The Link Between Dementia and Aspiration
Aspiration is the entry of food, liquid, or saliva into the airway (trachea) and lungs. While a healthy person can cough or clear their throat to expel the material, people with advanced dementia lose this ability, leaving them vulnerable to serious complications like aspiration pneumonia. The link is dysphagia, the medical term for swallowing difficulties, which affects most people in the later stages of the disease.
Unlike an acute event, such as a stroke, dysphagia in dementia is progressive. The neurological damage impairs the intricate, multi-stage process of swallowing, which involves over 40 muscles and a complex network of nerves. The result is a breakdown in coordination that worsens over time, making every meal a potential risk.
The Mechanisms Behind Aspiration in Dementia
Several factors contribute to the high risk of aspiration in people with dementia. The cognitive and motor decline affects every phase of the swallowing process, from preparing the food in the mouth to clearing the throat.
- Cognitive Decline: Dementia directly affects the brain regions responsible for controlling the act of swallowing, including the insular cortex, cingulate cortex, and basal ganglia. This can lead to apraxia of swallowing, where the person forgets how to perform the complex series of steps to swallow correctly, even if the muscles are physically capable.
- Delayed Swallowing Reflex: The reflex that automatically triggers swallowing is slowed or weakened in dementia patients. This prolonged delay between chewing and swallowing increases the chance of food or liquid entering the airway, a phenomenon often described as “tracheal penetration”.
- Weakened Muscles: The progressive loss of muscle mass and strength (sarcopenia) affects the tongue, throat, and chest muscles crucial for chewing and swallowing. This weakness can result in poor bolus control, where food and liquid are not properly contained in the mouth, and ineffective clearing of the throat, leaving residue behind.
- Sensory and Behavioral Changes: Altered sensation and reduced awareness can prevent the person from recognizing when they need to swallow. Behavioral issues, such as rapid or compulsive eating or refusing to eat, can also compromise safety during meals.
Comparison of Aspiration Types in Dementia
| Feature | Overt Aspiration | Silent Aspiration |
|---|---|---|
| Detection | Easily visible signs like coughing, choking, or gagging. | No obvious or visible symptoms of coughing or distress. |
| Symptom Profile | Coughing during or after meals, red-faced, watering eyes, difficulty breathing. | Can only be detected with specialized tests like a videofluoroscopy. |
| Associated Risk | High risk of choking and aspiration pneumonia. | Extremely high risk of aspiration pneumonia, often undetected until a severe chest infection occurs. |
| Why it Occurs | Protective cough reflex is still somewhat active but unable to clear the airway effectively. | Protective reflexes, such as the cough and swallow reflexes, are severely blunted or non-existent. |
Strategies for Preventing Aspiration
Preventing aspiration in people with dementia involves a multi-faceted approach, often guided by a speech-language pathologist. These strategies focus on modifying the eating environment, food, and feeding techniques to maximize safety.
Dietary Modifications:
- Thickened Liquids: For those who struggle with thin liquids, commercial thickening agents can be added to water, juice, and other beverages to make them easier to control during swallowing.
- Modified Food Textures: The consistency of food can be changed from regular solids to soft, minced, or pureed forms that are easier to chew and swallow.
- Sensory Stimulation: Serving food and beverages at distinct temperatures (hot or cold) or adding certain spices can enhance the swallowing reflex.
Environmental and Positional Strategies:
- Upright Positioning: Always ensure the person is sitting upright at a 90-degree angle during meals. This position should be maintained for at least 30 minutes after eating to aid digestion and prevent reflux.
- Minimize Distractions: A calm and quiet eating environment with minimal distractions, such as turning off the television, helps the person focus on the task of eating.
- Proper Meal Pacing: Encourage slow, small bites and sips. Caregivers should wait until one mouthful is completely swallowed before offering the next.
Oral Hygiene:
- Regular Oral Care: Maintaining excellent oral hygiene, including brushing teeth and cleaning dentures regularly, helps to reduce the number of bacteria in the mouth. When saliva is aspirated, this lowers the risk of aspiration pneumonia.
When Aspiration Leads to Pneumonia
Aspiration pneumonia is a serious and frequent consequence of repeated or silent aspiration. When food, fluid, or saliva enter the lungs, it provides a breeding ground for bacteria from the mouth to cause an infection. In advanced dementia, pneumonia is a leading cause of death, with high mortality rates.
Feeding tubes, such as PEG tubes, are often considered by families concerned about nutrition and aspiration. However, multiple studies show that feeding tubes do not prolong survival, improve quality of life, or reduce the risk of aspiration pneumonia in advanced dementia. The risk of aspirating saliva remains, and the body’s natural decline continues. In fact, careful hand-feeding can provide significant benefits in terms of comfort, taste, and human interaction, while still reducing aspiration risk.
Conclusion: Navigating Care for Swallowing Difficulties
Understanding why people with dementia aspiration is crucial for providing effective and compassionate care. The breakdown of the swallowing mechanism is a complex and progressive symptom of the disease, not simply a feeding issue. By recognizing the underlying causes and implementing proactive strategies, caregivers can significantly reduce the risk of aspiration and its severe complications. Working closely with healthcare professionals, including speech-language pathologists, is key to developing a personalized care plan that prioritizes safety, comfort, and dignity for the person with dementia.
Canadian Virtual Hospice: Swallowing Problems in Degenerative Brain Diseases
