Mechanical problems Flashcards
What is a chiari malformation?
When the brain tissue extends into the spinal canal causing the skull to be misshapen or smaller than is typical
What is a meningocele?
A birth defect where there is a spinal fluid sac protruding from the spinal column
Contains no neural tissue
What is a Encephalocoele?
A congenital neural tube defect where part of the skull has not formed properly so a portion of brain tissue and associated structures are outside the skull
May be covered in skin or a thin membrane
What is Spinal Dysraphism?
A spectrum of congenital anomalies resulting in a defective neural arch through which meninges or neural elements are herniated
What is a Myelomeningocele?
A sac that contains part of the spinal cord
What is spinal stenosis?
Narrowing within the spinal canal
- Central canal stenosis
- Lateral recess stenosis: narrowing of the sides of the bony tubular passageway, the lateral recess
- Neural foraminal stenosis: compression of the spinal nerves as they leave the spinal canal
How is mannitol used in neurosurgery?
To reduce brain tissue swelling and improve brain relaxation
Used to control raised intracranial pressure
What are the different types of herniation due to increased intracranial pressure?
- Subfalcine: involves the cingulate gyrus, which is pushed against the falx cerebri
- Transtenorial (uncal): involves the medial temporal lobe, which is often squeezed by a mass under and across the tentorium
- Central: involves herniation of both temporal lobes through the tentorial notch
What is degenerative disc prolapse?
What is Cushing’s response?
It’s the physiological response to raised ICP:
- Hypertension
- Bradycardia
- Respiratory irregularity
How does CO2 regulate how much blood gets to the brain?
It either dilates or contracts the vessels to control how much blood goes in
Vasodilation in raised ICP doesn’t help so patients are hyperventilated to reduce ICP
What is the Monro-Kellie hypothesis?
Theory for intracranial pressure
The sum of volumes of brain, CSF, and intracranial blood is constant and an increase in one should cause a decrease in one or both of the remaining two
What is deep brain stimulation therapy (DBS)?
Electrodes are placed within the brain to stimulate the brain
Used to treat Parkinson’s, tremors, dystonia, epilepsy, depression, and OCD
What is papilledema?
Swelling of your eye’s optic disks due to an imbalance of cerebral fluid and pressure in and around the brain
