The abducent nerve controls the lateral rectus muscle which moves the eye outward. It has three key parts:
1. The nucleus is located in the pons and controls horizontal eye movement.
2. It emerges between the pons and pyramid and travels through the cavernous sinus.
3. In the orbit, it innervates the lateral rectus muscle.
Isolated 6th nerve palsy can result from lesions along its course and is evaluated with imaging and lab tests to identify treatable causes like tumors or vascular abnormalities. Surgical correction is considered if weakness persists after 6 months of monitoring.
anatomy
Abducens nerve palsy is the most common ocular motor paralysis. The abducens (sixth) cranial nerve controls the lateral rectus muscle, which abducts the eye. Abducens nerve palsy causes an esotropia due to the unopposed action of the antagonistic medial rectus muscle. The affected eye turns in toward the nose and is unable to abduct properly. The deviation is constant and is usually greater at distance fixation than at near. The esotropia is also worse when the patient is looking toward the affected side.
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anatomy of optic nerve and its blood supply and clinical corelation
Presentation Layout: optic nerve anatomy
Embryology of optic nerve
Introduction
Parts of optic nerve
Blood supply
Clinical significance
For Further Reading
Wolff’s Anatomy of the eye and orbit by Bron, Tripathi and Tripathi
Anatomy and Physiology of eye by A.K. Khurana 2nd edition
Comprehensive Ophthalmology by A.K. Khurana 5th edition
AAO- Fundamentals & Principles of Ophthalmology : sec 2
Walsh and Hoyt’s Clinical Ophthalmology
Internet
anatomy
Abducens nerve palsy is the most common ocular motor paralysis. The abducens (sixth) cranial nerve controls the lateral rectus muscle, which abducts the eye. Abducens nerve palsy causes an esotropia due to the unopposed action of the antagonistic medial rectus muscle. The affected eye turns in toward the nose and is unable to abduct properly. The deviation is constant and is usually greater at distance fixation than at near. The esotropia is also worse when the patient is looking toward the affected side.
Direct Download Link ❤❤https://healthkura.com/eye-ppt/28/❤❤
Dear viewers Check Out my other piece of works at ❤❤❤ https://healthkura.com/eye-ppt/❤❤❤
anatomy of optic nerve and its blood supply and clinical corelation
Presentation Layout: optic nerve anatomy
Embryology of optic nerve
Introduction
Parts of optic nerve
Blood supply
Clinical significance
For Further Reading
Wolff’s Anatomy of the eye and orbit by Bron, Tripathi and Tripathi
Anatomy and Physiology of eye by A.K. Khurana 2nd edition
Comprehensive Ophthalmology by A.K. Khurana 5th edition
AAO- Fundamentals & Principles of Ophthalmology : sec 2
Walsh and Hoyt’s Clinical Ophthalmology
Internet
Sixth and seventh cranial nerves: anatomy and disordersUrusha Maharjan
Brief introduction to anatomy of sixth and seventh cranial nerves.
Brief introduction to some disorders in the nerve course and its related clinical features.
Few management for the problem.
#neuro-ophthalmology
Gross anatomical description of the medulla with associated significant clinical relevance
Relevant blood supply of the Medulla Oblongata.
Good revision guide
Ocular nerve palsies are tricky to understand and are confusing. Learning the features by correlating with the anatomy make it easy.
These are both congenital and acquired.
With differential diagnosis and by proper stepwise ocular evaluation takes us to final diagnosis.
The facial nerve is the seventh cranial nerve, or simply CN VII. It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
Ephaptic transmission of impulses between neighbouring neurons (i.e. coupling of adjacent nerve fibres due to local exchange of ions or local electric fields) leading to excessive or abnormal firing.
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.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
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
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
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ASA GUIDELINE
NYSORA Guideline
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TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
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Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
4. NUCLEUS
• Situated near the midline
in the tegmentum of the
pons ventral to the
colliculus facialis
• colliculus facialis is an
elevation in the floor of
the 4th ventricle ,
produced by the genu of
facial . N
5.
6. The medial longitudinal bundle is
ventromedial
• Partly intermingled with these larger neurons
are more numerous small multipolar cells
which form the so-called nucleus para
abducens
8. PARA PONTINE RETICULAR
FORMATION (PPRF)
• The gaze motor command involves specialized
areas of the reticular formation of the brain
stem which receive a variety of supra nuclear
inputs.
The main region for horizontal gaze is the
paramedian pontine reticular formation
(PPRF)
12. SUPERFICIAL EMERGENCE
• Emerges between lower
border of the pons &
lateral part of the
pyramid
• Emerge as seven or
eight rootlets
13. COURSE
• Passes upwards & anterolaterally in
subarachnoid space of posterior cranial fossa
• Pierces the arachnoid & dura lateral to the
dorsum sellae
14. • Ascends between the layers of dura on the
posterior surface of the petrous bone near its
apex
• Turns anteriorly to traverse the cavernous
sinus
15. • Enters the orbit through the superior orbital
fissure within the annular tendon to supply
the lateral rectus muscle
18. 1.AT EMERGENCE
• Abducent nerves are
about 1 cm apart
Between them is the
Basilary . A at its
formation from the 2
vertebral . A
• Lateral to each abducent
is the emergence of the
facial. N at the lateral
side of the olive
19. 2.POSTERIOR CRANIAL FOSSA
Just after its emergence , the nerve is crossed
by the ANTERIOR INFERIOR CEREBELLAR. A
• Usually the artery is ventral , but it may be
dorsal or pass between the abducent rootlets.
20. • Sleeved by the piamater
, it ascends
anterolaterally in the
cisterna pontis of the
subarachnoid space
between pons &
occipital bone
21.
22.
23. • At the upper border of the bone, it turns forward
at a right – angle under the Petro sphenoidal
ligament ( Gruber’s ligament )
• Thus passing through a canal called the Dorello’s
canal – to enter the cavernous sinus with the
inferior petrosal sinus
• Often the nerve pierces the inferior sinus,
entering the cavernous sinus within the inferior
petrosal sinus
27. Nerve is inferolateral to the horizontal portion
of the internal carotid artery with its
sympathetic plexus , which may communicate
with the nerve
28. • In the lateral wall of the
sinus , in descending
order are
• Oculomotor .N
• Trochlear . N
• Ophthalmic. N
• Maxillary. N
Abducent .N is usually in
the sinus, with a separate
sheath
29. 4.SUPERIOR ORBITAL FISSURE
Traverses the fissure
within the annulus of
Zinn
• At 1st below the division
of oculomotor.N
• Then between them &
lateral to nasociliary
nerve
30. 5.IN THE ORBIT
• Nerve divides into 3 or
4 filaments which enter
the ocular surface of
lateral rectus muscle
behind its midpoint
32. 1. At the level of nucleus
• ipsilateral weakness of
abduction
• failure of horizontal
gaze towards the side of
lesion
• ipsilateral LMN palsy of
facial nerve
33. AN ISOLATED 6TH NERVE PALSY IS THEREFORE
NEVER NUCLEAR IN ORIGIN
34. 2.PONTINE SYNDROMES – AT THE
LEVEL OF FASCICULUS
M
•MILLARD GUBLER SYNDROME
R
•RAYMOND CESTON SYNDROME
F
•FOVILLE SYNDROME
35. A. Foville syndrome
Involves fasciculus as it
passes through PPRF
5th nerve – facial
anaesthesia
6th nerve + gaze palsy
7th nerve – facial
weakness
8th nerve - deafness
36. B. Millard – Gubler syndrome
Involves fasciculus as it
passes through the
pyramidal tract
Ipsilateral 6th nerve
palsy
Contralateral
hemiplegia
37. C. Raymond – Ceston syndrome
Due to tumor of cerebral peduncles
Red nucleus – speech & gait disorder
Paralysis of lateral conjugate gaze
Ipsilateral 6th N palsy
5th nerve – facial anaesthesia
Contralateral hemiparesis
38. 3. At the pontomedullary junction:
ACOUSTIC NEUROMA:
• 1ST symptom – hearing
loss
• 1st sign - ↓ corneal
sensitivity
39. It is very important to test hearing &
corneal sensation in all patients with
6th nerve palsy
40. 4. In the basilar course
A. ↑ intracranial
tension:
• - downward
displacement of
brainstem
• - stretching of 6th nerve
over petrous tip
• b/l 6th nerve palsy –
false localizing sign
42. D. Gradenigo’s
syndrome:
• Mastoiditis/Petrositis
• - damage to 6th nerve at
the Dorello’s canal
• Facial weakness
• Pain
• Hearing difficulties
43. 5. INTRACAVERNOUS PART
• Situated close to the
internal carotid A
• More prone to damage
than other cranial
nerves
Intra cavernous 6th
nerve palsy is
accompanied by a
postganglionic Horner’s
syndrome
44. CLINICAL PRESENTATION
• HISTORY:
– Esotropia
– Head-turn
– Binocular diplopia (worse at distance)
– Vision loss
– Pain
– Hearing loss
– Symptoms of vasculitis, particularly giant cell arteritis
– Trauma
45. PHYSICAL FINDINGS
• An eso deviation that ↑
on ipsilateral gaze
• An isolated abduction
deficit
• Slowed ipsilateral
saccades
• Papilloedema
• Nystagmus
• Otitis media
• Orbital wall fracture
• Tender , non pulsatile
temporal arteries
46. CAUSES OF 6TH NERVE PALSY
ELEVATED INTRACRANIAL
TENSION
NEOPLASM
SUBARACHNOID SPACE
LESIONS
CONGENITAL ABSENCE
VASCULAR TRAUMATIC
METABOLIC POST LUMBAR TAP
DEMYELINATING DISEASE INFECTIONS
47. Classic teaching in pediatric ophthalmology
held that isolated sixth nerve palsies in
childhood should be considered the result of a
PONTINE GLIOMA until proven otherwise
48. DIFFERENTIAL DIAGNOSIS
1. myasthenia gravis
2. restrictive thyroid myopathy
3. medial orbital wall blow out fracture
4. orbital myositis
5. duane syndrome
6. convergence spasm
7. divergence paralysis
8. early onset esotropia
49. WORK UP
• LAB TESTS:
• CBC
• Glucose levels
• HbA1C
• ESR/C – reactive protein
• Rapid plasma reagin tests
• Fluorescent treponemal antibody – absorption test
• Lyme titre
• Anti nuclear antibody test
• IMAGING STUDIES
51. Indications of MRI
• Age < 45 years
• Associated pain or neurologic abnormality
• History of cancer
• Bilateral 6th nerve palsy
• Papilloedema
• In the event no marked improvement is seen
or other nerves become involved
52. OTHER TESTS
• Lumbar puncture
• Thyroid function tests
• Otoscopic examination
• Temporal artery biopsy
53. MANAGEMENT
• Medical Care
• Truly isolated cases often are benign.
• They can be followed with a serial
examination, at least every 6 weeks, over a 6-
month period to note decreasing symptoms
(diplopia) and resolution of the paretic lateral
rectus (increasing motility)
54. • Children : Amblyopia treatment
• Older patients in whom giant cell arteritis is a
consideration should start the standard
treatment with prednisone or intravenous
methylprednisolone as soon as possible.
55. SURGICAL CARE
• INDICATION:
• If after 6 months of follow up care the
remaining deviation is still unacceptable & is
too large to be corrected with prisms