Some seemingly simple signs - from sudden double vision and weakness in one arm or leg to changes in voice, constant muscle twitching and even unexplained suspiciousness - may indicate serious neurological disorders such as stroke, MS, Parkinson's or dementia. Neurologists warn that ignoring these signs or attributing them to aging can delay timely diagnosis and treatment.
Dr. Andrew Dorosh, chief of general neurology at the Rush University health system and a neurorehabilitation specialist, says: "Wherever there are nerves, a neurologist may be involved. Because nerves are present throughout the body, many problems can occur in the nervous system, and finding their cause sometimes requires precise and complex diagnostic follow-up."
He adds that people often ignore neurological signs such as: double vision, weakness in one arm or leg, speech problems, sudden headache during physical activity, numbness in the legs and fingers, persistent déjà vu, repeated difficulty rising from a chair, change in voice, constant muscle twitching, and suspiciousness for a long time, attributing them to aches and discomforts of aging or assuming they will resolve on their own - which is a mistake. Time, citing four neurologists, explains which signs need more attention and what each may indicate.
A specific type of double vision
One common sign that is often ignored is double vision that occurs with both eyes open and resolves or improves when either eye is closed. This condition is called "neurological double vision." It differs from monocular double vision - double vision that persists in one eye even when the other eye is closed - which is usually due to a problem in the eye itself or its visual system.
According to Dr. Luis Cruz Saavedra, a neurologist, neurological double vision can have various causes, including MS, stroke or aneurysm, myasthenia gravis (an autoimmune disease that causes muscle weakness), brain tumor or brain infection.
He adds that this sign should be taken seriously immediately, and if you suddenly experience double vision, you should go to the emergency department. Emergency physicians check vital signs and stroke warning signs, perform eye and neurological exams, and may order imaging such as a head CT scan or brain MRI.
Weakness in one arm or leg
Have you noticed one of your feet dragging on the ground or limping when you walk? Has lifting your morning coffee cup or writing with your dominant hand become difficult? If the answer is yes, make an appointment with your doctor.
Cruz Saavedra says: "In the clinic I am often surprised by how many people ignore weakness in one arm or leg. People present months after symptoms begin, but weakness is not something to ignore. Many think: it's just a pinched nerve, but the real cause could be a stroke, brain tumor, a disorder like MS, or some form of brain inflammation."
Neurologists typically assess muscle strength, reflexes, coordination and gait when examining patients with this type of weakness. These evaluations can help rule out some possible causes and guide the diagnostic process in the right direction.
Transient unresponsiveness
People with certain neurological problems sometimes lose connection with their surroundings for a few seconds and then return to normal without remembering the moments that passed. According to Cruz Saavedra, this state is usually associated with temporal lobe seizures - a type of seizure that occurs in regions of the brain important for short-term memory and emotional processing.
He adds: "Sometimes family members describe this because the patient may not truly notice it. For example, they say: I was talking to them and they suddenly stared at one point and after 10 to 15 seconds returned to normal. The patient may also say: Sometimes I don't notice the passage of time, it's as if I lose a short part of my day."
Speech problems
Stroke is a leading cause of death in the United States, but people often do not recognize its signs and delay seeking medical care longer than they should. Dr. Enrique Leira, director of the cerebrovascular disease division at the University of Iowa, says: "I've heard many times of someone having stroke symptoms but reacting: I'll sleep a bit to see if it goes away."
Stroke symptoms usually appear suddenly and are accompanied by impairment or loss of one of the body's functions due to brain injury. One manifestation is speech disturbance. According to Leira, a person may slur words, speak slowly, have trouble finding words, or even be unable to understand others' speech. He recommends seeking medical care immediately in such situations.
Sudden headache during physical activity
Evaluating headaches is difficult for neurologists because there are dozens of possible causes, many of which are benign. However, some headaches require urgent attention. Dr. Leira says if a headache "is unusually severe and sudden rather than gradually increasing over minutes or hours," it may raise concern for stroke, and he adds: "If a headache starts during exercise or physical activity, it is worrisome enough to need immediate evaluation."
Numbness in the legs and fingers
Patients who see Dr. Dorosh for numbness usually experience it in their legs or fingers. He says: "This often indicates that the nerves are not returning information to the brain as they should. A so-called sleepy nerve is malfunctioning or, unfortunately, in some cases has been lost. As a result, sensory information from the body is not transmitted to the brain." In this respect, numbness differs from tingling. Tingling is a pins-and-needles sensation indicating nerve irritation.
When someone has numbness, the first step is usually comprehensive testing to identify the affected nerves, the cause of the problem and the best treatment approach. Dorosh says some patients are ultimately diagnosed with diabetes, but many other possibilities exist. The person may have a genetic disease or the immune system may be attacking the nerves.
Persistent déjà vu
We have all experienced déjà vu - that strange, uncanny feeling that an event has happened before. However, Dorosh says: "If you frequently have episodes of déjà vu, it's better to get examined."
This state may be a warning sign of temporal lobe seizures. Dorosh recently treated a patient who had recurrent episodes of déjà vu every week or every two weeks, whereas people do not usually experience déjà vu with such frequency.
Repeated difficulty rising from a chair
With age, people generally develop difficulties with everyday movements such as stiffness or slowness. However, some problems should be taken more seriously. For example, if you repeatedly have trouble rising from a chair, it's better to make an appointment with your doctor.
Dorosh says: "There may be a joint problem, but we need to examine the person carefully to ensure their muscles, nerves or spinal cord are not at fault, because it could be a sign of Parkinson's disease or amyotrophic lateral sclerosis (ALS)."
Change in voice
Neurologists pay special attention to several types of voice change. One is hypophonia - the voice becoming unusually quiet or breathy. According to Dr. Alexandro Olaro, a neurologist at the University of Maryland, this can be a sign of Parkinson's disease.
Another change is slurred, fragmented speech, which may indicate a stroke.
Olaro says another concerning change is a voice that sounds gurgly or mixed with liquid due to saliva or phlegm buildup. He explains: "People lose control of the muscle mass at the back of the throat and can no longer manage their saliva properly. As a result, saliva pools in the back of the throat and when they speak it sounds as if there's liquid in your mouth." Parkinson's disease, ALS and MS are among the common causes of this condition.
Constant muscle twitching
Our muscles occasionally twitch at various points in the body. Olaro says sometimes you can even see "muscle rippling under the skin" or feel it by placing your hand on the muscle.
However, if these fasciculations - the medical term for muscle twitches - occur persistently in one specific spot, it's better to discuss the matter with your doctor. The person may have benign fasciculation syndrome, which is harmless, or a more serious disease such as spinal canal stenosis, ALS or chronic inflammatory demyelinating polyneuropathy; an autoimmune disease that targets the protective covering of peripheral nerves.
Neurologists typically recommend electromyography or nerve and muscle conduction studies (EMG); an electrical test to evaluate nerves and muscles that can help precisely identify the cause of the problem.
Suspiciousness
Behavior and personality can change suddenly because of conditions such as autoimmune encephalitis, frontotemporal dementia or other cognitive disorders. One common example is the sudden onset of suspiciousness. Dr. Cruz Saavedra says a person may feel they are being followed or harassed, that someone is plotting against them, or that their partner is cheating, even though these beliefs have no logical basis.
Neurologists also pay special attention to cases where a typically calm, serious person suddenly becomes flamboyant and talks incessantly. Sometimes people even become hypersexual and make inappropriate remarks or jokes. The opposite can also occur: a person who was always social and talkative suddenly becomes withdrawn.
Dementia may present as the emergence of compulsive behaviors unusual for the person or behaviors related to hoarding as well.