EXAMINATION FOR SUBTLE HEMIPARESIS [FIG. 6D(IV).58]

Pronator drift (Barre’s sign)

The patient stretches out both arms directly in front of him or her with palms upright (i.e. forearms

supinated) and closes his or her eyes.

This position is held for 20–30 seconds.

Normal response:

Palm will remain flat, elbows straight and the limbs horizontal OR

Symmetrical deviation from this position (i.e. on both the sides—dominant hand may pronate slightly more than the nondominant hand)

Positive pronator drift: Components of pronator drift as mentioned above are seen in the weaker side (asymmetric response)

which indicates a lesion in contralateral cortex

Positive with eyes open: Motor deficit

Positive with eyes closed: Sensory deficit (posterior column)

Outward and upward drift: Cerebellar drift

“Updrift” (involved arm rising overhead without patient awareness): Parietal lobe lesions (loss of position sense)

Drift without pronation: Functional upper limb paresis (conversion disorder)

Forearm rolling test [Fig. 6D(iv).59]

The patient bends each elbow and places both forearms parallel to each other.

He or she then rotates the forearms about each other, first in one direction and then the other.

In the abnormal response, the forearm contralateral to the lesion appears fixed while the other

arm rotates around it.

Rapid finger tapping test

The patient rapidly taps the thumb and index finger repeatedly at a speed of about two taps per

second.

Hemispheric lesions cause the contralateral finger and thumb to tap more slowly and with

diminished amplitude.

Foot tapping test

The seated patient taps one forefoot at a time for 10 seconds on the floor, as fast as possible,

while the heel maintains contact with the floor.

A discrepancy of more than five taps between the left and right foot indicates cerebral disease

contralateral to the slower foot.

Fig. 6D(iv).58: Examination for subtle hemiparesis.

Fig. 6D(iv).59: Forearm rolling test.

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3.

4.

5.

6.

D(v). REFLEXES

DEFINITION

A reflex is an involuntary response to a sensory stimulus.

MECHANISM OF REFLEX GENERATION [FIG. 6D(V).1]

Afferent impulses arising in a sensory organ produce a response in the effector organ. The response

can be sensory, motor or autonomic.

It has two components:

Segmental component Suprasegmental component

It consists of a local reflex center in the spinal cord or

brainstem and its afferent and efferent connections

It is made up of descending central pathways that control, modulate, and

regulate the segmental activity

Diseases may increase the activity of some reflexes, decrease activity of

others, and causes reflexes to appear that are not normally seen

TYPES OF REFLEXES

Deep tendon reflexes (monosynaptic reflex)

Superficial reflex (polysynaptic reflex)

Plantar reflex

Latent reflex

Primitive reflexes

Inverted and perverted reflexes.

GRADING OF REFLEXES (FOR DTR’S) NINDS SCALE

Absent reflex (even after reinforcement) Grade 0

Present but diminished Grade 1+

Normal Grade 2+

Increased but not necessarily to pathologic degree Grade 3+

Markedly hyperactive, pathologic, often with extrabeats or accompanying sustained clonus Grade 4+

REINFORCEMENT MECHANISM AND METHODS

Mechanism

Normally, when a muscle spindle is stimulated two kinds of responses are seen via the following nerves:

Fig. 6D(v).1: Schematic representation of innervation of muscle fiber and pathways.

Alpha motor neurons Gamma motor neuron* Inhibitory neuron

Causes: contraction of Extrafusal fibers

of muscle

Causes: contraction of intrafusal fibers of muscle

Causes: inhibition of reciprocal muscle

contraction

*Normally gamma motor neurons are under the inhibitory control of upper motor neurons and

reinforcement maneuvers remove the inhibitory effect on gamma motor neurons [Fig. 6D(v).1].

Note: Mnemonic—AntiEpileptics cause gastro intestinal disturbance. (A: Alpha neuron, E: Extrafusal

fibers), (G: Gamma neuron, I: Intrafusal fibers).

Reinforcement Maneuvers for Deep Tendon Reflexes (DTRs)

Distraction Talk to the patient and cause diversion

of thought process

Clenching the teeth or clenching the fist of the other arm [Fig. 6D(v).2] Traditionally done for upper limb

Jendrassik maneuver (interlocking the flexed fingers of the two hands and pull

one against each other) [Fig. 6D(v).3]

Preferably done for lower limb

Fig. 6D(v).2: Clenching the teeth for reinforcement of upper limb reflexes.

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Fig. 6D(v).3: Jendrassik maneuver for reinforcement of lower limb reflexes.

DEEP TENDON REFLEXES

These are monosynaptic reflexes.

Prerequisite for examination:

Good knee hammer (preferably Queen Square reflex hammer)

Expose adequately the muscle to be tested

Make sure patient is not anxious

The muscle should be placed in optimum position, slightly on stretch, but with plenty of room for

contraction.

The most commonly used specialized reflex hammers are grouped into three types by the shape of the head:

triangular/tomahawk shaped (Taylor), T-shaped (Tromner, Buck), or circular (Queen square, Babinski)

Tromner neurological reflex hammer

Taylor hammer

Babinski neurological reflex hammer

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Queen square neurological reflex hammer

Buck neurological reflex hammer

Reflex Root value

Biceps C5C6 (musculocutaneous nerve)

Supinator (brachioradialis) C5C6 (radial nerve)

Triceps C7C8 (radial nerve)

Knee L3L4 (femoral nerve)

Ankle S1S2 (medial popliteal nerve)

Mnemonic—S1,2: L3,4: C5,6:C7,8 (in sequence from below)

Few others

Pectoral C5-T1 (medial and lateral pectoral nerves)

Finger flexion C6-T1 (median nerve)

Reflex Method of elicitation Normal response

Biceps

[Figs.

6D(v).4A

to C]

Press the forefinger gently on the biceps tendon in the

antecubital fossa and then strike the finger with the

hammer

Flexion of the elbow with visible contraction of the biceps muscle

Supinator

[Figs.

6D(v).5A

to C]

Strike the lower end of the radius about 5 cm above the

wrist and watch for the movement of forearm and

fingers

Contraction of brachioradialis and flexion of elbow

Triceps

[Figs.

6D(v).6A

to D]

By holding the patient’s hand draw the arm across the

trunk and allow it to lie loosely in the new position. Then

strike the triceps tendon 5 cm above the elbow

Extension of elbow with visible contraction of triceps muscle

Knee

[Figs.

6D(v).7A

to C]

For right-handed examiner, the left arm is under both

the knees in order to flex them together and tap the

patellar tendon lightly on each side and compare the movements of lower leg and of quadriceps muscle

Extension of the knee and visible contraction of the

quadriceps (in case of lower leg amputation keep finger

just above the patella with legs extended and strike it in

peripheral direction and look for upward pull of patella)

Ankle

[Figs.

6D(v).8A

to E]

Patient’s leg should be externally rotated and slightly

flexed at the knee. Examiner uses the left hand to

dorsiflex the foot. For the left leg move to the other

side of the bed

Plantar flexion of foot and contraction of gastrocnemius

• The Achilles tendon is then struck

Few others

Pectoral

[Fig.

6D(v).9]

With patients arm in the mid position between adduction

and abduction hook your index finger on the tendon of

the pectoralis major muscle in the anterior fold of axilla

and strike with hammer

Adduction of the arm and visible contraction of the

pectoralis major

Finger

flexion

test [Fig.

6D(v).10]

Allow the patient’s hand to rest palm upwards, the

fingers slightly flexed. The examiner interlocks his

fingers with patient’s fingers and strikes them with the

hammer

Slight flexion of all the fingers and of the interphalangeal

joint of the thumb

Fig. 6D(v).4A: Demonstration of biceps reflex (right hand).

Fig. 6D(v).4B: Demonstration of biceps reflex supine position (right hand).

Fig. 6D(v).4C: Demonstration of biceps reflex (left hand). Fig. 6D(v).5C: Demonstration of supinator reflex in supine positi

Fig. 6D(v).5A: Demonstration of supinator reflex (right). Fig. 6D(v).6A: Demonstration of triceps reflex (right hand).

Fig. 6D(v).5B: Demonstration of supinator reflex (left). Fig. 6D(v).6B: Demonstration of triceps reflex (right hand) in sup

position.

Fig. 6D(v).6C: Demonstration of triceps reflex (left hand). Fig. 6D(v).7B: Demonstration of right knee jerk in supine positio

Fig. 6D(v).6D: Demonstration of triceps reflex (left hand) in supine

position.

Fig. 6D(v).7C: Demonstration of knee jerk (for comparing both

sides).

Fig. 6D(v).7A: Demonstration of knee jerk sitting position (for

pendular movement).

Fig. 6D(v).8A: Demonstration of ankle reflex of right leg.

Fig. 6D(v).8B: Demonstration of ankle reflex of left leg. Fig. 6D(v).8E: Demonstration of ankle reflex with foot dangling o

the edge of table.

Fig. 6D(v).8C: Demonstration of ankle reflex of left leg. Fig. 6D(v).9: Demonstration of pectoral reflex.

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Fig. 6D(v).8D: Demonstration of ankle reflex in prone position. Fig. 6D(v).10: Demonstration of finger flexion reflex.

Clonus

Clonus is a series of rhythmic involuntary muscular contractions induced by the sudden passive

stretching of a muscle or tendon.

Clonus Demonstration

Ankle clonus

[Figs. 6D(v).12A

and B]

Examiner supports the leg, preferably with one hand under the knee, grasps the foot from below with the

other hand, and quickly dorsiflexes the foot while maintaining slight pressure on the sole at the end of the

dorsiflexion

The leg and foot should be well relaxed, the knee and ankle in moderate flexion, and the foot slightly

everted

Right ankle clonus is examined by standing on the right side of the patient and left ankle clonus by

standing on the left side

Unsustained clonus fades away after a few beats; sustained clonus persists as long as the examiner

continues to hold slight dorsiflexion pressure on the foot

Patellar clonus

[(Figs. 6D(v).11A

and B]

Examiner grasps the patella between index finger and thumb and executes a sudden, sharp, downward

thrust, holding downward pressure at the end of the movement

Wrist clonus Sudden passive extension of the wrist produces wrist clonus

Fig. 6D(v).11A: Demonstration of right patellar clonus.

Fig. 6D(v).11B: Demonstration of left patellar clonus.

Fig. 6D(v).12A: Demonstration of right ankle clonus.

Fig. 6D(v).12B: Demonstration of left ankle clonus.

SUPERFICIAL REFLEXES

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These are the responses to stimulation of either the skin or mucous membrane.

Clinical Significance

Superficial reflexes are abolished by pyramidal tract lesions.

Superficial reflex Deep tendon reflex

Polysynaptic reflexes Monosynaptic reflexes

Respond slowly Faster response

Latency is longer Latency is slower

Fatigue easily Fatigue slowly

Not as consistently present as deep tendon reflexes Consistently present

Abolished by pyramidal tract lesions Exaggerated by pyramidal tract lesions

Superficial reflex Elicitation

Corneal (cranial nerve V

and VII)

Lightly touching the upper cornea with wisp of cotton or tissue, brought in from the side so the

patient cannot see

Abdominal [Fig. 6D(v).13]

Epigastric (T6-T9)

Mid abdominal (T9-T11)

Hypogastric (T11-L1)

Stimulus is delivered by stroking the abdominal wall (preferably towards the umbilicus) and watch

for contractions

Cremasteric [Fig. 6D(v).14]

(L1, L2)

Stroking the skin in upper inner aspect of thigh and watch for the upward movement of testes in

scrotum

Anal reflex (S2, S3) Contraction of external sphincter in response to stroking the skin or mucous membrane in the

perianal region

Bulbocavernosus reflex

(S2, S3)

[Fig. 6D(v).15]

Contraction of anal sphincter which is best appreciated by a gloved finger in the rectum on

stimulation of glans penis or clitoris

Fig. 6D(v).13: Demonstration of abdominal reflex.

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Fig. 6D(v).14: Direction of stimulus and movement of testes in cremasteric reflex.

Fig. 6D(v).15: Pictorial representation of bulbocavernosus reflex.

PLANTAR REFLEX AND VARIATIONS

Plantar Reflex

Stroking the plantar surface of foot from the heel forward is normally followed by plantar flexion of foot

and toes.

Babinski Sign

It is the pathologic variation of plantar reflex (i.e. extensor plantar response). It is part of primitive flexion

reflex. In higher vertebrates, the flexion response includes flexion at hip, flexion at knee, and dorsiflexion

of ankle (all of which help in removing the threatened part form danger). Normally the descending motor

pathway suppresses the primitive flexion response.

Positioning of

patient [Fig.

6D(v).16]

Best position is supine

Knee must be extended

Heels should rest on the bed

Prerequisites Rule out ankylosis of great toe

Stimulating agent Applicator stick

Blunt key

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•

Hand of reflex hammer

Broken tongue blade

Thumb nail

Strength of

stimulus

Variable strength with strong stimulus for thick soles and minimal stimulation when response is strongly

extensor

Site of stimulus Reflexogenic area of S1

Stimulus should begin near the heel on the lateral aspect of sole and carried up to metatarsophalangeal

joint of little toe and then carried medially falling short of 1st metatarsophalangeal joint [Fig. 6D(v).17]

Normal response Flexion of the great toe and other toes

Abnormal

response

(Babinski sign)

Dorsiflexion of great toe and small toes

Fanning of toes

Dorsiflexion of ankle

Flexion of knee joint

Flexion at hip joint

Contraction of tensor fascia lata

Reinforcement of

plantar reflex

By asking patient to rotate the head to opposite side

Fig. 6D(v).16: Position of leg for demonstration of plantar reflex.

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Fig. 6D(v).17: Direction of stimuli for demonstrating the plantar reflex.

Variants of Plantar Response

Equivocal response Rapid extension followed by flexion

Only great toe extension

Extension of great toe with flexion of fingers

No response to the plantar stimulus

Flexion at hip and knee, but no movement of toes

Minimal plantar response No toe movement

Contraction of tensor fascia lata with mild internal rotation and abduction of hip

Pseudo Babinski Voluntary extension of great toe due to hyperesthesia or strong painful stimulus

Dystonic posturing of great toe

Other method of obtaining plantar reflex

Method Elicitation

Chaddock [Fig.

6D(v).18]

Elicited by stimulating the lateral aspect of the foot, not the sole, beginning about under the lateral malleolus

near the junction of the dorsal and plantar skin, drawing the stimulus from the heel forward to the small toe

The Chaddock is the only alternative toe sign that is truly useful

It may be more sensitive than the Babinski but is less specific

It produces less withdrawal than plantar stimulation

Reverse

Chaddock

The stimulus moves from the small toe toward the heel

Oppenheim

[Fig. 6D(v).19]

Dragging the knuckles heavily down the anteromedial surface of the tibia from the infrapatellar region to the

ankle.

The response is slow and often occurs toward the end of stimulation

Shaeffer’s sign

[Fig. 6D(v).20]

Deep pressure on Achilles tendon

Gordon’s sign

[Fig. 6D(v).21]

Squeezing of calf muscles

Bing’s sign

[Fig. 6D(v).22]

Pricking dorsum of foot with a pin

Moniz’ sign

[Fig. 6D(v).23]

Forceful passive plantar flexion at ankle

Throckmorton’s

sign

Percussing over dorsal aspect of metatarsophalangeal joint of great toe just medial to EHL tendon

Stransky Small toe forcibly abducted, then released

Szapiro Pressure against dorsum of second through fifth toes, causing firm passive plantar flexion while stimulating

plantar surface of foot

Strümpell’s

phenomenon

Forceful pressure over anterior tibial region

Cornell

response

Scratching dorsum of foot along inner side of EHL tendon

Combining two methods may elicit minimal reflexes

[Fig. 6D(v).24]

Fig. 6D(v).18: Chaddock’s sign.

Fig. 6D(v).19: Openheim’s technique.

Fig. 6D(v).20: Shaeffer’s technique.

Fig. 6D(v).21: Gordon’s technique.

Fig. 6D(v).22: Bing’s sign. Fig. 6D(v).23: Moniz’s sign.

Fig. 6D(v).24: Eliciting plantar by simultaneous stimulus from Openheim’s and plantar strike.

LATENT REFLEXES OF UPPER LIMB

Reflex Elicitation

Wartenberg’s

reflex [Fig.

6D(v).25]

Patient’s fingers are interlocked with examiner’s fingers and pulled apart. Normally thumb extends. However

in pyramidal lesions thumb is adducted and flexed. This sign is equivalent of Babinski of lower limb

Hoffman’s reflex

[Fig. 6D(v).26]

Flexion of the interphalangeal joint of middle finger of patient produces flexion response in other fingers along

with adduction of thumb

Tromner’s reflex

[Fig. 6D(v).27]

Examiner holds the patient’s partially extended middle finger, letting the hand dangle, then, with the other

hand, thumps or flicks the finger pad. The response is the same as that in the Hoffmann test

Fig. 6D(v).25: Wartenberg’s sign.

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•

Fig. 6D(v).26: Hoffman’s reflex.

Fig. 6D(v).27: Tromner’s reflex.

PRIMITIVE REFLEXES

Reflex Elicitation

Glabellar tap

(Myerson’s sign)

[Fig. 6D(v).28]

Repetitive tapping of the forehead between the eyebrows causing blinking, which usually stops within

few taps. However if blinking persists, it suggests positive frontal release sign.

Note: To avoid visual stimulus bring the hand from above and behind

Palmomental reflex

of Marinesco–

Radovici

[Fig. 6D(v).29]

Stroke the thenar eminence in a proximal to distal direction using a sharp object such as the pointed

end of a reflex hammer, key, paper clip, or fingernail and watch for twitch of chin muscle

This reflex does not have any localizing value, and is commonly seen in elderly patients with

degenerative disease of the cortex

Sucking reflex

[Fig. 6D(v).30]

Sucking reflexes may be seen in response to tactile stimulation in the oral region, or in response to the

insertion of an object (for example, a spatula) into the mouth

Rooting reflex

[Fig. 6D(v).31]

Rooting responses are seen when the mouth turns towards an object gently stroking the cheek (tactile

rooting), or towards an object (for example, tendon hammer) brought into the patient’s field of view

(visual rooting)

Pout and snout

reflex

The snout reflex is present when the lips pucker in response to gentle pressure over the nasal philtrum

•

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[Fig. 6D(v).32]

Grasp reflex

[Fig. 6D(v).33]

If the examiner’s fingers are placed in the patient’s hand, especially between the thumb and forefinger,

or if the palmar skin is stimulated gently, there is slow flexion of the digits

The patient’s fingers may close around the examiner’s fingers

Fig. 6D(v).28: Glabellar tap.

Fig. 6D(v).29: Palmomental reflex. Fig. 6D(v).30: Sucking reflex.

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