Cranial Nerves and dysfunctions
Prof.Dr. S. Naz Yeni
I. Cranial nerve; olfactorius
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Loss of olfaction; ANOSMIA
Causes; fractures at the base of the skull
Tumors at the base of frontal lobe (meningioma like..)
Sphenoidal wing tumors
Hypophis tumors
Craniophranygeoma
Menengitis
Vitamin, zinc deficiencies,
• Olfactory hallucinations; temporal lobe seizures
• Examination; check each nostril with non irritating odours
II. Cranial nerve; opticus
• Blindness, amourosis (blindness as a result of
indirect reasons), ampliyopia (blindness as a
result of eye and related structures)
Examination
Light reflex; light source
Funduscopy; ophtalmascope
Visual acuity; finger counting
Visual fields; confrontation test
Visual field defects
Heteronym
hemianopsia
Homonym
hemianopsia
One sided
amplyopia;
inflamation,
ischemia, tumors
(glioma ), toxic
reasons
MS(optic neuritis)
orbital tumors
One sided transient
Amourosis fugax
III. Cranial nerve; oculomotorius
• The Edinger-Westphal nucleus supplies
parasympathetic fibres to the eye via the ciliary
ganglion, and thus controls the sphincter pupillae
muscle (affecting pupil constriction) and the
ciliary muscle (affecting accommodation).
• It innervates levator palpebrae superioris.
• It innervates ocular muscles; medial rectus,
inferior oblique, superior, inferior rectus muscles
Features
• Ptosis
• Diplopia (eye deviates to laterally)
• Mydriasis (anisocoria)
Etiology
Vascular lesions in the midbrain
Multipl sclerosis (demyelinating
lesions in the midbrain)
Tumors
Uncal herniation
Aneurysms
Meningitis
Cavernous sinus trombosis
Diabetes Mellitus
Thyroid ophtalmopathy
IV cranial nerve; trochlearis
It innervates
superior oblique
muscle
Features; diplopia
while reading books,
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SOM when
contracted
The eye converges
Etiology
Trauma
Meningitis
Cavernous sinus trombosis
Fissura orbitalis superior inflamations
Thyroid ophtalmopathy
VI cranial nerve; abducens nerve
• It innervates lateral rectus
muscle
• The eye deviates to the
lateral side.
• 6. nerve palsy
Features; diplopia, deviation of
the eye medially
Etiologies
• Increased intarcranial
pressure
• Vascular
• MS
• Meningitis
• Nasopharyngeal tumors
• Cavernous sinus trombosis
• Fissura orbitalis superior
tumors, inflamations
• Thyroid ophtalmopathy
V cranial nerve; trigeminus
• Three sensory divisions;
ophtalmic (FOS),
maxillary (FR),
mandibular(FO)
• Innervates facial
sensation
• Afferent of cornea
reflex
• Massaters , temporalis
muscles
•Loss of touch and pain
and temperature
sensation
•Weakness in mast.
muscles
•Loss of corneal reflex
•Pain
Etiologies
After gasserian ganglion…
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Vascular
Tumors
MS
Herpes zoster (zona)
Meningitis
Cavernous sinus
trombosis ( I. Division)
• Fissura orbitalis superior
inflamations (I. Division)
• Trigeminal neuralgia
VII cranial nerve; facialis
• Parasymphatic
• Sensory
• Motor
Nervus intermedius;
lacrimation
Chorda tympani;
2/3 tongues taste sensation,
salivation
Motor branches;
m. stapedius,mimic muscles
Peripheral vs central type of VII. Nerve
palsy
Lower motor fibers dont have
bilateral innervation.
Peripheral 7. nerve palsy
• Motor fibers for blink ,
eye brows have bilateral
supranucleer
innervation
Central type of
palsy; spare of
upper muscles
All mimic
muscles
7. Nerve palsy
Etiologies
Peripheral
• Bell’s palsy
• Herpes zoster
• Trauma
• Menengitis
Central
• Vascular
• MS
• Tumors
VIII cranial nerve; acousticus
• Hearing loss (sensorineural
type)
• Vertigo
• Tinnitus
Weber –Rinne tests
Etiologies
Vascular
MS
Meningitis
Acoustic nörinoma
Acoustic –petrous bone tumors,
infections
Trauma
IX. Cranial nerve; glossopharnygeus
X. Cranial nerve; vagus
• Motor, sensory, autonomic functions
• Muscle stylopharnygeus (elevates larenks while
swallowing; 9), rest 10. nerve
• 1/3 of taste sensation of the tongue (9)
• Somatic sensation of pharyngeus, tonsilla,
laryngeus, external auricula, membrane
tympanicus(9, 10).
• Innervates parotis gland(9).
• Chemo, baro reseptors in carotid body(9)
• Autonomic functions of visceral organs(10)
IX. Glossopharyngeal nerve
X. Vagus nerve
• Nuclei are located in
the medulla oblangata.
• they leave from
foramen jugulare
together with n.
Accessorius.
• Close to arteria carotis
interna and vena
jugularis in the neck.
Examination
• Gag reflex (swallowing difficulty)
• Afferent is 9. nerve, efferent is 10.nerve.
Lesions;
• Pseudobulbar palsy
• Vascular lesions in the bulb
• Foramen jugulare tumors
• Trauvma
• DM
• 9. nerve nevralgia
XI. Cranial nerve; accessorius
• The nuclei is in the medulla oblangata and
upper spinal cord.
• Fibers enter the intracranial cavity through
foramen magnum and joins to intracranial
portion and leave the cavity through foramen
jugulare.
• It innervates SCM,
trapezius muscles
Lesions
• Vascular
• Motor neuron disease
• Syringobulbi, syringomyeli
• Tumors
• Trauma
• Nasopharnygeal tumors
Torticollis
XII. Cranial nerve; hypoglossus
• It innervates tongues intrinsic muscles.
• It leaves the cavity through foramen hypoglossi;
ıt is close to 10, 11 nerves.
Lesions
Vascular
Tumors
Motor neuron disease
Nasopharnygeal tumors
Trauma
Carotis interna
dissections
In the mouth; the
tongue deviates to
healthy side.
After protrusion
out; it deviates to
the palsied side