Neurology Nerve Provoking no Pons intended

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Neurology Nerve Provokingno Pons intended

• Student Grand Rounds April 23rd,2008.

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Neurology Motor PE Mantra

• Look
• Tone
• Power
• Co-ordination
• Reflexes

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Look

• Rash
• Erythema
• Deformity
• Atrophy
• Swelling
• Shakes (fasciculations)

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Tone

• spasticity (clasp knife)
• velocity dependent
• assessed by a quick flexion/extension of the knee
  or the elbow or quick supination/pronation of the
  arm
• feature of an UMN lesion and maybe minor
• Accompanying features may include
• Spasms
• Clonus
• Increased deep tendon reflexes
• Extensor plantar response.

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Tone (cont.)

• rigidity (lead pipe)
• continuous and not velocity dependent
• continuous resistance to passive movement
• may be continuous or ratchety (cogwheeling)
• movement should be performed slowly
• seen in extrapyramidal disorders such as
  Parkinsons disease

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Tone (cont.)

• hypotonia (flaccidity)
• decreased tone
• more difficult to appreciate
• seen with LMN or cerebellar lesions

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Power

• power is tested by comparing the patients
  strength against your own
• start proximally and move distally
• compare one side to the other
• grade strength using the Medical Research Council
  (MRC) scale

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Co-ordination

• To perform tasks of co-ordination one requires
  normal motor, sensory, and cerebellar systems
• Lesions affecting any of these areas could give
  rise to abnormal tests of co-ordination
• Upper extremities
• Finger nose
• Lower extremities
• Toe finger

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Reflexes

• Deep tendon reflexes tested
• Upper extremities
• biceps (C5, C6)
• brachioradialis (C5, C6)
• triceps (C6, C7)
• finger flexors (C6-T1)
• Lower extremities
• knee or patellar (L2, 3, 4)
• ankle (S1, S2)
• Babinski
• Reflexes are graded using a 0 to 4 scale
• Except Babinski

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UMN vs. LMN Lesions

• UMN
• Hypertonia
• Hyperreflexia
• Weakness
• No wasting (initially)
• LMN
• Hypotonia
• Hyporeflexia
• Weakness
• Wasting
• Fasciculations

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Case 1

• 23 year old
• Female
• Post-op (thyroidectomy)
• Presenting with hoarseness of voice

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• VS
• Normal
• PE
• Surgical wound healed no signs of infection
• No focal neurological signs
• Checking for signs of hypocalcaemia due to
  removal of parathyroid glands
• Chvosteks sign and Trousseaus sign ve

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• FBC
• normal
• Electrolytes
• normal (no hypocalcemia)
• Creatinine
• normal
• BGL
• normal
• Diagnosis
• Damage to recurrent laryngeal nerve

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Recurrent Laryngeal Nerve

• Branches of vagus (X) nerve
• Loop around
• Subclavian artery on R
• More susceptible to damage because of more medial
  position
• Aortic arch on L
• Near thyroid and pass in front, behind or between
  branches of inferior thyroid artery
• Supply
• All laryngeal muscles except cricothyroid
  (supplied by superior laryngeal nerve)
• Subglottis sensation

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Vagus (X) The Wanderer

• Mixed nerve
• Somatic Motor
• Nucleus Ambiguus
• Visceral Motor
• Dorsal Motor Nucleus
• Visceral Sensory
• Nucleus Solitarius
• Somatic Sensory
• Sensory Nucleus V

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• Somatic Motor
• Pharynx (swallowing)
• Larynx
• Levator veli palatini
• Visceral Motor
• Thoracic and abdominal viscera
• Visceral Sensory
• Epiglottis (taste)
• Pharynx
• Larynx
• Trachea
• Oesophagus
• Thoracic and abdominal viscera
• Somatic Sensory
• External ear, posterior 1/3 of tongue

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Case 2

• 45 year old
• Male
• Diabetic ? poorly managed
• Presents to ED with fear of having had a stroke
• Unable to move R side of face
• Cannot blink R eye
• Cannot seal lips

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• PE
• R sided facial muscles flaccid
• Under forced closure of eye, eye-ball rotates
  upward (Bells phenomenon)
• Cognitive function normal
• When asked to smile right side of mouth remails
  flaccid

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• FBC normal
• Electrolytes normal
• LFTs normal
• BGL hyperglycaemic
• Diagnosis
• Bells palsy

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Bells Palsy

• Most patients presenting to the ED ? ?stroke
  ?intracranial tumor
• The most common complaint is of weakness on one
  side of their face
• Postauricular pains
• 50 of patients experience pain in the mastoid
  region
• frequently occurs simultaneously with the
  paresis, but precedes the paresis by 2-3 days in
  25 of patients
• Tear flow
• 2/3 of patients complain about tear flow
• due to reduced function of the orbicularis oculi
  in transporting the tears
• fewer tears arrive at the lacrimal sac and
  overflow occurs
• production of tears is not accelerated
• Altered taste
• only 1/3 of patients complain about taste
  disorders, four fifths of patients show a reduced
  sense of taste
• may be explained by only half the tongue being
  involved
• Dry eyes
• Hyperacusis
• Impaired tolerance to typical levels of noise due
  to an increased irritability to the sensory
  neural mechanism

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• Most cases are idopathic
• Complication of
• Diabetes
• Sarcoidosis
• AIDS
• Lyme Disease
• Tumours
• Treatment
• Corticosteroids antivirals eye care

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Facial Nerve (VII)

• Mixed nerve
• Somatic Motor
• Facial Nucleus
• Visceral Motor
• Superior Salivatory Nucleus
• Visceral Sensory
• Nucleus Solitarius
• Somatic Sensory
• Sensory Nucleus V

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• Somatic Motor
• Muscles of facial expression, stapedius
• Visceral Motor
• Lacrimal gland, submaxillary and sublingual
  glands
• Visceral Sensory
• Anterior 2/3 of tongue - taste
• Somatic Sensory
• External ear

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Examination of VII

• observe for asymmetry
• widening of the palpebral fissure
• flattening of the nasolabial fold
• observe for involuntary facial movements
• ask the patient to wrinkle their forehead by
  raising their eyebrows and close their eyes
  tightly
• observe for asymmetry of ability to burry the
  eyelashes and palpate for differences of ability
  to resist eye opening
• ask the patient to show their teeth, puff out
  their cheeks and appose their lips
• recall that the efferent limb of the corneal
  reflex (see trigeminal nerve) is through the 7th
  cranial nerve.

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Examination VII (cont.)

• Normal Response
• although patients may have an asymmetric face,
  there should be no facial weakness
• Abnormal Response
• LMN weakness causes weakness of the entire side
  of the face with equal involvement of upper and
  lower facial muscles
• UMN lesion of the contralateral supranuclear
  pathway results in weakness primarily of lower
  muscles of facial expression
• the upper muscles of facial expression (frontalis
  and orbicularis oculi) are much less affected
  because the facial nucleus that innervates them
  receives partial input from the ipsilateral
  hemisphere

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Case 3

• 75 year old
• Male
• Difficulty swallowing (dysphagia)
• Worsened over past several months
• Increased pain during urination (dysuria)
• Difficulty starting the flow of urine

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• VS
• normal
• PE
• weakness of R pharyngeal and laryngeal muscles
• Atrophy of sternocleidomastoid and trapezius
• DRE ? rock hard, fixed mass in prostate

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• PSA
• markedly increased
• Increased acid phosphatase and alkaline
  phosphatase
• CT
• mass in neck near jugular foramen
• TRUS biopsy
• high-grade prostatic adenocarcinoma
• Diagnosis
• prostate cancer with metastases to axial skeleton

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Glossopharyngeal (IX)

• Mixed nerve
• Somatic Motor
• Nucleus Ambiguss
• Visceral Motor
• Inferior Salivatory Nucleus
• Visceral Sensory
• Nucleus Solitarius
• Somatic Sensory (medulla)
• Sensory Nucleus V

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• Somatic Motor
• Stylopharyngeus (swallowing)
• Visceral Motor
• Parotid gland
• Visceral Sensory
• Posterior 1/3 of tongue (taste)
• Pharynx
• Carotid body and sinus
• Somatic Sensory
• External ear, posterior 1/3 of tongue

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Examination of IX and X

• IX and X are tested together
• check palatial elevation by having the patient
  sustain an "ah"
• when observing palatal movement, look at the
  palate rather than the uvula
• assess the gag reflex by gentling stroking the
  soft palate on each side
• swallowing can be assessed by giving the patient
  a sip of water and observing them swallow
• listen to the patients speech. Is there a nasal
  quality?
• assess palatal articulation with a "KA" sound,
  guttural with a "GO" sound and labial with a "PA"
  sound.

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Exam. IX and X(cont.)

• Normal Response
• the palate should elevate symmetrically, both
  when sustaining an "AH" and in response to
  stimulation on either side
• some patients however do not have a gag response
  and this can be normal if it is absent
  bilaterally
• patients should also be asked if they feel the
  stimulus.
• Abnormal Response
• with unilateral palatal weakness, the palate
  fails to elevate on the weak side and the gag
  reflex will be absent on that side

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Spinal Accessory (XI)

• Somatic Motor
• Starts as a spinal nerve that enters the skull
  via the foramen magnum, meets up with X and exits
  via jugular foramen
• Only cranial nerve to enter and exit the skull
• Sternocleidomastoid
• Trapezius

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Examination of XI

• observe for atrophy or asymmetry of the muscles
• observe for quickness of shoulder shrug and ask
  the patient to shrug their shoulders against
  resistance
• ask the patient to turn their head to the
  opposite side against resistance, both watch and
  palpate the sternocleidomastoid muscle
• ask the patient to flex their head forward
  against resistance, placing your opposite hand
  against the back of the head gently to support
  the patients neck

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Case 4

• 28 year old
• Male
• 2 days ago
• strange movements of tongue
• Cannot stick tongue out normally
• HIV ve for 2 years

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• VS
• Normal
• PE
• L side of tongue appears
• Atrophied
• Flaccid
• Fasiculations present
• When asked to protrude tongue deviates to L
• Deviates to affected side due to unopposed action
  of contraction of contralateral genioglossus
  muscle
• Diagnosis
• Cervical lymphadenitis impinging on XII

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Hypoglossal (XII)

• Somatic Motor
• Tongue
• Hypoglossal nucleus
• Exits anterior to inferior olivary nucleus
• All other CNs in medulla exit posterior to the
  olive

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Examination of XII

• observe for tongue atrophy or enlargement
• ask the patient to protrude the tongue
• ask the patient to push the tongue into each
  cheek or alternatively to protrude the tongue and
  push it laterally against a tongue depressor
• ask the patient to move the tongue quickly from
  side to side
• if there is facial weakness, correct this by
  supporting the upper lip on the side of weakness
• otherwise there may appear to be deviation of the
  tongue but once the facial weakness is corrected
  for, the tongue will no longer appear to deviate

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Examination of XII (cont.)

• Normal Response
• the tongue should be able to protrude relatively
  straight
• Minimal degrees of deviation (i.e. only
  millimeters) affecting only the tip are
  insignificant
• Abnormal Response
• with tongue weakness, the tongue deviates towards
  the weak side.