CNS Examination

Done ByAbdullah Mohd. Jan

6th year medical student-2007

Aspects of Examination

1. General 2. The cranial nerves3. The upper limbs ( Motor + Sensory + coordenation )4. The lower limbs ( Motor + Sensory + coordenation)5. The skull and spine for local disease6. The carotid arteries for bruits

General Examination

• Assessment of the higher centers

• Speech ( reception & production )

• Neck stiffness

• Abnormal movements

General Examination1. Assessment of the higher centers • Consciousness • Orientation ( Person , Place , Time )

• Cognetion • Memory asses both short & long term memory

• Handedness to determine the dominant hemisphere

2. Speech ( reception & production )• Flow of speech• Comprehension (yes – No)

• Repetition

3. Neck stiffness looking for meningism ( meningitis – sub

arachnoid haemorrhage

• Abnormal movements

Cranial Nerves Examination

• you have to know how to examine all cranial nerves in detail but we will focus on the most important ones ( 3rd , 4th , 5th , 6th , 7th , 11th & 12th ) .

• You have to know the location of the nuclei of the cranial nerve as it gives you a hint about the site of the lesion.

• 3rd & 4th cranial nerves are located in the mid brain

• 5th , 6th , 7th & 8th cranial nerves are located in the pons

• 9th , 10th , 11th & 12th cranial nerves are located in the medulla oblongata

• Inspection of pupil• Light reflex• Eye Movement & nystagmus• Convergence & accomodation

CN III, IV, VI: Oculomotor, Trochlear, Abducent

• Look at pupils: shape, relative size, • ptosis.• Shine light in from the side to look for

pupil's light reaction.• Assess both direct and consensual responses.• Assess afferent pupillary defect by moving light in arc from pupil to pupil. 

• "Follow finger with eyes without moving head": test the 6 cardinal points in an H pattern.• Look for failure of movement, nystagmus [pause to check it during upward/ lateral gaze].

• Convergence by moving finger towards bridge of pt's nose.

• Test accommodation by pt looking into distance, then a hat pin 30cm from nose.

• Sensory • Motor• Reflex (deep + superficial)

CN V: Trigeminal

• Facial sensation: sterile sharp item on forehead, cheek, jaw.• Repeat with cotton at the same parts.

• Motor: pt opens mouth, clenches teeth (pterygoids).• Palpate temporal, masseter muscles as they clench.

• Test jaw jerk: – Dr's finger on tip of jaw. – Grip patellar hammer halfway up shaft and

tap Dr's finger lightly.

– Usually nothing happens, or just a slight closure.

– If increased closure, think UMNL, esp  pseudobulbar palsy.

• Corneal reflex: patient looks up and away.• Touch cotton wool to other side.• Look for blink in both eyes, ask if can sense it.• Repeat other side [tests V sensory, VII motor].

• Inspection• Motor• Taste sensation

CN VII: Facial

CN VII: Facial• Inspect for facial droop or asymmetry.

• Facial expression muscles: pt looks up and wrinkles forehead.• looking for wrinkling loss.

• Pt shuts eyes tightly: compare each side.

• Pt smile: compare nasolabial grooves.

• Pt show teeth, puff out cheeks.

• Taste sensation in the anterior 2/3 of the tongue.

CN XI: Accessory• Inspection From behind, examine for

trapezius atrophy, asymmetry.

• Pt. shrugs shoulders (trapezius).

• Pt. turns head against resistance: watch, palpate SCM on opposite side.

CN XII: Hypoglossal

• Listen to articulation.

• Inspect tongue in mouth for wasting, fasciculations.

• Protrude tongue: unilateral deviates to affected side.

Motor system

don’t forget to compare both limbs • Inspection• Palpation ( muscle bulk + tenderness )• Muscle tone • Muscle power• Reflexes :. ( superficial + deep )

Motor system

1. Upper limbs (compare)• Inspect for muscle wasting ( proximal &

Distal ) – scars – deformity – fasciculation – skin pigmentation.

• Drift test

• Feel the muscle bulk ( proximally & Distally ) – muscle tenderness.

• Tone ( normo – hypo – hypertonia ) by passive movement of wrist and elbow

joints.

• Power ( 0 – 5 ) by active movement at the shoulder ,

elbow , wrists and fingers.

• Reflexes ( 0 - ++++ ) Biceps ( C5,C6 ) – Triceps ( C7,C8 ) –

Brachioradialis ( C5,C6 )

• Coordination Finger to nose test – Finger to finger test

– Dysdiadochokinesis – Rebound test

2. Lower limbs • Inspect the gait of the patient

• Expose both thighs and legs.

• Inspect for muscle wasting – scars – deformity – posture -fasciculation – skin pigmentation .

• Feel the muscle bulk and muscles for tenderness.

• Tone ( normo – hypo – hypertonia ) by passive movement of the knee and

ankle joints

• Clonus more than 3 ankle and knee clonus

• Power ( 0 – 5 ) by active movement at the hip , knee ,

ankle , and tarsal joints

• Reflexes ( 0 - ++++ ) Knee jerk ( L3,L4 ) – Ankle jerk (S1,S2 ) –

Plantar reflex ( L5, S1 , S2 )

• Coordination Heal to shin test –

Toe finger test – Foot tapping test

Sensory system• Spinothalamic pathway Pain and Temperature ( usually temperature is

not tested )

• Posterior column pathway Vibration and Proprioception Romberg Sign

• Light touch with cotton wool

Back

• Inspect for deformity – scars – neurofibromas .

• Palpate for tenderness over the vertebral bodies

• Do the straight leg raising test

Auscultation

• Auscultate over the carotid arteries looking for bruits.