Transcript DENTAL GROSS ANATOMY CASE 1 CAVERNOUS SINUS

DENTAL GROSS ANATOMY
CASE 1
CAVERNOUS SINUS
THROMBOSIS
HISTORY
 Patient develops a boil on his upper lip after cutting
himself shaving on a hunting trip
 He presents to his physician with a high fever and
severe headaches
 Patient does not improve with penicillin injections and
is admitted to a hospital
EXAMINATION
 Rigidity of neck muscles
 Upper lip swollen and oozing pus
 Cheek, side of nose and eyelids swollen
 Exophthalmos
 Edema of optic nerve at papilla
 Inability to move eye
 Paresthesia of forehead, side of nose and upper cheek
 Blood culture positive for Staphylococcus aureus
DIAGNOSIS
 Staphylococcic infection of upper lip and infectious
cavernous sinus thrombosis
THERAPY AND FURTHER COURSE
 Patient is put on intravenous antibiotics
 Warm, moist dressings applied to face
 Narcotics given for pain
 Patient responds slowly to antibiotics and ocular
functions improve only gradually
 After three weeks patient has made a complete recovery
and is discharged
PATIENT WITH CAVERNOUS SINUS THROMBOSIS
1. Where is the cavernous sinus
located?
Cavernous sinus
2. What anatomical features
does the cavernous sinus
share with other venous
sinuses and in what respects
does it differ?
Cavernous sinus
Optic chiasm
Hypophysis
Differences from
other sinuses
III
IV
Int. carotid a.
(w/sympathetic plexus)
VI
Similarities with
other sinuses
Within dura
Lined by endothelium
Lacks muscular coat
Lacks valves
V1
V2
Contains
trabeculae
Sphenoid sinuses
within body of sphenoid bone
3a. What are the tributaries to
the cavernous sinus?
b. What veins directly drain
the cavernous sinus?
Tributaries
Cavernous sinus
Sup. ophthalmic v.
Inf. ophthalmic v.
(not shown)
Central v. of retina
(inside optic n.)
Sphenoparietal
sinus
Superficial
middle cerebral v.
Drainage
Sup. petrosal
sinus
Inf. petrosal
sinus
Intercavernous sinus
3c. Into what vein does the
blood in the cavernous
sinus ultimately drain?
Sup. petrosal sinus
Inf. petrosal sinus
Sigmoid sinus
To int. jugular v.
4a. What is the definition of an
emissary vein? Can the
ophthalmic veins be
regarded as emissary veins?
b. What is the direction of blood
flow in emissary veins?
c. In view of your answer (to b)
above, what is the clinical
significance of emissary veins?
Sup. ophthalmic v.
Angular v.
Cavernous sinus
Facial v.
Inf. ophthalmic v.
5. Describe the venous pathway
by which infectious material
reached the cavernous sinus
in this patient.
Sup. ophthalmic v.
Angular v.
Facial v.
Sup. labial v.
6. How do you explain the
swelling of the eyelids and
conjunctivae, the exophthalmos,
the dilation of the retinal veins
and the edema of the optic nerve
in this patient?
Retinal v.
Optic n.
Central v. of retina
Optic disc
(papilla)
7. What cranial nerves have been
affected by this infectious
thrombosis? (Give reasons for
your answers). Through what
openings do these nerves leave
the cranial cavity?
SO4, LR6, R3
Levator palpebrae
superioris m.
Sup. oblique m.
Sup. rectus m.
III
IV
VI
Inf. oblique m.
Inf. rectus m.
Med. rectus m.
Lat. rectus m.
Ophthalmic n. (V1)
Maxillary n. (V2)
Mandibular n. (V3)
Optic canal
(II)
Sup. orbital fissure
(III, IV, VI, V1)
F. rotundum
(V2)
8. What might be the consequence
if the infectious material invaded
the internal carotid artery within
the sinus?
Mid. cerebral a.
Ant. cerebral a.
Cavernous sinus
containing ICA
Ant. cerebral a.
Ant. communicating a.
ICA
Mid. cerebral a.
Post. communicating a.
Post. cerebral a.
Basilar a.
Vertebral a.
Superficial middle
cerebral v.
9. Explain how osteomyelitis
(inflamation of the bone and
marrow) of the upper or lower
jaw following tooth extraction
could lead to infectious cavernous
sinus thrombosis. (Hint: What
important venous structure lies
in the infratemporal fossa?)
Emissary v. connecting
w/ cavernous sinus via
f. ovale
Post. sup. alveolar v.
Pterygoid plexus of vv.
Inf. alveolar v.
Additional Note
Infectious cavernous sinus thrombosis was almost invariably fatal
prior to the advent of antibiotics. In this era of intensive antibiotic
treatment the condition is not as common as it used to be but the
prognosis, should one contract it, is grim —
80% mortality and in the survivors 75% after effects, mainly involving
eye muscles and changes in visual acuity.
END