OnExam

Mental Status

Cranial Nerves

  • I – Olfactory
    • Test sense of smell in each nostril while occluding contralateral nostril
  • II – Optic
    • Visual acuity in each eye independently with best corrected vision using Snellen eye chart
    • Fundoscopy
      • Disc
        • Sharpness or clarity of disc outline
        • Colour of disc
        • Size of the central physiological cup
        • Comparative symmetry
      • Retina-arteries, veins, fovea, macula
    • Visual fields, one eye at a time
      • Test visual fields in four quadrants moving your hands in a fishbowl pattern from the patient towards you
  • II, III – Optic, Oculomotor
    • Pupillary reactions
      • Symmetry and size of pupils
      • Pupillary reaction to light: direct and consensual
      • Near response to accommodation
  • III, IV, VI - Oculomotor, Trochlear, Abducens
    • Extraocular movements
    • Superior oblique = CN IV, lateral rectus = CN VI
      • LR6SO4
    • Look for nystagmus, ptosis, lid lag, dysconjugate gaze, and convergence of eyes.
    • Ask patient if they experience any diplopia with EOM
  • V – Trigeminal
    • Motor
      • Muscles of mastication
      • Palpate temporalis and masseter muscles with jaw clenched
    • Sensory
      • Pain: alternate sharp and dull
      • If abnormal, test temperature alternating hot and cold
      • Light touch
    • Corneal reflex using corner of tissue with patient looking up and away
      • Sensory: CN V
      • Motor: CN VII
  • VII - Facial
    • Ears (stapedius), tears (lacrimation), taste (anterior 2/3 of tongue unilateral), face (5 motor branches)
    • Noting weakness/asymmetry
      • Raise both eyebrows
      • Close eyes tightly (orbicularis oculi), resist examiner opening
      • Smile
      • Frown
      • Show top and bottom teeth
      • Puff out both cheeks
  • VIII – Vestibulocochlear
    • Whisper test while occluding one ear
    • Weber test for lateralization (512 Hz)
    • Rinne test for air and bone conduction (512 Hz)
  • IX, X - Glossopharyngeal and Vagus
    • Voice for hoarseness
    • Difficulty swallowing
    • Movements of soft palate for symmetry
    • Gag reflex
    • Glossopharyngeal also carries taste from posterior 1/3 of tongue
  • XI - Spinal accessory
    • Trapezius muscle: shrug both shoulders upwards against resistance
    • Sternocleidomastoid muscle: patient turns head each direction against resistance of hand
    • Inspect for fasciculations or atrophy; compare bilaterally
  • XII - Hypoglossal
    • Articulation of the patient’s words
    • Ask patient to protrude tongue
      • Atrophy or fasciculations
      • Deviation from midline: away from cortical lesion
      • Movements from side to side
      • Ask patient to push tongue against the inside of each cheek while palpating externally; note strength and symmetry

Motor Function

  • Muscle Strength
    • Use a scale of 0-5 when assessing muscle power
    • 0 - No muscle contraction detected
    • 1 - Barely detectable flicker or trace of contraction
    • 2 - Active movement of the bady with gravity eliminated
    • 3 - Active movement against gravity
    • 4 - Active movement aagainst gravity with some resistance
    • 5 - Active movement against full resistance without evident fatigue. This is normal muscle strength
  • Meningismus: physical findings that develop after miningeal irritation from inflammation, tumour, or hemorrhage
  • A more detailed muscle strength assessment can be found here

Cerebellar Function

  • Four physical signs are fundamental to cerebellar disease: ataxia, nystagmus, hypotonia, and dysarthria
  • Ataxia: uncoordinated voluntary movements that lack the speed, smoothness, and appropriate direction seen in normal persons.
  • Tests of ataxia: gait analysis, finger-to-nose, heel-knee-shin, rapid alternating movements

Sensory Testing

  • Testing pain sensation has a better chance of detecting subtle radiculopathies and peripheral nerve disorders compared to light touch testing
  • Diminished pain sensation (tested with a safety pin) detects small nerve fiber loss with a sensitivity of 88%, specificity of 81%
  • Vibration sensation
    • Often first sensation to be lost in peripheral neuropathy

Assess the sensory system for increased, decreased, altered or absent sensations as indicated. Evaluate:

  • Light touch (spinothalamic tracts and posterior columns)
  • Pain and temperature (spinothalamic tracts)
  • Vibration and position (posterior column)
  • Discriminative sensation (sensory cortex)
Key upper extremity dermatomes:
  • C4 – Top of shoulder
  • C5 – Sargeant’s patch (lateral deltoid)
  • C6 – Thumb webspace and top of forearm
  • C7 – Middle finger
  • C8 – Little finger
  • T1 – Medial forearm and medial elbow
Key lower extremity dermatomes:
  • L2 – Oblique pattern lateral to medial upper thigh proximal to groin
  • L3 – As above mid-thigh
  • L4 – Over knee
  • L5 – Great toe webspace
  • S1 – Lateral foot and ankle
  • S2 – Medial calf
Ask the patient to close their eyes and then assess symmetric areas on each side of the body for:
  • Light touch sensation:
    • Ask the patient to identify every time a touch is felt
    • Touch the patient’s skin with a wisp of cotton and with eyes closed identify when their skin is being touched
  • Pain sensation
    • Ask the patient to identify every time whether the object they feel is sharp or dull
    • Using a broken tongue depressor, paper clip, or pin, apply pressure to the patient’s skin
    • Randomly substitute sharp and blunt ends of object as you move along the various dermatomes
  • Temperature
    • Often assessed only if sensory deficits present during pain testing
    • Ask the patient to identify every time whether the object they feel is hot or cold
    • Using two test tubes (filled with hot and cold water), apply pressure to the patient’s skin
    • Randomly substitute sharp and blunt ends of object as you move along the various dermatomes
  • Vibration sensation
    • Tap and place a 128 Hz tuning fork on the patient’s bony prominences, starting with the distal joints of the extremities
    • Accuracy may be improved by having patient close eyes and determine when vibration stars/stops (as you manually stop the fork)
  • Position sensation (proprioception)
    • Assess position by grasping patient’s finger or toe at its sides and moving it up or down
    • Grasp the patient’s finger or toe at its sides and move it upward or downward
    • If proprioception is abnormal distally work your way to the more proximal joints
  • Discriminative sensations
    • Stereognosis
    • Graphesthesia
    • Two-point discrimination
    • Point localization
      • Touch a point on the patient’s skin
      • Ask the patient to open their eyes and point to the area touched
      • Inability to localize points accurately is considered a positive finding
    • Extinction
      • Touch a point on the patient’s skin equally on both sides of the body at the same time
      • Ask the patient to open their eyes and point to the area touched
      • Recognition of only one stimulus is considered a positive finding; the side of the extinguished stimulus is opposite that of the damaged cortex

Deep Tendon Reflexes


Assess for hypoactive or absent reflexes (hyporeflexia) seen in lower motor neuron lesions, or hyperactive reflexes (hyperreflexia) seen in upper motor neuron lesions.
  • Have patient relax and position limbs properly according to the reflex
  • Hold reflex hammer loosely and strike tendon briskly with rapid wrist movement
  • Distracting patient if they are tense may be helpful, fingers of the two hands are locked together and one hand pulls agaisnt the other while you perform the reflex.
  • Note the amplitude and symmetry of all reflexes tested using the following scale:
    • 0 – Absent
    • 1+ – Depressed
    • 2+ – Normal
    • 3+ – Increased
    • 4+ – Clonus

Biceps Reflex (C5, C6)

  • Place your thumb on the patient’s bicep tendon in the elbow crease with the patient’s elbow slightly flexed
  • Strike your thumb directly with reflex hammer and note contraction of the biceps muscle and flexion at the elbow

Triceps Reflex (C7)

  • Flex the patient’s arm at the elbow
  • Strike the triceps tendon above the olecranon process and note contraction of the triceps muscle extension at the elbow

Brachioradialis Reflex (C6)

  • Have patient rest his or her hand on their lap with the forearm slightly pronated
  • Strike the radius 1-2 inches proximal to the wrist and watch for flexion and supination of the forearm

Knee Reflex (L4)

  • Ensure the patient's knee is flexed
  • strike the patellar tendon just below the patella and note contraction of the quadriceps and extension of the knee

Ankle Reflex (S1)

  • Dorsiflex the patient's foot at the ankle
  • Strike the Achilles tendon and note plantar flexion at the ankle
  • If hyperactive reflex present, assess for ankle clonus

Plantar Response

  • Use a tongue depressor or back end of reflex hammer to stroke the sole of the foot
  • Begin at the heel and briskly move up to the ball of the foot and finish medially at the big toe
  • Plantar flexion of the toes is expected
  • Babinski response: dorsiflexion of great toe suggesting CNS lesion in corticospinal tract (upper motor neuron)

Abdominal Reflex (T8-10 above umbilicus, T10-12 below)

  • With the patient lying down, use a tongue depressor to briskly but lightly stroke each side of the abdomen above and below the umbilicus (four quadrants)
  • Muscle contraction and movement of the umbilicus in the direction of the stimulus is expected

Anal Reflex (anal wink, S2, S3, S4)

  • Stroke outward in four quadrants from anus with cotton swab watching for muscle contraction
  • Anal sphincter contraction is expected

References

  1. Bickley, Lynn S. Bates' Guide to Physical Examination and History Taking. 8th ed. Philadelphia, PA: Lippincott Williams & Wilkins: 2003.
  2. Lincoln, Matthew, McSheffrey eds. Essentials of Clinical Examination Handbook. 6th ed. Toronto, ON: University of Toronto Medical Society: 2010.