Thrombosis Of Cerebral Veins and Venous Sinuses

Question 1

How is the superficial venous system structured?

Answer 1

In superior, middle and inferior cerebral groups

Question 2

How is the deep venous system structured?

Answer 2

Veins drain into the internal cerebral vein and the basilar vein of Rosenthal

due to the large interconnections, only occlusions of both will obstruct the deep venous flow

Question 3

Which population is most affected by CVST?

Answer 3

in 75% of cases: women, between 20 - 40 yoa.

in total accounts for 0.5 - 1% of all strokes

Question 4

Which mechanisms lead to CVST?

Answer 4

Thrombosis of cerebral veins (edema, ischemia, neurological damages)
Thrombosis of major sinuses
Occlusion of major sinuses (intracranial HTN)

Question 5

Which kinds of edema do occur in CVT?

Answer 5

cytotoxic edema: due to ischemia of the cell membrane pumps, leading to intracellular edema

vasogenic edema: due to disruption of BBB and leakage of plasma into interstitial space

Question 6

What are the risk factors for CVST?

Answer 6

genetic and aquired prothrombotic states
infections
inflammatory and AI diseases
malignancies
hematological diseases
drugs
mechanical causes

most common causes:
gen. and aqu. prothromb. states
pregnancy, purepartum
infections

Question 7

What are the causes for septic thrombophlebitis?

Answer 7

infections:
middle ear, mastoid cells, paranasal sinuses, skin around eye, upper lip, nose

meningitis, epidural abscess, subdural empyema, brain abscess

Question 8

Clinical signs in CVST?

Answer 8

-headache: most common symptom, localized, gradual onset
in case of intracranial pressure: severe, dull, worsens with vasalva maneuver

• encephalopathy: delirium, apathy, frontal lobe syndrome
• focal signs and symptoms: motor weakness, mono- and hemiparesis, aphasia
• seizure: focal or general seizures, st. epilepticus

Question 9

Which imaging methods are used for venous thrombosis?

Answer 9

CT, MRI, CT venography, angiography

most commonly used: CT

Question 10

What signs can be seen in a CT of the cerebral veins?

Answer 10

• direct signs:
  dense clot sign: hyperdense triangular or round shaped
  empty delta sign: triangular pattern, hypodense central area
  cord sign: linear hyperdensity, caused by thrombosed cortical veins
• indirect signs:
  small ventricles
  parenchymal abnormalities: hemorrhagic and nonhemorraghic lesions

Question 11

Treatment for CVST?

Answer 11

• acute antithrombotic treatment:
  anticoagulants: IV unfractioned heparin, subcutaneous LMWH
• prevention of early complications:
  intercranial pressure: elevate head, mannitol,osmotic diuretics, hyperventilation to PaCO2 of 30 - 35mmHg, monitoring
  seizure control: anticonvulsants
• AB and surgical drainage of infectious source
• analgetics

during pregnancy: LMWH

Question 12

superior saggital sinus thrombosis signs

Answer 12

headache, intracranial hypertension, motor deficits

Question 13

transverse saggital sinus thrombosis signs

Answer 13

isolated headaches, seizures, aphasia

Question 14

cavernous sinus thrombosis signs

Answer 14

orbital pain, chemosis, proptosis, oculomotor palsies

loss of sensibility of face

Question 15

anatomy of brain venous circulation

Answer 15

superficial venous system (sup, midd, inf. groups)
deep venous system (internal cerebral vein, basilar vein of rosenthal)
venous sinuses (saggital, transverse, cavernous, petrosal, torcular herophili)

Question 16

deep cerebral venous thrombosis signs

Answer 16

coma, mental status changes, motor deficits, bilateral thalamic involvement