Deena and I have been focusing on the word “sentinel” lately, in the context of her aneurysm. This is a word that has largely escaped me, probably because we used the term “precursor” back in the day. “Sentinel,” seems slightly more romantic to me, however. Yet, there is nothing romantic about the problem your sentinel wants you to be aware of. One of the hallmarks of a teacher is the desire to share something new and interesting with the “class.” Hence, and without a contract this semester, I am sharing this with you.
AN ANALOGY
The human body is like a busy city. Various types of blood cells rush about like cabs, busses, trucks and bicycles, occasionally clogging a major thoroughfare, sometimes with grave consequences. Neural impulses travel at speeds approaching 300 miles per hour in your body, but sometimes the impulses go awry. One suffers the physiological equivalent of brownouts and blackouts, and these are seen as tremors and seizures. Structures here and there in the city (your body) are being torn down or built up. So it is with the muscles in your body. This is called catabolism and anabolism. Red blood cells live for about 115 days, and they are replaced by other cells. In fact, you may not have a single cell today that you had when you were born. Yet, you are still you!
Sometimes, dangerous hombres from out of town invade and attack the peaceful, productive occupants of a city and those cells who call your body home. On a street-level, this can all be very bewildering, and even more so on a cellular level. Someone must call for help.
The feature photo represents such a scene. Watching all of the activity very closely and silently is a sentinel, a robocop if you will, ready to sound the alarm and spring into action if the need arises. Nothing escapes the sentinel’s notice. This post is about sentinels, particularly the sentinels in your body, what they are and what they do. And, just as you hopefully have been raised to respect authority and obey the authorities over you, you should pay attention to what your sentinels are telling you, because they have your best interests at heart.
To begin with, no one knows your body better than yourself. You’ll know tonight how you’d expect to feel tomorrow morning. You can guess if you’ll be happy, depressed, whether you’ll awaken with a painful ankle that you just sprained, or with a hangover from the alcohol you just consumed. You’ll know if your body will crave nicotine, or caffeine, or some other substance as soon as you awaken. But what if in the morning there is a painful, tender lump in your neck, or you have an unusual headache, or trouble focusing your eyes, or trouble standing on you feet? These symptoms are not normal for you, and your body may be trying to tell you something. Your sentinels are warning you to get it checked.
Let’s look at what a sentinel is and what else sentinels do.
DEFINITION
Paul Revere was a sentinel on April 18, 1775 when he watched for the British. His “Midnight Ride” provided the colonists with a warning that the British Army was about to attack. He was captured later that night, questioned, and released. Credit AI generator (Shutterstock.)
A sentinel is someone who guards or keeps watch over another person or perhaps something of value. Or, a sentinel can be some thing (like an intruder alarm.) Whether a person or a machine, a sentinel (sentry) sounds an alarm when there is something amiss, such as imminent danger (e.g., a fire alarm or smoke detector.)
Some say that the word “sentinel” is derived from two old Italian words sentina, meaning “vigilance,” and sentire, “to hear or perceive.”
In medicine, a sentinel is a symptom, sign or event that suggests that there is some sort of undiagnosed disease or disorder present in a person. A symptom is usually a subjective feeling (e.g., dizziness, sensitivity to light, a ringing in the ears, etc.) A sign is something that can be measured, like a pulse, blood pressure, elevated blood count and so on. An event is a combination of variables that combine to cause an emergency, such as a heart attack, drug overdose, a seizure, an attempted suicide to name just a few possibilities.
TYPES OF SENTINEL EVENTS
There are also sentinel events in nature. For example, people have known for well over a century that a falling barometric pressure usually suggested a thunder storm, perhaps favorable conditions for tornados, or that a tropical storm or a hurricane storm was on its way. Unusual activity in the animal kingdom may be related to future and potentially catastrophic events. Scientific studies involving goats indicated that they–and other animals–become alarmed hours and possibly a day or more before an event such as a volcanic eruption or an earthquake takes place. Animals may be sensitive to micro-vibrations or the trace release of elements such as sulfur that people cannot perceive. Often, these sentinel variations cause the animals (geese, goats, elephants) to become increasingly vocal, restless and alarmed, alerting people that some unknown event is imminent.
Animals can also be trained to act as sentinels. Likely watch dogs or police dogs that sniff out drugs or explosives come to mind. But I’ve had high school students in the pass who occasionally had a service dog accompany them to class. These youngsters had diabetic related problems (like hypoglycemia) and the dog would lick the students hand every few minutes. The dog was trained to alert the student whenever it perceived low blood sugar in the child. At that point, the students would take a piece of candy or sugar paste. Eventually, the child would be able to learn the S/Sx of low blood sugar and the dog could stay home, which was just fine by me.
Sometimes we discover strange relationships between people and nature. One such relationship we’re discovering is between powerful magnetic solar storms and epilepsy. Sunspots, solar flares and so on do not cause epilepsy, of course, but many epileptics have more seizures during a geomagnetic event than when the sun is quiet. We don’t yet know why this is true, but the relationship is strong enough for epileptics to be sure they have an adequate plan for their safety if a solar storm is predicted. In this relationship, the events on the sun portend increased numbers of seizures in some epileptics (or not, since the correlation is not one hundred percent.)
Photo of Bret Michaels taken the year his aneurysm ruptured. Photo by: Gregorio T. Binuya/Everett Collection (Alamy–Used with permission.)
As far as people and their health is concerned, there are several events that I’d like to mention if only briefly that have prominent sentinel signs and symptoms (abbreviated in medical notation as “S/Sx.”)
First of all, there are children born with double whorls (crowns) on the top of their head. Normally, there is only one. Two whorls may just be a curious effect with no significance. However, people with Neurofibromatosis type I (NF1), or von Recklinghausen Syndrome which causes tumor development often have double whorls, and in fact, there is a statistical relationship between the two, strong enough that a pediatrician might take note of the observation and order an eye exam, a physical exam, or an analysis of the 17th chromosome to see if the beginning of von Recklinghausen Syndrome is present.
Another sentinel sign can warn of possible heart problems in a person. This is when there is a prominent crease a person’s earlobe, usually best noted in middle age. It appears exactly the same of each of the person’s ears, though a crease could be the result of other factors as well. It takes a trained physician to recognize it.
A diagonal ear lobe crease (DELC), or Frank’s sign, is a deep crease or wrinkle extending to the earlobe. Some studies suggest this indicates a greater risk for coronary artery disease, which can cause heart attacks.”
The health of a patient’s gums can also suggest the presence of heart-related issues hidden elsewhere in the body.
There are other cardiac events that inform you that your heart is not beating regularly, or that not every extremity in your body is getting equally good circulation. There are events that herald the development or metastasis of cancer, primarily affecting the lymph nodes, or unexplained pain in your body, possibly blood in your urine or stools. Then, there are those sentinel-related, emotional S/Sx suggesting the imminence of a suicide attempt, such as when one gives away precious or expensive objects which were previously meaningful to them. There are S/Sx which may announce an approaching migraine headache (this is known as an aura) and sentinel S/Sx dealing with aneurysms, particularly intracranial aneurysms. Aneurysms are weaknesses in the wall of an artery that cause the arterial wall to “bulge” outwards. Under certain circumstances, the “bulge” can leak or rupture. A ruptured aneurysm is serious where ever it occurs in your body, but particularly serious if it occurs in your brain.
Since addressing each of these major problems and identifying the sentinels for each would take too much of your time, I’d like to focus on one problem–that of cerebral (intracranial) aneurysms.
SENTINEL S/Sx OF AN INTRACRANIAL ANEURYSM
Neurosurgeons will tell you that unless an intracranial (i.e., a cerebral) aneurysm is fairly large (seven tenths of a centimeter or more), you will probably not have any indication that it is even there. However, sometimes an aneurysm can press on a nerve or adjacent structure, and in that case, you may have unusual signs or symptoms, including:
Eye pain
Facial pain
Headache
Neck pain
Double vision
Eyelid drooping
Dropping of one side of the face
Seizures
Numbness or weakness in the face or one side of the body
Exactly what you might experience depends on where in your brain the aneurysm lies. Once the aneurysm starts to leak or burst, you can expect the worse headache you ever had in your like. It is described in the literature as a “thunderclap headache.” People experiencing this claim they can hear a sound like a gunshot:
Many individuals hear what they believe is a perceived gun shot sound or extremely loud explosion (sometimes as they are sleeping) and ask others around them if they heard the same thing; however, the sound is strictly internal to the person with a brain aneurysm and is not something heard by others.”
Bret Michaels, frontman for the rock group Poison had a ruptured aneurysm in 2010. Michaels first thought was that a burglar had shot him in the back of the head. The (then) forty-seven year old musician spent two weeks in intensive care recovering from it. As he recalls it:
It’s called a Thunderclap, so you can’t explain it. It just the weirdest sound. If anyone’s never broken a bone and you hear a sound inside your body, when you hear that sound, it was instant and it was instantly I knew something like it. The pain is like an elephant standing on your skull. That’s what a brain bleed does. The pressure is what normally kills you eventually. And so I knew I was in trouble and my adrenaline — after years and years of being diabetic through some horrific situations — immediately my adrenaline was on 10.
“I could barely speak. I knew I’d had some form of a stroke, because my face was drooping and I knew it was bad. I got rushed straight down to the emergency room and they knew instantly and they did the MRI. And then I went from that over to [Phoenix’s Barrow Neurological Institute], and I don’t remember for three days. I came back around to a nurse, and they’re massaging your legs so you don’t get a blood clot. … I never would have thought that was gonna happen. Like, that wouldn’t have been on my plate of stuff.”
Some people have terrible headaches for their whole life. That is something that may or may not respond to medication. But if a person who is 40 years old suddenly develops painful headaches, then this needs to be evaluated. There are tension headaches, cluster headaches, sinus headaches and, of course, migraines. But a tumor growing inside someone’s head (whether malignant or benign, it matters not) can cause headaches as well. Your doctor will likely order a CT-Scan or MRI if you have late in life onset headaches, and this will in almost all cases rule out whether you have an aneurysm.
The pain is a sentinel that can herald many different problems, and they are almost all serious. It’s important that you listen to your sentinel.
