Ask the Expert: Why Do Many People with LBD Respond Poorly to Surgery?

Wh do LBD patients respond poorly to sugery?

By Farzana Pervin, M.D. and Carol F Lippa, M.D., Drexel University College of Medicine

Need to make a decision on surgery for someone with Lewy body dementia (LBD)? Family members and caregivers of those with LBD are sometimes challenged in this scenario. Making an informed decision is extremely important because LBD patients may respond poorly to surgery, anesthesia, and pain. People with LBD may develop delirium (a sudden change in mental status) or motor/movement decline after surgery. Anesthesia, pain medications, old age, and surgery-related stresses may each be a culprit behind these complications.

LBD is the second most common degenerative dementia in our elderly population. It is caused by aggregation of an abnormal protein (alpha synuclein) in brain nerve cells, in the form of Lewy bodies and Lewy neurites. The disease process damages cholinergic and dopaminergic neurons (brain cells) that produce two neurotransmitters (chemical messengers) called acetylcholine and dopamine. Lower levels of these neurotransmitters impact the neurons’ ability to communicate with each other.

Cholinergic brain cells that produce acetylcholine regulate higher cognitive functions such as attention, memory and learning new skills. Most types of general anesthetic agents reduce the release of acetylcholine and may depress the cholinergic system in the central nervous system. This causes impaired consciousness and inattention, as well as changes in movement. Research has shown that the cholinergic system is already mildly impaired in the elderly people because of the age related changes. When anesthesia is used for surgery, it further impacts these neurons in normal elderly people. The effect is more pronounced in elderly LBD patients because of their marked baseline cholinergic losses. Alzheimer’s disease patients also have cholinergic losses, and may suffer from clinical worsening when exposed to these agents but they are not as severe as those of LBD patients.

Patients with LBD may undergo surgery at different stages of their dementia and have a variety of mood and behavioral symptoms before surgery. All LBD patients are inherently sensitive to stresses, including changes in environment, daily routines and medications, which can affect their cognition and behavior. The unfamiliar environment of the operating room and hospital may trigger challenging behavior and changes in cognition; the physical stresses on their body from the surgery can also alter their cognition. Other age- related changes and health conditions unrelated to LBD can impair their ability to respond to stresses as well.

Delirium is another common complication for older patients who undergo surgery, and is common in LBD. Delirium is a complex neuropsychiatric syndrome in which there is a sudden worsening of a person’s mental state, and includes varying levels of confusion and obvious problems with orientation and attention. There are some risk factors for the development of delirium after surgery, such as old age, dementia, multiple health conditions, anesthetic agents, pain, and stresses associated with surgery. Certain medications can also contribute to delirium, such as narcotic pain medications, non-steroidal anti-inflammatory drugs (NSAIDs) anti-cholinergic medications, levodopa and sedatives like Valium. Recent studies have shown that individuals who experience delirium are at risk for not returning to their pre-surgery functional ability. They also face more risk of a prolonged hospital stay, increased medical problems and mortality.

Assessment of pain is another challenge for the patients with cognitive impairment due to communication difficulty. Dementia impairs a person’s perception of pain and their ability to report it to the caregivers or physicians. Some people with dementia show worsening behavior instead of communicating that they are in pain, or may not be able to rate their level of pain or identify where it is. In such cases, health care professionals can evaluate the pain by using non-verbal techniques such as facial expression, moaning, body movement, and change in activity or behavior patterns. It is important to note that poor pain management may impair cognitive function. Since many patients with dementia worsen when in pain, it is important to provide them careful and adequate pain management while undergoing surgery.

Overall, surgery can improve health or quality of life for people with LBD, but the risks and benefits must be weighed by the physician and family. Assessing cognition, other medical comorbidities, and reviewing medications for modifiable risk factors is important prior to performing surgery on someone with LBD. This helps to minimize hospital stays, unnecessary medications, and have a caregiver available and prepared to function as an advocate. Family members and caregivers should share information about the person with LBD and any medication sensitivities already identified with healthcare professionals prior to surgery. This will aid in making the best decision on surgery and developing strategies to manage all relevant medical and behavioral needs before and after surgery.