neurology 1.pptx

NEUROLOGY Facial nerve • This nerve contains only motor fibers supplying the facial muscles (muscles of expression). It is accompanied in a part of its course by: 1- Secretomotor fibres to salivary glands. 2- Sensory fibres to external auditory meatus carrying taste from the anterior 2/3 of the...

NEUROLOGY Facial nerve • This nerve contains only motor fibers supplying the facial muscles (muscles of expression). It is accompanied in a part of its course by: 1- Secretomotor fibres to salivary glands. 2- Sensory fibres to external auditory meatus carrying taste from the anterior 2/3 of the tongue. • The nucleus is situated in the pons. • The fibres pass dorsally to form a loop round the nucleus of the 6th nerve • turning forward to emerge from the lower border of pons medial to the 8th cranial nerve. • The three nerves then pass through the subarachnoid space of the posterior fossa to internal auditory meatus. • In the facial canal the nerve gives off: • A branch to the stapedius muscle. • The chorda tympani • After emerging from the latter it divides within the parotid gland into the branches which innervate the facial muscles. Functions of the facial nerve: Secretory to the submaxillary and sublingual salivary glands Motor Sensations of the external auditory meatus Taste sensation from anterior 2/3 of the tongue Causes of Facial Paralysis I. Supranuclear lesions: II. Nuclear and infranuclear lesions: III.Neuromuscular and Muscular lesions Character of upper motor neurone facial lesion.(supranuclear ) 1. Paralysis of the lower half of the face because the upper half receives a bilateral supply, so that patient can close his eyes and corrugates the forehead. 2. Although the patient can not move his paralysed muscles voluntarily, yet on emotional excitement he will move the paralysed side since emotional control comes from the frontal lobe is still intact outside the damaged pyramid fibres. 3. There is no reaction of degeneration. 4. Usually it is a part of hemiplegia, on the same side of facial weakness. Characters of lower motor neurone facial lesion. 1.Paralysis of the Both upper and lower facial muscles are involved on one side 2.Both Voluntary and emotional fibers are affected 3.There is reaction of degeneration.. Bell's Palsy • Definition: • A lower motor neurone facial palsy of acute onset due to non suppurative inflammation of the 7th nerve within the stylomastoid foramen. Etiology: Age: Any age but commonest in the young adults. Sex: equal Precipitating factors: exposure to cold or air drafts. Pathology: Interstitial neuritis Periostitis at stylomastoid foramen Clinical picture: 1. Usually unilateral, very rarely bilateral. 2. The onset of facial paralysis is usually preceded by pain behind the ear. The paralysis is rapid and within few hours. 3. Paralysis affects both upper and lower facial muscle with loss of both voluntary and emotional movements. 4. Deviation of the angle of mouth to the healthy side. 5. 6. Accumulation of food under the affected cheek because of paralysis of the buccinator muscle. Obliteration of the nasolabial fold. 7. Drooping of the eyebrow with inability to raise it with loss of forehead corrugations. 7. Inability to whistle 8. The cheek puffs out in respiration and on blowing. 9. Eversion of the lower lid with tearing 10.Inability to close the eye with upward rolling of the eye ball on trying to do so. (Negrois sign or Bell's phenomenon). Prognosis: 1. Complete recovery in most of the cases within few weeks (1-3 months) 2. Contracture may develop in the paralyzed muscle 3. facial spasm may occur due to partial recovery. 4. Crocodile tears: Unilateral lacrimation on eating due to regenerating facial nerve fibers to the lacrimal gland. 5. Recurrent facial palsy is rare Treatment • Approximately 60% of cases of Bell palsy recover completely without treatment, • Treatment with corticosteroids (prednisone 60 mg orally daily for 5 days followed by a 5-day taper • Treatment with acyclovir or valacyclovir is only indicated when there is evidence of herpetic vesicles in the external ear canal. • It is helpful to pretest the eye with lubricating drops (or lubricating ointment at night) and a patch if eye closure is not passible. • There is no evidence that surgical procedures to decompress the facial nerve are of benefit. • Physical therapy may improve facial function Case scenario • A 60 years old male patient presented to the emergency by sudden onset difficulty in speech and swallowing associated with upper and lower facial palsy . • No past history of head trauma ,fever ,HTN or diabetes • Recent onset of autalgia and decreasing in hearing adequacy • Urgent CT brain was done and revealed • Mass at stylomastoid foramen Answer the following questions • Could you consider the case facial palsy or not ? Why ? • Could you consider the case Bells palsy or not ? Why ? • What are the differential diagnosis of the CT brain findings ? THANKS