A good clinician can sometimes make a provisional diagnosis on the basis of history of the nature, onset, extent, and duration of the chief complaint and associated complaints. This should include previous diseases, personal and family history, occupational data, and social history. A complete listing of medications is essential. It may be desirable—or necessary—to interview relatives and friends.
Detailed information is particularly important in regard to the following:
Note the duration, time of onset, location, frequency, severity, progression, precipitating circumstances, associated symptoms, and response to medications. A worsening headache, or "the worst headache of my life," is especially concerning.
B. Seizures and Episodic Loss of Consciousness
Record the character of the individual episode, age at onset, frequency, duration, mental status during and after episodes, associated signs and symptoms, aura, and type and effectiveness of previous treatment.
The frequency, or progression of scotomas, acuity changes, diplopia, field changes, and associated phenomena should be noted.
Has the patient become weak? Has the patient lost coordination? Are distal muscles (eg, those of the hand or foot) affected more than proximal ones (eg, those of the upper arm or leg)? Are there abnormal muscle movements?
Has the patient noticed numbness or tingling? Over which part of the body? What is the location of the sensory loss? Can the patient tell where his or her legs are located? Is there a history of painless burns?
F. Cranial Nerve Function
Is there double vision? Note any facial drooping, slurred speech, difficulty swallowing, problems with balance, tinnitus (a ringing or buzzing sound in one or both ears), or impaired hearing.
Assess the onset, location, progression, frequency, characteristics, effect of physical measures, associated complaints, and type and effectiveness of previous treatment.
It is important to obtain a clear picture of the time course of the disorder. Was onset of symptoms sudden or gradual? If gradual, over what time scale (hour, days, months)? Are symptoms always present, or are they intermittent? What precipitates symptoms, and what relieves them?
Even before beginning the formal physical examination, important information may be gleaned by observing the patient while the history is given. Is the patient well groomed or unkempt? Is the patient aware of and appropriately concerned about the illness? Does the patient attend equally well to stimuli on the left and right sides; that is, does the patient relate equally well to the physician when asked questions from the left and then the right? The examiner can learn much simply by interacting with the patient and observing closely.
A general physical examination should include assessment of the circulatory, respiratory, genitourinary, gastrointestinal, and skeletal systems. The temperature, pulse rate, respiratory rate, and blood pressure should be routinely recorded. Note any deformity or limitation of movement of the head, neck, vertebral column, or joints. If there is any question of disease involving the spinal cord, determine whether there is tenderness or pain on percussion over the spinal column. (Immobilize the neck in any patient in whom acute cervical spinal cord injury is suspected.) Inspect and palpate the scalp and skull for localized thickening of the skull, clusters of abnormal scalp vessels, depressed areas, abnormal contours or asymmetry, and craniotomy and other operative scars. Percussion may disclose local scalp or skull tenderness over diseased areas and, in hydrocephalic children, a tympanic cracked-pot sound. Auscultate the skull and neck for bruits.
THE NEUROLOGIC EXAMINATION
Level of Consciousness and Alertness
The level of consciousness and degree of alertness should be noted. Is the patient conscious and fully alert, lethargic, stuporous, or comatose? Depressed consciousness can be the first clue, for example, in patients harboring subdural hematomas.
Note the patient's ability to focus attention. Is the patient fully alert or confused (ie, unable to maintain a coherent stream of thought)? Confusional states occur with a variety of focal lesions in the brain and are commonly seen as a result of metabolic and toxic disorders.
Some changes in mental status have important localizing value; that is, they suggest the presence of focal brain lesions in particular areas. Wernicke's and Broca's aphasia, for example, are seen with lesions involving Wernicke's and Broca's areas in the dominant cerebral hemisphere (see Chapter 21). Spatial disorientation suggests disease involving the dominant parietal lobe. Hemispatial neglect, in which the patient neglects stimuli, usually in the left-hand side of the world, suggests a disorder involving the right hemisphere. Early neurologic disease may occur without significant physical, laboratory, imaging, or other special diagnostic findings, and changes in mental status as a side effect of medications may further complicate the clinical picture.
The examiner can learn much by observing the patient's behavior, mode of speech, appearance, grooming, and degree of cooperation. Can the patient give a coherent and accurate history? Is the patient appropriately concerned about the illness? Does the patient interact appropriately with family members who are present in the examining room?
Look for anxiety, depression, apathy, fear, suspicion, or irritability.
Listen to spontaneous language and to the response to your verbal questions. Is the patient's speech fluent, nonfluent, or effortful? Is word choice appropriate? Can the patient name simple objects (pen, pencil, eraser, button), colors (point to various objects), and body parts? Is the patient able to repeat simple words ("dog") or phrases of varying complexity ("President Kennedy"; "no ifs, ands, or buts"; "if he were here, then I would go home with him")? Check comprehension of spoken language. This can be accomplished even in the patient who cannot speak by asking the patient to "make a fist"; "show me two fingers"; "point to the ceiling"; "point to the place where I entered the room"; or by asking the patient to nod "yes" or "no" in response to questions such as "is school meant for children?" and "Do helicopters eat their young?"
Check the patient's ability to read and write. (Make sure the patient is wearing reading glasses, if necessary, or use a large-print newspaper.)
Check for orientation with respect to person, place, time, and situation.
Ask about details and dates of recent and remote events, including such items as birth date, marriage date, names and ages of children, and specific details of the past few days and more remote times. Ask about objective facts ("What happened in sports last week?", "Who won the World Series?", "Who is the president?", "Who was president before that?").
F. Ability to Acquire and Manipulate Knowledge
These questions should be adapted to the patient's background and education. Examples are the names of prominent political and world figures, the capitals of countries and states, and current events in politics and sports.
2. Similarities and differences
Have the patient compare wood and coal; president and king; dwarf and child; human and plant; lie and mistake.
The patient should count backward from 100 by 7s; that is, subtract 7s from 100 (eg, 100 - 7 = 93; 93 - 7 = 86; 86 - 7 = 79). Add, multiply, or divide single numbers (eg, 3 × 5, 4 × 3, 16 × 3) and double-digit numbers (11 × 17 = 187). Calculate interest at 6% for 18 months. The examiner should make the calculations easier or more difficult depending on the patient's educational background.
Ask the patient to repeat digits in natural or reverse order. (Normally, an adult can retain seven digits forward and five backward.) After instruction, ask the patient to repeat a list of three cities and three two-digit numbers after a pause of 3 minutes.
5. Right-left orientation; finger recognition
The patient's ability to distinguish right from left and to recognize fingers can be tested with the request "Touch your left ear with your right thumb." Defective right–left orientation and inability to recognize fingers are seen (together with impaired ability to calculate and difficulty writing) in Gerstmann's syndrome as a result of lesions in the left angular gyrus.
Ask the patient for the symbolic or specific meaning of simple proverbs such as the following: "A stitch in time saves nine," "A rolling stone gathers no moss," "People who live in glass houses should not throw stones."
7. Memory and comprehension
The content of a simple story from a newspaper or magazine can be read and the patient's retention, comprehension, and formulation observed. Alternatively, the examiner tells a story, which is then retold in the patient's own words. The patient is also asked to explain the meaning of the story. The following stories can be used.
a. Cowboy story—A cowboy went to San Francisco with his dog, which he left at a friend's house while he went to buy a new suit of clothes. Dressed in his brand-new clothing, he came back to the dog, whistled to it, called it by name, and patted it. But the dog would have nothing to do with him in his new coat and hat. Coaxing was to no avail, so the cowboy went away and put on his old suit, and the dog immediately showed its joy in seeing its master as it thought he ought to be.
b. Gilded-boy story— At the coronation of one of the popes, about 300 years ago, a little boy was chosen to play the part of an angel. So that his appearance might be as magnificent as possible, he was covered from head to foot with a coating of gold foil. The little boy fell ill, and although everything possible was done for his recovery except the removal of the fatal golden covering, he died within a few hours.
Thought content may include obsessions, phobias, delusions, compulsions, recurrent dreams or nightmares, depersonalization, or hallucinations.
Olfaction should be assessed in cases in which head trauma has occurred, when disease at the base of the skull is suspected, and in patients with abnormal mental status. (Subfrontal meningiomas and frontal lobe gliomas can compress the underlying olfactory nerve.) Use familiar odors, such as peppermint, coffee, or vanilla, and avoid irritants, such as ammonia and vinegar. The patient must identify the substance with eyes shut and one nostril held closed. Anosmia is considered to be significant in the absence of intranasal disorders and can suggest, for example, compression of the olfactory tract by a tumor.
A Snellen chart can be used to measure visual acuity and determine whether improvement is obtained with correction. A pinhole can be used to correct nearsightedness. For individuals with severe defects, cruder tests may be used, for example, the ability to count fingers and detect hand movements and changes from dark to light.
2. Ophthalmoscopic examination
Examine each optic fundus. Details of the ophthalmoscopic examination should include the color, size, and shape of the optic disk; the presence or absence of a physiologic cup; the distinctness of the optic disk edges; the size, shape, and configuration of the vessels; and the presence of hemorrhage, exudate, or pigment. Papilledema or disk pallor, if present, should be explicitly noted.
Test the visual fields by confrontation, with the patient seated about 1 m from the examiner. With the left eye covered, the patient looks at the examiner's left eye. The examiner slowly raises both hands upward from a position where they can barely be seen in the lower two quadrants, and the patient signifies when the examiner's moving hands first become visible. The upper quadrants are similarly tested, with the examiner's hands moving downward. The left eye of the patient is then tested against the right eye of the examiner.
More accurate visual field examination can be carried out using a perimeter or tangent screen.
C. Oculomotor (III), Trochlear (IV), and Abducens (VI) Nerves
Strabismus, nystagmus, ptosis, exophthalmos, and pupillary abnormalities can be detected on initial examination. Test ocular movements by having the patient follow the movement of an object (eg, a finger or a light) to the extremes of the lateral and vertical planes.
Note the size and shape of each pupil. In addition, note the reactions of both pupils to a bright light flashed into one eye in a darkened room while the patient gazes into the distance. The direct light reaction is the response of the pupil of the illuminated eye; the consensual light reaction is the reaction of the opposite pupil, which is shielded from the stimulating light.
In testing the accommodation-convergence response, the examiner asks the patient to focus alternately on two objects, one distant and the other 15 cm (6 in) from the patient's face.
Note whether nystagmus (rhythmic, jerking movements of the eyes) is present, and if so, the direction of its fast and slow phases at rest or elicited by gaze in a particular direction. Nystagmus can indicate disease of the vestibular system, cerebellum, or brain stem.
The ability to perceive a pinprick or the touch of a bit of cotton is tested over all three divisions of the face and anterior half of the scalp. Corneal sensation may be tested by approaching the cornea from the side and lightly touching it with a strand of sterile cotton as the patient looks upward. Test the motor function of the trigeminal nerve by palpating the contraction of the masseter and temporalis muscles induced by a biting movement of the jaws.
Notice facial expression, mobility, and symmetry. Assess the voluntary movements of the lower facial musculature by having patients smile, whistle, bare their teeth, and pucker their lips. Maneuvers such as closing the eyes or wrinkling the forehead are ways of testing the upper facial musculature.
Minor degrees of facial asymmetry may be long-standing and are not necessarily a sign of neurologic disease. Examination of an old photograph (eg, on a driver's license) may reveal whether facial asymmetry is new or old.
In selected patients (primarily those in whom facial nerve injury is suspected), it may be appropriate to test taste sensation of the anterior two-thirds of the tongue. This is done by applying test solutions to the protruded tongue with cotton applicators. The test solutions used are sweet (sugar), bitter (quinine), salt (saline), and sour (vinegar). The patient responds by pointing to a labeled card.
F. Vestibulocochlear Nerve (VIII)
The patient's ability to hear the examiner's voice in ordinary conversation is noted. The ability to hear the sound produced by rubbing the thumb and forefinger together is then tested for each ear at distances up to a few centimeters. The farthest distance from either ear at which the ticking of a loud watch or the spoken voice is heard can be measured.
Use a tuning fork vibrating at 256 Hz to test air and bone conduction for each ear (see Table 16–1): In Rinne's test, the vibrating tuning fork is placed on the mastoid process and then in front of the ear. Normally, the fork is heard for several seconds longer when it is placed in front of the ear than when it is placed on the mastoid. In injury to the cochlear nerve, there may be complete or partial inability to hear the vibrating tuning fork (nerve deafness). When partial hearing remains, air conduction exceeds bone conduction. In disease of the middle ear with impaired hearing, bone conduction of the sound of the tuning fork is better than air conduction (conduction deafness).
In Weber's test, a vibrating tuning fork (256 Hz) is placed on the bridge of the nose or over the vertex of the scalp. Normally, the sound is heard equally well in both ears. In patients with unilateral deafness as a result of middle-ear disease, the sound is heard best in the affected ear.
When vestibular dysfunction is suspected, the caloric test can be used to evaluate vestibular function. The eardrum is first examined to ensure that no perforations exist. The patient sits with the head tilted slightly forward to test the vertical canals or lies supine with the head tilted back at an angle of 60° to test the horizontal canals. The examiner slowly and steadily irrigates one external auditory canal with cool (30°C) or warm (40°C) water. Normally, cool water in one ear produces nystagmus on the opposite side; warm water produces it on the same side. (A mnemonic for this is COWS: cool, opposite; warm, same.) Irrigation is continued until the patient complains of nausea or dizziness or until nystagmus is detected. This normally takes 20 to 30 seconds. If no reaction occurs after 3 minutes, the test is discontinued.
G. Glossopharyngeal Nerve (IX)
Taste over the posterior third of the tongue can be tested as previously described for the anterior two-thirds of the tongue. Sensation (usually touch) is tested on the soft palate and pharynx using a tongue blade or cotton swab. The pharyngeal response (gag reflex) is tested bilaterally.
Test swallowing function by noting the patient's ability to drink water and eat solid food. The pharyngeal wall contraction is observed as part of the gag reflex. Movement of the median raphe of the palate and uvula when the patient says "ah" is recorded. In unilateral paralysis of the vagus nerve, the raphe and uvula move toward the intact side, and the posterior pharyngeal wall of the paralyzed side moves like a curtain toward the intact side. Note the character, volume, and sound of the patient's voice.
Instruct the patient to rotate his or her head against resistance applied to the side of the chin. This tests the function of the opposite sternocleidomastoid muscle. To test both sternocleidomastoid muscles together, the patient flexes the head forward against resistance placed under the chin. Shrugging a shoulder against resistance is a way of testing trapezius muscle function.
J. Hypoglossal Nerve (XII)
Examine the tongue for atrophy and for fasciculations or tremors when it is protruded and when it is lying at rest in the mouth. Note any deviation of the tongue on protrusion; a lesion of the hypoglossal nerve or nucleus causes deviation to the same side.
Assess muscle bulk, tone, strength, and abnormal movements.
Atrophy or hypertrophy of muscles is judged by inspection and palpation and by measuring the circumferences of the limbs. The differences between the circumferences on the two sides may be related to the handedness or occupation of the patient but often result from atrophy.
If fasciculations (involuntary contraction or twitchings of groups of muscle fibers) are present, there location should be noted.
Muscle tone is judged by palpation of the muscles of the extremities and by passive movements of the joints by the examiner. Describe increased or decreased resistance to passive movement. Note tone alterations, including clasp-knife spasticity, cogwheel rigidity, spasms, contractures, and hypotonia.
Test the power of muscle groups of the extremities, neck, and trunk. Where there is an indication of diminished strength, test smaller muscle groups and individual muscles (see Appendix B). If there is a tremor, does it occur at rest (a resting tremor), with sustained posture (a postural tremor), or with movement (an intention tremor)? Describe involuntary movements, including athetosis, chorea, tics, and myoclonus.
Coordination, Gait, and Equilibrium
Watch the patient walk. Observe the patient's posture, gait, coordinated automatic movements (swinging arms), and ability to walk a straight line and make rapid turning movements while walking. Determine whether the patient can walk heel to toe. Record a full description of the stance and gait.
Have the patient stand with heels and toes together and eyes closed. Increased swaying occurs in patients with dysfunction of cerebellar or vestibular mechanisms. Patients with disease of the posterior columns of the spinal cord may fall when their eyes are closed, although they are able to maintain their position well with the eyes open. (This "positive Romberg sign" suggests dysfunction of the posterior columns or the vestibular system.)
C. Finger-to-Nose and Finger-to-Finger Tests
In the finger-to-nose test, the patient places the tip of a finger on his or her nose and then touches the examiner's finger, which is placed at arm's length; this is repeated as rapidly as possible. In the finger-to-finger test, the patient attempts to approximate the tips of the index fingers after the arms have been extended forward. Dysmetria, with overshooting of the mark, is often observed in cerebellar disorders.
The patient places one heel on the opposite knee and then moves the heel along the shin. Dysmetria, with overshooting the mark, is often observed in cerebellar disorders.
E. Rapidly Alternating Movements
The patient rapidly flexes and extends the fingers or taps the table rapidly with extended fingers. Test supination and pronation of the forearm in continuous rapid alternation. The inability to perform these movements quickly and smoothly is a feature of dysdiadochokinesia, an indication of cerebellar disease.
The following reflexes are routinely tested, and the response elicited is graded from 0 to 4+ (2+ is normal). For each deep tendon reflex, the right and left side should be compared. Particular attention should be paid to asymmetries, that is, reflexes that are brisker on one side than on the other. The examiner should use several senses: The reflex response of a limb can be seen, but it can also be felt by the examiner's hand that supports the limb. It can also be heard, in the form of a dull thud as the reflex hammer hits an areflexic limb.
Asymmetry of only one reflex is often a reflection of hyporeflexia on the side of a nerve or spinal root injury. In contrast, if all or most of the deep tendon reflexes are brisker on one side, the patient may be displaying hyperreflexia resulting from damage to the pyramidal system.
When the patient's elbow is flexed at a right angle, the examiner places a thumb on the patient's biceps tendon and then strikes the thumb. Normally, a slight contraction of the biceps muscle occurs.
With the patient's elbow supported in the examiner's hand, the triceps tendon is sharply percussed just above the olecranon. Contraction of the triceps muscle, with extension of the forearm, usually results.
The patellar tendon is tapped with a percussion hammer. The patient is usually seated on the edge of a table or bed, with the legs hanging loosely. For patients who are bedridden, the knees can be flexed over the supporting arm of the examiner, with the heels resting lightly on the bed.
This is best elicited by having the patient kneel on a chair, with ankles and feet projecting over the edge of the chair. The Achilles tendon is then struck with a percussion hammer.
With the patient lying supine with relaxed abdominal muscles, stroke the skin of each quadrant of the abdomen briskly with a pin from the periphery toward the umbilicus. Normally, the local abdominal muscles contract, causing the umbilicus to move toward the quadrant stimulated.
In men, stroking the skin of the inner side of the proximal third of the thigh causes retraction of the ipsilateral testicle.
Stroke the outer surface of the sole of the foot lightly with a large pin or wooden applicator from the heel toward the base of the little toe and then inward across the ball of the foot. The normal plantar response consists of plantar flexion of all toes, with slight inversion and flexion of the distal portion of the foot. In abnormal responses, there may be extension of the great toe, with fanning and flexion of the other toes (Babinski's reflex). The Babinski reflex (also termed the "extensor plantar" response) suggests dysfunction of the corticospinal system, although it does not, in itself, tell the examiner the rostrocaudal location (spinal cord vs. brain stem vs. cerebrum) of the lesion.
Clonus (repeated reflex muscular movements) may be elicited in patients with exaggerated reflexes. Wrist clonus is sometimes elicited by forcible flexion or extension of the wrist. Patellar clonus can be elicited by sudden downward movement of the patella, with consequent clonic contraction of the quadriceps muscle. Ankle clonus is tested by quickly flexing the foot dorsally, producing clonic contractions of the calf muscles. Clonus can be sustained or transient (usually measured in number of beats; three to four beats of clonus can be elicited at the ankles in some normal individuals).
Sensory examination depends on the patient's subjective responses and thus can be tiring for both the patient and the examiner. The patient should be rested and in a cooperative frame of mind. Abnormalities, especially of minor degree, should be checked by reexamination. The following modalities are tested and charted.
Test the patient's ability to perceive pinprick or deep pressure. If there is an abnormality, note the topographic pattern (over a specific dermatome? distal, over the hands and feet in a "stocking-and-glove" distribution?).
To check for the ability to detect and distinguish between warm and cold, use a test tube of warm water and one of cold water. Alternatively, check whether the patient perceives the flat side of the tuning fork as cold.
Test the ability to perceive light stroking of the skin with cotton.
The patient should be able to feel the buzz of a tuning fork (at a frequency of 128 Hz) applied to the bony prominences. Compare the patient's ability to sense vibration with your own, with the fork applied to the malleoli, patellas, iliac crests, vertebral spinous processes, and ulnar prominences.
This is tested by having the patient determine the position of toes and fingers when these are grasped by the examiner. A digit is grasped on the sides, and the patient, with eyes closed, attempts to determine whether it is moved upward or downward. Test the ankles, wrists, knees, and elbows if impairment is demonstrated in the digits.
To test the patient's capacity to recognize the forms, sizes, and weights of objects, place a familiar object (eg, a coin, key, or knife) in the patient's hand and ask him or her to identify the object without looking at it.
G. Two-Point Discrimination
The shortest distance between two separate points of a compass or calipers at which the patient perceives two stimuli is compared for homologous areas of the body. (Normal: fingertips, 0.3–0.6 mm; palms of hands and soles of feet, 1.5–2 mm; dorsum of hands, 3 mm; shin, 4 mm.)
With the patient's eyes closed, the examiner touches the patient's body. The patient then points to the spot touched, enabling the examiner to assess the patient's ability to localize tactile sensation. Similar areas of both sides of the body are compared. Extinction on double simultaneous stimulation (eg, the ability to perceive tactile sensation on the right hand when presented alone but not when presented simultaneously with a stimulus to the left hand) suggests a disorder involving the contralateral parietal lobe.
The neonatal neurologic examination is usually performed shortly after birth. Repeat examinations at weekly intervals may be desirable. The examination should be planned with little stimulation of the infant occurring initially so that spontaneous behavior can be observed.
Observe the motor pattern and supine and prone body posture and evaluate the reflexes throughout the examination.
In normal infants, the limbs are flexed, the head may be turned to the side, and there may be kicking movements of the lower limbs. Extension of the limbs can occur with intracranial hemorrhage, opisthotonos with kernicterus, and asymmetry of the upper limbs with brachial plexus palsy. Paucity of movements may occur with brachial plexus palsy and meningomyelocele.
THE NEUROLOGIC EXAMINATION
Test the infant's blink response to light. Ophthalmoscopic examination should be made at the end of the examination.
B. Oculomotor (III), Trochlear (IV), and Abducens (VI) Nerves
Check the size, shape, and equality of the pupils and pupillary responses to light. Lateral rotation of the head causes rotation of the eyes in the opposite direction (doll's eye reflex).
C. Trigeminal (V) and Facial (VII) Nerves
The sucking reflex is elicited by placing a finger or nipple between the infant's lips. In the rooting reflex, the infant's mouth will open and turn toward the stimulus if a fingertip touches the infant's cheek.
D. Vestibulocochlear Nerve (VIII)
The blink response occurs in reaction to loud noise. To test the labyrinthine reflex, the infant is carried and held up by the examiner, who makes several turns to the right and then to the left. A normal infant will look ahead in the direction of rotation; when rotation stops, the infant will look back in the opposite direction.
E. Glossopharyngeal (IX) and Vagus (X) Nerves
Notice the infant's ability to swallow.
Motor System and Reflexes
Spontaneous and induced motor activity are noted. If the infant is inactive and quiet, the Moro reflex (see later discussion) may be used or the infant may be placed in the prone position to induce movement.
A. Incurvation Reflex (Galant's Reflex)
With the infant prone, tactile stimulation of the normal thoracolumbar paravertebral zone with a finger produces contraction of the ipsilateral long muscles of the back, so that the head and legs curve toward the stimulated area and the trunk moves away from the stimulus.
Assess muscle tone by palpating muscles during activity and relaxation. Resistance to passive extension of the elbows and knees is noted.
Determine the infant's ability to move a limb from a given position. Notice any asymmetries in movements of the right versus left limbs.
Flex the infant's hip and knee joints to check the pull of gravity when the infant is briefly held head down in vertical suspension.
Stimulation of the ulnar palmar surfaces causes the infant to grasp the examiner's hands forcefully.
Contraction of shoulder and neck muscles occurs when a normal infant is gently pulled from the supine to a sitting position.
The normal infant makes stepping movements when held upright with the feet just touching the table.
H. Placing and Supporting Reactions
Drawing the dorsum of the infant's foot across the lower edge of a moderately sharp surface (eg, the edge of the examining table) normally produces flexion at the knee and hip, followed by extension at the hip (placing reaction). If the plantar surface comes in contact with a flat surface, extension of the knee and hip may occur (positive supporting reaction).
I. Moro Reflex (Startle Response)
The Moro reflex is present in normal infants. A sudden stimulus (eg, a loud noise) causes abduction and extension of all extremities, with extension and fanning of digits except for flexion of the index finger and thumb. This is followed by flexion and adduction of the extremities.
J. Other Reflexes and Responses
Knee-jerk, plantar response (normal response is extensor), abdominal reflex, and ankle clonus are tested with the infant quiet and relaxed.
Withdrawal of the stimulated limb and sometimes also the unstimulated limb may be caused by pinprick of the sole of the foot.