Cranial Nerves IX-X-XI-XII

By: Dr. WALID REDA ASHOUR, MD

GLOSSOPHARYNGEAL NERVE (IX)

This is a mixed nerve carrying motor, sensory &

autonomic (parasympathetic) fibres.

1. Motor fibres: to the - Stylopharyngeus.

- Constrictors of the pharynx.

2. Sensory fibres:

- General sensations from the posterior 1/3 of tongue,

pharynx & tonsils.

- Taste sensation from the posterior 1/3 of tongue.

3. Autonomic fibres: Parasympathetic fibres to the Parotid

gland.

LESION:

1 . Ipsilateral loss of taste & general sensations

from the posterior V3 of the tongue.

2. Ipsilateral loss of the pharyngeal reflex (afferent

Cr 9, efferent Cr 10).

N.B.: Isolated lesions of the glossopharyngeal nerve

do not occur as it is usually damaged in

association with the vagus & accessory nerves at

the jugular foramen (jugular foramen syndrome).

VAGUS NERVE ( X )

This is a mixed nerve carrying motor, sensory &

autonomic (parasympathetic) fibres.

1. Motor fibres: to the soft palate, pharynx & larynx.

2. Sensory fibres: from

- The skin over the external auditory meatus.

- The thoracic & abdominal viscera.

3. Autonomic fibres: Parasympathetic fibres to the

heart (inhibitory), the G.I.t. & the bronchial tree

(secretory & motor).

LESION:

1. Palato-pharyngeo-laryngeal paralysis resulting in

"True Bulbar Palsy" manifested by:

- Bulbar symptoms: Dysphagia,

Dysarthria, Dysphonia & Nasal regurge.

- Ipsilateral loss of palatal &

pharyngeal reflexes.

2. Tachycardia & constipation.

ACCESSORY NERVE

)XI(

This nerve is purely motor & is formed of 2 parts:

1. Cranial part: It arises in the medulla & runs with the vagus

nerve to share in the motor innervation of the soft palate &

pharynx.

2. Spinal part: It arises from the A.H.C. of the upper five

cervical segments, ascends along side the spinal cord and

enters the cranial cavity through the foramen magnum. It

joins the cranial portion to exit through the jugular foramen

to supply the Sternomastoid & Trapezius muscles.

LESION: Ipsilateral paralysis of the Sternomastoid &

Trapezius muscles.

HYPOGLOSSAL NERVE )XII (

This is a purely motor nerve which supplies the intrinsic

muscles of the tongue.

LESION:

1. U.M.N.L.: - Unilateral: Deviation of the tongue to the

opposite side of the lesion.  

- Bilateral: Inability to protrude the tongue

(spastic tongue)

In both cases there is no wasting or fasciculation.

2. L.M.N.L.: - Unilateral: Deviation of the tongue to the side of

the lesion.

- Bilateral: Inability to protrude the tongue. In

both cases there is wasting and fasciculation.

• The Motor nuclei of the Cranial Nerves are arranged in the

Brain Stem as follows:

Cr 3 & 4 in Midbrain * Cr 5, 6 & 7 in Pons

* Cr 9, 10, 11 & 12 in Medulla

The Pyramidal System: It supplies the opposite side of the

body.

  It originates in the motor area (4) & premotor area (6) &

terminates at:

* The anterior horn cells (A.H.C.) of the different levels of the

spinal cord (Corticospinal Tract).

* Motor nuclei of the Cranial Nerves at different levels of the

brain stem (Corticonuclear Tract).

PSEUDO-BULBAR PALSY

Pseudo-bulbar palsy

U.M.N. lesion In the brain stem or the cerebral hemisphere

(i.e. above motor nuclei of Cr 9, 10, 11 & 12 in Medulla)

1. Bulbar symptoms:

- dysphagia. - nasal regurgitation.

- dysarthria. - hoarseness of voice.

2. Spastic quadriplegia.

3. Exaggerated palatal and pharyngeal reflexes.

4. Exaggerated jaw reflex (if the lesion is above the pons).

5. Emotional and mood changes may be present.

Commonest Causes Of PSEUDOBULBAR PALSY

1. Vascular: Bilateral stroke (double hemiplegia).

2. Inflammatory: - Encephalitis.

- General paralysis of the insane.

3. Neoplastic: - Midline brain stem tumours.

- Syringobulbia.

4. Demyelinating: - M.S.

5. Degenerative: - Motor neurone disease (MND).

True bulbar palsy

True bulbar palsy

Lesion in cranial nerve motor nuclei.

1. Bulbar symptoms:

- dysphagia. - nasal regurgitation.

- dysarthria. - hoarseness of voice.

2. Absent palatal and pharyngeal reflexes.

3. The tongue is wasted and shows fasciculations.

4. There is no quadriplegia, or emotional changes.

The commonest causes of TRUE BULBAR PALSY

1. Vascular: - Vertebrobasilar insufficiency.

2. Inflammatory: - Diphtheria. - Bulbar poliomyelitis

3. Neoplastic: - Brain stem tumours.  

4. Degenerative: - Motor neurone disease.

THANK YOU