From the Guidelines
Memantine is the most effective medication for delaying cognitive decline in patients with metastatic brain cancer, particularly when used concurrently with whole-brain radiotherapy (WBRT) and hippocampal avoidance. This recommendation is based on the most recent and highest quality study available, which demonstrated that memantine given concurrently and for six months following WBRT delayed time to cognitive decline following WBRT in a randomized, double-blind, placebo-controlled trial 1.
When considering treatment options for cognitive deficits in patients with metastatic brain cancer, it is essential to prioritize a comprehensive approach that addresses the underlying cancer, as well as contributing factors such as depression, anxiety, fatigue, and medication side effects. Other medications like methylphenidate (Ritalin) at doses of 5-10 mg twice daily or modafinil (Provigil) 200 mg daily may provide some benefit for attention and processing speed, though evidence for their efficacy is limited 1. Donepezil (Aricept) 5-10 mg daily has shown modest benefits in some cancer patients with cognitive impairment, but its effectiveness in patients with metastatic brain cancer is not well established 1.
Key considerations in managing cognitive deficits in patients with metastatic brain cancer include:
- Individualized treatment plans that balance potential benefits against side effects
- Comprehensive approaches that incorporate cognitive rehabilitation, exercise, and adequate sleep
- Addressing contributing factors like depression, anxiety, fatigue, and medication side effects
- Considering the patient's overall condition, prognosis, and goals of care when making treatment decisions.
In the context of whole-brain radiotherapy, the use of memantine and hippocampal avoidance is recommended to minimize cognitive decline 1. This approach has been shown to improve cognitive preservation in patients with brain metastases, and should be considered as part of a comprehensive treatment plan.
From the Research
Medication Options for Cognitive Deficits in Metastatic Brain Cancer
- Memantine has been shown to provide some benefit in reducing the rate of decline in cognitive function and time to cognitive failure in patients with brain metastasis receiving whole-brain radiotherapy 2, 3, 4.
- The use of memantine prior to and during whole-brain radiotherapy has been shown to significantly delay time to cognitive failure and reduce the rate of decline in memory, cognitive function, and processing speed 4.
- Memantine offers a promising safety profile with high tolerability and limited side effects 4.
Studies on Memantine Usage
- A narrative review of the therapeutic role of memantine for the prevention of cognitive decline in cancer patients with brain metastasis receiving whole-brain radiotherapy found that memantine use has been shown to provide some benefit in reducing the rate of decline in cognitive function and time to cognitive failure 2.
- A review of the pathology or mechanism of cognitive function impairment after brain irradiation and strategies available to preserve cognitive function after radiation therapy found that memantine was beneficial in preserving cognitive function 3.
- A population-based study found that despite phase 3 evidence supporting memantine utilization among patients receiving whole-brain radiotherapy, rates of memantine prescription are strikingly low, although memantine utilization seems to be increasing since publication of RTOG 0614 5.
Other Interventions for Cognitive Deficits
- Both pharmacological interventions and cognitive rehabilitation programmes have been used to treat or prevent cognitive impairment in patients with brain tumours, although most studies have reported some successes, these are often difficult to interpret owing to limitations in the methods used 6.
- Investigations of newer, targeted therapies have reported delays in cognitive deterioration, but these need to be confirmed in future studies 6.
- Neuroprotection represents another potentially promising, novel approach to prevention of cognitive impairment in this vulnerable population of patients 6.