Understanding neurological issues in the outdoors

Neurology is the study of the brain and nervous system – the system responsible for how we take in and respond to information, how we sense and move, and vital bodily functions like breathing and heart rate – which is why pinpointing neurological issues can be complex and elusive. Is your arm tingling because your backpack is cutting off circulation? Is your dizziness from an ear problem? Or are these neurological issues?

To make matters more complicated, taking yourself outdoors in a new environment can add unique stressors to your neurological system that make determining the culprit of your symptoms more uncertain. An innocuous headache could be from poor sleep, dehydration, high altitude, or extreme heat.

Even if you have service (let alone being offline in the backcountry) you can’t really google your way to an answer. This is where GOES’ digital first aid and assessment shine. Learn to sift through the confusion and determine whether your neurological problems stem from the environment or internal factors. This can determine if you can play through or should seek medical care and your next life-saving steps.

What could be causing this headache? 

An exhausted backpacker on White Mountain has just enjoyed her well earned dinner and is now suffering from a massive headache and is feeling dizzy. She begins to wonder about the root of her symptoms.

Could it be from dehydration after an arduous uphill hike that day? Or was it in fact the rapid ascent in elevation, going from 4,000 ft to 12,500 ft in one day?

Is the dizziness worse when she rapidly moves her head back and forth, making her inner ear the likely culprit? Or is her dizziness accompanied by an unsteady balance and numbness on one side of her body, because she forgot her high blood pressure medications on this trip?

Getting to the bottom of this requires assessing for both internal and external causes.

The brain is a beacon

As there are over seven trillion nerves in the human body and all of that is controlled by the brain, any injury or illness to the nervous system can show up in many different ways.

The brain represents only 2% of total body weight, but consumes approximately 20% of the body’s oxygen. This very high metabolic demand can have the brain act as an early warning signal that something is wrong. The complexity of the nervous system means it can be very challenging to understand if vague symptoms like a headache above are just a nuisance or could be the beginning of a serious consequential problem.

Neurological issues can start from within

Recognize the signs and symptoms of a stroke

A stroke can be caused by an internally damaged or a blocked blood vessel. In other words, a literal bleed in the brain. This sudden interruption of blood flow to the brain deprives the nerve cells of oxygen. Each year in the United States there are almost 800,000 strokes and is one of the leading causes of death and disability for Americans. 

Depending on where the stroke occurs in the brain and the extent of nerve cell damage, strokes can have a range of symptoms, including:

• loss of balance
• weakness or numbness to one side of the face or limbs
• trouble speaking
• visual changes

Recognizing the symptoms early and acting promptly is critical for a patient’s survival and quality of life. Awareness of these symptoms can rapidly identify over 90% of strokes and help to save lives. If someone experiences a stroke during a trip, act as quickly as you can to evacuate and get to the nearest medical center.

Environmental factors can cause neurological issues

Headaches caused by outdoor conditions

We see 3.5 million emergency department visits for a headache every year. While headaches are a neurologic disorder, it can also be caused by environmental factors in the outdoors. 

For example, headaches are the most common neurologic complaint at high altitude, found in up to 75% of those who rapidly ascend. Headaches are also found in 30-40% of those with heat illness. Headaches can also be caused head injuries or a viral illness. 

In remote situations, it’s important to consider your surroundings and contributing factors to ensure the headache does not get worse. While managing symptoms quickly is important for the comfort of your outdoor experience, a headache could be an indicator of something more severe and may require following up with your doctor.

a dizzying, blurry image of a forest

The source of the neurological issue can be tricky to determine

Don’t ignore the signs of dizziness or vertigo

Dizziness is often described as a feeling of lightheadedness or a sensation you’re about to pass out (known as syncope). Syncope can be due to an interruption of the body’s normal oxygen delivery system to the brain or blood flow to other vital organs. Doctors can sometimes use dizziness as a warning sign and risk factor to predict more serious problems.

Dizziness is a common patient complaint in the emergency department with many different potential causes. Even with modern medicine, the diagnosis remains unclear in ​​40 – 50% of those admitted with syncope to US hospitals. In the outdoors, dizziness is found in 57% of those with heat stroke, 80% with hyponatremia, and 50% of those with acute mountain sickness.

Dizziness could also be from internal causes such as a stroke, an ear issue, or motion sickness. It can be a subtle sign of a bleeding ulcer, infection, blood clot in the lungs, or even a painless heart attack. Each person has their own individual risk profile, making “dizziness” a vague complaint that is often challenging to clarify with potentially serious outcomes.

Dizziness can be a feeling of things spinning around you (known as vertigo). It can be debilitating and cause nausea and loss of balance. This can be particularly dangerous when you’re affected while actively participating in outdoor activities like hiking, climbing, etc. Determining when to pause activities and rest is critical.

Vertigo may result from a stroke that impacts the balance center of the brain or it may be an issue with the inner ear. When the problem is the inner ear, a simple procedure called the Epley maneuver can help alleviate the symptoms in 80% of cases.

Confusion can be confusing

Confusion typically looks like disorientation, a lack of awareness or alertness, impaired thinking, or a disruption in a person’s ability to think or speak. This brain malfunction can be a result of stroke, illness, injury, or environmental causes. Or it could simply be from drinking one too many beers. 

When the brain does not function normally, it causes confusion or an altered mental state. If the confusion is due to an environmental cause, that is usually a sign of severe illness. The confused person needs to be safely removed from the cause quickly to stop the confusion from getting worse and to prevent unconsciousness or even death.

Severity of seizures

Seizures are a type of abnormal electrical activity in the brain that causes a person to have changes in behavior or states of consciousness. They are typically portrayed and recognized with jerking physical movements, but some seizures are so subtle you may not even recognize it happening in front of you. 

Seizures may be due to an underlying disorder (such as epilepsy), caused by a head injury, or due to a number external factors such as hyponatremia, heat stroke, or high altitude edema.

Pinpointing the exact cause of what’s interfering with the brain’s normal function in a medical setting is difficult as is. (Medical students learn a nine letter mnemonic that runs through possible causes of the confused patient, demonstrating the complicated nature of this problem.)

In the outdoors, the seizure itself is not treated directly, but rather it is important to address the conditions causing the confusion. This means being preventative and seeking safety from environmental factors. If they’re suffering from heat stroke, rapidly cool their body down. If it’s from high altitude, bring them to lower elevation. Understanding the severity of a person’s condition experiencing a seizure or confusion is vital so that you can act swiftly.

Assessing neurological issues in the outdoors

Whether at home or on the road, there are many factors and conditions that could trigger neurological issues. Brain and nerve problems can be due to both environmental or internal factors that also vary depending on a person’s medical history. GOES has the step-by-step guides to help you determine and make sense of vague symptoms based on your context.