A double-blind, placebo-controlled study of the use of amphetamine in the treatment of aphasia

Neurostimulant Use for Rehabilitation and Recovery After Stroke: A Narrative Literature Review

BACKGROUND

Stroke often results in significant impairments across various domains, including movement, language, cognition, and mood. Neurostimulants have been proposed as potential therapeutic interventions to enhance recovery in these areas.

METHODS

This narrative literature review examines clinical trials investigating the efficacy of neurostimulants in poststroke recovery. It evaluates outcomes related to aphasia, motor deficits, cognition, fatigue, and depression.

RESULTS

The qualitative analysis included 34 trials testing the following neurostimulants: methylphenidate (n=6), amphetamines (n=8), memantine (n=2), modafinil (n=2), levodopa (n=14), amantadine (n=1), bromocriptine (n=3), and ropinirole (n=1). Of the 34 studies, 31 were randomized, placebo-controlled (double-blind, n=27; single-blind, n=2; unblinded n=2), 2 were randomized and not placebo-controlled, and 1 was not randomized. Study design was either multiarm (n=23), crossover (n=10), or used subjects as their own control (n=1). Mean sample size was 49.4 (5-593).

CONCLUSIONS

Current evidence suggests that memantine may be effective for aphasia, although few phase III trials exist, whereas bromocriptine and amphetamines lack sufficient evidence for long-term recovery of aphasia. Levodopa may improve motor aphasias but has not shown long-term benefits for motor recovery. Similarly, ropinirole has not been shown to improve poststroke motor outcomes. Methylphenidate has limited efficacy for cognitive improvement but may enhance poststroke functionality and mood. Modafinil may help with poststroke fatigue. In conclusion, there are promising results of positive effects of neurostimulants with few side effects, though studies are limited by heterogeneous designs and small sample sizes. Neurostimulant efficacy must be assessed in conjunction with specific rehabilitation modalities as part of larger, well-designed studies to best understand their effects on impairment.

The effect of venlafaxine on language function in patients with subcortical aphasia

OBJECTIVE

To investigate the effect of venlafaxine on the recovery of language function in patients with subcortical aphasia by using functional magnetic resonance imaging (fMRI) and to provide a theoretical basis for clinical drug treatment in patients with subcortical aphasia.

METHODS

Thirty-two patients with subcortical aphasia after acute stroke were randomly divided into a venlafaxine group and a control group, with 16 patients in each group. Behavioral assessments of speech function and fMRI were performed three times at 3 ± 2 days (V1), 30 ± 7 days (V2), and 90 ± 7 days (V3) after symptom onset. Behavioral assessments of speech function included the Chinese version of the Western Aphasia Test, the spontaneous word frequency test, and the image naming test. fMRI examinations include task-fMRI, resting-state fMRI (rs-fMRI), and diffusion tensor imaging (DTI).

RESULTS

① There were no differences in language function scores between the venlafaxine and control groups at pretreatment (P > 0.05); however, the venlafaxine group scores were higher than those of the control group at time points V2 and V3 (P < 0.05), and the venlafaxine group scores were significantly greater at V2 than at V1 (P < 0.05) and at V3 than at V2 (P < 0.05). ② Regarding fMRI results, there were no significant between-group differences at V1, whereas compared with those in the control group, the venlafaxine group had greater activation and functional connection of the bilateral Broca area and structural connectivity of nerve fibers in the nondominant dorsal and ventral pathways at V2 and greater activation and functional activity of the bilateral Broca region and increased structural connectivity of the bilateral ventral pathway nerve fibers at V3.

CONCLUSION

Early application of venlafaxine can significantly promote the recovery of language function in patients with subcortical aphasia. With the recovery of language function, we observed corresponding changes in the fMRI data of patients at various stages after stroke. These results are helpful for understanding the mechanism of language function recovery in patients with subcortical aphasia and provide new ideas for the treatment of aphasia after stroke.

Hallmarks of Brain Plasticity

Cerebral plasticity is the ability of the brain to change and adapt in response to experience or learning. Its hallmarks are developmental flexibility, complex interactions between genetic and environmental influences, and structural-functional changes comprising neurogenesis, axonal sprouting, and synaptic remodeling. Studies on brain plasticity have important practical implications. The molecular characteristics of changes in brain plasticity may reveal disease course and the rehabilitative potential of the patient. Neurological disorders are linked with numerous cerebral non-coding RNAs (ncRNAs), in particular, microRNAs; the discovery of their essential role in gene regulation was recently recognized and awarded a Nobel Prize in Physiology or Medicine in 2024. Herein, we review the association of brain plasticity and its homeostasis with ncRNAs, which make them putative targets for RNA-based diagnostics and therapeutics. New insight into the concept of brain plasticity may provide additional perspectives on functional recovery following brain damage. Knowledge of this phenomenon will enable physicians to exploit the potential of cerebral plasticity and regulate eloquent networks with timely interventions. Future studies may reveal pathophysiological mechanisms of brain plasticity at macro- and microscopic levels to advance rehabilitation strategies and improve quality of life in patients with neurological diseases.

Efficacy and safety of DL-3-N-butylphthalide in the treatment of ischemic poststroke aphasia: A randomized clinical trial

OBJECTIVE

Poststroke aphasia (PSA) has a high prevalence and requires a long recovery period, severely impairing life and work. Its existing behavioral interventions, principally speech and language therapy, are limited by numerous factors. The aims of this study are to evaluate the efficacy and safety of DL-3-N-butylphthalein (NBP) and explore its mechanism in the treatment of ischemic PSA.

METHODS

Patients hospitalized in the Second Hospital of Hebei Medical University in China were randomly administered NBP soft capsules or placebo orally for 6 months from July 1, 2021, to February 25, 2023. Language skills were assessed using the Western Aphasia Battery-Aphasia Quotient (WAB-AQ). We collected plasma samples and detected neurotransmitters by liquid chromatography-mass spectrometry.

RESULTS

In total, 118 out of 124 patients were included in the outcome analysis. Compared with the control group, AQ values in the NBP group significantly improved at 6 months (U = 1187.5, p = 0.003). After eliminating baseline interference, NBP treatment was independently associated with the 6-month AQ improvement [mean difference (MD) 0.106, 95% confidence interval (CI) 0.018, 0.195, p = 0.019]. We observed no statistically significant difference between the groups in abnormal liver function at 1 month [relative risk (RR) 1.07, 95% CI 0.89, 1.28] and 6 months [RR 0.99, 95% CI 0.86, 1.42]. Statistically significant differences were observed in tyrosine (p = 0.043) and 5-hydroxytryptophan (p = 0.041) between the two groups.

INTERPRETATION

NBP treatment might promote the recovery of WAB-AQ in patients with ischemic PSA by increasing levels of monoamine neurotransmitters.

Amphetamine and methylphenidate potential on the recovery from stroke and traumatic brain injury: a review

The prevalence of stroke and traumatic brain injury is increasing worldwide. However, current treatments do not fully cure or stop their progression, acting mostly on symptoms. Amphetamine and methylphenidate are stimulants already approved for attention deficit hyperactivity disorder and narcolepsy treatment, with neuroprotective potential and benefits when used in appropriate doses. This review aimed to summarize pre-clinical and clinical trials testing either amphetamine or methylphenidate for the treatment of stroke and traumatic brain injury. We used PubMed as a database and included the following keywords ((methylphenidate) OR (Ritalin) OR (Concerta) OR (Biphentin) OR (amphetamine) OR (Adderall)) AND ((stroke) OR (brain injury) OR (neuroplasticity)). Overall, studies provided inconsistent results regarding cognitive and motor function. Neurite outgrowth, synaptic proteins, dendritic complexity, and synaptic plasticity increases were reported in pre-clinical studies along with function improvement. Clinical trials have demonstrated that, depending on the brain region, there is an increase in motor activity, attention, and memory due to the stimulation of the functionally depressed catecholamine system and the activation of neuronal remodeling proteins. Nevertheless, more clinical trials and pre-clinical studies are needed to understand the drugs' full potential for their use in these brain diseases namely, to ascertain the treatment time window, ideal dosage, long-term effects, and mechanisms, while avoiding their addictive potential.

A Systematic Search and Review of Registered Pharmacological Therapies Investigated to Improve Outcomes after a Stroke

INTRODUCTION

Stroke burden is largely due to long-term impairments requiring prolonged care and loss of productivity. We aim to identify and assess studies of different registered pharmacological therapies as treatments for improving post-stroke impairments and/or disabilities.

METHODS

In a systematic search and review (PROSPERO registration: CRD42022376973), studies of treatments that have been investigated as recovery-enhancing or recovery-promoting treatments in adult patients who had suffered a stroke will be searched for, screened, and reviewed based on the following: participants (P): adult humans, aged 18 years or older, diagnosed with stroke; interventions (I): registered or marketed pharmacological therapies that have been investigated as recovery-enhancing or recovery-promoting treatments in stroke; comparators (C): active or placebo or no comparator; outcomes (O): stroke-related neurological impairments and functional/disability assessments. Data will be extracted from included papers, including patient demographics, study methods, keystroke inclusion criteria, details of intervention and control, and the reported outcomes.

RESULT

"The best available studies" based on study design, study size, and/or date of publication for different therapies and stroke subtypes will be selected and graded for level of evidence by consensus.

CONCLUSION

There are conflicting study results of pharmacological interventions after an acute stroke to enhance recovery. This systematic search and review will identify the best evidence and knowledge gaps in the pharmacological treatment of post-stroke patients as well as guide clinical decision-making and planning of future studies.

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.

Pharmacotherapy for post-stroke aphasia: what are the options?

INTRODUCTION

Aphasia is a common, long-lasting aftermath of stroke lesions. There is an increased integration of pharmacotherapy as an adjunctive strategy to speech and language therapy (SLT) for post-stroke aphasia (PSA). Nevertheless, more research in pharmacotherapy for acute and chronic PSA is necessary, including the election of drugs that target different neurotransmitter systems and deficits in specific language domains.

AREAS COVERED

This article updates the role of pharmacotherapy for PSA, focusing the spotlight on some already investigated drugs and candidate agents deserving of future research. Refining the precision of drug election would require using multimodal biomarkers to develop personalized treatment approaches. There is a solid need to devise feasible randomized controlled trials adapted to the particularities of the PSA population. The emergent role of multimodal interventions combining one or two drugs with noninvasive brain stimulation to augment SLT is emphasized.

EXPERT OPINION

Pharmacotherapy can improve language deficits not fully alleviated by SLT. In addition, the 'drug-only' approach can also be adopted when administering SLT is not possible. The primary goal of pharmacotherapy is reducing the overall aphasia severity, although targeting language-specific deficits (i.e. naming, spoken output) also contributes to improving functional communication. Unfortunately, there is still little information for recommending a drug for specific language deficits.

Outcomes in Patients with Minor Stroke: Diagnosis and Management in the Post-thrombectomy Era

In the era of mechanical thrombectomy and better preventative strategies, a higher number of patients are being discharged home from the hospital with the so-called minor strokes. This has significantly changed the landscape of stroke recovery. Unfortunately, while symptoms may be categorized as mild compared to individuals with higher NIH Stroke Scale scores, the physical, cognitive, and emotional sequelae can be disabling and result in failure to return to work and poor quality of life in a population with significant potential to recover fully. In this review, we discuss the current state of minor stroke, the most common pattern of resulting deficits, what is known about the underlying pathophysiology that leads to a relatively global pattern of impaired cognition following an infarct in any location, and special considerations for treatment based on this population's unique needs. Raising awareness of the current morbidity associated with minor stroke, the need for a uniform definition that allows for comparisons of individuals across studies, and further research focused on this population to optimize outcomes, has the potential to significantly improve recovery.

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.

Protocol for Escitalopram and Language Intervention for Subacute Aphasia (ELISA): A randomized, double blind, placebo-controlled trial

In this forthcoming multicenter, prospective, randomized, double-blind placebo-controlled trial, we will investigate the augmentative effects of a selective serotonin reuptake inhibitor, escitalopram, on language therapy in individuals with post-stroke aphasia. We hypothesize that, when combined with language therapy, daily escitalopram will result in greater improvement than placebo in an untrained picture naming task (Philadelphia Naming Test short form) administered one week after the end of language therapy. We also will examine whether escitalopram's effect on language is independent of its effect on depression, varies with lesion location, or is associated with increased functional connectivity within the left hemisphere. Finally, we will examine whether individuals with BDNF met alleles show reduced response to treatment and reduced changes in connectivity. We expect to enroll 88 participants over four years. Participants are given escitalopram or placebo within one week of their stroke for 90 days and receive fifteen 45-minute computer-delivered sessions of language treatment beginning 60 days from the start of drug therapy. Patients then complete a comprehensive assessment of language at one, five, and twenty weeks after the last language therapy session. ELISA is the first randomized, controlled trial evaluating the effect of a selective serotonin reuptake inhibitor on the improvement of language in people with aphasia undergoing language treatment during the acute to subacute post-stroke period. Trial registration: The trial is registered with ClinicalTrials.gov NCT03843463.

Novel Advances to Post-Stroke Aphasia Pharmacology and Rehabilitation

Aphasia is one of the most common clinical features of functional impairment after a stroke. Approximately 21–40% of stroke patients sustain permanent aphasia, which progressively worsens one’s quality of life and rehabilitation outcomes. Post-stroke aphasia treatment strategies include speech language therapies, cognitive neurorehabilitation, telerehabilitation, computer-based management, experimental pharmacotherapy, and physical medicine. This review focuses on current evidence of the effectiveness of impairment-based aphasia therapies and communication-based therapies (as well as the timing and optimal treatment intensities for these interventions). Moreover, we present specific interventions, such as constraint-induced aphasia therapy (CIAT) and melodic intonation therapy (MIT). Accumulated data suggest that using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) is safe and can be used to modulate cortical excitability. Therefore, we review clinical studies that present TMS and tDCS as (possible) promising therapies in speech and language recovery, stimulating neuroplasticity. Several drugs have been used in aphasia pharmacotherapy, but evidence from clinical studies suggest that only nootropic agents, donepezil and memantine, may improve the prognosis of aphasia. This article is an overview on the current state of knowledge related to post-stroke aphasia pharmacology, rehabilitation, and future trends.

Treatment of post-stroke aphasia: A narrative review for stroke neurologists

This review is intended to help physicians guide patients to optimal management of post-stroke aphasia. We review literature on post-stroke aphasia treatment, focusing on: (1) when and for whom language therapy is most effective, (2) the variety of approaches that can be effective for different individuals, and (3) the extent to which behavioral therapy might be augmented by non-invasive brain stimulation and/or medications.

Current Approaches to the Treatment of Post-Stroke Aphasia

Aphasia, impairment of language after stroke or other neurological insult, is a common and often devastating condition that affects nearly every social activity and interaction. Behavioral speech and language therapy is the mainstay of treatment, although other interventions have been introduced to augment the effects of the behavioral therapy. In this narrative review, we discuss advances in aphasia therapy in the last 5 years and focus primarily on properly powered, randomized, controlled trials of both behavioral therapies and interventions to augment therapy for post-stroke aphasia. These trials include evaluation of behavioral therapies and computer-delivered language therapies. We also discuss outcome prediction trials as well as interventional trials that have employed noninvasive brain stimulation, or medications to augment language therapy. Supported by evidence from Phase III trials and large meta-analyses, it is now generally accepted that aphasia therapy can improve language processing for many patients. Not all patients respond similarly to aphasia therapy with the most severe patients being the least likely responders. Nevertheless, it is imperative that all patients, regardless of severity, receive aphasia management focused on direct therapy of language deficits, counseling, or both. Emerging evidence from Phase II trials suggests transcranial brain stimulation is a promising method to boost aphasia therapy outcomes.

A Review of Pharmacologic Neurostimulant Use During Rehabilitation and Recovery After Brain Injury

OBJECTIVE

To describe the efficacy and safety of pharmacologic neurostimulants after neurological injuries such as ischemic or hemorrhagic stroke and traumatic brain injury (TBI), critically evaluate the available literature, and make recommendations regarding which neurostimulants should be considered for use in clinical practice.

DATA SOURCES

A literature search of PubMed was performed (1953 to October 2020) to identify relevant articles. Search terms included the following: "neurostimulant, neurorehabilitation" AND "traumatic brain injury, cerebrovascular accident, or stroke." This review is limited to prospective studies and observational trials.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language studies conducted in humans were considered.

DATA SYNTHESIS

Cognitive and motor deficits caused by stroke and TBI account for high rates of long-term disability. Although not well-established, pharmacologic agents, broadly characterized as neurostimulants, may be prescribed after brain injury to treat these deficits. When prescribing these medications, it is imperative to be aware of the supporting evidence in order to accurately gauge the risk-benefit profile of each agent.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The following presents a literature review critically evaluating clinical studies that investigate neurostimulant use after brain injury. The intent of this review is to serve as an evidence-based guide for clinicians.

CONCLUSIONS

The pharmacologic agent with the most supporting literature is amantadine used for cognitive improvement after TBI. Other neurostimulants with positive, despite more limited, evidence include methylphenidate, modafinil, levodopa, and citalopram. Caution is warranted with other neurostimulants given higher rates of adverse effects or lack of benefit observed in clinical trials.

Adjunctive Approaches to Aphasia Rehabilitation: A Review on Efficacy and Safety

Aphasia is one of the most socially disabling post-stroke deficits. Although traditional therapies have been shown to induce adequate clinical improvement, aphasic symptoms often persist. Therefore, unconventional rehabilitation techniques which act as a substitute or as an adjunct to traditional approaches are urgently needed. The present review provides an overview of the efficacy and safety of the principal approaches which have been proposed over the last twenty years. First, we examined the effectiveness of the pharmacological approach, principally used as an adjunct to language therapy, reporting the mechanism of action of each single drug for the recovery of aphasia. Results are conflicting but promising. Secondly, we discussed the application of Virtual Reality (VR) which has been proven to be useful since it potentiates the ecological validity of the language therapy by using virtual contexts which simulate real-life everyday contexts. Finally, we focused on the use of Transcranial Direct Current Stimulation (tDCS), both discussing its applications at the cortical level and highlighting a new perspective, which considers the possibility to extend the use of tDCS over the motor regions. Although the review reveals an extraordinary variability among the different studies, substantial agreement has been reached on some general principles, such as the necessity to consider tDCS only as an adjunct to traditional language therapy.

Cognitive Impairments in First-Episode Drug-Naïve Versus Medicated Depressive Patients: RBANS in a Chinese Population

Cognitive deficits are a core feature of major depressive disorder (MDD). However, there are no previous studies that directly compare cognitive performance between first-episode drug-naive depressive patients (FDDP) and medicated depressive patients (MDP). Therefore, the aim of this study was to investigate whether there were the differences in cognitive functions between FDDP and MDP. Sixty-two FDDP, 111 MDP and 90 healthy controls were enrolled in a Chinese population. Cognitive functions were assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). There were the differences in the RBANS total score (F = 26.55, p < 0.001), subscales of immediate memory (F = 3.95, p = 0.02), language (F = 54.11, p < 0.001) and delayed memory (F = 11.19, p = 0.001) among the three groups after controlling for gender, education, smoking and body mass index (BMI). These differences in the RBANS total score, subscales of language and delayed memory passed the Bonferroni corrections (all, p < 0.05). Compared to healthy controls, FDDP and MDP had poorer cognitive performance including the RBANS total score, and subscales of language and delayed memory (all, p < 0.05) after controlling for the variables. FDDP experienced greater language deficits than MDP (p < 0.05) after controlling for the variables. Education was correlated with the language score in FDDP (r = 0.61, p < 0.001). Multivariate regression analysis indicated that education was an independent contributor to the language score in FDDP (ß = 3.11, t = 5.48, p < 0.001). Our findings indicated that FDDP had poorer language performance than MDP. Moreover, education could influence the language performance in FDDP.

Central Noradrenergic Agonists in the Treatment of Ischemic Stroke-an Overview

Ischemic stroke is the leading cause of morbidity and mortality with a significant health burden worldwide and few treatment options. Among the short- and long-term effects of ischemic stroke is the cardiovascular sympathetic autonomic dysfunction, presented in part as the by-product of the ischemic damage to the noradrenergic centers of the brain. Unlike high levels in the plasma, the brain may face suboptimal levels of norepinephrine (NE), with adverse effects on the clinical and functional outcomes of ischemic stroke. The intravenous administration of NE and other sympathomimetic agents, in an attempt to increase cerebral perfusion pressure, often aggravates the ischemia-induced rise in blood pressure (BP) with life-threatening consequences for stroke patients, the majority of whom present with hypertension at the time of admission. Unlike the systemic administration, the central administration of NE reduces BP while exerting anti-inflammatory and neuroprotective effects. These characteristics of centrally administered NE, combined with the short latency of response, make it an ideal candidate for use in the acute phase of stroke, followed by the use of centrally acting noradrenergic agonists, such as NE reuptake inhibitors and B2-adrenergic receptor agonists for stroke rehabilitation. In addition, a number of nonpharmacological strategies, such as transcutaneous vagus nerve stimulation (tVNS) and trigeminal nerve stimulation (TNS), have the potential to enhance the central noradrenergic functional activities and improve stroke clinical outcomes. Many factors could influence the efficacy of the noradrenergic treatment in stroke patients. These factors include the type of the noradrenergic agent; the dose, frequency, and duration of administration; the timing of administration in relation to the acute event; and the site and characteristics of the ischemic lesions. Having this knowledge, combined with the better understanding of the regulation of noradrenergic receptors in different parts of the brain, would pave the path for the successful use of the centrally acting noradrenergic agents in the management of ischemic stroke.

Safety and improvement of movement function after stroke with atomoxetine: A pilot randomized trial

Background: Intensive, task-oriented motor training has been associated with neuroplastic reorganization and improved upper extremity movement function after stroke. However, to optimize such training for people with moderate-to-severe movement impairment, pharmacological modulation of neuroplasticity may be needed as an adjuvant intervention.

Objective: Evaluate safety, as well as improvement in movement function, associated with motor training paired with a drug to upregulate neuroplasticity after stroke.

Methods: In this double-blind, randomized, placebo-controlled study, 12 subjects with chronic stroke received either atomoxetine or placebo paired with motor training. Safety was assessed using vital signs. Upper extremity movement function was assessed using Fugl-Meyer Assessment, Wolf Motor Function Test, and Action Research Arm Test at baseline, post-intervention, and 1-month follow-up.

Results: No significant between-groups differences were found in mean heart rate (95% CI, –12.4–22.6; p = 0.23), mean systolic blood pressure (95% CI, –1.7–29.6; p = 0.21), or mean diastolic blood pressure (95% CI, –10.4–13.3; p = 0.08). A statistically significant between-groups difference on Fugl-Meyer at post-intervention favored the atomoxetine group (95% CI, 1.6–12.7; p = 0.016).

Conclusion: Atomoxetine combined with motor training appears safe and may optimize motor training outcomes after stroke.

Neuroimaging of stroke recovery from aphasia - Insights into plasticity of the human language network

The role of left and right hemisphere brain regions in language recovery after stroke-induced aphasia remains controversial. Here, we summarize how neuroimaging studies increase the current understanding of functional interactions, reorganization and plasticity in the language network. We first discuss the temporal dynamics across the time course of language recovery, with a main focus on longitudinal studies from the acute to the chronic phase after stroke. These studies show that the functional contribution of perilesional and spared left hemisphere as well as contralesional right hemisphere regions to language recovery changes over time. The second section introduces critical variables and recent advances on early prediction of subsequent outcome. In the third section, we outline how multi-method approaches that combine neuroimaging techniques with non-invasive brain stimulation elucidate mechanisms of plasticity and reorganization in the language network. These approaches provide novel insights into general mechanisms of plasticity in the language network and might ultimately support recovery processes during speech and language therapy. Finally, the neurobiological correlates of therapy-induced plasticity are discussed. We argue that future studies should integrate individualized approaches that might vary the combination of language therapy with specific non-invasive brain stimulation protocols across the time course of recovery. The way forward will include the combination of such approaches with large data sets obtained from multicentre studies.

Combined Dextroamphetamine and Transcranial Direct Current Stimulation in Poststroke Aphasia

There is a growing need for various effective adjunctive treatment options for speech recovery after stroke. A pharmacological agent combined with noninvasive brain stimulation has not been previously reported for poststroke aphasia recovery. In this "proof of concept" study, we aimed to test the safety of a combined intervention consisting of dextroamphetamine, transcranial direct current stimulation, and speech and language therapy in subjects with nonfluent aphasia. Ten subjects with chronic nonfluent aphasia underwent two experiments where they received dextroamphetamine or placebo along with transcranial direct current stimulation and speech and language therapy on two separate days. The Western Aphasia Battery-Revised was used to monitor changes in speech performance. No serious adverse events were observed. There was no significant increase in blood pressure with amphetamine or deterioration in speech and language performance. Western Aphasia Battery-Revised aphasia quotient and language quotient showed a statistically significant increase in the active experiment. Comparison of proportional changes of aphasia quotient and language quotient in active experiment with those in placebo experiment showed significant difference. We showed that the triple combination therapy is safe and implementable and seems to induce positive changes in speech and language performance in the patients with chronic nonfluent aphasia due to stroke.

Noradrenergic antagonists mitigate amphetamine-induced recovery

Brain injury, including that due to stroke, leaves individuals with cognitive deficits that can disrupt daily aspect of living. As of now there are few treatments that shown limited amounts of success in improving functional outcome. The use of stimulants such as amphetamine have shown some success in improving outcome following brain injury. While the pharmacological mechanisms for amphetamine are known; the specific processes responsible for improving behavioral outcome following injury remain unknown. Understanding these mechanisms can help to refine the use of amphetamine as a potential treatment or lead to the use of other methods that share the same pharmacological properties. One proposed mechanism is amphetamine's impact upon noradrenaline (NA). In the current, study noradrenergic antagonists were administered prior to amphetamine to pharmacologically block α- and β-adrenergic receptors. The results demonstrated that the blockade of these receptors disrupted amphetamines ability to induce recovery from hemispatial neglect using an established aspiration lesion model. This suggests that amphetamine's ability to ameliorate neglect deficits may be due in part to noradrenaline. These results further support the role of noradrenaline in functional recovery. Finally, the development of polytherapies and combined therapeutics, while promising, may need to consider the possibility that drug interactions can negate the effectiveness of treatment.

An update on medications and noninvasive brain stimulation to augment language rehabilitation in post-stroke aphasia

INTRODUCTION

Aphasia is among the most debilitating outcomes of stroke. Aphasia is a language disorder occurring in 10-30% of stroke survivors. Speech and Language Therapy (SLT) is the gold standard, mainstay treatment for aphasia, but gains from SLT may be incomplete. Pharmaceutical and noninvasive brain stimulation (NIBS) techniques may augment the effectiveness of SLT. Areas covered: Herein reviewed are studies of the safety and efficacy of these adjunctive interventions for aphasia, including randomized placebo-controlled and open-label trials, as well as case series from Pubmed, using search terms 'pharmacological,' 'tDCS' or 'TMS' combined with 'aphasia' and 'stroke.' Expert commentary: Relatively small studies have included participants with a range of aphasia types and severities, using inconsistent interventions and outcome measures. Results to-date have provided promising, but weak to moderate evidence that medications and/or NIBS can augment the effects of SLT for improving language outcomes. We end with recommendations for future approaches to studying these interventions, with multicenter, double-blind, randomized controlled trials.

Poststroke Communication Disorders and Dysphagia

Communication and swallowing disorders are common after stroke. Targeted surveillance followed by prompt evaluation and treatment is of paramount importance. The overall goals of rehabilitation for impaired swallowing and communication and swallowing deficits may differ based on the specific deficits caused by the stroke but the main goal is always to improve the patient's everyday interpersonal interactions and optimize participation in society. Fortunately, therapeutic or compensatory interventions can decrease the effects that communication and swallowing deficits have on the quality of life of stroke survivors.

Computational models and motor learning paradigms: Could they provide insights for neuroplasticity after stroke? An overview

Computational approaches for modelling the central nervous system (CNS) aim to develop theories on processes occurring in the brain that allow the transformation of all information needed for the execution of motor acts. Computational models have been proposed in several fields, to interpret not only the CNS functioning, but also its efferent behaviour. Computational model theories can provide insights into neuromuscular and brain function allowing us to reach a deeper understanding of neuroplasticity. Neuroplasticity is the process occurring in the CNS that is able to permanently change both structure and function due to interaction with the external environment. To understand such a complex process several paradigms related to motor learning and computational modeling have been put forward. These paradigms have been explained through several internal model concepts, and supported by neurophysiological and neuroimaging studies. Therefore, it has been possible to make theories about the basis of different learning paradigms according to known computational models. Here we review the computational models and motor learning paradigms used to describe the CNS and neuromuscular functions, as well as their role in the recovery process. These theories have the potential to provide a way to rigorously explain all the potential of CNS learning, providing a basis for future clinical studies.

Pharmacotherapy to Enhance Cognitive and Motor Recovery Following Stroke

Stroke is a leading cause of disability among older adults and more than half of stroke survivors have some residual neurological impairment. Traditionally, managing the aftermath of stroke has been by the implementation of several physical and language therapy modalities. The limitations of these rehabilitation efforts have sparked an interest in finding other ways to enhance neurological recovery. Some of these novel approaches have included pharmacological interventions, cell-derived treatments, and cortical magnetic stimulation. Mounting evidence over the last 2 decades suggests that pharmacological manipulations may have the potential to modulate practice-dependent neuroplasticity and potentially improve neurological recovery after stroke. Multiple pharmacological agents with different mechanisms of action have been evaluated, showing conflicting results. Some studies suggest some promise, yet the quality of the available studies is suboptimal overall, with most of the studies being underpowered. So far, the most promising agents include the antidepressants for motor recovery and acetylcholinesterase inhibitors and memantine for aphasia. However, large, well-designed clinical trials are needed to address the shortcomings of the available data and before any pharmacological agent can be recommended for routine use as part of the standard algorithm of stroke management.

Amphetamine and other pharmacological agents in human and animal studies of recovery from stroke

Neuromodulation with pharmacological agents, including drugs of abuse such as amphetamine, when paired with behavioral experience, has been shown to positively modify outcomes in animal models of stroke. A number of clinical studies have tested the efficacy of a variety of drugs to enhance recovery of language deficit post-stroke. The purpose of this paper is to: (1) present pertinent animal studies supporting the use of dextro-amphetamine sulfate (AMPH) to enhance recovery after experimental lesions with emphasis on the importance of learning dependent activity for lasting recovery; (2) briefly review neuropharmacological explorations in the treatment of aphasia; (3) present a pilot study in aphasia exploring a drug combination of AMPH and donepezil hydrochloride paired with behavioral treatment to facilitate recovery; and (4) conclude with comments regarding the role of adjunctive pharmacotherapy in the rehabilitation of aphasia, particularly AMPH.

Levodopa enhances explicit new-word learning in healthy adults: a preliminary study

OBJECTIVE

While the role of dopamine in modulating executive function, working memory and associative learning has been established; its role in word learning and language processing more generally is not clear. This preliminary study investigated the impact of increased synaptic dopamine levels on new-word learning ability in healthy young adults using an explicit learning paradigm.

METHOD

A double-blind, placebo-controlled, between-groups design was used. Participants completed five learning sessions over 1 week with levodopa or placebo administered at each session (five doses, 100 mg). Each session involved a study phase followed by a test phase. Test phases involved recall and recognition tests of the new (non-word) names previously paired with unfamiliar objects (half with semantic descriptions) during the study phase.

RESULTS

The levodopa group showed superior recall accuracy for new words over five learning sessions compared with the placebo group and better recognition accuracy at a 1-month follow-up for words learnt with a semantic description.

CONCLUSIONS

These findings suggest that dopamine boosts initial lexical acquisition and enhances longer-term consolidation of words learnt with semantic information, consistent with dopaminergic enhancement of semantic salience.

The use of stimulant medications for non-core aspects of ADHD and in other disorders

Psychostimulants play a central role in the management of ADHD. Here we review the evidence pertaining to the use of methylphenidate, dexamphetamine and related amphetamine salts, the prodrug lisdexamfetamine and modafinil for the management of comorbid ADHD and non-ADHD indications. There is a growing consensus that stimulant medications are helpful at improving the emotional dysregulation and lability, and oppositional and conduct symptoms that are often associated with ADHD. There is some evidence that psychostimulants may improve outcomes in those with treatment resistant depression, reduce negative symptoms and improve cognitive performance in schizophrenia, and that methylphenidate may reduce binge eating in those with bulimia nervosa. In general medicine, whilst the evidence is at times contradictory, psychostimulants have been shown in some studies to be effective treatments for chronic fatigue and narcolepsy, and to improve outcomes post stroke, post head injury, in dementia and various cancers. It seems likely that these effects often result from a combination of, reduction in fatigue, improvements in concentration and cognitive functioning and a lifting of mood which may be a direct or indirect consequence of the medication. Further studies seem warranted and these should focus on efficacy, effectiveness and long term safety. This article is part of the Special Issue entitled 'CNS Stimulants'.

Modafinil combined with cognitive training is associated with improved learning in healthy volunteers--a randomised controlled trial

Improving cognition in people with neuropsychiatric disorders remains a major clinical target. By themselves pharmacological and non-pharmacological approaches have shown only modest effects in improving cognition. In the present study we tested a recently-proposed methodology to combine CT with a 'cognitive-enhancing' drug to improve cognitive test scores and expanded on previous approaches by delivering combination drug and CT, over a long intervention of repeated sessions, and used multiple tasks to reveal the cognitive processes being enhanced. We also aimed to determine whether gains from this combination approach generalised to untrained tests. In this proof of principle randomised-controlled trial thirty-three healthy volunteers were randomised to receive either modafinil or placebo combined with daily cognitive training over two weeks. Volunteers were trained on tasks of new-language learning, working memory and verbal learning following 200 mg modafinil or placebo for ten days. Improvements in trained and untrained tasks were measured. Rate of new-language learning was significantly enhanced with modafinil, and effects were greatest over the first five sessions. Modafinil improved within-day learning rather than between-day retention. No enhancement of gains with modafinil was observed in working memory nor rate of verbal learning. Gains in all tasks were retained post drug-administration, but transfer effects to broad cognitive abilities were not seen. This study shows that combining CT with modafinil specifically elevates learning over early training sessions compared to CT with placebo and provides a proof of principle experimental paradigm for pharmacological enhancement of cognitive remediation.

Drug treatment of poststroke aphasia

Impairment of language function (aphasia) is one of the most common neurological symptoms after stroke. Approximately one in every three patients who have an acute stroke will suffer from aphasia. The estimated incidence and prevalence of stroke in Western Europe is 140 and 800 per 100,000 of the population. Aphasia often results in significant disability and handicap. It is a major obstacle for patients to live independently in the community. When recovery from aphasia occurs, it is usually incomplete and patients are rarely able to return to full employment and other social activities. Currently, the main treatment for aphasia is conventional speech and language therapy. However, the effectiveness of this intervention has not been conclusively demonstrated and empirical observations suggest that spontaneous biological recovery may explain most of the improvement in language function that occurs in aphasics. The generally poor prognosis of the severe forms of poststroke language impairment (Broca, Wernicke and global aphasia), coupled with the limited effectiveness of conventional speech and language therapy has stimulated the search for other treatments that may be used in conjunction with speech and language therapy, including the use of various drugs. Dopamine agonists, piracetam (Nootropil), amphetamines, and more recently donepezil (Aricept), have been used in the treatment of aphasia in both the acute and chronic phase. The justification for the use of drugs in the treatment of aphasia is based on two types of evidence. Some drugs, such as dextroamphetamine (Dexedrine), improve attention span and enhance learning and memory. Learning is an essential mechanism for the acquisition of new motor and cognitive skills, and hence, for recovery from aphasia. Second, laboratory and clinical data suggest that drug treatment may partially restore the metabolic function in the ischemic zone that surrounds the brain lesion and also has a neuroprotective effect following acute brain damage. An example of this is the nootropic agent piracetam. Extensive animal studies have demonstrated the beneficial effects of this and other drugs on neural plasticity, but data on humans are still sparse. This review provides a critical analysis of the current evidence of the effectiveness of these drugs in the treatment of acute and chronic aphasia.

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.

Psychostimulants and cognition: a continuum of behavioral and cognitive activation

Psychostimulants such as cocaine have been used as performance enhancers throughout recorded history. Although psychostimulants are commonly prescribed to improve attention and cognition, a great deal of literature has described their ability to induce cognitive deficits, as well as addiction. How can a single drug class be known to produce both cognitive enhancement and impairment? Properties of the particular stimulant drug itself and individual differences between users have both been suggested to dictate the outcome of stimulant use. A more parsimonious alternative, which we endorse, is that dose is the critical determining factor in cognitive effects of stimulant drugs. Herein, we review several popular stimulants (cocaine, amphetamine, methylphenidate, modafinil, and caffeine), outlining their history of use, mechanism of action, and use and abuse today. One common graphic depiction of the cognitive effects of psychostimulants is an inverted U-shaped dose-effect curve. Moderate arousal is beneficial to cognition, whereas too much activation leads to cognitive impairment. In parallel to this schematic, we propose a continuum of psychostimulant activation that covers the transition from one drug effect to another as stimulant intake is increased. Low doses of stimulants effect increased arousal, attention, and cognitive enhancement; moderate doses can lead to feelings of euphoria and power, as well as addiction and cognitive impairment; and very high doses lead to psychosis and circulatory collapse. This continuum helps account for the seemingly disparate effects of stimulant drugs, with the same drug being associated with cognitive enhancement and impairment.

Pharmacologic approaches to cerebral aging and neuroplasticity: insights from the stroke model

Brain plasticity is an intrinsic characteristic of the nervous system that allows continuous remodeling of brain functions in pathophysiological conditions. Although normal aging is associated with morphological modifications and decline of cerebral functions, brain plasticity is at least partially preserved in elderly individuals. A growing body of evidence supports the notion that cognitive enrichment and aerobic training induce a dynamic reorganization of higher cerebral functions, thereby helping to maintain operational skills in the elderly and reducing the incidence of dementia. The stroke model clearly shows that spontaneous brain plasticity exists after a lesion, even in old patients, and that it can be modulated through external factors like rehabilitation and drugs. Whether drugs can be used with the aim of modulating the effects of physical training or cognitive stimulation in healthy aged people has not been addressed until now. The risk:benefit ratio will be the key question with regard to the ethical aspect of this challenge. We review in this article the main aspects of human brain plasticity as shown in patients with stroke, the drug modulation of brain plasticity and its consequences on recovery, and finally we address the question of the influence of aging on brain plasticity.

Treating impaired cognition in schizophrenia: the case for combining cognitive-enhancing drugs with cognitive remediation

Cognitive impairment is a well-documented feature of schizophrenia and represents a major impediment to the functional recovery of patients. The therapeutic strategies to improve cognition in schizophrenia have either used medications (collectively referred to as 'cognitive-enhancing drugs' in this article) or non-pharmacological training approaches ('cognitive remediation'). Cognitive-enhancing drugs have not as yet been successful and cognitive remediation has shown modest success. Therefore, we may need to explore new therapeutic paradigms to improve cognition in schizophrenia. The optimal approach may require a combination of cognitive-enhancing drugs with cognitive remediation. We review the available data from animal and human studies that provide the conceptual basis, proof-of-concept and illustrations of success of such combination strategies in experimental and clinical paradigms in other conditions. We address the major design issues relevant to the choice of the cognitive-enhancing drugs and cognitive remediation, as well as the timing and the duration of the intervention as will be relevant for schizophrenia. Finally, we address the practical realities of the development and testing of such combined approaches in the real-world clinical situation and conclude that while scientifically attractive, there are several practical difficulties to be overcome for this approach to be clinically feasible.

Beneficial effects of physical exercise on neuroplasticity and cognition

The human brain adapts to changing demands by altering its functional and structural properties ("neuroplasticity") which results in learning and acquiring skills. Convergent evidence from both human and animal studies suggests that physical activity facilitates neuroplasticity of certain brain structures and as a result cognitive functions. Animal studies have identified an enhancement of neurogenesis, synaptogenesis, angiogenesis and the release of neurotrophins as neural mechanisms mediating beneficial cognitive effects of physical exercise. This review summarizes behavioral consequences and neural correlates at the system level following physical exercise interventions in humans of different ages. The results suggest that physical exercise may trigger processes facilitating neuroplasticity and, thereby, enhances an individual's capacity to respond to new demands with behavioral adaptations. Indeed, some recent studies have suggested that combining physical and cognitive training might result in a mutual enhancement of both interventions. Moreover, new data suggest that to maintain the neuro-cognitive benefits induced by physical exercise, an increase in the cardiovascular fitness level must be maintained.

Chinese medicine NeuroAiD efficacy stroke recovery-extension study (CHIMES-E study): an observational multicenter study to investigate the longer-term efficacy of NeuroAiD in stroke recovery

BACKGROUND

Stroke carries a poor long-term prognosis for death and disability. There are few acute treatments that reduce death and disability after stroke. The ongoing international, multicenter, randomized, placebo-controlled, double-blind CHIMES trial is currently testing the hypothesis that a 3-month course of the traditional Chinese medicine MLC601 (NeuroAiD) is superior to placebo in reducing neurological deficit and improving functional outcome after acute ischemic stroke in patients receiving standard stroke care. This extension study tests the hypothesis that at 2 years, an initial 3-month administration of NeuroAiD is superior to placebo in reducing neurological deficit and improving functional outcome in patients with cerebral infarction of an intermediate range of severity.

METHODS

Study subjects will be those who are already participants in CHIMES - aged above 21 years, had signs and symptoms of acute stroke, 6 ≤ NIHSS ≤ 14, neuroimaging consistent with ischemic stroke, and received study medication within 72 h of stroke onset. A subject will not be eligible for inclusion in CHIMES-E if they have withdrawn consent from all participation and follow-up for CHIMES. Subjects will be contacted at 6, 12, 18 and 24 months after CHIMES enrollment. After verbal consent is obtained, subjects will be assessed for functional state by the modified Rankin scale (mRS) and Barthel Index (BI), and a history of recurrent vascular events as well as medical events. The primary outcome measure will be the mRS at month 24. Secondary outcome measures will be mRS and BI at 6, 12 and 18 months, and BI at 24 months. Analysis will be based on the intention-to-treat principle. If the number of patients lost to follow-up is substantial, a sensitivity analysis based on the last observation carried forward method will be carried out, to compare the results with those from the main analysis without imputation. Based on a cumulative odds ratio of 1.5 for the NeuroAiD group, a two-sided test of 5% type I error and an expected 30% dropout rate after 2 years of follow-up for the 1,100 patients recruited into CHIMES, the 770 subjects with mRS data expected to be available at year 2 yields an 89% power to detect a difference in efficacy between NeuroAiD and placebo.

CONCLUSIONS

This study will provide evidence for the longer-term efficacy of an initial course of a neurorestorative therapy after acute ischemic stroke of intermediate severity.

The modulation of venlafaxine on cortical activation of language area in healthy subjects with fMRI study

RATIONALE

Previous studies have shown that selective serotonin reuptake inhibitors, activators of the cortex, apparently improved language functional recovery after brain damage rather than simply affective disorders.

OBJECTIVE

Our aim was to determine whether venlafaxine (an agonist of both norepinephrine and 5-hydroxytryptamine) could modulate language cortex function.

METHODS

A double-blind, crossover, randomized design was used to compare two 7-day treatment sessions with either venlafaxine (75 mg per day) or placebo. A functional magnetic resonance imaging experiment and two language function tests were performed on eight healthy males (mean age, 28.25 ± 3.15 years) at the end of each session, i.e., study entry, after venlafaxine, and after placebo (days 0, 7, and 18). Hyperactivation (venlafaxine minus placebo >0) or hypoactivation (placebo minus venlafaxine >0) by venlaxafine was assessed on the basis of the activation-baseline contrast.

RESULTS

The naming score (P < .001) and spontaneous language fluency (P < .001) were significantly higher after venlafaxine than after placebo. Functional magnetic resonance imaging (fMRI) showed that (1) picture naming activated the left posterior gyrus frontalis medius and the bilateral fusiform gyrus and the bilateral outer occipital lobes, (2) hyperactivation was observed in the adjoining area of posterior upper Broca area and premotor area in the dominant hemisphere in venlafaxine session (after venlafaxine), (3) the hyperactivation of the left gyrus frontalis medius on fMRI and the increase in naming test score were positively correlated, and (4) by contrast, we observed hypoactivation in the temporo-parieto-occipital region in venlafaxine session (after venlafaxine). This improvement may be related to increased phonics-related output in the frontal language cortex of the dominant hemisphere.

A noradrenergic theory of cognitive reserve: implications for Alzheimer's disease

The gap between symptoms and pathology in Alzheimer's disease has been explained by the hypothetical construct of "cognitive reserve"--a set of variables including education, intelligence, and mental stimulation which putatively allow the brain to adapt to-and hence mask--underlying pathologies by maintaining cognitive function despite underlying neural changes. This review proposes a hypothesis that a biological mechanism may mediate between these social/psychological processes on the one hand, and apparently reduced risk of Alzheimer's disease on the other, namely repeated activation of the noradrenergic system over a lifetime by the processes implicated in cognitive reserve. Noradrenaline's neuroprotective effects both in vivo and in vitro, and its key role in mediating the neuroprotective effects of environmental enrichment on the brain, make noradrenaline's key role in mediating cognitive reserve--by disease compensation, disease modification, or a combination of both--a viable hypothesis.