Principles of Herniation
In uncal herniation, is the pupil blown on the ipsilateral or contralateral side? is the hemiparesis on the ipsilateral or contralateral side?
Pupil - ipsilateral
Hemiparesis - contralateral
What is his name? Where is he from?
Abubakar Okefore. Nigeria.
What artery is usually ruptured?
meningeal artery, a branch of the maxillary artery
In subdural hematoma, what is ruptured an artery or a vein? Why is this clinically significant?
Bridging veins. Because they are veins there is lower pressure so symptoms are less. These veins drain blood into dural sinuses.
Subarachnoid hemorrhage is usually due to a rupture of what type of aneurysm?
Usually from rupture of berry aneurysms in the circle of willis. Associated with AVMs. Patients present with nausea, vomiting, loss of consciousness.
What type of herniation most typically leads to a " blown pupil"? Why does the pupil dilate?
Uncal - medial temporal lobe herniation. Cranial nerve 3 compression causes loss of parasympathetic innervation leading to the dilated pupil. Can also get collapse of posterior cerebral artery leading to visual loss.
you are too smart, free 200 points for you and you get to choose again!
BAM
What is the typical shape seen on CT in this type of bleed?
Convex shape.
Where does blood accumulate in a subdural hematoma? Does this bleed cross the suture lines?
between the dura and arachnoid. These DO cross the suture lines but NOT the falx or tentorium.
In a patient with a subarachnoid hemorrhage secondary to a berry aneurysm, what is the treatment?
Surgical clipping.
Medical therapy includes oral nimodipine to prevent vasopasm and manage blood pressure to prevent rebleeding.
Which region of the brain is typically compressed in a cerebellar tonsilar herniation?
the brain stem. Mass lesion in the posterior fossa.
What was his GCS and BP upon presentation to the ED?
15, 80/40.
What is the imaging modality used for this bleed: noncontrast or contrast CT?
noncontrast head CT.
note: Although MRI has a higher sensitivity, it is slower than performing a CT scan, making it unsuitable for unstable patients. It is also not as widely available as CT. If there is a strong suspicion of epidural hematoma but no hematoma is visible on CT, an MRI may be used additionally.
What is the typical pathophysiology of a subdural hematoma and how does this lead to bleeding?
Head trauma → rapidly changing velocities of the brain within the skull → stretching of bridging veins → tearing and rupture of bridging veins → SDH
What is cerebral amyloid angiopathy and how does this relate to patients getting recurrent hemmoragic strokes>
these patients get current hemorrhagic strokes in the frontal and parietal lobes. Beta amyloid deposits in their artery walls which make them very prone to rupture and thus they get recurrent hemorrhagic strokes.
What artery is at risk of rupturing in a central transtentorial herniation?
THe brain stem can get caudally displaced and this can rupture the basilar artery branches. This is called a Duret hemorrhage and is fatal.
On neuro exam, what unusual reflex did our patient have? ( infants)
Bilateral babinski
Describe the treatment: initial resuscitation, management of elevated ICP and surgical management?
Initial resuscitation
IV fluids (if hypotension is present)
Intubation
Management of elevated intracranial pressure
Head elevation
If patient is intubated, hyperventilation
Osmotic diuresis with mannitol or hyperosmotic saline solution
Surgical management
First-line: urgent craniotomy and hematoma evacuation
Second-line: emergency burr hole
In subarachnoid hemorrhage, where is the bleeding?
Bleeding between arachnoid and pia matter. So the bleeding is into the subarachoid space = The space between the arachnoid layer and pia mater that contains cerebrospinal fluid. The major arteries of the brain, including the circle of Willis, lie in the subarachnoid space.
What is the most common area effected in a hemorrhagic stroke?
Putamen stroke which causes contralateral hemiparesis, sensory loss of face, arms and legs, gaze deviation toward the side of the bleed. Typical case is someone with left paralysis and sensory less PLUS eyes deviating to the right.
In a subfalcine hernation ( cingulate gyrus herniation) what artery gets dragged along with the herniation? Hint - can cause leg paralysis on contralateral side
anterior cerebral artery
Upon seeing the CT scan, Dr. Patel diagnosed our patient with what type of bleed?
Epidural hematoma
What is the lucid interval?
you get a severe concussion -> then they get up-> but they are bleeding internally so in 30 minutes they pass out.
The separation of dura matter from the calvarium leads to the formation of an arteriovenous shunt that allows blood to accumulate in the epidural space without raising intracranial pressure. This delay in the appearance of symptoms is known as a lucid interval and explains why the patient may be awake and alert on arrival at the emergency department.
What is xanthochromia and how does it relate to the diagnosis of SAH?
yellowing of CSF on spinal tap.
If initial CT is unremarkable, can do lumbar puncture or CT angio.
Sensitivity is almost 100% within the first 6 hours of hemorrhage with noncontrast head CT. If you are still suspicious after a negative CT you can run a lumbar puncture and will see:
Increased RBC count with red discoloration, increased protein and xanthochromia - yellow discoloration of CSF due to presence of xanthematin which is a yellow pigment derived from hematin that is released when RBCs are broken down. Normal glucose.
What is a charcot bouchard aneurysm?
these are tiny microaneursyms off the middle cerebral artery, specifically branches of the lenticulate striate arteries. These are usually the origin of hypertensive ICH.