Blue boxes: dural sinuses Flashcards
What is thrombophlebitis of the facial vein?
There is inflammation int eh facial vein with a secondary thrombus formation and the infected clot can cause an infection in the cavernous sinus
What is the triangle of death on the face? Why is this the triangle of death?
The triangular area from the upper lip to the bridge of the nose
How can thrombophlebitis of the facial vein occur?
From a laceration in the nose, to popping a pimple on the nose within the triangle of death; this can cause an infection that can spread to the cavernous sinus which is deadly because then it can get to the rest of the body
What can happen to the dura during a blunt trauma to the head?
The periosteal layer can separate from the calvaria
if there is a fracture to the skull near the base, the dura can also fracture and can cause a leakage of CSF
What is a tentorial herniation?
The tentorial notch is the opening for the tentorium cerebelli that goes to the brainstem
In a herniation, the temporal lobe may be lacerated by the tentorium cerebelli and the oculomotor nerve can become compressed or stretched which causes paralysis to the ocular muscles
Describe bulging of the diaphragma sellae
Pituitary tumors can extend superiorly into he diaphragma sellae, which can produce endocrine disturbances and can cause compression of the optic chasm, resulting in vision changes
Which venous sinuses are most commonly thromboses?
Transverse, cavernous, and superior sagittal
Describe the metastasis of tumor cells to the dural venous sinuses
The intervertebral venous systems and the dural sinuses are valveless, so something that increases the pressure in the thoracic area such as heavy coughing, straining can force blood from these areas up into the dural sinuses along with the cancer cells, which are able to metastasize up there
Describe a fracture of the cranial base that has caused an arteriovenous fistula.
The fracture of the cranial base has caused the internal carotid artery to be torn, and caused an influx of arterial blood into the cavernous sinus, which causes it to swell and send blood into the venous tributaries
The tributary that is most commonly affected is the ophthalmic veins, which results in the eye popping forward with notable pulses (pulsating exophthalmos)
Which nerves are surrounding the cavernous sinus?
III IV V1 V2 VI
Why is it possible to get a headache following a lumbar puncture?
When the CSF was removed, there was a slight sag in the brain, which pulls on the dura, and causes a headache
Describe leptomeningitis
Inflammation of the leptomeninges from pathogenic microorganisms; typically confined to the subarachnoid space but can travel through the blood and stuff
Define a cerebral concussion
Brief loss of consciousness immediately after a severe head injury
concussion can occur without the loss of consciousness as well
Define a cerebral contusion
results from brain trauma where the pia is stripped from the injured surface of the brain and may be torn, allowing the blood to enter the subarachnoid space
What is a cerebral laceration and when does it typically occur?
A cerebral laceration is a laceration in the brain that causes bleeding into the brain and subarachnoid space which can increase intracranial pressure
usually caused by a depression fracture of the skull
What are possible ways in which a cerebral compression can occur?
- intracranial collection of blood
- obstruction of CSF circulation
- intracranial tumors or abscesses
- brain swelling or edema
What is a cisternal puncture
The LP for children and infants (rmr we don’t know where their nerves actually end in their back)
a needle is inserted into the posterior atlanto-occipital membrane into the cerebromedullary cistern to retrieve the CSF
Describe hydrocephalus
- Overproduction of CSF
- obstruction of the flow of the CSF
- interference with CSF absorption
Results in excess fluid in the brain ventricles and enlargement of the head by separating the bones of the calvaria in infants,
What could occur if there is a fracture in the floor of the middle cranial fossa?
CSF leakage from the external acoustic meatus if the meninges superior to the middle ear is torn and the TM is ruptured
What could occur if there is a fracture in the floor of the anterior cranial fossa
If there is a fracture in the cribiform plate or the ethmoid bone, then there can be leakage of CSF from the nose
True or false: The cerebral arterial circle has several variations that can be present in people
TRUE
Describe a stroke
Acute disruption of the normal blood flow of the brain that results in death of brain cells that results in a brain malfunction
two types are hemorrhagic which is due to bleeding and ischemic which is due to lack of blood getting to the brain
typically only cause deficits and not death
Describe a brain infarction
A piece of plaque from a vessel that is clogged can get dislodged and travel into the arteries of the brain and get lodged and impede blood flow to the brain, causing that area of the brain to potentially die if there are no anastomoses to that area
Describe a transient ischemic attack
Ischemia of the brain that lasts for less than 24 hours resulting in minimal neurological damage
small stroke basically but not as severe
