A Significant Brain Injury

It’s important for family members who may be present to know that in patients with markedly low levels of consciousness, pain is expressed much differently than it is in conscious individuals. First, I address the patient gently and then more loudly, and then I shake the individual. Eventually, I apply a stimulus that would cause pain in a fully conscious person. A grimace in a comatose patient may not be the same as one in someone who’s fully alert. A painful stimulus is necessary and only applied if a patient is in a deep coma. I do not apply it to patients who display episodes of consciousness. Neurologists are fully aware that we can do more harm than good by inducing unnecessary pain. We also know that it can be traumatic for a family member to watch as a physician approaches their seemingly unresponsive loved one and compresses the nail bed with a metal object to evoke a reaction. Along with checking the patient’s reaction to pain, I check several other reflexes. I grade motor responses as following a simple command to localization, meaning that the patient notices a pinch, usually by moving an arm toward it. When a patient lapses into a deeper level of coma, localization disappears. Usually, I apply an unpleasant stimulus at the nail bed, which may cause the patient to quickly flinch and withdraw.

Are They Humans Being?

It also may yield a primitive response in which the patient more gradually bends an arm and wrist. The worst sign is when patients stretch out their arms and legs when a stimulus is administered. This is known as extensor posturing and indicates a major brainstem abnormality, often a sign of one of the deepest levels of coma and permanent injury. For family members in the room, these tests are hard to watch, and family may not completely understand why I’m doing them. It’s also a good indicator of the depth of coma and a baseline for monitoring the patient’s progress. Grimacing may falsely suggest discomfort or even pain. Tears running down the cheek may falsely suggest crying. The body stiffening when pinched may falsely suggest the patient is fending off the examiner. These spasms are primitive responses that are innate in all of us, but they’re usually suppressed by a normally functioning brain. When the brain is injured, these reflexes reappear. The stiffening response eventually may improve to bending the elbow or trying to touch other parts of the body. An example is when a patient knows where I’m pinching or can find catheters and tubes and attempts to remove them.

Crippled Inside

We always look for those signs and changes from one motor response to another on our daily rounds. Comatose patients may exhibit specific actions just for a brief period. Often, they do it while their families are at the bedside but not when a member of the health care team is there. We always trust the observations of family members and continue to watch for the actions they notice, particularly when the changes are major, such as progressing from a reflex response to being able to follow some instructions. After checking a patient’s motor responses, I assess brainstem reflexes. I’m evaluating the size of the pupils and how they respond to light directed into the eyes. The normal response to light focused on an eye is contraction and narrowing of the pupil. Lack of that response is an important indicator of a significant brain injury, either compression of the nerves that contract the pupil or an injury in the center of the brainstem, where the nerves originate. Among individuals who are comatose, asymmetry of the pupils is common. One pupil may be slightly larger than the other or the pupils may be of very different sizes. I also find it useful to assess the corneal reflex because its function tracks through the brainstem. Using a piece of cotton or a squirt of water, I stimulate the cornea, which typically results in closing of the eyelid.

The Inner Light

I then look for the presence of a breathing drive. Can the patient breathe independently, or is the ventilator providing all the breaths? There are many situations in which medication or abnormal bloodwork values make it impossible for a patient to breathe independently, and physicians are well aware of them. All of the tests I’ve described are necessary to assess the depth of coma. We use the words brain death if all reflexes are absent and the patient isn’t breathing independently and needs blood pressure support with intravenous drugs. Their eyes are open, but they don’t move. They may be breathing on their own and have all other brain reflexes. Stimulating these patients might lead to localization, but they don’t follow commands or speak. This condition is called abulia and can mimic coma. Also, unresponsiveness in patients who have all other reflexes may indicate aphasia, which is inability to speak aside from making sounds. Unfortunately, bystanders often interpret unresponsiveness in patients as unconsciousness. However, a variety of situations can cause acute muteness, which is different from coma or a diminished level of consciousness. It’s also important to recognize the signs indicating that a patient is coming out of a seizure. Bystanders often witness only the end of a seizure and not the full episode, with twitching and contraction. So they see someone who’s somewhat agitated or simply unwilling to cooperate. Individuals emerging from a seizure have an expressionless stare, fluttering eye movements and twitching in the fingers. And they may not respond when spoken to. That’s because they may still be having an active seizure even if large parts of their bodies aren’t convulsing. When examining a comatose patient, I typically look for the major causes of coma and unresponsiveness. If something stands out and points towards a certain diagnosis, I spend a little more time on the symptoms we typically see with that diagnosis and discard or accept findings as we go along. We take a hierarchical approach as we gather the strands.