introduction to neurological examination

INTRODUCTIONTO

NEUROLOGICAL EXAMINATION

Adrian PaceNeurology Registrar

Why neurological exam is different

1. The CNS cannot be directly palpated, percussed, auscultated etc, so its intactness is only induced indirectly via functional testing.

2. Major part of the exam is stimulus-response testing.

3. Exam findings must then be correlated with (1) patient symptoms and (2) knowledge of neuroanatomy to come to a diagnosis

DIFFICULTIES:

- Neuroanatomy is complex- Neurology covers a very wide area of disease- Exam very reliant on patient cooperation- Functional tests are potentially endless

IMPRESSIONS

- Neurology is medical ‘voodoo-land’- Neurologists all have OCD

(SOME) NEUROLOGICAL SYMPTOMS

• Headache• Dizzyness• Seizures• Altered

consciousness• Personality change• Memory loss• Weakness• Stiffness• Disordered sensation• Loss of vision• Loss of hearing• Loss of smell• Abnormal

movements• Speech problems• Swallowing problems

• Altered mobility• Sphincter control disorders• Sleep disorders• Facial palsy• Coordination difficulties

and so on.....

The GP The GP Practice Somewhere in Plymouth PL& $XY

Dear Neurology,

I would be grateful if you would see this gentleman/lady I am concerned about......

.....unexplained collapse........peculiar movements........history of funny turns.......possibly confused........ there might have been some weakness........

Neurological examination appeared grossly normal

Could there be something going on (aka a tumour??)

REFERRAL LETTER

1) Is there a problem ?- Presence of neurological abnormality

2) Where is the problem ?- Location of problem (CNS / PNS)

3) What is the problem ?- structural / chemical- intrinsic / extrinsic- benign / malignant

3 questions of neurological diagnosis

NOTE : THIS PRESENTATION

DOES NOT COVER HISTORY

• OBSERVE - gait - appearance - general inspection• Conscious state• Cognition• Head / Arms / Legs

- Cranial nerves- Motor (tone / power / reflexes)- Sensory- Coordination

Basic Plan

OBSERVATION

SOME ABNORMAL GAITS

• Spastic• Hemiparetic• Parkinsonian• Foot drop• Ataxic• Waddling (myopathic)

SOME ABNORMAL FACIES

ABNORMALITIES ON CLOSER INSPECTION

• Muscle wasting• Muscle fasiculations• Abnormal posture• Tremors• Involuntary movements

- Focal seizures- Chorea- Athetosis- Myoclonic jerks

LEVEL OF

CONSCIOUSNESS

Created to reflect measure of global brain function

Limited value, many processes selectively affect components

Omitted in OP settings, mainly used on acute admissions

COGNITION

MMSE

Broad screening test of cognitive functionincluding attention, memory, language

Good for diagnosing / monitoring certain types of dementia especially A.D.

Other types of dementia / cognitive problems require different tests

• “ Frontal” functions– Attention & concentration ( digit span ) – Abstraction ( explain proverb )– Judgment

• child lost in street..what would you do?– Planning

• How to plan a holiday / draw a clock

• Neglect – Failure to pay attention to area of space (usually due to

parietal lesions with neglect of contralateral space.

• Praxis:– ability to perform learned action (e.g. dressing , combing

hair)

• ‘Frontal release’ signs during neuro exam

Glabellar tap Rooting Pouting

GraspingPalmomental reflex

CRANIAL NERVES

• I - smell (rarely tested)

• II - Acuity (Snellen chart)- Fundi- Fields ( confrontation)- Pupils

• III, IV, VI- Ptosis- Movement- Saccades and smooth pursuit- Diplopia / Nystagmus

• V - Facial sensation

- Muscles of mastication- Jaw jerk- Corneal reflex

Afferent = VEfferent = VII

• VII - Muscles of facial expression - Taste ant 2/3 tongue - Tensor Tympani

• VIII - Nystagmus - Hearing

• IX, X - Say ahh (X) - Gag reflex

• XI - sternocleidomastoid & trapezius

• XII ( tongue) - Observation ( atrophy, fasciculations) - Protrusion (?deviated) - Power - Dexterity ( fast movement side-to- side)

THE MOTOR SYSTEM

• Cell body within motor cortex• Axon terminates :

– Cranial nerve motor nucleus (corticobulbar)

– Anterior horn of spinal cord (corticospinal)

Upper motor neurone

Lower motor neurone• Cell body of

– Motor cranial nerve nucleus– Anterior horn cell

• Axon terminates on neuromuscular junction

TONE• Reduced muscle tone.

• Increased tone: 1) SPASTICITY (ie pyramidal) 2) RIGIDITY (ie extrapyramidal)

POWER• The standard neurological examination involves testing power

of two movements at each joint (agonists and antagonists)

• The history may suggest more localised problems which require examination of individual muscles (eg nerve lesions of the hand)

MRC GRADING OF MUSCLE POWER

• GRADE 5: NORMAL POWER

• GRADE 4: WEAK BUT SOME RESISTANCE

• GRADE 3: JUST OPPOSES GRAVITY

• GRADE 2: MOVES BUT CANNOT OPPOSE GRAVITY

• GRADE 1: VISBLE/ PALPABLE MUSCLE FLICKER

• GRADE 0: NOTHING

PATTERNS OF WEAKNESS

• Weak arm and leg (same side): HEMIPARESIS

• Weak legs, normal arms: PARAPARESIS

• All four limbs weak: TETRAPARESIS

• One limb weak: MONOPARESIS

• Proximal muscle weakness

• Distal muscle weakness

EXAMPLES OF LESIONS CAUSING PATTERNS

• Hemiparesis: hemispheric stroke, tumour, abscess

• Paraparesis: spinal cord lesion below cervical spine

• Tetraparesis: cervical cord lesion

• Monoparesis: Tumour at brachial plexus

• Proximal weakness: myopathy

• Distal weakness: peripheral neuropathy

REFLEXESA reflex, is an involuntary and nearly instantaneous movement in response to a stimulus.

Reflex actions are mediated via the reflex arc, comprised of sensory neurone that perceives the stimulus signal and transfers the signal to inter neurone(s) in your spinal cord then out to motor neurone and to an effector, like muscle to react to the stimulus.

REFLEXESUPPER MOTOR NEURON LESIONS: increased tendon reflexes, reflex spread and extensor plantar responses

LOWER MOTOR NEURON LESIONS: reduced or absent reflexes. may be generalised eg neuropathy, or focal eg single nerve or root lesion

Upper Motor Neurone

Lower Motor Neurone

Inspection of muscles

Normal(disuse atrophy)

AtrophyFasciculations

Tone Increased (unless acute)

Decreased(or normal)

Power (MRC scale) decreased decreased

Tendon Reflexes Increased(unless acute)

Decreased or Normal

Pathological reflexes Present Absent

THE SENSORY SYSTEM

SENSORY EXAM

• VIBRATION – 128 hz tuning fork

• JOINT POSITION SENSE• PIN PRICK• TEMPERATURE

Start distally and move proximally

HIGHER CORTICAL SENSATIONS

• GRAPHESTHESIA• STEREOGNOSIS• DOUBLE SIMULTANEOUS STIMULATION• TEXTURES

COORDINATION

CO-ORDINATION

• Two main types of ataxia:• Cerebellar ataxia (lesions of the cerebellum

and its connections)• Sensory ataxia: peripheral neuropathies and

spinal cord lesions where dorsal columns are affected

COORDINATION TESTS

• Tandem gait• Romberg’s test• Finger to nose test• Rapid alternating movements (looking for

dysdiadochokinesis)• Heel to shin test

THANK YOU