Drug treatment of poststroke aphasia

Right hemisphere structural adaptation and changing language skills years after left hemisphere stroke

Stroke survivors with acquired language deficits are commonly thought to reach a ‘plateau’ within a year of stroke onset, after which their residual language skills will remain stable. Nevertheless, there have been reports of patients who appear to recover over years. Here, we analysed longitudinal change in 28 left-hemisphere stroke patients, each more than a year post-stroke when first assessed—testing each patient’s spoken object naming skills and acquiring structural brain scans twice. Some of the patients appeared to improve over time while others declined; both directions of change were associated with, and predictable given, structural adaptation in the intact right hemisphere of the brain. Contrary to the prevailing view that these patients’ language skills are stable, these results imply that real change continues over years. The strongest brain–behaviour associations (the ‘peak clusters’) were in the anterior temporal lobe and the precentral gyrus. Using functional magnetic resonance imaging, we confirmed that both regions are actively involved when neurologically normal control subjects name visually presented objects, but neither appeared to be involved when the same participants used a finger press to make semantic association decisions on the same stimuli. This suggests that these regions serve word-retrieval or articulatory functions in the undamaged brain. We teased these interpretations apart by reference to change in other tasks. Consistent with the claim that the real change is occurring here, change in spoken object naming was correlated with change in two other similar tasks, spoken action naming and written object naming, each of which was independently associated with structural adaptation in similar (overlapping) right hemisphere regions. Change in written object naming, which requires word-retrieval but not articulation, was also significantly more correlated with both (i) change in spoken object naming; and (ii) structural adaptation in the two peak clusters, than was change in another task—auditory word repetition—which requires articulation but not word retrieval. This suggests that the changes in spoken object naming reflected variation at the level of word-retrieval processes. Surprisingly, given their qualitatively similar activation profiles, hypertrophy in the anterior temporal region was associated with improving behaviour, while hypertrophy in the precentral gyrus was associated with declining behaviour. We predict that either or both of these regions might be fruitful targets for neural stimulation studies (suppressing the precentral region and/or enhancing the anterior temporal region), aiming to encourage recovery or arrest decline even years after stroke occurs.

Piracetam for Aphasia in Post-stroke Patients: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Aphasia is a common symptom in post-stroke patients. Piracetam is a commonly used nootropic agent that promises various benefits to brain function, including language improvement.

OBJECTIVE

We performed a systematic review and meta-analysis to assess whether piracetam facilitates the rehabilitation of language performance in post-stroke patients.

METHODS

Randomized controlled trials (RCTs) of piracetam treatment in post-stroke patients published in any language were included, excluding those involving pre-existing cognitive disorders such as dementia and mood disturbances. We searched several databases including PubMed, EMBASE, Cochrane Central, CINAHL, Web of Science, and PsycINFO for RCTs published up to 31 December 2015. We conducted a meta-analysis using RevMan (version 5.3), with standardized mean differences (SMDs) and fixed-effect models, and used StataSE (version 13) for the detection of publication bias. This study has been submitted to PROSPERO, and its registration number is CRD42016034088.

RESULTS

We identified 1180 titles and abstracts, and finally included seven RCTs in this meta-analysis. The number of participants in each study ranged from 19 to 66, summing up to 261 patients overall. The dose of piracetam was consistent while the frequency and time of therapy varied. The assessment of the language at the end of trials showed no significant improvement in overall severity of aphasia [SMD 0.23, 95 % confidence interval (CI) -0.03 to 0.49, P = 0.08], but written language (SMD 0.35, 95 % CI 0.04 to 0.66, P = 0.03) showed pronounced improvement. Subgroup analyses indicated a dissociation of effectiveness between short- and long-term assessment in overall severity (P = 0.008, I (2) = 85.6 %) in terms of tests for subgroup differences, and a mild trend toward dissociation in written subtests (P = 0.30, I (2) = 5.1 %). Funnel plots and Egger's test identified no obvious publication bias in the primary variable.

CONCLUSIONS

Piracetam plays a limited role in the rehabilitation of overall language impairment and only benefits written language ability at the end of trials. Its effect on overall linguistic level and written language tends to emerge within a short period and declines thereafter.

Effect of Donepezil on Wernicke Aphasia After Bilateral Middle Cerebral Artery Infarction: Subtraction Analysis of Brain F-18 Fluorodeoxyglucose Positron Emission Tomographic Images

Aphasia is one of the most common neurologic deficits occurring after stroke. Although the speech-language therapy is a mainstream option for poststroke aphasia, pharmacotherapy is recently being tried to modulate different neurotransmitter systems. However, the efficacy of those treatments is still controversial. We present a case of a 53-year-old female patient with Wernicke aphasia, after the old infarction in the territory of left middle cerebral artery for 8 years and the recent infarction in the right middle cerebral artery for 4 months. On the initial evaluation, the Aphasia Quotient in Korean version of the Western Aphasia Battery was 25.6 of 100. Baseline brain F-18 fluorodeoxyglucose positron emission tomographic images demonstrated a decreased cerebral metabolism in the left temporoparietal area and right temporal lobe. Donepezil hydrochloride, a reversible acetylcholinesterase inhibitor, was orally administered 5 mg/d for 6 weeks after the initial evaluation and was increased to 10 mg/d for the following 6 weeks. After the donepezil treatment, the patient showed improvement in language function, scoring 51.0 of 100 on Aphasia Quotient. A subtraction analysis of the brain F-18 fluorodeoxyglucose positron emission tomographic images after donepezil medication demonstrated increased uptake in both middle temporal gyri, extended to the occipital area and the left cerebellum. Thus, we suggest that donepezil can be an effective therapeutic choice for the treatment of Wernicke aphasia.

Does long term use of piracetam improve speech disturbances due to ischemic cerebrovascular diseases?

Aphasia causes significant disability and handicap among stroke survivors. Language therapy is recommended for aphasic patients, but not always available. Piracetam, an old drug with novel properties, has been shown to have mild beneficial effects on post-stroke aphasia. In the current study, we investigated the effects of 6 months treatment with piracetam on aphasia following stroke. Thirty patients with first-ever ischemic strokes and related aphasia were enrolled in the study. The scores for the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), modified Rankin Scale (mRS), and Gülhane Aphasia Test were recorded. The patients were scheduled randomly to receive either 4.8 g piracetam daily or placebo treatment for 6 months. At the end of 24 weeks, clinical assessments and aphasia tests were repeated. The level of improvement in the clinical parameters and aphasia scores was compared between the two groups. All patients had large lesions and severe aphasia. No significant difference was observed between the piracetam and placebo groups regarding the improvements in the NIHSS, BI and mRS scores at the end of the treatment. The improvements observed in spontaneous speech, reading fluency, auditory comprehension, reading comprehension, repetition, and naming were not significantly different in the piracetam and placebo groups, the difference reached significance only for auditory comprehension in favor of piracetam at the end of the treatment. Piracetam is well-tolerated in patients with post-stroke aphasia. Piracetam taken orally in a daily dose of 4.8 g for 6 months has no clear beneficial effect on post-stroke language disorders.

Pharmacotherapy in stroke rehabilitation

BACKGROUND

Pharmacotherapy is commonly given to patients recovering from a stroke to prevent further complications (e.g. recurrent stroke, seizures) or enhance recovery. However, some drugs may have a negative impact on neuroplasticity.

OBJECTIVES

This review examines currently used drugs that are believed to promote recovery from motor and cognitive disturbances associated with stroke.

METHODS

Literature regarding the properties, efficacy, safety, and dosing of drugs used to promote recovery after stroke was reviewed.

RESULTS

The data on pharmacotherapy are insufficient to support a claim of significantly improved rehabilitation outcomes. Moreover, a growing body of evidence indicates that some agents can impair functional reorganization and slow the recovery process. However, a few chemicals are reported to be beneficial for stroke rehabilitation. The most promising are noradrenergic and dopaminergic agents, as well as several growth factors; these should be the future focus of extensive randomized clinical trials.

CONCLUSIONS

Currently there is no drug with proven efficacy in enhancing poststroke recovery.

Poststroke Aphasia

Aphasia, the loss or impairment of language caused by brain damage, is one of the most devastating cognitive impairments of stroke. Aphasia is present in 21-38% of acute stroke patients and is associated with high short- and long-term morbidity, mortality and expenditure. Recovery from aphasia is possible even in severe cases. While speech-language therapy remains the mainstay treatment of aphasia, the effectiveness of conventional therapies has not been conclusively proved. This has motivated attempts to integrate knowledge from several domains in an effort to plan more rational therapies and to introduce other therapeutic strategies, including the use of intensive language therapy and pharmacological agents. Several placebo-controlled trials suggest that piracetam is effective in recovery from aphasia when started soon after the stroke, but its efficacy vanishes in patients with chronic aphasia. Drugs acting on catecholamine systems (bromocriptine, dexamfetamine) have shown varying degrees of efficacy in case series, open-label studies and placebo-controlled trials. Bromocriptine is useful in acute and chronic aphasias, but its beneficial action appears restricted to nonfluent aphasias with reduced initiation of spontaneous verbal messages. Dexamfetamine improves language function in subacute aphasia and the beneficial effect is maintained in the long term, but its use is restricted to highly selected samples. Pharmacological agents operating on the cholinergic system (e.g. donepezil) have shown promise. Data from single-case studies, case series and an open-label study suggest that donepezil may have beneficial effects on chronic poststroke aphasia. Preliminary evidence suggests that donepezil is well tolerated and its efficacy is maintained in the long term. Randomised controlled trials of donepezil and other cholinergic agents in poststroke aphasia are warranted.