Gross Anatomy Day 2 Flashcards
What regions are in the supratentorial compartment?
Telencephalon and diencephalon
What cranial nerves are in the supratentorial compartment
I and II
What actions/functions/behaviors are associated with the supratentorial compartment?
- awake and oriented
- olfactory and visual systems
- cognition and language
- emotion and behavioral regulation
- hypothalamic and pituitary functions
What are the regions in the infratemporal compartment?
Brainstem and cerebellum
What part of the brainstem is in the infratentorial compartment
CN 3-12
What major part of the brain is in the infratentorial compartment and what does it do?
Cerebellum, motor coordination
What is contained in the vertebral compartment
Spinal cord, dorsal and ventral roots
When motor and somatosensory exams re conducted, what compartment is being tested?
Vertebral compartment
What compartment is responsible for reflexes
Vertebral compartment
What causes herniation syndrome?
Various intracranial masses
What are 4 types of cranial herniations
- subfalcine herniation
- central herniation
- uncal transtentorial herniation
- tonsillar herniation
Herniations: effects on brain tissue vs dural partitions
- initially, it is the brain tissue that is displaced and injured
- with progression of mass effect, dural partitions can be displaced as well
- in radiology, shifts in dural partitions and brain can be detected
What could cause a midline shift
Supratentorial mass, causing subfalcine herniation
What is the average normal value for intracranial pressure?
<20cm (200mm) H20
<15cm (150mm) Hg
How is intracranial pressure measured?
- lumbar puncture (subarachnoid space around cauda equina)
- neurosurgical insertion of intracranial monitors/ catheters
Contra indications for lumbar punctures
- suspected increased supratentorial pressure (can cause herniations!)
- infection or mass in the path of manometer needle insertion
What are some causes of intracranial pressure
- hydrocephalus (too much CSF)
- brain edema (accumulation of water content)
- hemorrhage
- tumor or other mass
Symptoms of increases intracranial pressure
- headache
- nausea and vomiting (vomiting can occur in the absence of nausea)
- impaired consciousness
- skull (bulging fontanelles)
- increases systemic blood pressure
- papilledema
Increases intracranial pressure causes rippled effect along perimeter (elevation) and loss of sharp contours, due to congestion and swelling of axons
Papilledema
Sensory (pain) innervation of dura, falx, tentorium
Mostly trigeminal nerve (CN5), some vagus (CN10), cervical nerves
Meningeal irritation syndrome
- Headache/pain
- Neck stiffness (nuchal rigidity)
- Impairment or loss of consciousness
Mechanism of neck stiffness in meningeal irritation syndrome
Might be cervical spinal reflex circuit: sensory input activates motonerons and increases muscle tone in neck
Various potential causes or sources of meningeal irritation syndrome
- inflammation
- infection (meningitis)
- pressure (bleeding, growing intracranial mass)
Does intracranial pressure have to be present to have meningeal irritation syndrome?
No