia. It is also the first study to report improvement in auditory comprehension and naming by administration of atomoxetine.

Better language through chemistry: Augmenting speech-language therapy with pharmacotherapy in the treatment of aphasia

Speech and language therapy is the standard treatment of aphasia. However, many individuals have barriers in seeking this measure of extensive rehabilitation treatment. Investigating ways to augment therapy is key to improving poststroke language outcomes for all patients with aphasia, and pharmacotherapies provide one such potential solution. Although no medications are currently approved for the treatment of aphasia by the United States Food and Drug Administration, numerous candidate mechanisms for pharmaceutical manipulation continue to be identified based on our evolving understanding of the neurometabolic experience of stroke recovery across molecular, cellular, and functional levels of inquiry. This chapter will review evidence for catecholaminergic, glutamatergic, cholinergic, and serotonergic drug therapies and discuss future directions for both candidate drug selection and pharmacotherapy practice in people with aphasia.

Enhancing Recovery after Stroke with Noradrenergic Pharmacotherapy: A New Frontier?

Despite much progress in stroke prevention and acute intervention, recovery and rehabilitation have traditionally received relatively little scientific attention. There is now increasing interest in the development of stroke recovery drugs and innovative rehabilitation techniques to promote functional recovery after completed stroke. Experimental work over the past two decades indicates that pharmacologic intervention to enhance recovery may be possible in the subacute stage, days to weeks poststroke, after irreversible injury has occurred. This paper discusses the concept of “rehabilitation pharmacology” and reviews the growing literature from animal studies and pilot clinical trials on noradrenergic pharmacotherapy, a new experimental strategy in stroke rehabilitation. Amphetamine, a monoamine agonist that increases brain norepinephrine levels, is the most extensively studied drug shown to promote recovery of function in animal models of focal brain injury. Further research is needed to investigate the mechanisms and clinical efficacy of amphetamine and other novel therapeutic interventions on the recovery process.

Review : The Neurobiology of Stroke Rehabilitation

Cerebrovascular disease plays a paramount role in mortality and morbidity, and the clinical and basic sci entific study of acute stroke has blossomed, leading both to increased survival and to increasing numbers of people with disabilities from stroke. Neurobiological study of the chronic form of this prevalent neurological disease has lagged behind investigation of the acute illness. This article reviews how and why this situation will change. Four major points are addressed: 1) The anatomical organizations of functional brain systems are less topographically precise than commonly believed. 2) Cortical plasticity exists in adults and takes a number of forms, including unmasking of existing circuits, growth of new synapses via axonal sprouting or dendritic proliferation, and development of compensatory processes. 3) It is possible to manipulate this plasticity with behavioral and pharmacological interventions, and such manipulations can have a beneficial effect on recovery. 4) Functional neuroimaging, particularly the noninvasive method of fMRI, can be used to study in vivo both cerebral plasticity after stroke and the interventions that might influence recovery by affecting this plasticity. Although there is much to be accomplished, the prognosis is extremely good for a neuroscience of stroke rehabilitation. NEUROSCIENTIST 4:426-434, 1998

Psycholinguistics of Aphasia Pharmacotherapy: Asking the Right Questions

BACKGROUND

Among the obstacles to demonstrating efficacy of pharmacological intervention for aphasia is quantifying patients' responses to treatment in a statistically valid and reliable manner. In many of the review papers on this topic (e.g., Berthier et al., 2011; de Boissezon, Peran, de Boysson, & Démonet, 2007; Small & Llano, 2009), detailed discussions of various methodological problems are highlighted, with some suggestions on how these shortcomings should be addressed. Given this deep understanding of caveats associated with the experimental design of aphasia pharmacotherapy studies (e.g., Berthier et al., 2011), investigations continue to produce inconsistent results.

AIM

In this review paper we suggest that inclusion of theory-driven linguistic measures in aphasia pharmacotherapy studies would add an important step toward elucidating precise patterns of improvement in language performance resulting from pharmacotherapeutic intervention.

MAIN CONTRIBUTION

We provide a brief review of the clinical approaches currently used in pharmacotherapy studies of aphasia, which often lack psycholinguistic grounding. We then present ways in which psycholinguistic models can complement this approach, offering a rationale for task selection, and as a result, lead to a better understanding of treatment effects. We then follow with an example of how such an integrative approach can be implemented in studies targeting stress reduction in people with aphasia, via beta-blocking agents, as a means to augment language performance, using the psycholinguistic framework of "linguistic anxiety" outlined in Cahana-Amitay et al, 2011 as our guideline.

CONCLUSION

We conclude that the incorporation of psycholinguistic models into aphasia pharmacotherapy studies can increase the resolution with which we can identify functional changes.

Neuronal plasticity in poststroke aphasia: insights by quantitative electroencephalography

After stroke, the interhemispheric reorganization of the neural network implicated in language is hypothesized to be a function not only at the site of the lesion but also of dynamic right hemispheric and subcortical neural systems. These neural systems may have different functional shares in the utilization of particular language tasks. Important insights in language rehabilitation have been gained by quantitative topographical electroencephalography. It has been demonstrated that abnormalities within and outside speech relevant areas are related to restitution of poststroke aphasia. In the ischemic regions they indicate local disturbances, outside they reflect failures in neuronal networks involved in the generation and propagation of the alpha-rhythm. Treatment by a neuromodulatory agent has shown a significant shift of alpha-rhythm from frontal to occipital regions which may be due to a restitution of corticothalamic circuits in parallel to an improvement of neuropsychological scores in different language domains.

Repairing the human brain after stroke. II. Restorative therapies

Spontaneous behavioral recovery is usually limited after stroke, making stroke a leading source of disability. A number of therapies in development aim to improve patient outcomes not by acutely salvaging threatened tissue, but instead by promoting repair and restoration of function in the subacute or chronic phase after stroke. Examples include small molecules, growth factors, cell-based therapies, electromagnetic stimulation, device-based strategies, and task-oriented and repetitive training-based interventions. Stage of development across therapies varies widely, from preclinical to late-phase clinical trials. The optimal methods to prescribe such therapies require further studies, for example, to best identify appropriate patients or to guide features of dosing. Likely, anatomic, functional, and behavioral measures of brain state, as well as measures of injury, will each be useful in this regard. Considerations for clinical trials of restorative therapies are provided, emphasizing both similarities and points of divergence with acute stroke clinical trial design.

The explicit learning of new names for known objects is improved by dexamphetamine

A randomised, double-blind, placebo-controlled, between subjects study design (N=37) was used to investigate the effects of dexamphetamine on explicit new name learning. Participants ingested 10mg of dexamphetamine or placebo daily over 5 consecutive mornings before learning new names for 50 familiar objects plus fillers. The dexamphetamine group recognised and recalled the new names more accurately than the placebo group over the 5 days and 1 month later. Word learning success was not associated with baseline neuropsychological performance, mood, cardiovascular arousal, or sustained attention. These results may have implications for the pharmacological treatment of acquired naming difficulties.

Impaired cognition and attention in adults: pharmacological management strategies

Cognitive psychology has provided clinicians with specific tools for analyzing the processes of cognition (memory, language) and executive functions (attention-concentration, abstract reasoning, planning). Neuropsychology, coupled with the neurosciences (including neuroimaging techniques), has authenticated the existence of early disorders affecting the "superior or intellectual" functions of the human brain. The prevalence of cognitive and attention disorders is high in adults because all the diseases implicating the central nervous system are associated with cognitive correlates of variable intensity depending on the disease process and the age of the patient. In some pathologies, cognitive impairment can be a leading symptom such as in schizophrenia, posttraumatic stress disorder or an emblematic stigmata as in dementia including Alzheimer's disease. Paradoxically, public health authorities have only recognized as medications for improving cognitive symptoms those with proven efficacy in the symptomatic treatment of patients with Alzheimer's disease; the other cognitive impairments are relegated to the orphanage of syndromes and symptoms dispossessed of medication. The purpose of this review is to promote a true "pharmacology of cognition" based on the recent knowledge in neurosciences. Data from adult human beings, mainly concerning memory, language, and attention processes, will be reported. "Drug therapeutic strategies" for improving cognition (except for memory function) are currently rather scarce, but promising perspectives for a new neurobiological approach to cognitive pharmacology will be highlighted.

Metacognition in stroke: bedside assessment and relation to location, size, and stroke severity

BACKGROUND

Frontal syndromes are poorly represented on stroke scales, yet may constitute an important component of the neurologic deficit impacting treatment and rehabilitation efforts.

AIMS

To validate an assessment of a frontal network syndrome score (FNSS) in stroke and to ascertain the relationship of the FNSS to lesion location, volume, and severity in young people with stroke.

METHODS

Accrual through a cognitive stroke registry of young, alert, nonaphasic, nonencephalopathic, nonsubstance abuse prone people who were tested with the 16 domain FNSS within 4 weeks of their stroke. Lesion location was determined by the Cerefy 3-dimensional, digital, coxial brain atlas identifying 6 regions of cerebral interest. Lesion severity was assessed by the National Institute of Health Stroke Score and infarct volume was measured in cubic centimeters.

RESULTS

From a sample of 456 cases in the registry after exclusions of encephalopathy, depression, and aphasia, cases with frontal network syndrome encompassed 132 of 341 persons (39%). Of these patients (n=80) with mean age 45.7 years [confidence interval (CI): 43.4, 48.1], educational level 13.1 years (CI:12.5, 13.6), mean National Institute of Health Stroke Score of 3.3 (CI: 2.6, 4.0), and mean lesion volume 30.3 mL (CI: 13.7, 46.9), had full testing with the FNSS battery yielding sensitivity (93%), specificity (74%), positive predictive value (79%), negative predictive value (90%), and a good interrater reliability (kappa=0.89, P=0.001). Construct validity testing with 15 frontal neuropsychologic tests revealed good to excellent significant Pearson r values in 14 of 15 of the tests. There was no correlation (Pearson's) for lesion volume (r=0.07, P=0.52) but significant correlation with stroke severity (r=0.23, P=0.03). Analysis of variance testing of the FNSS revealed significant differences for all 6 domains without intergroup significant differences for frontal network syndrome domains in the stroke group.

CONCLUSIONS

The FNSS is a valid, practical measure of frontal syndromes in stroke. Frontal syndromes are common in young people with stroke and may be present no matter where the lesion, are not dependent on size of stroke and have a low correlation with stroke severity.

Long-Term Antidepressant Treatment with Moclobemide for Aphasia in Acute Stroke Patients: A Randomised, Double-Blind, Placebo-Controlled Study

BACKGROUND AND PURPOSE

Pharmacotherapy aimed at stroke rehabilitation through direct central nervous effects may be assumed to work in a similar way for language recovery and sensory-motor recovery. Some data suggest that antidepressant drugs could be beneficial also for functional improvement. This prompted us to investigate whether regression from aphasia after acute stroke could be enhanced by antidepressive drug therapy.

METHODS

We randomised 90 acute stroke patients with aphasia to either 600 mg moclobemide or placebo daily for 6 months, within 3 weeks of the onset of stroke. Aphasia was assessed prior to treatment and at 6 months, using Reinvang's 'Grunntest for afasi' and the Amsterdam-Nijmegen-Everyday-Language-Test (ANELT).

RESULT

The degree of aphasia decreased significantly at 6 months, with no difference between the moclobemide- and the placebo-treated groups. Multivariate regression analysis including treatment group, activities of daily living, aetiology of stroke, ANELT, and Reinvang's coefficient at baseline, and neurological deficit confirmed these results. In all, 13 in the moclobemide and 10 in the placebo group stopped taking the study medication. No further change was found in the 56 aphasic patients followed up for another 6 months with no medication.

CONCLUSIONS

Compared to placebo, treatment with moclobemide for 6 months did not enhance the regression of aphasia following an acute stroke.

Cognitive impairment in isolated subtentorial stroke

BACKGROUND

Recent case reports have implicated subtentorial lesions of the brainstem or cerebellum as part of the neurocognitive circuitry.

AIM

To determine whether cognitive impairment is part of the neurological deficit in isolated brainstem (IBSS) or cerebellar stroke (ICS), using bedside screening and formal neurocognitive assessment of higher cortical function.

METHODS

Accrual occurred through a hospital based stroke registry. Cognitive bedside tests and neuropsychological tests were employed for the detection of higher cortical function. Scores from each test were converted to age and education based z-scores. Scores at or below -1.5 SD were clinically defined 'impaired'. Scores were averaged across tests in each functional area.

RESULTS

Of the stroke patients (n = 1360), the infarct was isolated within the brainstem (IBSS) in (45 of 120 or 38%) and isolated within the cerebellum (ICI) in (37 of 79 or 46.8%). Comparison of the IBSS patients with cognitive impairment in one or more domains to those with brainstem (24 of 45 or 53%) and hemispheric cerebral infarcts: (43 of 72 or 58%) (Pearson Chi Square) was not significantly different (P = 0.49). The admission Canadian Neurological Score (mean 10.2, 95% CI: 9.7-10.2) and Rankin score at 1 month (mean 1.7, 95% CI: 2.1-1.4). Comparison of the number of ICI patients with cognitive impairment in one or more domains (13 of 37 or 35.1%) to those with cerebellar and hemispheric cerebral infarcts who had abnormal cognitive testing in one or more domains (16 of 36 or 44.4%) (Pearson Chi Square) was not significantly different (P = 0.41). The mean admission Canadian Neurological Scores for the ICI cases was 10.9 (95% CI: 10.5-11.2) on average. Their mean admission Rankin score was 1.7 (95% CI: 1.4-2.1). Neuropsychological testing for frontal/executive skills, immediate and delayed memory, and visuospatial abilities (n = 15), revealed that frontal abilities were most impacted by the isolated strokes in these patients (average frontal impairment index = -1.29 +/- 0.79) followed by delayed recall of verbal and visual information (mean = -1.18 +/- 1.17). Immediate memory (-0.51 +/- 0.75) and visuoconstructive skills (-0.06 +/- 0.88) were relatively spared. Overall, 47% of the patients showed impairment on frontal tasks while 40% had significant impairment in delayed recall. In contrast, only 13% had scores below the cutoff for immediate memory and none fell below the cutoff for visuoconstructive skills.

CONCLUSION

Cognitive impairment is a common sequel of isolated subtentorial stroke. The frequency of impairment is similar either because of isolated brainstem or isolated cerebellar infarct, and similar to cognitive impairment with cerebral hemispheric lesions. Frontal networks or metacognition is the most frequently involved domain.

Fluoxetine modulates motor performance and cerebral activation of patients recovering from stroke

In order to determine the influence of a single dose of fluoxetine on the cerebral motor activation of lacunar stroke patients in the early phase of recovery, we conducted a prospective, double-blind, crossover, placebo-controlled study on 8 patients with pure motor hemiparesia. Each patient underwent two functional magnetic resonance imaging (fMRI) examinations: one under fluoxetine and one under placebo. The first was performed 2 weeks after stroke onset and the second a week later. During the two fMRI examinations, patients performed an active controlled motor task with the affected hand and a passive one conducted by the examiner with the same hand. Motor performance was evaluated by motor tests under placebo and under fluoxetine immediately before the examinations to investigate the effect of fluoxetine on motor function. Under fluoxetine, during the active motor task, hyperactivation in the ipsilesional primary motor cortex was found. Moreover, fluoxetine significantly improved motor skills of the affected side. We found that a single dose of fluoxetine was enough to modulate cerebral sensory-motor activation in patients. This redistribution of activation toward the motor cortex output activation was associated with an enhancement of motor performance.

The meaning of skilled care providers' relationships with stroke and aphasia patients

Little is known about the reciprocal influence of communication difficulties on the care relationship. To illuminate care providers' lived experiences of relationships with stroke and aphasia patients, narrative interviews were conducted with providers particularly successful at communicating with patients. A phenomenological hermeneutic analysis of the narratives revealed three themes: Calling forth responsibility through fragility, restoring the patient's dignity, and being in a state of understanding. The analysis disclosed caring with regard to the patient's desire, which has its starting point in intersubjective relationship and interplay, in which nonverbal communication is essential--that is, open participation while meeting the patient as a presence. Thus, care providers prepare for deep fellowship, or communion, by being available. They described an equality with patients, interpreted as fraternity and reciprocity, that is a necessary element in presence as communion. The works of Marcel, Hegel, Stern, and Ricoeur provided the theoretical framework for the interpretation.

Neuroimaging of recovery of function after stroke: implications for rehabilitation

Stroke is a leading cause of morbidity and mortality in individuals. Many patients have good functional recovery after stroke. The mechanisms of recovery remain largely unknown. Neuroimaging of patients recovering from stroke may provide important insight into the mechanisms of recovery as well as assist in the development of new rehabilitation techniques. The first part of this article reviews previous neuroimaging studies that have monitored the reorganization within the motor and language areas after stroke. In the second section, a unifying theory based on John Hughlings Jackson's "Principles of Compensation" is presented as a possible theory for recovery of function. In the final portion of the article, possible implications and future applications of neuroimaging studies for rehabilitation are presented.

Effects of bromocriptine in a patient with crossed nonfluent aphasia: a case report

OBJECTIVE

Because studies have shown some positive effects of the dopaminergic agent bromocriptine for improving verbal production in patients with nonfluent aphasia, we examined its effect in a patient with an atypical form of crossed nonfluent aphasia from a right hemisphere lesion.

DESIGN

Open-label single-subject experimental ABAB withdrawal design.

PATIENT

A right-handed man who, after a right frontal stroke, developed nonfluent aphasia, emotional aprosodia, and limb apraxia.

INTERVENTION

Escalating doses up to 20mg of bromocriptine in 2 separate phases.

MAIN OUTCOME MEASURES

We measured verbal fluency (words/min in discourse, Thurstone letter fluency), expression of emotional prosody, and gesture production.

RESULTS

The patient showed substantial improvement in both verbal fluency measures and no significant improvement in gesture or emotional prosody. Verbal fluency improvements continued in withdrawal phases.

CONCLUSIONS

Our results are less likely caused by practice or spontaneous recovery because we observed little improvement in emotional prosody and gesture tasks. Verbal fluency improvements during treatment and withdrawal phases suggest that the effects of bromocriptine may be long-lasting in its influence on the neural networks subserving verbal initiation.

Pharmacological treatment for aphasia following stroke

BACKGROUND

Aphasia describes language impairment associated with a brain lesion.

OBJECTIVES

The objective of this review was to assess the effects of drugs on language abilities when given to people with aphasia following stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Register (last searched: May 2001), and reference lists of relevant articles to December 1998. We also contacted academic institutions and other researchers to identify further published and unpublished trials. MEDLINE was searched from 1966-1998, and CINAHL from 1982-1998. We searched the International Journal of Disorders of Communication by hand (known by other names in the past), from 1969 to 1998.

SELECTION CRITERIA

Randomised controlled trials comparing: ~bullet~Any drug given to improve language, versus no treatment, or versus placebo ~bullet~Any drug given to improve language versus speech and language therapy ~bullet~One drug given to improve language versus another drug given with the same aim

DATA COLLECTION AND ANALYSIS

The principal reviewer collected the data, and assessed the quality of the trials with independent data checking and methodological advice. If we could not perform a statistical combination of different studies, we sought missing data. Failing that we provided a description. We sought missing data from authors, or where appropriate, a drug company.

MAIN RESULTS

We considered fifty two studies in detail, from which we identified ten trials suitable for the review. In most cases the methodological quality was unassessable, and only one trial reported sufficient detail for us to complete a description and analysis. This study did lose a large number of patients during its course. Drugs used in the trials identified were piracetam, bifemalane, piribedil, bromocriptine, idebenone, and Dextran 40. We found weak evidence that patients were more likely to have improved on any language measure at the end of the trial if they had received treatment with piracetam (odds ratio 0.46, 95% confidence interval 0.3 to 0.7). The evidence is considered weak because of the large numbers of drop outs from the trials identified, who were lost to follow up. Patients who were treated with piracetam were no more likely (considering statistical significance) than those who took a placebo to experience unwanted effects, including death (odds ratio 1.29, 95% confidence interval for difference 0.9 to 1.7). However, the differences in death rates between the two groups, even though not not statistically significant, do give rise to some concerns that there may be an increased risk of death from taking piracetam. We could not determine if drug treatment is more effective than speech and language therapy. We could not determine whether one drug is more effective than another.

REVIEWER'S CONCLUSIONS

The main conclusion of this review is that drug treatment with piracetam may be effective in the treatment of aphasia after stroke. Further research is needed to explore the effects of drugs for aphasia, in particular piracetam. If a trial is done, this must be large enough to have adequate statistical power. The safety of the drug should be of primary interest. Researchers should examine the long term effects of this treatment, and whether it is more effective than speech and language therapy.

Functional imaging correlates of recovery after stroke in humans

The mechanisms that are responsible for the remarkable potential for functional recovery from stroke in humans remain unclear, and functional tomographic neuroimaging techniques increasingly are being used to investigate this issue. Such studies confirmed that recovery of function is related to the volume of penumbra tissue that escapes infarction. For language, reactivation of the primary functional areas in the dominant hemisphere is associated with the best prognosis. Evidence for functional plasticity in the immediate vicinity of infarcts, as demonstrated under experimental conditions with invasive methods, is still limited after stroke in humans, probably because of the limitations of spatial resolution of most currently available methods. Often, functional changes in the large-scale networks that support motor (for example, supplementary and premotor cortex) and language functions (for example, prefrontal cortex) have been found, more extensively after lesions acquired during childhood than at adult age. A frequent finding is an increase in the cerebral blood flow response in corresponding regions of the healthy hemisphere during unilateral motor activation or language activation. It is, however, not yet clear whether that is related to functional recovery, and there are several observations indicating that it is often inefficient. Further systematic follow-up studies and therapeutic intervention trials are needed to clarify these issues.

Psychostimulant treatment of stroke and brain injury

Psychopharmacology is rapidly becoming an adjuvant treatment to traditional rehabilitation strategies for patients with stroke or brain injury because it helps to facilitate recovery in a time-efficient manner. Norepinephrine, dopamine, acetylcholine, and serotonin appear to play important roles in recovery from stroke or brain injury. Animal models have shown that blockade of these neurotransmitters inhibits recovery, whereas recovery is promoted by drugs that promote norepinephrine, dopamine, acetylcholine, and serotonin activity. Preliminary evidence from human trials supports these findings. Further study is needed, but expanded use of pharmacologic agents for stroke and brain-injured patients appears imminent.

Cerebral functional magnetic resonance imaging activation modulated by a single dose of the monoamine neurotransmission enhancers fluoxetine and fenozolone during hand sensorimotor tasks

Fluoxetine inhibits the reuptake of serotonin, and dextroamphetamine enhances presynaptic release of monoamines. Although the excitatory effect of both noradrenaline and dopamine on motor behavior generally is accepted, the role of serotonin on motor output is under debate. In the current investigation, the authors evidenced a putative role of monoamines and, more specifically, of serotonin in the regulation of cerebral motor activity in healthy subjects. The effects on cerebral motor activity of a single dose of fluoxetine (20 mg), an inhibitor of serotonin reuptake, and fenozolone (20 mg/50 kg), an amphetamine-like drug, were assessed by functional magnetic resonance imaging. Subjects performed sensorimotor tasks with the right hand. Functional magnetic resonance imaging studies were performed in two sessions on two different days. The first session, with two scan experiments separated by 5 hours without any drug administration, served as time-effect control. A second, similar session but with drug administration after the first scan assessed drug effects. A large increase in evoked signal intensity occurred in the ipsilateral cerebellum, and a parallel, large reduction occurred in primary and secondary motor cortices (P < 10(-3)). These results are consistent with the known effects of habituation. Both drugs elicited comparable effects, that is, a more focused activation in the contralateral sensorimotor area, a greater involvement of posterior supplementary motor area, and a widespread decrease of bilateral cerebellar activation (P < 10(-3)). The authors demonstrated for the first time that cerebral motor activity can be modulated by a single dose of fluoxetine or fenozolone in healthy subjects. Drug effects demonstrated a direct or indirect involvement of monoamines and serotonin in the facilitation of cerebral motor activity.

Dopamine and the origins of human intelligence

A general theory is proposed that attributes the origins of human intelligence to an expansion of dopaminergic systems in human cognition. Dopamine is postulated to be the key neurotransmitter regulating six predominantly left-hemispheric cognitive skills critical to human language and thought: motor planning, working memory, cognitive flexibility, abstract reasoning, temporal analysis/sequencing, and generativity. A dopaminergic expansion during early hominid evolution could have enabled successful chase-hunting in the savannas of sub-Saharan Africa, given the critical role of dopamine in counteracting hyperthermia during endurance activity. In turn, changes in physical activity and diet may have further increased cortical dopamine levels by augmenting tyrosine and its conversion to dopamine in the central nervous system (CNS). By means of the regulatory action of dopamine and other substances, the physiological and dietary changes may have contributed to the vertical elongation of the body, increased brain size, and increased cortical convolutedness that occurred during human evolution. Finally, emphasizing the role of dopamine in human intelligence may offer a new perspective on the advanced cognitive reasoning skills in nonprimate lineages such as cetaceans and avians, whose cortical anatomy differs radically from that of primates.

L-DOPS-Accelerated recovery of locomotor function in rats subjected to sensorimotor cortex ablation injury: pharmacobehavioral studies

Central norepinephrine (NE) has been shown to play a beneficial role in amphetamine-facilitated recovery of behavior. To give insight into understanding the mechanism, the present studies were conducted to examine (a) the effects of L-threo-3,4-dihydroxyphenylserine (L-DOPS) combined with benserazide (BSZ; a peripheral aromatic amino acid decarboxylase inhibitor) and L-3,4-dihydroxyphenylalanine (L-DOPA), precursors of NE and dopamine (DA), respectively, on the recovery from beam-walking performance deficits in rats subjected to unilateral sensorimotor cortex ablation injury, and (b) the relationships between the behavioral recovery and the frequency of postoperative training and the size of ablation injury. It was found that the combined treatments with L-DOPS and BSZ promoted the recovery of locomotor function as early as 24 hours after injury. L-DOPA alone, however, did not facilitate behavioral recovery. The results of assay for the tissue levels of NE and its major metabolite (3-methoxy-4-hydoxyphenylethylene glycol; MHPG) in the brain using high-pressure liquid chromotography showed MHPG, but not NE, significantly increased in the cerebellum and the hippocampus. The behavioral recovery was also significantly correlated with the frequency of training subsequent to injury, but inversely with the size of cortex ablation. These results suggest that NE is likely to modulate functional recovery in this rodent model.

Discourse studies in neurologically impaired populations: a quest for action

Organism and environment are in a state of constant interaction, and discourse is viewed as one form of manifestation of this interaction. Through the study of discourse insights can be gained into those components that bring about mental events. Verbal structure, communication of beliefs and action/interaction are highly interactive dimensions of discourse. Taking this perspective as a framework, the findings of discourse studies with a particular emphasis on right-hemisphere brain-damaged individuals are discussed. Neurolinguistic studies of discourse can be divided into four categories: (1) studies that focus primarily at providing a detailed description of the structural and interactional abilities of brain-damaged individuals, (2) studies that are mainly concerned with investigating the processing aspects of discourse, (3) studies that investigate the influence of cognitive systems such as attention or memory on discourse processing, and (4) studies that try to relate discourse processing mechanisms to underlying biological substrates or neurophysiological mechanisms. A quest is made for future research to base discourse studies on well-defined processing theories, to include different processing components and levels, and to systematically investigate the impact of facets of cognitive systems on such processing. Established methodological approaches should be complemented by electrophysiological procedures (such as the event related potentials technique) or functional imaging techniques (such as fMRI) to tackle relationships between discourse processing mechanisms, cognitive systems and underlying biological mechanisms. Consideration of the influence of biochemical processes (such as asymmetries of neurotransmitters, endocrine functions, or influence of pharmacological agents) on component processes may add to our insights.

Different neural circuits subserve reading before and after therapy for acquired dyslexia

Rehabilitative measures for stroke are not generally based on basic neurobiological principles, despite evidence from animal models that certain anatomical and pharmacological changes correlate with recovery. In this report, we use functional magnetic resonance imaging (fMRI) to study in vivo human brain reorganization in a right handed patient with an acquired reading disorder from stroke. With phonological dyslexia, her whole-word (lexical) reading approach included inability to read nonwords and poor reading of function words. Following therapy, she was able to read nonwords and function words, and preferred a decompositional (sub-lexical) strategy in general. fMRI was performed during a reading task before and after treatment. Prior to therapy, her main focus of brain activation was in the left angular gyrus (area 39). After therapy, it was instead in the left lingual gyrus (area 18). This result suggests first that it is possible to alter brain physiology with therapy for acquired language disorders, and second, that two reading strategies commonly used in normal reading use distinct neural circuits, possibly reconciling several conflicting neuroimaging studies of reading.

Piracetam as an adjuvant to language therapy for aphasia: a randomized double-blind placebo-controlled pilot study

OBJECTIVE

To determine whether piracetam 4.8 g/day together with intensive language therapy improved language function more than language therapy alone.

DESIGN

Double-blind, placebo-controlled parallel group study.

SETTING

Referral speech and language clinic of a university department of neurology.

PATIENTS

Sixty-six inpatients with aphasia present between 4 weeks and 36 months.

INTERVENTIONS

Intensive language therapy for 6 weeks in all patients. Thirty-two patients received piracetam 4.8 g daily and 34 patients received placebo.

MAIN OUTCOME MEASURE

The Aachen Aphasia Test (AAT), a standardized procedure for evaluating the severity of aphasia, was performed at baseline and after 6 weeks' treatment.

RESULTS

In 50 patients evaluated for efficacy, a trend toward improvement in the active group was observed in all subtests of the AAT. This trend was statistically significant for absolute differences in recovery of "written language" and "profile level."

CONCLUSION

Piracetam appears to have a positive adjuvant effect on the recovery of aphasia in patients receiving intensive language therapy.