Neurologic exam



Definition

A neurological examination is an essential component of a comprehensive physical examination. It is a systematic examination that surveys the functioning of nerves delivering sensory information to the brain and carrying motor commands (peripheral nervous system) and impulses back to the brain for processing and coordinating (central nervous system).

Purpose

A careful neurological evaluation can help to determine the cause of impairment and help a clinician begin to localize the problem. Symptoms that occur unexpectedly suggest a blood vessel or seizure problem. Those that are not so sudden suggest a possible tumor. Symptoms that have a waning course with recurrences and worsen over time suggest a disease that destroys nerve cells. Others that are chronic and progressive indicate a degenerative disorder. In cases of trauma, symptoms may be evident upon inspection and causes may be explained by third party witnesses. Some patients may require extensive neurological screening examination (NSE) and/or neurological examination (NE) to determine the cause. The NE will assist the clinician in diagnosing illnesses as diverse as seizure disorders, narcolepsy , migraine disorders, dizziness , and dementia.

Description

A neurological screening is an essential component of every comprehensive physical examination. In cases of neurological trauma, disease, or psychological disorders, patients are usually given an in-depth neurological examination. The examination is performed in a systematic manner, which means that there is a recommended order for procedures.

Neurological screening examination

The NSE is basic procedure, especially in patients who have a general neurological complaint or symptoms. The NSE consists of six areas of assessment :

  • mental status: assessing normal orientation to time, place, space, and speech
  • cranial nerves: checking the eyes with a special light source (ophthalmoscope) and also assessing facial muscles strength and functioning
  • motor: checking for tone, drift, and heel and toe walking
  • sensory: cold and vibration testing
  • coordination: observing the patient walk and finger to nose testing
  • reflexes: using a special instrument the clinician taps an area above a nerve to emit a reflex (usually movement of muscle groups)

Neurological examination

The NE should be performed on a patient suspected of having neurological trauma, or neurological or psychological diseases. The NE is performed in a systematic and comprehensive manner. It consists of several comprehensive and in-depth assessments of mental status, cranial nerves, motor abilities, reflexes, sensory acuity, and posture and walking (gait) abilities.

MENTAL STATUS EXAMINATION (MSE) There are two types of MSE, informal and formal. The informal MSE is usually done as clinicians are obtaining historical information from a patient. The formal MSE is performed for a patient suspected of a neurological problem. The patient is commonly asked his/her name, the location, the day, and date. Determining the number of digits that can be repeated in sequence can assess retentive memory capability and immediate recall. Recent memory is typically examined by testing recall potential of a series of objects after defined times, usually within five and 15 minutes. Asking the patient to review in a coherent and chronological fashion his or her illness or personal life events can provide the opportunity for assessment of remote memory. Patient recall of common historical or current events can be used to assess general knowledge. Brain processing capabilities can be assessed by spontaneous speech, repetition, reading, naming, writing, and comprehension. Modifications can be made based on the age and maturity of the child. The child may be asked to perform tasks such as identification of fingers, whistling, saluting, brushing teeth motions, combing hair, drawing, and tracing figures. These procedures allow for assessment of dominant (left-sided brain) functioning or higher cortical function.

The MSE is particularly important in psychotherapy. Psychotherapists recommend an in-depth MSE for all patients with possible organic (physiologica) or psychotic disorders. This examination is also performed in a systematic and orderly manner. It is divided into several categories:

  • Appearance determines the child's presentation, i.e., how the child looks (clothes posture, grooming, and alertness).
  • Behavior assesses the patient's motor activity (movements) such as walking, gestures, muscular twitching, and impulse control.
  • Speech can be examined concerning volume, rate of speech, and coherence. Individuals who exhibit latent or delayed speech may be depressed, while those who have rapid or pressured speech may suffer from mania or anxiety .
  • Mood and affect indicate attitude or feeling. Normal mood (euthymia) is healthy. Variations in mood include: flat, labile, blunted, constructed, or inappropriate mood. The child can also be euphoric (elevated) or dysphoric (on the down side).
  • Thought processes and content is typically assessed by determining word usage (can indicate brain disease), thought stream (slow, restricted, blocked, or over-abundant), continuity of thought (associations among ideas), and content of thought (delusional as opposed to reality-bound).
  • Perception assessment examines the individual's sensory ability to hear, see, touch, taste, and smell. Certain psychological states may cause hearing and visual hallucinations. Impairments of smell and touch usually have medical (organic) causes or are side effects of certain medications.
  • Attention and concentration assessment indicates the child's ability to focus on a specific task or activity. Abnormalities in attention and concentration can indicate problems related to anxiety or hallucinations.
  • Orientation assessment determines if the child has a normal sense of time, place, and identification of self (can state his or her own name). Disturbances in orientation can be due to a medical condition (other than psychological), substance abuse, or to a side effect of certain medications such as those used to treat depression, anxiety, or psychosis, since these medications usually have a sedative affect.
  • Memory assessment includes determining the child's remote, recent, and immediate memory capabilities. Remote and recent memory can be assessed by the patient's ability to recall historical and current events. Immediate memory can be tested by naming three objects and asking the child to repeat the named objects immediately, then after five and 15 minute intervals.
  • Judgment assessment evaluates the individual's ability to exercise appropriate judgment. It also determines whether the individual has an understanding of consequences associated with their actions. This evaluation pertains primarily to older children.
  • Intelligence and information measurement can be obtained by administering specialized intelligence tests, However, a preliminary assessment of intelligence can be made based on the child's fund of age-appropriate information, general knowledge, awareness of current events, and the ability for abstract thinking.
  • Insight assessment pertains to determining the patient's awareness of their problem that prompted them to seek professional examination. Insight concerning the present illness can range from denial to fleeting admission of current illness.

CRANIAL NERVES (CN) Cranial nerves are nerves that originate in the brain and connect to specialized structures such as the nose, eyes, muscles in the face, scalp, ear, and tongue.

  • CN I: This nerve checks for visual capabilities. Patients are usually given the Snellen Chart (a chart with rows of large and small letters). Patients read letters with one eye at a time.
  • CN III, IV, and VI: These nerves examine the pupillary (the circular center structure of the eye that light rays enter) reaction. The pupils get smaller, normally when exposed to the light. The eyelids are also examined for drooping or retraction. The eyeball is also checked for abnormalities in movement.
  • CN V: The clinician can assess the muscles on both sides of the scalp muscles (the temporalis muscle). Additionally the jaw can be tested for motion resistance, opening, protrusion, and side-to-side mobility. The cornea located is a transparent tissue covering the eyeball and can be tested for intactness by lightly brushing a wisp of cotton directly on the outside of the eye.
  • CN VII: Examination of CN VII assesses asymmetry of the face at rest and during spontaneous movements. The patient is asked to raise eyebrows, wrinkle forehead, close eyes, frown, smile, puff cheeks, purse lips, whistle, and contract chin muscles. Taste for the front and middle portions of the tongue can also be examined.
  • CN VIII: Testing for this CN deals with hearing. The clinician usually uses a special instrument called a tuning fork and tests for air conduction and structural problems which can occur inside the ear.
  • CN IX and X: These tests evaluate certain structures in the mouth. The clinician will usually ask the patient to say "aah" and can detect abnormal positioning of certain structures such as the palatel-uvula. The examiner will also assess the sensation capabilities of the pharynx, by stimulating the area with a wooden tongue depressor, causing a gag reflex.
  • CN XI: This nerve is usually examined by asking the patient to shrug shoulders (testing a muscle called the trapezius) and rotating the head to each side (testing a muscle called the sternocleidomastoid). These muscles are responsible for movement of the shoulders and neck. The test is usually done with resistance, meaning the examiner holds the area while the patient is asked to move. This is done to assess patient's strength in these areas.
  • CN XII: This nerve tests the bulk and power of the tongue. The examiner looks for tongue protrusion and/or abnormal movements.

MOTOR EXAMINATION The motor examination assesses the patient's muscle strength, tone, and shape. Muscles could be larger than expected (hypertrophy) or smaller due to tissues destruction (atrophy). It is important to assess if there is evidence of twitching or abnormal movements. Involuntary movements due to tics can be observed. Additionally, movements can be abnormal during maintained posture in some neurological disorders. Muscle tone is usually tested by applying resistance to passive motion of a relaxed limb. Power is assessed for movements at each joint. Decreases or increases in muscle tone can help the examiner localize the affected area.

REFLEXES The patient's reflexes are tested by using a special instrument that looks like a little hammer. The clinician taps the rubber triangular shaped end in several different areas in the arms, knee, and Achilles heel area. The clinician will ask the patient to relax and gently tap the area. If there is a difference in response from the left to right knee, then there may be an underlying problem that merits further evaluation. A difference in reflexes between the arms and legs usually indicates of a lesion involving the spinal cord. Depressed reflexes in only one limb, while the other limb demonstrates a normal response usually indicates a peripheral nerve lesion.

SENSORY EXAMINATION Although an essential component of the NE, the sensory examination is the least informative and least exacting since it requires patient concentration and cooperation. Five primary sensory categories are assessed: vibration (using a tuning fork), joint position (examiner moves the limb side-to-side and in a downward position), light touch, pinprick, and temperature. Patients who have sensory abnormalities may have a lesion above the thalamus. Spinal cord lesions or disease can possibly be detected by pinprick and temperature assessment.

COORDINATION The patient is asked to repetitively touch his nose using his index finger and then to touch the clinician's outstretched finger. Coordination can also be assessed by asking the patient to alternate tapping the palm then the back of one hand on the thigh. For coordination in the lower extremities (legs), the patient lies on his or her back and is asked to slide the heel of each foot from the knee down the shin of the opposite leg and to raise the leg and touch the examiner's index finger with the big toe.

WALKING (GAIT) Normal walking is a complex process and requires use of multiple systems such as power, coordination, and sensation, all working together in a coordinated fashion. The examination of gait can detect a variety of disease states. Decreased arm swinging on one side is indicative of corticospinal tract disease. A high-stepped, slapping gait may be the result of a peripheral nerve disease.

Precautions

A neurologic examination is not invasive and there are no risks or dangers associated with these tests. The results and validity of this exam may be affected by the child's age and ability to cooperate.

Preparation

The MSE is the first step in a continuous assessment to determine the diagnosis. A psychotherapist should take a detailed medical history in the process of ruling out a general medical condition. Little preparation is needed for this assessment, but parents should explain to young children what will happen in order to encourage their cooperation.

Aftercare

For suspected neurological diseases, the doctor uses information gained from the NE for ordering further tests. These tests may include a complete blood analysis, liver function tests, kidney function tests, hormone tests, and a lumbar puncture to determine abnormalities in cerebrospinal fluid. In trauma cases (e.g. car accident, sports injury), the NE is a quick and essential component of emergency assessment. Once a diagnosis is determined, emergency measures may include further tests and/or surgery.

In psychological cases the treatment may include therapy and/or medication. In cases of an acute insult such as trauma, the patient is usually admitted to the hospital for appropriate treatment. Some neurological diseases are chronic and require conservative medical treatment and frequent follow-up visits for monitoring and stability or progression of the disease.

Risks

The MSE and NE are good diagnostic tools. There are no risks associated with initial neurologic assessment.

Parental concerns

Parental concerns center on the cause of the medical disease or psychological disorder, rather than around the procedure, which is straightforward and non-threatening.

KEY TERMS

Corticospinal tract —A tract of nerve cells that carries motor commands from the brain to the spinal cord.

Gait —Walking motions.

Reflex —An involuntary response to a particular stimulus.

Thalamus —A pair of oval masses of gray matter within the brain that relay sensory impulses from the spinal cord to the cerebrum.

Resources

BOOKS

Haslam, Robert H. A. "The Nervous System." In Nelson Textbook of Pediatrics , 17th ed. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.

Jozefowicz, Ralph F. "The Neurologic History." In Cecil's Textbook of Medicine , 21st ed. Edited by Lee Goldman et al. Philadelphia: Saunders, 2000.

WEB SITES

Blumenthal, Hal. "An Interactive Online Guide to the Neurologic Examination." neuroexam.com , 2001. Available online at http://www.neuroexam.com (accessed January 16, 2005).

Tish Davidson, A.M. Laith Farid Gulli, M.D. Bilal Nasser, M.Sc.



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