Also called: Neurologic Examination
A neurological examination is used to diagnose disorders of the brain, nerves, muscles and spinal cord. A neurological examination may be performed to detect any damage after an injury to the head – such as a concussion or brain aneurysm – or to locate the source of headaches. Patients who present symptoms of neurological conditions and diseases may also undergo neurological examinations.
Initially, a physician will compile a thorough medical history of the patient by asking questions about previous illnesses and current symptoms. After a medical history has been established, the physician will perform a specific type of physical examination and mental assessment of the patient. The neurological examination is the combination of this physical and mental assessment.
The neurological examination consists of six distinct parts:
- Mental status. Awareness and responsiveness to both the environment and the senses are observed in patients. Appearance and behavior, mood, thought content and intellectual abilities are also observed and tested.
- Cranial nerves. A specific examination of the functions of a dozen nerves that send messages between the brain, head and body. A patient’s vision, smell and facial muscle strength are among the functions evaluated.
- Motor exam. Examination of the motor system, which consists of nerves that activate the voluntary muscles that produce movement. Tests of muscle strength and tone make up this part of the assessment.
- Reflexes. The first signs of a neurological problem may be changes in reflexes, either failure to respond to stimuli or exacerbated responses to stimuli. This examination targets the deep tendon reflexes, which cause a contraction in the muscle when the attached tendon has been intentionally stimulated by a reflex hammer (e.g., knee–jerk test).
- Coordination and gait. A lack of coordination and an unusual pattern of walking may indicate signs of a neurological problem.
- Sensory exam. Neurological damage sometimes causes a loss of feeling or abnormal sensations in certain areas of the body. A patient’s reaction to minor pain and temperature changes can reveal if damage is present.
Certain additional diagnostic tests may also be performed. These may be used to make or confirm a diagnosis after the physical examination and mental assessment of the neurological examination are completed. These additional tests may include various types of imaging tests, electrodiagnostic testing, laboratory tests and spinal tap.
About neurological examination
A neurological examination uses a series of tests to reveal information about the condition of a person’s nervous system. Instruments such as a small flashlight, reflex hammer and tuning fork may be used during the examination, which is painless for most patients.
A neurological examination can be used to diagnose disorders and illnesses that affect the brain, nerves, muscles and spinal cord. Conditions that may be diagnosed through neurological examinations include infections (e.g., encephalitis, meningitis) and other diseases such as Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis (ALS) or epilepsy.
The nervous system is a network of cells, tissues and organs that regulates the body’s responses to internal and external stimuli. In humans, the nervous system consists of the following:
- Spinal cord
- Ganglia (a group of nerve cells forming a nerve center)
- Parts of the receptor and effector organs (e.g., muscle contractions, gland secretions)
The nervous system’s complexity can make it difficult for physicians to accurately measure how well the nervous system is performing, and to pinpoint the source of problems that arise. In addition, unlike many diseases, neurological disorders do not always present visible or palpable symptoms. As a result, a successful neurological examination depends on a combination of objective testing as well as insight and intuition on the part of the neurologist.
A neurological examination provides a series of inexpensive physical and mental evaluations that can help provide important clues about a patient’s neurological health. This test may be performed to detect any damage after an injury to the head, such as a concussion or brain aneurysm or to locate the source of headaches. Patients who experience symptoms of neurological conditions and diseases may also undergo a neurological examination.
Other symptoms that may cause physicians to recommend a neurological examination include:
- Balance and coordination problems
- Blurry vision
- Decreased movement in arms and legs
- Injuries to the back or neck
- Numbness and tingling in the arms or legs
- Slurred speech
- Muscle weakness
Neurological evaluations are noninvasive and extremely safe. Such exams are divided into six parts:
- Mental status
- Cranial nerves
- Motor examination
- Coordination and gait
- Sensory examination
Certain parts of the examination may not be practical for some patients. For example, patients who are in a coma cannot participate in tests that require them to answer questions or follow instructions.
During neurological examination and mental assessment
Initially, a physician will compile a thorough medical history of the patient by asking questions about previous illnesses and current symptoms. Questions that may be asked include:
- Where and how often do symptoms occur?
- How severe are symptoms and how long do they typically last?
- Can the patient still perform daily routines?
- Does the patient have a history of serious illnesses or operations?
- Does the patient have a family history of serious illness?
- Does the patient have any allergies?
- Which medications (if any) is the patient currently taking?
After a medical history has been established, the physician proceeds to the physical examination and mental assessment portion of the neurological examination. The order in which a patient is examined may vary from physician to physician. The extent of the examination may vary, depending on factors such as the patient’s age and health, and the type of symptoms a patient is experiencing. The six components of the neurological examination are:
1. Mental status
During this test, patients are observed in regard to their state of consciousness (awareness and responsiveness to both the environment and the senses), appearance and behavior, mood, thought content and intellectual abilities. The mental status portion of the neurological examination is often most valuable when other tests fail to reveal obvious signs of neurological problems.
In particular, the physician will observe the patient in three key areas: level of alertness, language and memory. During the level of alertness screening, the physician determines whether the patient is alert or generally unresponsive.
During language testing, patients are assessed in six key areas:
- Fluency. Includes phrases and sentences of normal length and correct grammar that are spoken easily and at a normal rate.
- Comprehension. Patients are asked to complete a series of tasks (such as sticking out their tongue, followed by a request that they stick out their tongue and touch their nose) that are increasingly complex with the goal of observing whether or not they have the capacity to understand and perform what is being asked of them.
- Repetition. Patients are asked to repeat phrases and sentences that become increasingly complex during the course of the test.
- Naming. Patients are asked to name an object (e.g., a shirt) and then to name a part of an object (e.g., a button on a shirt). The physician observes whether or not patients struggle to think of words during conversation.
- Reading. Patients are asked to read a written command.
- Writing. Patients are asked to compose both an original sentence and a sentence that is dictated to them. The physician will look for any words that are omitted or added.
Memory is tested with tools that focus on the three major types of memory (immediate, short-term and long-term), plus various aspects of memory recall. Tests include:
- Immediate memory. The physician recites a string of numbers, and the patient is asked to repeat the sequence.
- Short-term memory. Patients are asked to memorize three unrelated words and to repeat the list after their attention is distracted for a short period of time.
- Long-term memory. Patients are tested for two forms of long-term memory: recent memory and remote memory. Recent memory is tested by asking patients to provide details of their current time and place, and to recite details about events that have occurred in the past few days or weeks. Remote memory is tested by techniques such as asking the patient to recite the names of the presidents in reverse order as far back as they can recall.
- Calculation. Patients are asked to perform simple computations through adding and subtracting, and to solve basic word problems (e.g., How many quarters there are in $2.50).
- Construction. Patients may be asked to draw a clock, and place the hands so they indicate a certain time. Or, they may be asked to draw a cube.
- Abstraction. Patients may be asked to describe similarities (e.g., How are an orange and a grapefruit similar?) and differences (e.g., How do a radio and a computer differ?).
During the mental status evaluation, patients will also be assessed for hallucinations and delusional thinking. The physician may ask questions such as “Do you ever see things that others do not?” or “Do you have any special powers or abilities?” Suicidal or homicidal thoughts or plans will also be addressed to confirm the safety of the patient and others. Finally, the physician will assess the patient’s judgment and insight. This provides the physician with crucial information to help form decisions about whether a patient can continue to live independently or what level of supervision may be needed.
2. Cranial nerves
Cranial nerves are a dozen nerves that send messages between the brain, head and neck. These nerves help control motor and sensory functions. They include:
- Olfactory nerve. Provides sense of smell.
- Optic nerve. Helps control vision.
- Oculomotor nerve. Controls pupil size and eye movement.
- Trochlear nerve. Also helps with eye movement.
- Trigeminal nerve. Provides face/mouth sensation. Also moves chewing muscles.
- Abducens nerve. Helps with eye movement.
- Facial nerve. Provides taste sensation and moves face muscle.
- Acoustic nerve. Allows hearing.
- Glossopharyngeal nerve. Provides taste sensation and contributes (along with the vagus nerve) to the gag reflex.
- Vagus nerve. Provides swallowing, gag reflex, and part of speech and taste.
- Accessory nerve. Involved in movement of shoulders and neck.
- Hypoglossal nerve. Responsible for tongue movement.
The cranial nerve evaluation can help reveal systemic diseases and localize dysfunctions of the central nervous system (CNS), which includes the brain and spinal cord. During this part of the neurological examination, functions of the cranial nerves are tested, including:
- Vision. In one of the most commonly used tests, patients’ visual field is assessed by looking at the physician’s nose while the physician holds up one finger on each hand. The examiner then moves one or both fingers and asks the patient to identify where movement occurs. Each eye is tested separately. Visual acuity is tested by having the patient read an eye chart. Other eye tests may also be performed, including watching the patient’s eyelids for the droopiness (ptosis).
- Smell. A scent such as peppermint or cinnamon may be placed under the patient’s nose, and the patient is asked to identify it.
- Facial strength. Areas that are tested include muscles of mastication (patient opens and closes jaws against resistance), muscles of facial expression (patient closes eyes tightly, wrinkles forehead and smiles), hearing, palatal movement (patient is asked to yawn or say “ah” and the palate is observed), dysarthria (patient’s speech is listened to for this impairment of speech production brought on by a motor function problem), head rotation and shoulder elevation (patient tries to resist physician’s attempt to manually turn the head and physician tries to resist patient’s attempt to raise shoulders), tongue movement (patient is asked to perform a number of actions with the tongue, such as poking it out of the mouth or wagging it from side to side).
3. Motor exam
The motor system is made up of nerves that activate the voluntary muscles that produce movement. Damage to a motor nerve can result in weakness or paralysis of muscles supplied by the nerve. In addition, an absence of stimulation to a peripheral nerve can cause the corresponding muscle to shrivel or shrink (atrophy).
Problems in the motor system are often revealed through tests and observation that help measure muscle strength and tone. Patients may be asked to push or pull against resistance. All of the major muscle groups may be tested for strength. In addition, patients are usually asked to undress so the examiner can look for muscle atrophy, twitching, tics and other involuntary movements or other abnormalities.
Reflexes involve involuntary responses of the body to a stimulus. When reflexes react abnormally, it is usually one of the earliest signs of a neurological problem. An abnormal response to reflex testing may indicate injury to the nervous system pathways that produce the reflex response.
Although science has identified hundreds of reflexes, the deep tendon reflexes are often the only reflexes tested during a neurological examination. These reflexes, also known as “muscle stretch reflexes,” are a response to tendons that have been stimulated. They are tested using a soft rubber hammer. When the examiner taps the tendon, the muscle fibers contract, resulting in the reflex response. Reflexes that are tested include those of the biceps, triceps and brachioradialis on the arm, and the knee and ankle on the leg.
Testing for a reaction known as the Babinski response will take place in this phase of the neurological examination. The Babinski response occurs when an examiner strokes or scratches the outer side of the sole of the foot (from heel to toe) and the toes point upward and fan laterally. In infants, this is a normal response. However, in people ages 2 and older, the toes should automatically curl downward as the CNS becomes more developed. If the toes react with a Babinski response after these ages, a brain or spinal cord injury is likely.
Newborns and infants may undergo testing of infant-specific reflexes (automatisms). These reflexes slowly disappear as an infant grows. Some automatisms include:
- Blinking. Infants close their eyes in response to bright light.
- Moro reflex. Quick changes in position cause infants to throw their arms outward, open their hands and throw back their heads.
- Palmar and plantar grasp. An infant’s fingers or toes should curl around an adult’s finger that is placed in the area.
- Startle. Loud noises cause infants to extend and flex their arms while the hand remains in a fist.
5. Coordination and gait
Abnormalities in coordination may indicate a neurological disorder located in the cerebellum. This is the region of the brain that controls voluntary movement and motor coordination, including posture.
During coordination testing, patients may be asked to touch their nose, and then move their finger to the examiner’s upright finger and back to their own nose (finger-nose test). Patients may also be asked to tap their fingers together quickly, move one hand on top of the other or turn their palm up and down as rapidly as possible. The physician will examine these movements for speed, accuracy and consistency of rhythm. Lower limbs may also be tested, with patients being asked to rub a heel on one leg up and down smoothly over the shin on the other leg.
A person’s gait is a description of how they walk. Walking is a sophisticated physiological process that includes many nervous system reflexes. A poor gait may be a sign of an underlying neurological condition. A physician looks for lack of steadiness or asymmetry of movement during this portion of the neurological examination.
Patients may be asked to walk in different ways while the examiner looks for any abnormalities. Various methods of walking that may be requested include:
- Heel-to-toe in a straight line
- Abrupt turns
- Walking on the toes
- Walking on the heels
6. Sensory exam
Sensory nerves help people to feel sensations such as pressure, temperature, vibration, the position of body parts, and the shape of objects. People feel various sensations when receptors in the skin, muscles, tendons and other organs are stimulated. These receptors then send impulses along nerve fibers to the central nervous system.
The sensory exam can help reveal a loss of feeling in the body, as well as abnormal sensations. It can also help identify the quality and nature of impairment to sensation and the degree and extent of tissue involvement.
Some of the sensations examined through various tests might include:
- Light touch. Patients are asked to close their eyes and to indicate which hand is being touched when the physician lightly touches one or both hands simultaneously.
- Pain. A series of pinpricks might be administered throughout the body. The response from different parts or opposite sides of the body will be noted. The examiner may also use a blunt instrument to test the patient’s ability to discern between sharp and dull sensations.
- Temperature. Cold and warm objects may be used to test the sensation of temperature.
- Position. Patients may be asked to close their eyes while the examiner moves a part of their body, such as a finger or toe. The patient will be asked to determine which direction the body part is being moved.
- Pressure. The examiner may trace a number or letter on the patient’s body and ask the patient to identify what has been traced.
- Vibration. A tuning fork may be struck against a surface, and then held to a patient’s finger or toe to see if the resulting vibration is detected.
Other diagnostic tests
In some cases, additional diagnostic testing may be performed after the physical examination and mental assessment portions of the neurological examination are complete. These additional diagnostic tests may include:
- Computed axial tomography (CAT) scan. A scanning technique that uses computer enhancement to generate three-dimensional, high-resolution images.
- Magnetic resonance imaging (MRI). Another scanning technique that uses a powerful magnetic field to produce highly refined images of the body
- Echoencephalography. Creates an ultrasound image of the brain. It is used mainly in children younger than 2 years of age because their skulls are thin enough for ultrasound waves to pass through.
- Positron emission tomography (PET) scan. Uses positron emitters (a special type of radionuclide) injected into the body to produce images of the brain’s inner structures.
- Single photon emission computed tomography (SPECT). Uses radionuclides injected into the body to produce information about blood flow and metabolic function in the brain.
- Electroencephalogram (EEG). The brain’s electrical activity is recorded and traced through a series of electrodes placed on the scalp.
- Electromyography (EMG). Small needles are inserted into a muscle to record electrical activity generated by muscles in response to nerve stimulation. This is generally performed in conjunction with a nerve conduction velocity test to identify damage to the muscles or nerves.
- Nerve conduction velocity (NCV) test. Surface electrodes are placed on the skin and minor electrical impulses are used to test the speed and strength of nerve impulses. This is generally performed in conjunction with an EMG to test for damage to the nerves and muscles.
- Biopsy. Muscle or nerve biopsies involve surgically taking a small tissue sample of an affected area of the body for laboratory analysis.
- Spinal tap. Cerebrospinal fluid is drawn with a needle from the spinal canal. This fluid is usually clear and colorless, and should not contain any blood or bacteria. Analysis of this fluid may reveal abnormalities (e.g., discoloration, presence of blood or bacteria), which may indicate a disorder.
- Cerebral angiography. Dye is injected into an artery that supplies blood flow to the brain. With the addition of imaging, it may reveal blood vessel abnormalities, such as a bulge in the artery (cerebral aneurysm), arterial inflammation (arteritis), abnormal artery configuration (arteriovenous malformation) or a blocked blood vessel (stroke).
- Doppler ultrasound scanning. Measures blood flow through the carotid arteries or through the arteries at the base of the brain. This can help reveal a patient’s risk of stroke.
- Myelography. Dye is injected and a CAT scan or x-ray image of the spine is taken.
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to neurological examinations:
- Why do you recommend that I have a neurological examination?
- How much experience have you had with neurological examinations?
- How long will my testing take?
- Which particular tests do you suspect will be most helpful in diagnosing my condition?
- What are some of the signs and symptoms you will look for during my examination?
- What information might my examination provide?
- Do I need to prepare in any way for my examination?
- Will my examination cause me any discomfort?
- What role does the examination play in my overall diagnosis?
- Will I need to undergo any follow-up testing to confirm the diagnosis?
- Which treatments might follow my examination?