Motor ,sensory,cerebellar Reflexes, how to do that and what are the normal and abnormal findings, how to grade that

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deep tendon reflex grading scale neurological examination

I now have comprehensive information from Harrison's (22E), Bradley & Daroff's Neurology, Textbook of Family Medicine, and Adams & Victor's. Let me compile the full answer.

Neurological Examination: Motor, Sensory, Cerebellar & Reflexes

1. MOTOR EXAMINATION

How to Do It

A. Appearance / Inspection

Inspect and palpate muscle groups in good light, patient in a comfortable, symmetric position.
Look for: muscle atrophy, hypertrophy, fasciculations, tenderness.
Observe for involuntary movements at rest (e.g., pill-rolling tremor of Parkinson's), during maintained posture (essential tremor), or with voluntary movement (intention tremor of cerebellar disease).

B. Muscle Tone Test by measuring resistance to passive movement of a relaxed limb. Distract the patient to minimize voluntary contraction.

Region	Technique
Upper limb	Rapid pronation/supination of forearm + flexion/extension at wrist
Lower limb	Patient supine; examiner places hands behind knees and rapidly raises them — with normal tone, the ankles drag along the table before rising

C. Strength Testing

Pronator drift: Ask patient to hold both arms fully extended, parallel to the ground, with eyes closed for ~10 seconds. Any flexion at elbow/fingers or pronation of the forearm (especially asymmetric) = sign of weakness.
Isolate each muscle group and ask patient to exert maximal effort against examiner resistance.

Muscle Strength Grading (MRC Scale)

Grade	Meaning
0	No movement
1	Flicker/trace of contraction, no joint movement
2	Movement with gravity eliminated
3	Movement against gravity, not against resistance
4−	Movement against mild resistance
4	Movement against moderate resistance
4+	Movement against strong resistance
5	Full power

Normal vs. Abnormal Findings

Finding	Normal	Abnormal
Tone	Slight, symmetric resistance to passive movement	Spasticity (corticospinal tract) · Rigidity/cogwheeling (extrapyramidal/Parkinson's) · Flaccidity (LMN/peripheral nerve) · Paratonia (frontal lobe)
Strength	5/5 all muscle groups	≤4 = weakness; pattern matters (see below)
Pronator drift	No drift in 10 seconds	Drift = contralateral corticospinal lesion
Involuntary movements	None at rest	Fasciculations (LMN), tremor, chorea, myoclonus, dystonia

Pattern of Weakness:

Pyramidal pattern (UMN) — upper limb extensors + lower limb flexors weak → corticospinal tract lesion
Bilateral proximal → myopathy
Bilateral distal → peripheral neuropathy
UMN features — increased tone, hyperreflexia, Babinski sign
LMN features — wasting, fasciculations, decreased tone, absent reflexes

2. SENSORY EXAMINATION

How to Do It

Test five primary sensory modalities in each limb:

Modality	Technique	Pathway
Light touch	Wisp of cotton / fingertip — single gentle touches	Dorsal column / spinothalamic
Pain (pinprick)	New pin; ask "sharp or dull?"	Spinothalamic (lateral)
Temperature	Metal tuning fork immersed in cold/warm water	Spinothalamic (lateral)
Vibration	128-Hz tuning fork on distal phalanx of great toe or index finger at nail bed; examiner places finger on opposite side of joint to compare thresholds	Dorsal column
Joint position (proprioception)	Grasp digit laterally, make 1–2 mm excursions; patient identifies "up" or "down"	Dorsal column

Romberg Maneuver: Patient stands with feet together, eyes open → then closed. Loss of balance with eyes closed = abnormal (proprioceptive loss — peripheral or posterior column).

Cortical Sensation (only test if primary sensation intact):

Double simultaneous stimulation — touch both hands; parietal lesion = extinction of contralateral stimulus
Two-point discrimination — ability to distinguish two closely placed stimuli
Stereognosis — identify object by touch alone
Graphesthesia — identify numbers/letters written on skin

Normal vs. Abnormal Findings

Test	Normal	Abnormal
Light touch	Felt equally both sides	Loss in dermatomal, glove-stocking, or hemisensory pattern
Pinprick	Sharp perceived symmetrically	Dissociated sensory loss (pain/temp lost, vibration intact) = spinothalamic lesion
Vibration	Felt at distal phalanx; diminishes symmetrically with age	Early loss in peripheral neuropathy; posterior column disease
Joint position	Correctly identifies all movements	Loss → sensory ataxia, pseudoathetosis
Romberg	Stable with eyes closed	Positive Romberg = posterior column or peripheral proprioceptive loss
Cortical sensation	Correctly identifies all bilateral stimuli	Extinction, astereognosis, agraphesthesia → parietal lesion

3. CEREBELLAR EXAMINATION (Coordination)

The cerebellar exam covers 5 domains: eyes, speech, hands, legs, and gait. The SARA scale is used for formal rating.

How to Do It

Test	Technique	What Is Assessed
Finger-to-nose	Patient touches their index finger → nose → examiner's outstretched finger (which moves each rep)	Limb dysmetria, intention tremor
Finger chase	Patient's index finger follows examiner's moving finger	Dysmetria, overshoot
Rapid alternating movements (RAM/dysdiadochokinesis)	Patient makes fist → extends index finger → taps distal thumb as fast as possible; lower limb = rapid foot tapping	Cerebellar hemisphere function
Heel-knee-shin	Supine patient lifts heel → places on opposite knee → slides down shin to ankle	Leg dysmetria
Gait	Walk normally, then tandem (heel-to-toe), walk up/down stairs	Truncal ataxia, wide-based gait
Stance	Stand with feet together → tandem stance → one foot → hop	Truncal sway, balance
Speech	Listen during history	Scanning/staccato speech
Eye movements	Fixation, smooth pursuit, saccades	Nystagmus, saccadic pursuit

Normal vs. Abnormal Findings

Finding	Normal	Abnormal (Cerebellar Sign)
Finger-to-nose	Smooth, accurate	Intention tremor (tremor worsens as approaching target), dysmetria (past-pointing)
RAM	Fast, rhythmic, symmetric	Dysdiadochokinesis (imprecise, irregular rhythm/amplitude)
Heel-knee-shin	Heel stays on shin smoothly	Heel falls off shin
Gait	Normal stride, arm swing	Wide-based, staggering, veering to one side
Stance	Stable feet-together	Truncal sway (even while sitting without support)
Speech	Clear, fluent	Scanning speech — slow, slurred, irregular syllable force
Eye movements	Smooth pursuit, accurate saccades	End-gaze nystagmus, saccadic pursuit, square-wave jerks

Important: Slow RAM compared with contralateral side suggests a pyramidal tract lesion rather than cerebellar — distinguish carefully.

4. REFLEX EXAMINATION

How to Do It

Key principle: Patient must be relaxed; position muscle midway between full contraction and extension. Compare both sides. Find the smallest stimulus to elicit the reflex (not the maximal response).

Jendrassik Maneuver (reinforcement): To enhance reflexes — upper limb reflexes reinforced by voluntary teeth-clenching; Achilles reflex by hooking the flexed fingers of both hands together and trying to pull apart.

Standard Deep Tendon Reflexes (DTRs)

Reflex	Technique	Spinal Level
Biceps	Strike biceps tendon with finger interposed	C5, C6
Brachioradialis	Strike brachioradialis tendon at radial styloid	C5, C6
Triceps	Strike triceps tendon above olecranon	C6, C7
Finger flexor	Strike examiner's finger over patient's finger flexors	C8, T1
Patellar (knee jerk)	Legs hanging freely; strike patellar tendon just below patella	L3, L4
Achilles (ankle jerk)	Foot slightly dorsiflexed; strike Achilles tendon	S1, S2

Patellar reflex with Jendrassik maneuver

Eliciting the patellar reflex with the Jendrassik maneuver (patient interlocks fingers and pulls apart)

Brachioradialis reflex technique (C5–C6)

Reflex Grading Scale

Grade	Meaning
0	Absent
1	Present but diminished
2	Normoactive (normal)
3	Increased (hyperreflexia) without clonus
4	Clonus present

Cutaneous Reflexes

Reflex	Technique	Normal	Abnormal
Plantar (Babinski)	Stroke lateral sole from heel across ball to great toe with noxious stimulus	Plantar flexion of toes	Babinski sign = extension of great toe + fanning of other toes → UMN lesion above S1
Superficial abdominal	Stroke abdomen diagonally near umbilicus	Umbilicus pulls toward stimulated quadrant	Absent with UMN lesion; helps localize spinal level (T9–T12)
Cremasteric	Stroke medial thigh	Ipsilateral testicular elevation	Absent with L1–L2 or UMN lesion
Anal	Scratch perianal skin	Anal sphincter contraction	Absent → S2–S4 injury or cord lesion

Primitive (Frontal Release) Reflexes

Normally absent in adults; reappear with frontal lobe disease:

Reflex	Stimulus	Response
Suck	Light touch center of lips with tongue blade	Sucking movement
Root	Touch corner of lips	Mouth turns toward stimulus
Grasp	Touch palm between thumb and index finger	Patient grabs examiner's hand
Palmomental	Scratch palm diagonally	Ipsilateral chin muscle (mentalis) contraction

Summary: UMN vs. LMN Pattern

Feature	UMN Lesion	LMN Lesion
Tone	Increased (spasticity)	Decreased (flaccidity)
Reflexes	Hyperreflexia, clonus	Hyporeflexia / areflexia
Babinski	Positive (extensor)	Absent (normal plantar flexion)
Atrophy	Minimal	Significant, early
Fasciculations	Absent	Present
Weakness pattern	Pyramidal distribution	Segmental / dermatomal

Sources: Harrison's Principles of Internal Medicine 22E, pp. 3424–3425 · Bradley and Daroff's Neurology in Clinical Practice · Textbook of Family Medicine 9e, p. 1214 · Adams and Victor's Principles of Neurology, 12th Edition, p. 174

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