Thrombosis of the sigmoid sinus is a condition where a blood clot forms in the sigmoid sinus, a large vein located in the brain. It can lead to symptoms such as headache, dizziness, visual disturbances, and in severe cases, neurological deficits. Causes include trauma, infections, dehydration, and clotting disorders. Treatment typically involves anticoagulation therapy and addressing the underlying cause. In some cases, surgery may be necessary to remove the clot or improve blood flow. Early diagnosis and treatment are crucial to prevent complications such as stroke or brain damage.

1. SIGMOID SINUS
THROMBOSIS
SHRUTI GUSAIN
GROUP 5

2. What is Sigmoid Sinus Thrombosis ?
u Lateral sinus thrombosis ,also known as
sigmoid sinus thrombosis forms when infection
from the adjacent mastoid contacts and
penetrates the venous wall and forms a
thrombus.
u SST Is a rare but serious medical condition
that occurs when a blood clot forms in the
sigmoid sinus, a large vein located at the
base of the brain that drains blood from the
brain.
u The clot can block blood flow and lead to a
buildup of press In brain and cause relative
symptoms .
u Embolisation of the thrombus can cause
distal disease

3. Etiology ?
u Genetic prothrombotic conditions:
-Antithrombin deficiency, Protein C and protein S deficiency, Factor V Leiden mutation,
Prothrombin mutation (the substitution of A for G at position 20210), homocysteinemia caused by
gene mutations in methylenetetrahydro-folate reductase.
u Acquired prothrombotic states: Nephrotic syndrome, Antiphospholipid antibodies,
Homocysteinemia,
Pregnancy, Puerperium.
u Infections: Otitis, mastoiditis, sinusitis, Meningitis, Systemic infectious disease.
u Inflammatory disease: Systemic lupus erythematosus, Wegener's granulomatosis, Sarcoidosis
Inflammatory bowel diseases, Behçet's syndrome
u Hematologic conditions: Polycythemia, primary and secondary ThrombocythemiaLeukemia ,
anemia, including paroxysmal nocturnal hemoglobinuria .
u Drugs: Oral contraceptives ,Asparaginase
u Mechanical causes, trauma
u Miscellaneous: Dehydration, especially in children , Cancer.

4. Anatomy & Spread ?
u Formed by the confluence of the
superior petrosal and transverse
sinuses .
u Becomes internal jugular vein at its
exit from foramen jugulare.
u Directly through bone erosion due
to granulation and
cholesteatoma.
u Thrombophlebitis of the mastoid
emissary veins.
• Griesinger’s Sign – erythema ,
edema and tenderness over
mastoid area.

6. Epidemiology
u Age – ADULTS OR OLDER CHILDREN
u 6- 10 % of all Intracranial complication of chronic otitis media.
u Types of ear infections associated- most common with
cholesteatoma.
Ø May occur from other forms of chronic mastoiditis.
Ø Acute otitis media in rare cases – caused by
osteothromophlebitis.
§ Other associated intracranial complications- meningitis,
epidural abscess, subdural empyema , cerebellar abscess.

12. Clinical features:
u In the era of antibiotics, may be present without symptoms
• Classical presentation is very rare- components were:
1. There was severe febrile illness with rigors in patient with
middle ear disease.
2. Rise of temperature to 39-40 c and rapid fall of temperature
with sweating( picket fence fever pattern due to periodic
release of streptococci in blood from septic thrombus.
3. Shivering used to be so severe so as to shake the bed.
4. Headache and neck pain ( due to incr. ICP —>papilledema
).
5. Anaemia with emaciation was also seen in classical cases.

13. Clinical features:
o Feeling of being ill.
o Persistent fever ( but without violent swings and rigors
as seen in pre antibiotic era) .
o Headache, vomiting( due to raise ICP and bacteremia
).
o Otalgia with mastoid tenderness .
o Neck pain, Neck torticollis along with tenderness along
jugular vein.
o When thrombosis extend to subclavian vein -engorged
collateral veins over shoulder maybe seen.
o development of hydrocephalus
o Chemosis or proptosis of one eye
o drowsiness, lethargy, coma

14. Examination Findings?
u Otoscopic findings suggestive of middle ear
infections.
u Tenderness over mastoid process and
sternomastoid .
u Fundus examination- Papilloedema .
u Griesingers sign - pitting edema over the occipital
region well behind the mastoid process caused
by clotting within large mastoid emissary vein.
u Anemia and emaciation
u Positive Tobey- Ayer’s Test.
u Positive Crow- Beck’s Test.
u Kernig’s and Brudzinski’s Sign.

16. Bacteriology & Labs
u ACUTE
o Hemolytic streptococcus
o Pneumococci
o Staphylococci
u CHRONIC
o Bacillus Proteus
o Pseudomonas pyocyaneus
o E.coli
o Bacteroides
o Staphylococci
u Increase Polyp on CBC.
u CSF exam show increased
ICP.
u Lumbar puncture should
be performed if
papilloedema does not
suggest that raised intra
cranial pressure may lead
to coming.
u CSF analysis done in cases
of suspected meningitis.

21. Treatment?
u Medical + Surgery —à combination therapy
u Medicine:
• I/V antibiotics
• Anticoagulant only if clot in superior sagittal sinus
or increased ICP persists despite medical
management.

22. u Surgical:
o Mastoidectomy + removal of clot from sinus.
o ASOM - Cortical + removal of sinus plate.
o CSOM + Cholesteatoma : radical
o Refractory Septicaemia: UV litigation to stop emboli
being thrown into circulation.
ü Follow up: -
o Post op antibiotic for 2- 3 weeks
o Post op MRI & MRV.

23. Complications?
Ø Complications of sigmoid sinus thrombosis may include:
ü Increased pressure in the brain: Sigmoid sinus thrombosis can cause an
increase in intracranial pressure, which can lead to headaches,
nausea, vomiting, and changes in vision.
ü Neurological deficits: Depending on the location and extent of the clot,
sigmoid sinus thrombosis can cause neurological deficits, such as
weakness, numbness, or paralysis on one side of the body.
ü Hearing loss: Sigmoid sinus thrombosis can affect the inner ear and
cause hearing loss or ringing in the ears.
ü Seizures: In some cases, sigmoid sinus thrombosis can lead to seizures,
which can cause sudden, uncontrolled movements and loss of
consciousness.
ü Meningitis: Sigmoid sinus thrombosis can lead to the development of
meningitis, which is a serious infection that can cause inflammation of
the brain and spinal cord.
ü Pulmonary embolism: In rare cases, a blood clot from the sigmoid sinus
can break off and travel to the lungs, causing a pulmonary embolism.

24. Case study
u A 35-year-old woman presented to the emergency department with a severe headache that
had been ongoing for the past two days. She had no significant medical history and was not
taking any medications. On examination, she had a fever of 38.5°C and was sensitive to light.
She also had tenderness over the left ear.
u A CT scan of the head showed no abnormalities, but a subsequent MRI with contrast revealed
a thrombus in the left sigmoid sinus. The patient was diagnosed with sigmoid sinus thrombosis
and was started on intravenous antibiotics and anticoagulation therapy.
u Over the next few days, the patient's symptoms gradually improved, and she was discharged
from the hospital on oral anticoagulation therapy. A follow-up MRI after six months showed
resolution of the thrombus.
u Although the exact cause of the thrombus was not determined, the patient reported having a
recent upper respiratory tract infection, which may have contributed to the development of
the clot. The patient was advised to seek medical attention immediately if she experienced
any recurrent symptoms.

25. Links to additional videos
u https://youtu.be/Ip4xT4DQ0U4
u https://youtu.be/v7wiFiHzaEU
u https://youtu.be/qMpXDbcLX9o
u https://youtu.be/SZKTnrHmS4I