Cranial Nerves and dysfunctions Prof.Dr. S. Naz Yeni I. Cranial nerve; olfactorius • • • • • • • • 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, …. 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… • • • • • • 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