The effectiveness of methylphenidate in improving cognition after brain injury in adults: a systematic review

Pharmacotherapy to Improve Cognitive Functioning After Acquired Brain Injury: A Meta-Analysis and Meta-Regression

Cognitive impairments, common sequelae of acquired brain injury (ABI), significantly affect rehabilitation and quality of life. Currently, there is no solid evidence-base for pharmacotherapy to improve cognitive functioning after ABI, nevertheless off-label use is widely applied in clinical practice. This meta-analysis and meta-regression aims to quantitatively aggregate the available evidence for the effects of pharmacological agents used in the treatment of cognitive impairments following ABI. We conducted a comprehensive search of Embase, Medline Ovid, and Cochrane Controlled Trials Register databases for randomized controlled and crossover trials. Meta-analytic effects were calculated for each pharmaceutical agent and targeted neuromodulator system. Cognitive outcome measures were aggregated across cognitive domains. Of 8,216 articles, 41 studies (4,434 patients) were included. The noradrenergic agent methylphenidate showed a small, significant positive effect on cognitive functioning in patients with traumatic brain injury (TBI; k = 14, d = 0.34, 95% confidence interval: 0.12-0.56, P = 0.003). Specifically, methylphenidate was found to improve cognitive functions related to executive memory, baseline speed, inhibitory control, and variability in responding. The cholinergic drug donepezil demonstrated a large effect size, albeit based on a limited number of studies (k = 3, d = 1.68, P = 0.03). No significant effects were observed for other agents. Additionally, meta-regression analysis did not identify significant sources of heterogeneity in treatment response. Our meta-analysis supports the use of methylphenidate for enhancing cognitive functioning in patients with TBI. Although donepezil shows potential, it warrants further research. These results could guide clinical decision making, inform practice guidelines, and direct future pharmacotherapeutic research in ABI.

Methylphenidate improves cognitive function and health-related quality of life in survivors of childhood brain tumours

OBJECTIVES

The growing population of survivors of childhood brain tumors present the challenge of long-term quality of survival. The domains most affected by tumor and treatment are those implicated in development of typical intellectual functions: attention, working memory, and processing speed, with consequent effects upon function and quality of life. In this paper we present service evaluation data on the 12-month effect upon processing speed, visual and auditory attentional domains in 29 patients receiving methylphenidate aged 5-16 years (Mean=10.6).

METHODS

Patients received immediate-release methylphenidate and were converted to modified-release as appropriate. Mean optimal dose of immediate-release methylphenidate was 0.34 mg/kg per dose (range 0.2-0.67).

RESULTS

Patients showed a significant positive impact of methylphenidate on attention in all tests of selective visual attention from the Test of Everyday Attention for Children 2. A significant improvement was also shown on response time. Significant change was not found on psychometric measures of sustained auditory or visual attention, or selective auditory attention. Ratings of Health-Related Quality of Life showed a positive benefit of methylphenidate at 12 months. Side effects were minimal and not statistically significant.

CONCLUSIONS

Survivors of childhood brain tumor with attentional and processing speed deficit show clinical benefit from methylphenidate.

INCOG 2.0 Guidelines for Cognitive Rehabilitation Following Traumatic Brain Injury, Part V: Memory

INTRODUCTION

Memory impairments affecting encoding, acquisition, and retrieval of information after moderate-to-severe traumatic brain injury (TBI) have debilitating and enduring functional consequences. The interventional research reviewed primarily focused on mild to severe memory impairments in episodic and prospective memory. As memory is a common focus of cognitive rehabilitation, clinicians should understand and use the latest evidence. Therefore, the INCOG ("International Cognitive") 2014 clinical practice guidelines were updated.

METHODS

An expert panel of clinicians/researchers reviewed evidence published since 2014 and developed updated recommendations for intervention for memory impairments post-TBI, a decision-making algorithm, and an audit tool for review of clinical practice.

RESULTS

The interventional research approaches for episodic and prospective memory from 2014 are synthesized into 8 recommendations (6 updated and 2 new). Six recommendations are based on level A evidence and 2 on level B. In summary, they include the efficacy of choosing individual or multiple internal compensatory strategies, which can be delivered in a structured or individualized program. Of the external compensatory strategies, which should be the primary strategy for severe memory impairment, electronic reminder systems such as smartphone technology are preferred, with technological advances increasing their viability over traditional systems. Furthermore, microprompting personal digital assistant technology is recommended to cue completion of complex tasks. Memory strategies should be taught using instruction that considers the individual's functional and contextual needs while constraining errors. Memory rehabilitation programs can be delivered in an individualized or mixed format using group instruction. Computer cognitive training should be conducted with therapist guidance. Limited evidence exists to suggest that acetylcholinesterase inhibitors improve memory, so trials should include measures to assess impact. The use of transcranial direct current stimulation (tDCS) is not recommended for memory rehabilitation.

CONCLUSION

These recommendations for memory rehabilitation post-TBI reflect the current evidence and highlight the limitations of group instruction with heterogeneous populations of TBI. Further research is needed on the role of medications and tDCS to enhance memory.

INCOG 2.0 Guidelines for Cognitive Rehabilitation Following Traumatic Brain Injury, Part II: Attention and Information Processing Speed

INTRODUCTION

Moderate to severe traumatic brain injury (MS-TBI) commonly causes disruption in aspects of attention due to its diffuse nature and injury to frontotemporal and midbrain reticular activating systems. Attentional impairments are a common focus of cognitive rehabilitation, and increased awareness of evidence is needed to facilitate informed clinical practice.

METHODS

An expert panel of clinicians/researchers (known as INCOG) reviewed evidence published from 2014 and developed updated guidelines for the management of attention in adults, as well as a decision-making algorithm, and an audit tool for review of clinical practice.

RESULTS

This update incorporated 27 studies and made 11 recommendations. Two new recommendations regarding transcranial stimulation and an herbal supplement were made. Five were updated from INCOG 2014 and 4 were unchanged. The team recommends screening for and addressing factors contributing to attentional problems, including hearing, vision, fatigue, sleep-wake disturbance, anxiety, depression, pain, substance use, and medication. Metacognitive strategy training focused on everyday activities is recommended for individuals with mild-moderate attentional impairments. Practice on de-contextualized computer-based attentional tasks is not recommended because of lack of evidence of generalization, but direct training on everyday tasks, including dual tasks or dealing with background noise, may lead to gains for performance of those tasks. Potential usefulness of environmental modifications is also discussed. There is insufficient evidence to support mindfulness-based meditation, periodic alerting, or noninvasive brain stimulation for alleviating attentional impairments. Of pharmacological interventions, methylphenidate is recommended to improve information processing speed. Amantadine may facilitate arousal in comatose or vegetative patients but does not enhance performance on attentional measures over the longer term. The antioxidant Chinese herbal supplement MLC901 (NeuroAiD IITM) may enhance selective attention in individuals with mild-moderate TBI.

CONCLUSION

Evidence for interventions to improve attention after TBI is slowly growing. However, more controlled trials are needed, especially evaluating behavioral or nonpharmacological interventions for attention.

Pharmacologic Therapies to Promote Recovery of Consciousness

Pharmacologic interventions are commonly used to support rehabilitation efforts of patients with disorders of consciousness (DoC). The 2018 practice guidelines recommend amantadine in adults with traumatic DoC to promote functional recovery, though several other stimulants are used off-label in clinical practice and trials, such as methylphenidate, bromocriptine, levodopa, and zolpidem. Differences in the mechanisms of action, adverse effects, pharmacokinetics, and drug-drug interactions should be considered when selecting the best agent for each individual patient. Overall, pharmacologic stimulants may provide a safe and inexpensive pathway to increased functionality and participation in rehabilitation. This article provides a concise summary of scientific evidence supporting the use of pharmacologic therapies to stimulate recovery of consciousness in patients with DoC.

Role of the Dopaminergic System in the Striatum and Its Association With Functional Recovery or Rehabilitation After Brain Injury

Disabilities are estimated to occur in approximately 2% of survivors of traumatic brain injury (TBI) worldwide, and disability may persist even decades after brain injury. Facilitation or modulation of functional recovery is an important goal of rehabilitation in all patients who survive severe TBI. However, this recovery tends to vary among patients because it is affected by the biological and physical characteristics of the patients; the types, doses, and application regimens of the drugs used; and clinical indications. In clinical practice, diverse dopaminergic drugs with various dosing and application procedures are used for TBI. Previous studies have shown that dopamine (DA) neurotransmission is disrupted following moderate to severe TBI and have reported beneficial effects of drugs that affect the dopaminergic system. However, the mechanisms of action of dopaminergic drugs have not been completely clarified, partly because dopaminergic receptor activation can lead to restoration of the pathway of the corticobasal ganglia after injury in brain structures with high densities of these receptors. This review aims to provide an overview of the functionality of the dopaminergic system in the striatum and its roles in functional recovery or rehabilitation after TBI.

The relationship between vocal affect recognition and psychosocial functioning for people with moderate to severe traumatic brain injury: a systematic review

The purpose of this review was to explore how vocal affect recognition deficits impact the psychosocial functioning of people with moderate to severe traumatic brain injury (TBI). A systematic review following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines was conducted, whereby six databases were searched, with additional hand searching of key journals also completed. The search identified 1847 records after duplicates were removed, and 1749 were excluded through title and abstract screening. After full text screening of 65 peer-reviewed articles published between January 1999 and August 2019, only five met inclusion criteria. The methodological quality of selected studies was assessed using the Mixed Methods Appraisal Tool (MMAT) Version 2018 with a fair level of agreement reached. A narrative synthesis of the results was completed, exploring vocal affect recognition and psychosocial functioning of people with moderate to severe TBI, including aspects of social cognition (i.e., empathy; Theory of Mind) and social behaviour. Results of the review were limited by a paucity of research in this area, a lack of high-level evidence, and wide variation in the outcome measures used. More rigorous study designs are required to establish more conclusive evidence regarding the degree and direction of the association between vocal affect recognition and aspects of psychosocial functioning. This review is registered with Prospero.