The facial nerve is a mixed nerve that is predominantly motor. It innervates the muscles of facial expression and the scalp, ear, and neck. It has motor, sensory, and parasympathetic secretomotor functions. The facial nerve exits the brainstem and travels through the internal acoustic meatus, facial canal, and stylomastoid foramen before branching in the parotid gland. It gives off several branches including the chorda tympani, nerve to stapedius, and branches to neck muscles.
hypoglossal nerve, origin course an termination of hypoglossal nerve, function of hypoglossal nerve, clinical examination of hypoglossal nerve, hypoglossal nerve palsy
introduction to skull, parts of skull, bones involved forming skull, different views of skull, norma basalis, anterio cranial middle cranial and posterior cranial fossa, clinical aspects of cranial fossa, foramens present in the cranial fossa
hypoglossal nerve, origin course an termination of hypoglossal nerve, function of hypoglossal nerve, clinical examination of hypoglossal nerve, hypoglossal nerve palsy
introduction to skull, parts of skull, bones involved forming skull, different views of skull, norma basalis, anterio cranial middle cranial and posterior cranial fossa, clinical aspects of cranial fossa, foramens present in the cranial fossa
Fifth cranial nerve
Have a large sensory root and a small motor root.
Motor root arises – arises from the lateral aspect of lower pons (cranially) the motor root cross the apex of the petrous temporal bone beneath the superior petrosal sinus, to enter the middle cranial fossa.
Sensory root – arises from the lateral aspect of lower pons (caudally).
RELATIONS
Medially
(a) internal carotid artery
(b) posterior part of cavernous sinus
Laterally - middle meningeal artery
Superiorly - parahippocampal gyrus
Inferiorly
motor root of trigeminal nerve
(b) greater petrosal nerve
(c) apex of the petrous temporal bone
(d) foramen lacerum.OPTHALIMIC DIVISION
Terminal branches of Ophthalmic division of trigeminal nerve, are
1. Frontal
Supratrochlear
Supraorbital
2. Nasociliary
Branch of ciliray ganglion
2-3 long ciliary nerves
Posterior ethmoidal
Infratrochlear
Anterior ethmoidal
3. Lacrimal
Branches
From main trunk
Meningeal branch
Nerve to medial pterygoid
From the anterior trunk
Sensory branch
Buccal nerve
Motor branch
Masseteric
Deep temporal nerve
Nerve to lateral pterygoid
From the posterior trunk
Auriculotemporal
Lingual
Inferior alveolar nerves
Facial nerve presentation by Dr Salison Salim Panicker.pptxSalison Salim
Facial nerve Presentation by Dr Salison Salim { RelentCare Ent center Thrissur} , facial nerve development, course, anatomy ,injuries, complications, treatments, reanimation techniques everything presented in a concise manner
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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facial nerve is the 7th cranial nerve. it supplies the parts of the face and also the muscles of mastication. it helps in the expression of the face too.
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facial nerve is the seventh cranial nerve supplies the submandibular, sublingual, lacrimal glands, the mucosal glands of the nose, palate, pharynx and taste fibres, and on being injured it leads to loss of lacrimation, loss of salivation, loss of taste sensation and paralysis of the muscles of facial expression.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
2.
ANATOMY AND PHYSIOLOGY
It is a MIXED nerve, predominantly motor.
Supplies muscles of
Facial expression
Scalp
Ear
Buccinator
Stylohoid
Posterior belly of digastric
Platysma
Stapedius
Parasympathetic secretory fibres to
Submandibular, sublingual glands, lacrimal gland, mucous membranes of oral and
nasal cavities
3.
Sensory function
Taste from anterior 2/3rd
of tongue
Exteroceptive sensation from the eardrum and external auditory canal
Proprioceptive from muscles it supplies
General visceral sensation from salivary glands and mucosa of the nose and
pharynx
4.
Segments
Brain stem / intramedullary segment
Brainstem nuclei to the exit point
Cisternal segment
Exit point to the entrance into the IAC
Meatal / canal segment
Course thru the IAC
5.
Labyrinthine segment
To the geniculate ganglion
Short horizontal segment
To the pyramidal eminence of the posterior wall of the
tympanic cavity
Mastoid segment
To the stylomastoid foramen
Extratemporal / peripheral segment
To the pes anserinus
6.
MOTOR PORTION
L/3rd
contralateral precentral gyrus, facial area,
motor homonculus
Corticobulbar tract thru corona radiata
Genu of internal capsule
Medial portion of cerebral peduncles
Pons – decussate
Facial nuclei
7.
This scheme applies to voluntary facial movements
Unconscious, emotional, involuntary supranuclear control follows different
pathway and may have different degrees of involvement.
8.
Aberrant pyramidal tract
Some fibres descent in the aberrant pyramidal
tract to medullary levels
Decussate there
Ascent contralaterally in the dorsolateral medulla
to reach the facial nucleus.
Yamashita and Yamamoto, showed that it is a
normal descending fibre tract in the medial
lemniscus in the upper medulla.
9.
Corticofacial fibres
Majority – fibres travel in the base of the pons, cross at the
level of facial nucleus
In some – they form an “aberrant bundle” in a
paralemniscal position at the dorsal edge of the pontine
base
In some – they loop down to the upper ventral medulla,
cross the midline and ascent in the dorsolatral medulla,
ipsilateral to the facial nucleus
10.
These suggest that facial paresis due to brainstem lesion
may be a contralateral supranuclear facial paresis by a lesion
in
Cerebral peduncle
Pontine base
Aberrant bundle
Ventral medulla
Supranuclear facial paresis ipsilateral to the lesion side may
result from a lesion in the
Lateral medulla
Supranuclear type maybe imitated by a lesion of the
peripheral nerve in
11.
FACIAL NUCLEUS
It is special visceral efferent or branchiomotor.
It lies in the tegmentum of the caudal pons
Related as : anteromedial to nucleus of spinal tract of
CN V
Anterolateral to the nucleus of CN VI
Posterior to the superior olivary nucleus
It has medial, lateral and dorsal subnuclei, arranged in
columns.
Lateral subnucleus – lower fafcial muscles, buccinator
Medial – posterior auricular, platysma, occipital,
stapedius
Dorsal – upper facial muscles
13.
INTRAMEDULLARY SEGMENT
Arises from the dorsal surface of the nucleus, encircles
around the abducens nucleus
Forms an INTERNAL GENU.
Forma facial colliculus
Relations with
Fibres and nucleus of CN VI, pontine paramedian reticular
formation, CN V, CN VIII, long tracts thru pons.
Two components – motor root (70% fibres) and sensory
(30%)
Sensory root forms the NERVUS INTERMEDIUS (NI) OF
WRISBERG
Contains both sensory and autonomic fibres,
Intramedullary segment contains all three types of axons
14.
CISTERNAL SEGMENT
Nerve exits the pons laterally at the pontomedullary
junction, just caudal to the roots of CN V between
the olive and the inferior cerebellar peduncle
The NI is a small bundle that usually leaves the pons
closer to CN VIII than CN VII and runs between the
larger trunks across the cerebellopontine angle
(CPA).
In about 20% of specimens, the NI is not identifi able
as a separate structure in the CPA.
At the entrance to the IAC, the facial nerve motor
root lies in a groove on the anterosuperior surface of
the vestibulocochlear nerve, with the NI in between.
The facial nerve at this point lies in close proximity to
the anterior inferior cerebellar artery (AICA).
the subarachnoid space extends along the facial
nerve to the geniculate ganglion.
17.
MEATAL SEGMENT
At the bottom or lateral end of the IAC, the nerve
pierces the meninges and enters the facial canal,
or fallopian aqueduct.
The point of entry is the narrowest portion of the
canal.
The facial nerve and the NI merge as the nerve
enters the canal.
In traversing the facial canal, the nerve makes
two abrupt, tortuous turns, creating two external
genus.
In its course through the petrous bone, from its
entrance into the facial canal until its exit from the
stylomastoid foramen, the nerve has three
segments: labyrinthine, horizontal or tympanic,
and mastoid or vertical.
18.
LABYRINTHINE SEGMENT
The labyrinthine segment lies laterally between the cochlea and vestibule,
toward the medial wall of the tympanic cavity, running perpendicularly to
the long axis of the petrous pyramid.
The labyrinthine segment ends at the first external genu where the
geniculate ganglion lies.
20.
HORIZONTAL / TYMPANIC SEGMENT
the nerve turns abruptly and runs horizontally for about 1 cm (the horizontal or
tympanic segment), then turns backward and arches downward behind the tympanic
cavity (mastoid or vertical) segment.
The branch to the stapedius muscle arises from the distal tympanic or upper end of
the mastoid segment.
At the end of the tympanic segment, the nerve encounters the second external genu
as it makes a 90-degree turn to enter the mastoid segment.
21.
MASTOID SEGMENT
The mastoid segment then descends toward the stylomastoid foramen,
gives off the chorda tympani about 6 mm before its exit, and emerges
from the stylomastoid foramen.
The tight confi nes of the bony canal may make the nerve particularly
vulnerable to damage from infl ammation and edema, a point of possible
signifi cance in some CN VII neuropathies
22.
VARIATIONS
It may split into two or three strands at or distal to the geniculate ganglion.
The more proximal the division into strands, the more bizarre the
subsequent course.
Facial motor fi bers may run in an enlarged chorda tympani, diminishing
the distal facial nerve into a tenuous strand exiting through a narrowed
stylomastoid foramen.
CN VII runs along with the labyrinthine branch of the AICA, but there is
evidence to suggest it is less well vascularized in its intrapetrous segment,
particularly in the labyrinthine segment, than elsewhere along its course.
In patients with Bell’s palsy, the involved side usually correlates with the
side of the narrower facial canal as determined by high-resolution
computed tomography (CT).
23.
EXTRATEMPORAL SEGMENT
Just after exit, the posterior auricular, digastric, and
stylohyoid branches arise.
The posterior auricular branch supplies the
occipitalis, posterior auricular, and transverse and
oblique auricular muscles.
The digastric and stylohyoid branches supply
respectively the posterior belly of the digastric and
the stylohyoid.
The nerve turns forward and passes into the parotid
gland.
Within the substance of the parotid, it divides into
temporofacial and cervicofacial divisions at the pes
anserinus (intraparotid plexus) in the cleft between
the superficial and deep lobes of the gland
The temporofacial branch crosses the zygoma about
1 cm anterior to the ear, where it is vulnerable to
injury.
24.
NERVUS INTERMEDIUS
The NI is the sensory and autonomic component of the facial nerve.
It runs in a position intermediate between CNs VII and VIII across the
CPA, moving ever closer to the main facial nerve trunk as it enters the
facial canal.
At the external first external genu, the NI fuses with the geniculate
ganglion.
The sensory cells located in the geniculate ganglion are general
somatic afferent (GSA) and special visceral afferent (SVA).
The GSA fibers carry exteroceptive impulses from the region of the
external auditory canal and tympanic membrane.
The SVA fibers convey taste from the anterior two-thirds of the tongue.
The autonomic component of the NI consists of preganglionic general
visceral efferent parasympathetic fibers from the superior salivatory
and lacrimal nuclei, which consist of scattered cells in the reticular
formation near the caudal end of the motor nucleus.
Their axons are bound for the submandibular gland enroute to the
sublingual and submaxillary glands, the lacrimal glands, and glands in
the nasal mucosa.
25.
COURSE AND BRANCHES
GREATER (SUPERFICIAL) PETROSAL NERVE
Carries preganglionic parasympathetic fibres,
conveyed by NI to the geniculate ganglion.
They pass thru the ganglion, without
synapsing into the GPN, which goes forward
thru the hiatus of the facial canal to join the
DEEP PETROSAL NERVE from the carotid
sympathetic plexus to form the VIDIAN
NERVE / NERVE OF THE PTERYGOID
CANAL, which runs to the sphenopalatine
ganglion, from where postganglionic fibers
proceed to thelacrimal gland.
26.
BRANCH TO OTIC GANGLION
A branch from the geniculate ganglion joins
the lesser petrosal nerve and is then carried
to the otic ganglion
This conveys secretomotor fibres in the
auriculotemporal nerve to the parotid gland.
It also carries sympathetics from the carotid
artery to the blood vessels of the gland.
27.
NERVE TO STAPEDIUS
Arises from the distal tympanic / upper
mastoid segment
Passes forward through a small canal to
reach the muscle.
28.
CHORDA TYMPANI
Leaves the main trunk, slightly above the
stylomastoid foramen.
Carries taste and general visceral afferent
fibres as well as preganglionic
parasympathetics.
Runs forward and upward in a canal in the
posterior wall of the tympanic cavity, acquires
a mucous membrane investment, enters and
crosses the middle ear.
Sometimes, visible as a small cord behing
the eardrum, on otoscopy.
It runs to exit the skull and join the lingual
nerve, branch of CN V3, on its posterior
border.
29.
Somatosensory afferents in the chorda tympani, have their cell bodies in
the geniculate ganglion.
They carry sensatiions from the part of EAC, tympanic membrane, lateral
surface of the pinna, small area behind the ear and over the mastoid
process.
The central processes terminate in the spinal tract and nucleus of the
trigeminal nerve.
Taste sensations from the anterior 2/3rd
of the tongue is carried through
the lingual nerve to the chorda tympani, then to the geniculate ganglion.
CN VII carries taste sensation from the mucosa of the soft palate throught
the sphenopalatine gangliion.
30.
Their central processes carrying taste and GVA sensations, terminate in
the nucleus of the solitary tract.
The solitary tract sends communications to the superior and inferior
salivatory nuclei, which send parasympathetics to the salivary glands.
Other fibres synapse in the reticular formation; next order neurons form a
component of the reticulospinal tract bilaterally to synapse with the
sympathetic neurons in the intermediolateral gray column of the uppeer
thoracic cord.
These send sympathetic innervation via the superior cervical ganglion to
the salivary glands.
The taste fibres ascent via the contralateral medial lemniscus to the
thalamus.
31.
The primary gustatory cortex, located in the anterior insula, the frontal
operculum, mediates the perception of taste.
Taste fibres also communicate with the hypothalamus and the olfactory
system.
The chorda tympani also carries preganglionic parasympathetic fibres to
the submandibular gland.
Postganglionic fibres convey secretory and vasodilator impulses the the
submandibular and sublingual glands and mucuous membranes of the
mouth and tongue.
They also receive sympathetics from the superior cervical ganglion and
the carotid plexus.
34.
TWIGS TO THE VAGUS AND GLOSSOPHARYNGEAL
At the stylomastoid foramen, small branches join the
above nerves.
POSTERIOR AURICULAR NERVE
Supplies the muscles of the ear, occipital belly of
occipitofrontalis
BRANCHES TO THE MUSCLES OF FACIAL
EXPRESSION
They pass through the parotid gland
They are temporal, zygomatic, buccal, marginal,
mandibular and cervical
CUTANEOOUS BRANCHES distributed with the auricular
branch of vagus, supplying the skin on both the sides
of the auricle and part of EAC and TM.
35.
CLINICALLY IMPORTANT FEATURES
For clinical purposes, CN VII is purely motor, apart from sensory
component to the EAC, carried in the auricular branch of vagus.
Taste sensations via chorda tympani, it joins the nerve in middle ear,
theoritically, it has great localising value. But in practice, taste fibres are
often spared in lesions proximal to the middle ear.
Stapedius with tensor tympani (by CN V), contracts to damp down the
stapes when subjected to high intensity sound. Complete seventh nerve
lesion will therafore alter auditory acuity on the affected side.
It contributes to forced eye opening and ptosis is not a feature of the
seventh palsy. However, there will be weakness in clenching the eyelids to
bury the eyelashes.
Test platysma and wiggle the ears
36.
Disorders of facial nerve function
Facial weakness – two types
Peripheral / lower motor neuron
Central / upper motor neuron
37.
Peripheral facial palsy
Flaccid weakness of all the muscles of facial
expression on the involved side –
prosopoplegia
38.
Bell’s phenomenon
Levator sign of Dutemps and Cestan – patient to look down, then close
the eyes by the slowly, because of the function of the LPS is no longer
counteracted by orbicularis oculi, the upper eyelid on the paralysed side
moves slowly upwards
Bergera Wartenberg sign – loss of fine vibrations palpable with the
thumbs or fingertips resting lightly on the lids as the patient tries to close
the eyes as tightly as p ossible.
Platysma sign of Babinski – asymmetrtic contraction of the platysma, less
on the affected side, when the mough is opened.
House-Breckman scale, Burres-Fisch Index, facial nerve function index
39.
Lack of tearing – indicates very proximal involvement, above the origin of
GSPN.
Corneal reflex – direct limb absent, consensual reflex present
41.
Bell’s Palsy
Idiopathic, peripheral facial paralysis or paresis of acute onset
Both the sexes equally affected
Any age may be affectedbut incidence rises with increasing age
Positive family h/o in 6-8 %
Risk factors – diabetes, pregnancy
Clinical features :
Sudden onset, unable to close eyes
Bell’s phenomenon
Dribbling of saliva, epiphora, assymetrical face
42.
Pain in ear precede or accompany the paralysis
Noise intolerance and loss of taste
Etiology :
Viral infection – HSV, herpes zoster, EBV
Vascular ischemia – primary ischemia induced by cold / emotional stress
Hereditary – fallopian tube is narrow making it susceptible to early
compression
Autoimmune disorder – T lymphoccyte changes observed
43.
Diagnosis :
History, ENT examination
Nerve excitability test
Treatment :
Reassurance, pain relief
Eye care
Facial physiotherapy
44.
Medical management :
Steroids – prevents synkinesis, shortens the
recovery time
Others – vasodilators, vitamins, mast cell
inhibitors, anti HT – not proven
Surgical treatment
Nerve decompression relieves pressure and
improves microcirculation
45.
Brainstem causes / Nuclear causes
Motor neurons of CN VII nucleus
Motor neuron disease, Mobius syndrome
Progressive bulbar palsy
Mobius Syndrome (Congenital oculofacial paralysis)
It is the association of congenital facial nerve palsy with paraolysis of
EOMS , esp lateral rectus due to hypoplasia or aplasia of the CN nuclei.
It is sporadic
46.
Pontine lesions
Fascicular lesions may / not involve tearing and taste
Ischemic lesions are common
Millar – Gubler syndrome :
Ipsilateral facial palsy with contralateral hemiparesis – due to pontine
stroke, hemorrhage or tumor.
CN VI palsy is often but incorrectly included as a part of MGS.
Foville syndrome :
Ipsilateral facial palsy with horizontal gaze palsy with contralateral
hemiparesis.
Eight and half syndrome :
Is one and half syndrome with facial weakness due to pontine lesion.
48.
CPA lesions
Acoustic neuroma, meningioma, epidermoid - commonly involve CN VII,
NI, CN VIII, CN V, the cerebellar peduncles and cerebellum.
No hyperacusis due to associated hearing loss.
Findings – hearing loss, facial sensory changes, ipsilateral ataxia,
nystagmus, facial weakness.
49.
Ramsay Hunt syndrome
Herpes zoster oticus, Hunt sydrome, geniculate herpes
Reactivation of varicella zoster visur involving the
geniculate ganglion.
Facial weakness is accompanied with taste impairment,
hyperacusis, dimunition of salivary and lacrimal secretion.
Pain in and behind the ear +
Vesicles on the TM, EAC, lateral surface of pinna and
mastoid process.
Two types :
Otalgic form – pain in the ear
Prosolgic form – pain deep in the face
50.
Preherpetic neuralgia – pain and dysesthesias preceeding the
development of rash.
Attacs beyond the facial nerve occur frequently.
Tinnitus, hearing loss, nausea, vomitting, tagmus from the vertigo,
nystagmus – from the involvement of CN VIII are common.
c/f Bells’ palsy, Ramsay Hunt syndrome patients have more severe
paralysis and less likely to recover completely.
Diabetes – four to five fold increased risk of developing acute PFP.
51.
Trauma
Petrous bone fractures – may injure facial nerve.
Longitudinal fractures along the long axis of petrous bone – the facial
nerve injury is due to edema, does not occur immidiately and tends to
resolve spontaneously.
Transverse fractures – comes on immediately, may be permanent., nerve
is often lacerated, contused or severed.
Rupture of the ear drum, bleeding from the ear – indicate longitudinal
fracture.
CSF otorrhoea – common with transverse fractues.
52.
Other causes
Melkersson syndrome (Melkersson-Rosenthal syndrome) is characterized
by recurrent attacks of facial palsy, nonpitting facial and lip edema, and a
congenitally furrowed and fissured tongue (lingua plicata, scrotal tongue);
It is sometimes familial and usually begins in childhood.
Its cause is unknown.
Myasthenia gravis
Marked facial weakness, bilateral, difficulty in both closing and opening
the eyes
Myasthenic smile – may look like a snarl.
Ectropion – worse in the afternoon, responds to antiCE
54.
Central facial paralysis
Lesions are most often in the cortex or internal capsule.
Occasionally, a lesion as far caudal as the medulla can cause a CFP
because of involvement of the aberrant pyramidal tract.
The upper face is not necessarily completely spared, but it is always
involved to a lesser degree than the lower face.
There may be subtle weakness of the orbicularis oculi, the palpebral
fissure may be slightly wider on the involved side, and there may be a
decrease in palpable lid vibrations.
However, involvement of the corrugator and frontalis is unusual, and the
patient should be able to elevate the eyebrow and wrinkle the forehead
with no more than minimal asymmetry.
Inability to independently wink the involved eye may be the only
demonstrable deficit.
55.
Hemifacial spasm
Repeated uncontrollable twitching of the facial muscles
2 types – 1) cause unknown
2) secondary – acoustic neuroma, congenital cholesteatoma, glomus
tumor
Irritation of the nerve
Microvascular decompression had met with surgical success.
Botulinum toxin – used in affected muscle
56.
blephaspasm
Twitcing and spasms are limitged to the orbicularis oculi – both sides
Eyes are closed
Cause is undertain
Lesion – basal ganglia
Treated by selective section of nerves