Cranial nerves - glossopharyngeal vagus accessory and hypoglossal

1. Cranial Nerves - IX, X, XI, XII
Chair Person: Dr Chandrashekar K
Student: Dr Kiran Revankar

2. 3 , 4
5, 6, 7, 8
9, 10, 11, 12

4. Glosso Nervepharyngea
l
Tongue Pharyn
x

5. GLOSSOPHARYNGEAL NERVE IX.

6. NUCLEI OF GLOSSOPHARYNGEAL NERVE:
Ambiguus nucleus SVE
Inferior salivatory nucleus GVE
Nucleus of the solitary tract SVA
Nucleus of the spinal trigeminal tr. GSA

10. • Motor Nucleus - Rostral part of the nucleus ambiguus in dorsolateral
medulla
• The cortical innervation is bilateral
• Supplies- Stylopharyngeus
Motor function

11. Sensory function
Sensory neurons - located in superior and inferior glossopharyngeal
ganglia.
GVA - convey information from carotid body and carotid sinus, as well
as visceral sensation from the pharynx;
SVA - convey taste sensation.
GSA – convey exteroceptive sensation from the mucous membranes
of the tympanic cavity, mastoid air cells, and auditory canal via the
tympanic plexus and tympanic branch.

12. Parasympathetic function
• Supplies parasympathetic innervation to
parotid gland and to mucous membranes
of posterior inferior mouth and pharynx.
• Parasympathetic nuclei inferior salivatory
and the dorsal motor nucleus of CN X
(DMNX).

13. Clinical Examination 9th Cranial
Nerve
• Taste sensation of posterior 3rd of the
tongue
• Gag Reflex

15. Localisation of lesions 9th CN
• SUPRANUCLER
– Unilateral – No deficit
– Bilateral- Pseudobulbar palsy
– Severe dysphagia, pseudo-bulbar signs
(pathological laughter and crying, spastic
tongue, spastic dysarthria) , exaggerated gag
reflex.

16. • NUCLEAR AND INTRAMEDULLARY
– Include Syringobulbia, demyelinating disease,
vascular disease, MND and Malignancy.
– Commonly involve other cranial nerve and
other brainstem structure.

17. Right Cortex Left Cortex
N
UMN
LMN
SUPRANUCLER
Unilateral – No deficit
Bilateral- Pseudobulbar palsy
Severe dysphagia, pseudo-bulbar
signs (pathological laughter and
crying, spastic tongue, spastic
dysarthria) , exaggerated gag reflex.
NUCLEAR AND INTRAMEDULLARY
Include Syringobulbia, demyelinating
disease, vascular disease, MND and
Malignancy
• Extramedullary Lessions
• Lesions within Retropharyngeal
and Retroparotid space

18. • EXTRAMEDULLARY LESSIONS
– Cerebellopontine angle syndrome –
• CP angle tumors especially acoustic tumors
• Associated with tinnitus, deafness and vertigo (CN VIII),
facial sensory abnormalities (cranial verve V) and
cerebellar signs.
– Jugular foramen syndrome (Vernet syndrome)
• Injure CN IX, X and XI, which travel through this
foramen.
• Glomus jugulare tumors, neuroma, metastasis,
cholesteatoma, meningioma, infections and giant cell
arteritis.

19. – Lesions within Retropharyngeal and
Retroparotid space
• May be injured by neoplasm ( nasopharyngeal
carcinoma) abscesses, adenopathy, aneurysm,
trauma or surgical procedures carotid
endarterectomy).
• Collet-Sicard syndrome ( CN IX, X, XI and XII)
• Villaret syndrome (CN IX, X, XI and XII,
sympathetic chain and occasionally CN VII).

21. Glossopharyngeal Neuralgia
Attacks of severe
lancinating pain(throat-
>tonsils->ear
Pain lasting for seconds to
minutes may be brought
on by talking, eating,
swallowing, or coughing.
GN v/s JN

22. Carotid sinus hypersensitivity :Inadvertent
activation of baroreceptors in carotid sinus
causing bradycardia and hypotension.
• Sometime associated during
glossopharyngeal neuralgia attacks
• Other causes like tight collar, malignancy
in the neck impinging on sinus.

23. Vagus Nerve

24. The Vagus Nerve(“wandering”)
•The vagus is the longest and most
widely distributed cranial nerve.
•A mixed nerve

25. (SVE)
(SVA)
(GSA)
(GVE)

28. Vagus nerve innervates
With branchialmotor SVE fibers
- levator veli palatini,
- middle constrictor of the pharynx
- inferior constrictor pharynx
- muscles of the larynx and esophagus
With somatosensory fibers
- mucous membrane of the larynx,
- mucous membrane of the inferior part of the pharynx
- epiglottic vallecules
- posterior part of the dura mater
- posterior part of the skin of the external acustic meatus

29. With special viscerosensory fibers
- the taste buds around the epiglottic
General viscerosensory and visceromotor fibers
the larynx, trachea, oesophagus, bronchi,
lungs, heart and abdominal viscera from the stomach to the
left colic flexura

30. Motor function
• The supranuclear innervation is bilateral
(corticobulbar tracts)
• Corticobulbar tracts to synapse in the
nucleus ambiguus
• Innervates muscle of pharynx and larynx

31. Muscles of the Pharynx
Constrictor muscles
– Superior,
– middle
– Inferior
Palatopharyngeus
Salpingopharyngeus
Palatoglossus
Muscles of soft palate

32. Muscles of the Larynx

33. Sensory function
• Sensory nuclei located in superior and inferior ganglion
in jugular fossa
• GVA carry sensations from pharynx, larynx, trachea,
esophagus and thoracic and abdominal viscera
• SVA taste sensation from posterior most part of tongue
and epiglottis
• GSA pain, temperature, and touch sensation from the
pharynx, larynx, ear canal, external surface of the
tympanic membrane, and meninges of posterior fossa

34. • SVA taste sensation from posterior most
part of tongue and epiglottis
• GSA pain, temperature, and touch
sensation from the pharynx, larynx, ear
canal, external surface of the tympanic
membrane, and meninges of posterior
fossa

35. Parasympathetic function
• Vagus nerve is main parasympathetic
outflow to the heart and GI system
• Parasympathetic component of CN X
arises from the Dorsal Nucleus of Vagus

36. Branches of the vagus nerve
Thoracic part
- cardiac branches
- bronchial branches
- pericardiac branches
- oesophageal branches
Adominal part
- branches for the viscera
- gastric plexus
- hepatic plexus
- coeliac plexus
- renal plexus

37. • The Heart
– Cardiac branches arise in the thorax,
conveying parasympathetic innervation to the
sino-atrial and atrio-ventricular nodes of the
heart

38. • Gastro-Intestinal System
– Sends branches to the oesophagus, stomach
and most of the intestinal tract – up to the
splenic flexure of the large colon.
– Stimulate smooth muscle contraction and
glandular secretions in these organs.

39. Localisations of lesion 10th CN
• SUPRANUCLEAR LESIONS
– Unilateral – No deficit
– Bilateral- Pseudobulbar palsy

41. • NUCLEAR LESIONS AND BRAINSTEM
LESIONS
– Nuclear- result in ipsilateral palatal,
pharyngeal and laryngeal paralysis and
usually associated with affection of other CN
nuclei, roots and long tracts.
– Causes- Vascular, tumors, syringobulbia,
MND and inflammatory disease.

42. • LESIONS WITHIN POSTERIOR FOSSA
– Lesion at this location usually also involve the
CN IX, XI and XII.
– Causes include primary (Glomus jugulare)
and metastatic tumors, carcinomatous
meningitis, sarcoidosis, GBS and trauma.

43. LESIONS OF RECURRENT
LARYNGEAL NERVE
– Tumors in neck, especially carcinoma of the
thyroid, cervical adenopathy, metastatic
lesions, Hodgkin disease, lymphosarcoma,
– Aortic aneurysms
– Mitral stenosis with enlargement of the left
atrium
– Mediastinal and apical tumor
– Stab wounds in the neck, or accidental
trauma during a thyroidectomy or other
surgical procedure.

45. • UNILATERAL- flaccid dysphonia with
breathlessness and mild inspiratory
stridor; Diplophonia may occur. On
laryngoscopy paralyzed vocal cord lies
near midline.

46. • BILATERAL – cause abduction impairment
and leave the vocal cords approximating
each other in the midline. Results in
dyspnea and inspiratory stridor. Can be
seen after thyroidectomy or carcinoma of
thyroid or esophagus.

47. • LESIONS OF SUPERIOR LARYNGEAL
NERVE
– Damaged by trauma, surgery or tumor.
– Mild hoarseness due to paralysis of
cricothyroid.

48. Spinal Accessory Nerve

50. Introduction
•The spinal accessory
nerve- motor nerve.
•Smaller cranial
portion(SVE)
•Major part of CN XI is
the spinal portion(C1 to C5)

52. DISORDERS OF FUNCTION
• Weakness of the muscles supplied by CN XI
supranuclear nuclear infranuclear lesions

53. Supranuclear
• Lesions -Corticobulbar fibres at any level from
cortex to brainstem.
• Ipsilateral cortical control.
• Hemiparesis – head turns to opposite side of
paresis
• In seizure -head turns away from discharging
hemisphere

54. Right Left
S
C
M
S
C
M

55. • SCM and trapezius are
frequently involved in
cervical dystonia(focal
dystonia causing
torticollis, anterocollis,
or retrocollis).

56. Nuclear
• Lesions of the lower brainstem or upper
cervical spinal cord
• Weakness is frequently accompanied by
atrophy and fasciculations.
• Seen in motor neuron disease, syringobulbia,
and syringomyelia.

57. Infranuclear
Infranuclear(peripheral lesions)—Extra medullary but
within the skull, in the jugular foramen, or in the neck
• Tumors in the foramen magnum or along the clivus can
compress CN XI.
• Lesions of CP angle occasionally extend caudaly to
foramen magnum and involve CN XI(MC- neurinomas
of hypoglossal nerve.
• Neurinomas involving CN IX or X may extend to involve
CN XI.
Other intracranial, extra medullary neoplasms -
meningioma's and neurofibromas, which may
extend through jugular foramen in dumbbell
fashion.
Basal skull fractures, meningitis, or processes
at/just distal to the skull base give rise to a
number of syndromes reflecting involvement of
the lower CNs affecting both the SCM and the
trapezius.

58. • In the posterior triangle of neck, the SA nerve is very
vulnerable(lies superficially, covered only by skin and
subcutaneous tissue).
• MCC of SA neuropathy in the posterior triangle is
trauma(iatrogenic).
• Radical neck dissection, lymph node biopsy, carotid
endarterectomy.
• In one series of 111 patients with SA injury, 93% were
iatrogenic and 80% were from L.N. biopsy.
• Others- severe cervical adenopathy, neoplasms, trauma,
abscesses.

59. • Traction injury may occur when the shoulder
is pulled down and the head turned in the
opposite direction.
• Carrying heavy loads on the shoulder may
cause SA injury due to local trauma/stretch.

60. Brain stem syndromes
• Jackson’s syndrome- (vago-accessory-hypoglossal
paralysis) -Medullary tegmentum- CN X fibers or
nucleus ambigus; CNs XI and XII
 Ipsilateral flaccid paralysis of soft palate, pharynx, and
larynx; flaccid weakness and atrophy of SCM, trapezius
(partial), and tongue
• Schmidt’s syndrome-(vago-accessory syndrome)-
Lower medullary tegmentum -Nucleus ambiguus;
bulbar and spinal nuclei of CN XI and/or their radicular
fibers
 Ipsilateral paralysis of soft palate, pharynx, and larynx;
flaccid weakness and atrophy of SCM and trapezius
(partial)

61. Tapia’s syndrome- Retroparotid space CN X; XII; +/− XI;
carotid sympathetics Weakness in the distribution of
involved nerves; Horner’s syndrome
tumor of parotid or skull base; occasionally carotid
aneurysm

63. Hypoglosal Nerve

64. Derived its name from ancient Greek,
‘hypo’ meaning under
‘glossal’ meaning tongue.
12th cranial nerve
Also called as final nerve
Purely somatic motor function, innervating the majority of the
muscles of the tongue.
Role in speech, mastication, swallowing, and airway protection.

66. Hypoglossal nerve
Innervates: all the extrinsic and intrinsic muscles of the tongue

68. DEEP ANSA CERVICALIS

69. Supranuclear control
• Originates in the inferior portion of the
precentral gyrus.
• Then course along with, and rostral to, the
corticospinal fibers through the internal
capsule, the cerebral peduncle, and into the
pons.
• Decussation of these fibers occurs in the
Ponto medullary junction.
• Fibers enter laterally each hypoglossal
nucleus, and provide bilateral, but primarily
crossed.
• Genioglossus muscle, which is solely
innervated by the contralateral corticobulbar
tract.

70. Movements and strength
• After noting the position and appearance
of the tongue at rest in the mouth, the
patient is asked to protrude it.
• Move it in and out, from side to side, and
upward and downward, both slowly and
rapidly.
• Tongue dexterity can be tested by having
repeat lingual sounds, as in la-la-la, or use
words with the t or d phoneme.
• Motor power can be tested by having the
patient press the tip against each cheek as
the examiner tries to dislodge it with finger
pressure.

71. Palpation
• We can feel the mass lesions
• Better to palpate the base of the mouth
• For spastic tongue in case of UMN lesions
• For flaccid tongue in case of LMN lesions

72. Percussion
• Clinical myotonia is expressed
by delayed relaxation of muscle
fibers after an activation
maneuver such as percussion.
• This can also be observed in the
tongue.
• Percussion of the tongue using
a reflex hammer on a tongue
blade may produce a dimple, or
an area of focal constriction.
This is also known as the
‘‘napkin-ring’’ sign.

73. • Facial muscle weakness or jaw deviation makes it difficult
to evaluate deviation of the tongue.
• Protruding the tongue may cause an appearance of
deviation toward the side of the facial weakness.
• Manually pulling up the weak side of the face eliminates the
“deviation.”

74. • If the paralysis is not accompanied by
atrophy, the tongue may appear to
bulge slightly and to be higher and
more voluminous on the paralyzed
side.
• When atrophy starts in the borders or
tip to give a scalloped appearance
• As the paralyzed side becomes
wasted, the protruded tongue may
curve strikingly toward the atrophic
side, assuming a sickle shape.
• Fasciculations should be checked only
when tongue lying rest inside the
mouth.

76. References;
• DeJong’s Neurologic Examination; 7th
edition
• Bickerstaff’s Neurological Examination in
Clinical Practice 6th edition

77. Thank you