Cognitive Decline

Memory refers to cognitive mechanisms involving the intake, storage, and retrieval of information. There are various types of memory, including:

• Semantic memory: general factual knowledge about the world.
• Episodic memory: the ability to recall personal life events.
• Procedural memory: memory related to performing tasks or skills.

As individuals age, memory or learning abilities may decline, leading to memory decline or mild forgetfulness (also termed age-related memory decline).

Causes of Memory Decline in Aging

Age-related memory issues may stem from physical changes in the brain such as:

• Brain atrophy or neuronal loss

• Loss of neural connections

• Decreased cerebral blood flow

Other contributing factors include:

• Stress

• Depression

• Dehydration

• Thyroid disorders

• Nutritional deficiencies

• Infections

• Adverse drug reactions

• Substance abuse

When memory loss is severe and unrelated to normal aging, medical consultation is necessary.

Prevention

• Encourage social and physical activities to maintain brain function.

• Use memory aids (e.g., mnemonics).

• Avoid multitasking or distracting environments.

Management

• Promote the learning of new skills.

• Engage patients in activities requiring both physical and mental skills.

• Recommend recording activities and appointments to prevent forgetfulness.

• Keep essential items consistently organized in designated areas.

• Ensure sufficient sleep and proper nutrition.

• Limit alcohol intake.

• Seek help if symptoms of depression arise.

When to See a Doctor

• Inability to perform daily activities.

• Failure to learn new information or follow instructions.

• Forgetting the names of close acquaintances.

• Repetitive questioning.

• Getting lost in familiar places.

• Increasing confusion with time or recognition of people/places.

• Neglect of personal care (e.g., hygiene, eating).

Treatment Options

1. Cholinesterase Inhibitors

Drugs like Donepezil, Galantamine, and Rivastigmine inhibit the breakdown of acetylcholine, enhancing neurotransmission in brain areas involved with memory and learning. They are mainly used for treating Alzheimer’s disease.

Dosage & Administration (Adults):

Drug	Initial Dosage and Titration	Administration
Donepezil	Start: 5 mg once daily at bedtime; increase to 10 mg once daily after at least 1 month.	With or without food
Rivastigmine	Start: 1.5 mg twice daily; increase by 1.5 mg every two weeks to a maximum of 6 mg twice daily. Restart with 1.5 mg twice daily if interrupted.	With food
Galantamine (Tab)	Start: 4 mg twice daily for 4 weeks, then increase to 8 mg twice daily; may titrate to 12 mg twice daily.	With food
Galantamine (MR cap)	Start: 8 mg once daily for 4 weeks, then increase to 16 mg once daily; max 24 mg once daily.	With food

Common side effects include dizziness, headache, nausea, vomiting, loss of appetite, and diarrhea.

Use should be avoided in patients with severe renal or hepatic impairment, epilepsy, cardiovascular disease, and in pregnant or breastfeeding women.

2. N-methyl-D-aspartate (NMDA) receptor antagonists

N-methyl-D-aspartate (NMDA) receptor antagonists, such as memantine, may be considered for patients with moderate to severe Alzheimer’s disease.

Dosage & Administration (Adults):

Drug	Initial Dosage and Titration	Administration
Memantine	Start: 5 mg once daily; increase by 5 mg weekly to a max of 20 mg/day.	With or without food

Common side effects include dizziness, headache, nausea, vomiting, loss of appetite, and diarrhea.

Use should be avoided in patients with severe renal or hepatic impairment, epilepsy, cardiovascular disease, Alkaline urine conditions, and in pregnant or breastfeeding women.

Additionally, co-administration with other NMDA antagonists (e.g., dextromethorphan, ketamine) should be avoided.

3. Nootropics and Neurotonics/Neurotrophics

• Neurotrophic agents (e.g., porcine brain-derived peptide) may support cognitive and emotional functions after brain injury (e.g., organic brain syndrome).

• Nootropic agents (e.g., nicergoline, piracetam) may be adjunctive treatments for cognitive decline:
• Piracetam: Improves oxygen utilization and inhibits platelet aggregation but must be avoided in severe renal impairment and hemorrhagic stroke.
• Citicoline: A derivative of choline and cytidine; supports lecithin synthesis and may enhance cerebral blood flow and oxygen utilization.

4. Peripheral Vasodilators & Cerebral Activators

• Nicergoline (ergot derivative): Enhances cerebral blood flow; not for use in porphyria or during pregnancy.

• Ginkgo biloba extract (e.g., EGb 761):
• May improve cognitive and social function in Alzheimer’s disease or vascular dementia.
• Potential mechanisms: antiplatelet effects, vasodilation, neurotransmitter modulation, and reduced brain glucose utilization.
• May also inhibit acetylcholinesterase.