Why test reflexes

Develop and improve products. List of Partners vendors. Some reflexes, such as the knee jerk, are normal. But others are abnormal and may signal a medical condition. Sometimes, the absence of a reflex can be an indication that something might be wrong. Learn more about some of the body's strangest reflexes and what they indicate about your health.

A reflex is one way that the body manages critical functions like standing upright without relying on the conscious part of the brain. Many reflexes don't need to go into the brain at all but can be managed entirely by the spinal cord. The most familiar reflex is the knee jerk, when a healthcare provider taps on the tendon below your knee with a reflex hammer and that leg kicks out.

The stimulus the hammer results in a signal being sent via a sensory nerve to the spinal cord. From the spinal cord, a response is immediately sent back via a motor nerve, which results in the kick.

This communication, from a sensory nerve to the spinal cord and on to a motor movement nerve without going to the brain , is known as a reflex arc. Many reflexes are normal. For example, the knee jerk is a normal reflex and the absence of this reflex would be considered abnormal.

Some reflexes can be a sign of disease but also occur fairly often in healthy people without any neurological condition. The body is capable of a plethora of reflexes. Take a closer look at some of the lesser-known, weirder, but totally normal, reflexes of the body, below. One of the more common reflexes that a neurologist may test is the Babinski reflex.

In this exam, a neurologist scratches the bottom of your foot with something irritating. In an adult, the toes will normally curl down. Yet in children until around the age of 2, and in adults with a brain or spinal cord injury, the toes instead go up and fan out.

In adults, this may signal a problem such as a stroke , a brain tumor, meningitis, or a spinal cord injury.

The snout reflex is a normal childhood reflex that usually vanishes with age, but may come back if the frontal lobes of the brain are damaged. A healthcare provider taps lightly on your upper lip with your lips held together and watches for a response. A response that's abnormal in adults but normal in babies is to have the lips purse, giving the appearance of a pig's snout.

It can be unilateral on one side or bilateral on both sides. The reflex is probably designed to help a baby suck. In an adult, the snout reflex response often indicates a frontal lobe problem such as frontal lobe head trauma or a frontal lobe stroke.

The area above the nose on the forehead and between the eyes is called the glabella. When tapped on the glabella, most people blink. Normally people stop blinking after a few taps, but if the blinking persists, it's called Myerson's sign, which often means that there's some brain abnormality.

This reflex is most commonly seen in people with Parkinson's disease. What is it? An interesting illustration of the physical exam If you put your stethoscope over this, what will you hear? A patient presents with foot pain and these chronic findings?

This patient presents with chest pain. Website Reaches Half a Million Visitors! A patient asks you… what is this? Verghese Welcome New Stanford Interns!!!! Teaching the teachers… Our methods. The snout reflex is present if tapping a tongue blade across the lips causes pursing of the lips. The rooting reflex is present if stroking the lateral upper lip causes movement of the mouth toward the stimulus.

The palmomental reflex is present if stroking the palm of the hand causes contraction of the ipsilateral mentalis muscle of the lower lip. Hoffmann sign is present if flicking down on the nail on the 3rd or 4th finger elicits involuntary flexion of the distal phalanx of the thumb and index finger.

For the glabellar sign , the forehead is tapped to induce blinking; normally, each of the first 5 taps induces a single blink, then the reflex fatigues.

Blinking persists in patients with diffuse cerebral dysfunction. Testing for clonus rhythmic, rapid alternation of muscle contraction and relaxation caused by sudden, passive tendon stretching is done by rapid dorsiflexion of the foot at the ankle. Sustained clonus indicates an upper motor neuron disorder. The superficial abdominal reflex is elicited by lightly stroking the 4 quadrants of the abdomen near the umbilicus with a wooden cotton applicator stick or similar tool.

The normal response is contraction of the abdominal muscles causing the umbilicus to move toward the area being stroked. Stroking the skin toward the umbilicus is recommended to rule out the possibility that movement was caused by the skin being dragged by the stroking. Depression of this reflex may be due to a central lesion, obesity, or lax skeletal muscles eg, after pregnancy ; its absence may indicate spinal cord injury.

Sphincteric reflexes may be tested during the rectal examination. To test sphincteric tone S2 to S4 nerve root levels , the examiner inserts a gloved finger into the rectum and asks the patient to squeeze it. Alternatively, the perianal region is touched lightly with a cotton wisp; the normal response is contraction of the external anal sphincter anal wink reflex. Learn more. The vagus nerve is the longest of the 12 cranial nerves.

Here, learn about its anatomy, functions, and the kinds of health problems that can occur. Muscle twitching refers to small muscle contractions in the body. Learn more about the causes and treatment here. Health Conditions Discover Plan Connect. Medically reviewed by Seunggu Han, M.

What are the symptoms of brisk reflexes? What causes brisk reflexes? How are brisk reflexes diagnosed? How are brisk reflexes treated? Can brisk reflexes cause complications? What is the outlook for brisk reflexes?

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