Neurological Exam: Still Important After All These

Years

Eric Kraus, MD

Neurology

Neurological “Levels”

Brain Brain stem Spinal cord Motor neuron Peripheral nerve Neuromuscular junction Muscle

Case 1

This is a 62 year-old male with chronic right leg weakness progressing over 6 months.

How do you use the motor exam to localize the problem to either a peripheral or central process?

Motor Exam

Strength Tone Bulk Fasciculations

MOTOR HOMUNCULUS

UPPER MOTOR NEURON

LOWER MOTOR NEURON

MUSCLE

Motor Exam

Central (UMN) Peripheral (LMN)

Strength Decreased Decreased

Tone Spasticity Normal or decreased

Bulk Normal Atrophy

Fasciculations No Yes (motor neuron dis., PN)

Case 1 Revisited

This is a 62 year-old male with chronic right leg weakness progressing over 6 months.

Does changing the history to acute right leg weakness over one day change your findings?

Central (UMN) Peripheral (LMN)

Strength Decreased Decreased

Tone Spasticity Normal or decreased

Bulk Normal Atrophy

Motor Exam

Grading» 5 = normal» 4 = weak with resistance» 3 = antigravity w/o resistance» 2 = less than antigravity» 1 = twitch» 0 = none

Grade only full effort Isolate each muscle

Functional testing Pronator drift Arm rolling test Hoover sign Spasticity in legs Bulk - symmetry and

experience

Case: Facial Weakness

Forehead has bilateral innervation Central weakness

» Pyramidal system» Forehead spared» Palpebral fissure normal

Peripheral weakness» 7th cranial nerve (Facial)» Forehead involved» Palpebral fissure large

– Not ptosis!

» Hyperacusis» Abnormal taste» Mastoid pain

III

CN7

CENTRAL

R

R

L

L

Case 2

This is a 62 year-old male with chronic bilateral leg weakness progressing over 6 months.

How do you use the reflex exam to localize the problem to either a peripheral or central process?

Reflex Exam

Central Peripheral

Reflexes Increased Decreased

Plantar stimulation Upgoing toe Downgoing toe

Upgoing toe = Babinski signUPPER MOTOR NEURON

LOWER MOTOR NEURON

MUSCLE

GOLGI RECEPTOR SENSORY NERVE

Reflexes Revisited

This is a 62 year-old male with chronic bilateral leg weakness progressing over 6 months.

Would changing the history to acute bilateral leg weakness over one day change your findings?

Central Peripheral

Reflexes Increased Decreased

Plantar stimulation Upgoing toe +/- Downgoing toe

Reflex Exam

Grading» 4 = Clonus» 3 = Hyperactive» 2 = Average» 1 = Hypoactive» 0 = none

Symmetry is critical Threshold testing Augmentation

0 3

1 3

0 2

2 2

2+ 2

Reflex Exam

Downgoing» “Mute” symmetrically is normal

Upgoing» Whole leg may flex» Reproducible

Withdrawal?» Movement at ankle, knee and hip» Variable movement» Decrease stimulation may help

Case 3

This is a 48 year-old woman with 2 years of numbness in her feet.

How do you use the sensory history and exam to localize the problem to either a peripheral or central process?

Sensory Exam

Posterior columns» Vibration» Proprioception» Light touch

Spinothalamic tract» Pain» Temperature

DORSAL ROOT GANGLION

POSTERIOR COLUMNSPINOTHALAMIC TRACT

SENSORY HOMUNCULUS

THALAMUS

Sensory Exam

Brain» Hemisensory

Brain stem» Hemisensory» Crossed face - body

Spinal cord» Sensory level» Separation of posterior column -

spinothalamic Peripheral nerve

» Symmetric - length dependent» Symmetric - proximal and distal» Focal or multifocal

DORSAL ROOT GANGLION

POSTERIOR COLUMNSPINOTHALAMIC TRACT

SENSORY HOMUNCULUS

THALAMUS

TRIGEMINAL NERVE

Sensory Exam Subjective Tuning fork Proprioception Sharp stick or pin Romberg Other “cortical” tests

Examples: Sensory

This is a 71 year-old woman with diabetes mellitus who noted onset of numb feet 6 months ago. On exam she can’t feel vibration until the ankle and light touch normalizes at the mid-shin.

Diabetic, length-dependent, peripheral neuropathy.

Examples: Sensory

This is a healthy 31 year-old construction worker who noted onset of numb hands 3 months ago. On exam he has decreased light touch in the thumb, index and middle fingers.

Carpal tunnel syndrome.

Examples: Sensory

This is a healthy 25 year-old woman with subacute onset of numbness from the abdomen down, weak legs, and urinary retention starting 2 days ago. On exam she has a T10 sensory level to pinprick.

T10 transverse myelitis.

Examples: Sensory

This is a healthy 25 year-old woman with subacute onset of numbness from the abdomen down, and weak right leg starting 2 days ago. On exam she has a T10 sensory level to pinprick on the left, and loss of vibration in the right leg.

T8 multiple sclerosis plaque on the right.

Examples: Sensory

This is a 80 year-old man with diabetes mellitus, HTN and hyperlipidemia who noted acute onset of left face/arm/leg numbness 2 hours ago. On exam he has decreased light touch on the left.

Right thalamic stroke.

Case 4

This is a 22 year-old female who feels clumsy.

How can you tell if poor coordination localizes to the cerebellum?

Cerebellar Exam

Very difficult exam» Finger-nose-finger» Heel-knee-shin» Rapid alternating movements » Tandem gait

Interfering issues» Weakness» Sensory loss» Vertigo» Normal imperfection» Side-to-side differences

Case 5

This is a 65 year-old male who keeps bumping into furniture on the left and crashed his car when turning left.

Can bedside visual field testing pick up a defect?

Visual Field Exam

Monocular blindness

Bitemporal hemianopia

Left homonymous hemianopia

Left superior quadrantanopia

Left homonymous hemianopia with central sparing

Visual Field Exam

Methods:» Static» Kinetic

Good (+)LR = 4.2-6.8 Poor (-)LR: Absence of

a defect does not rule one out

Arcuate defect

Case 6

This is a 63 year-old male with trouble walking.

How do you use the gait exam to localize the problem to either a peripheral or central process?

Gait Exam

Peripheral» Nerve

– Peripheral neuropathy

» Muscle– Muscular dystrophy

» Vision– Macular degeneration

» Vestibular– Meniere’s disease

» Joint– Hip arthritis

Central» Pyramidal

– Stroke

» Extrapyramidal– Parkinson disease

» Frontal lobes– Normal pressure hydrocephalus

» Cerebellar– Multiple sclerosis

» Psychiatric– Conversion disorder

Gait Exam

Walk down the hall

Motor Reflexes Sensory Cerebellar Vision

Gait Exam

Peripheral» Nerve

– Foot drop or steppage gait

» Muscle– Trendelenburg or

waddle gait

» Vision» Vestibular» Joint

– Antalgic gait

Gluteus medius

Gait Exam

Central» Pyramidal

– Hemiparetic or circumduction gait

» Extrapyramidal– Shuffling gait

» Frontal lobes» Cerebellar

– Ataxic gait

» Psychiatric

Case: Writing Trouble

Patient 1» Progressive for 2 months» Slow hand movements» No sensory loss

Patient 2» Progressive for 2 months» Slow hand movements» No sensory loss

Writing Trouble

Patient 1» Progressive for 2 months» Slow hand movements» No sensory loss» Right arm 4/5 + drift» Increased reflexes right arm» Action tremor

Patient 2» Progressive for 2 months» Slow hand movements» No sensory loss» No weakness or drift» Normal reflexes» Tone increased (cogwheel)» Rest tremor

Writing Trouble

Patient 1» Progressive for 2 months» Slow hand movements» No sensory loss» Right arm 4/5 + drift» Increased reflexes right arm» Action tremor

Patient 2» Progressive for 2 months» Slow hand movements» No sensory loss» No weakness or drift» Normal reflexes» Tone increased (cogwheel)» Rest tremor

Pyramidal: Brain tumor Extrapyramidal: Parkinson disease

Summary

The neurological exam is not any one part, but rather, the addition of multiple parts to localize the lesion.

Brain Brain stem Spinal cord Motor neuron Peripheral nerve Neuromuscular junction Muscle

CENTRAL

PERIPHERAL

END