hiloo

Pupillary changes related to location of damage

PERRLA - Are pupils equal, round, and reactive to light, accommodation.

\
\
`https://rb.gy/i890u`

\

Metabolic Imbalance - Pupils are smaller than normal, will react to light, and both pupils will react simultaneously(conjugately) also a brainstem dysfunction.

Pontine dysfunction - Both pupils are pinpoints (conjugate movement

Midbrain - Pupils are in middle position, fixed and will NOT react to light, both pupils will look the same.

Mass of something (ex. tumor, localized edema fluid) that is compressing the 3 cranial nerve (oculomotor nerve) -One pupil is dilated and fixed and the other is regular; NOT a good sign! Needs immediate attention!!! Will lead to coma and eventually death!

Tests that are ONLY done for patients in Coma to see if damage has extended to the brainstem!!!

Postural changes related to location of damage

https://youtu.be/kFjmgAo8UNE

Decorticate ("without cortex" problem with the cerebral cortices). we don't have the inhibition to posture movement operational; cerebral cortex is not providing inhibition, so the body gets rigid; there is adduction where the hands are drawn into the body; there is flexion of the hands; pronation of the wrists; full extension of the lower extremities; plantar extension of the feet; ability to inhibit muscle tightening has been suppressed in the cerebral cortex (NOT Good)

Decerebrate (midbrain dysfunction) of the brain stem. upper extremities are abducted (away from the body) pronation of wrist, flexion of the fists; (arching of the back) hard to see unless they're on a stretcher (EVEN Worse)

Flaccid (damage to the medulla). no muscle tone whatsoever, no movement "limp" (WORST of all!!!)

Cheyne-Stokes

(Due to problems in the cerebral hemispheres/cerebral cortex)

Crescendo/hyperpnea → decrescendo/apnea (found commonly in CHF left systolic heart failure pts) does NOT generally impact the PaCO2.

Post-hyperventilation apnea (PHVA)

(due to problems in the cerebral hemispheres/cerebral cortex)

Hyperventilation → apnea; responds only to PaCO2(often results in Respiratory Alkalosis)

Apneusis breathing

(due to problems in the middle part of the brain stem upper pons)

Prolonged inspiratory "cramp"(inspiration stays in the inflation mode) the patient takes a breath andthey retain inspiration; the breath is held in the chest cavity for awhile (kind of like with Emphysema)

Central Neurogenic Hyperventilation (CNH)

(due to problems in the upper part of the brain stem midbrain)

often results in Respiratory Alkalosis b/c were blowing off ourPaCO2 & our hypothalamus is unable to respond to that by telling the lungs to stop breathing.

(Clinical Manifestations: Dizziness)

Cluster Breathing

(due to problems in the mid/lower brain stem

lower pons)

Irregular pauses between breaths

Ataxic Breathing

(due to problems in the lower brain stem lower pons/upper medulla)

Completely irregular

Agonal Gasping

(you see this at End of Life "Death Rattle")(due to problems in the lower brain stem medulla)

Deep, slow breaths/gasps (very little rise and fall of the chest) mostly an upper airway movement; Sound like they're groaning; unable to move the secretions down or up. Patients will lift their head and neck to the side of the lesion.

(Doll's Eyes Test) Oculomotor

https://youtu.be/5dvqpxUGfcg

Taking the patient's head and rapidly moving it to the left and right to assess the brain stem function (Two-person test: One person moves the patient's head; the other person observes the patient's pupillary response)

Normal Response is that when you rapidly move the head to the left or right, the eyes will lag behind then move to that direction (allows for course correction); Pupils move conjugately (the move together)

Abnormal Responses:

o Disconjugate Movement - one eye is moving in the direction of the head and the other eye is looking somewhere else. No cranial nerve control over eye movement. This is creepy and indicative of brainstem damage.

o Absent Response is when the eyes follow the movement of the head (there is NO hesitation or lag) this is known as a Positive Doll's Eye Test with no hesitation or lag (eyes appear to be stuck to the patient's head). This is NOT normal, and it indicates damage to the brainstem.

*Before doing this test, you MUST rule out Cervical Spine Injury!!! If you perform this test with someone with CSI and you perform this test, you will paralyze them for life!!!

Oculomotor Responses: Oculovestibular (Caloric Test)

https://youtu.be/6F1sSfGnTXk

Fill a 60-cc syringe with 30-50 cc of water and inject that into someone's ear (noxious stimulus)

This test will exam the cranial nerves (eye reflexes) and vestibular apparatus (endolymphatic flow in the middle ear canal); patient needs to be a 30-degree semi-fowlers position (optimal elevation of the bed for the endolymphatic flow of fluid)

Normal Response is for both eyes to look towards the ear where the water is being poured as if to say, "What the heck are you doing?" Both eyes will move conjugately (both eyes move together)

Abnormal Responses:

o Disconjugate Response (Oculovestibular Caloric Test) where one eye moves in one direction and the other eye moves in another direction (this is creepy and is NOT normal); indicates brainstem damage

o Absent Response where there is not eye movement at all (no response); means brainstem damage

Brisk Doll's eyes

movement to the side where you'veturned the head is faster than normal (brisk movement);both eyes still move conjugately (together)

Roving Eyes

eyes that go everywhere (up, down, left,right, in circles, zig zag, creepy, BUT they do it conjugately,so this indicates there is NO brainstem damage

No Nystagmus

nystagmus is shimmying movement of the eyes (eyes go back and forth very rapidly) while they are still moving to the side of the ear where the water is being poured, they are just moving with a shimmying movement (this can be a normal response as long as eyes move conjugately); NO nystagmus means the eyes don't shimmy when they move!

Supratentorial herniation

Changes in LOC, pupils, breathing pattern, motor response

Transtentorial (Central) - downward displacement (even shift) (movement of brain tissue)

Downward shift of diencephalon (front of the brain)

Rapid ↓ LOC, Cheyne-Stokes → apnea, small →fixed & dilated pupils, decorticate → decerebrate.

Uncal - temporal lobe (uncus) shift from middle to posterior fossa (uneven shift)

Uncus or hippocampal gyrus shifts from middle fossa through tentorial notch into posterior fossa (hippocampus shifts backward into the brainstem resulting in unilateral pupil dysfunction

Compresses CN III → impairs parasympathetic function

decrease LOC, ipsilateral then contralateral pupillary fixation & dilation, Cheyne-Stokes → CNH(inflammation of pinna), decorticate → decerebrate.

Acute confusion states - pathophysiology, clinical manifestations

Attention, thought & action deficit (non-purposeful movement - early sign of delirium)

(Many things can cause this confusion - sustained for a substantial amount of time but it fluctuates (comes and goes) until they move into disorientation) RAS (a bundle of nerves that sits in your brainstem) disruption (upper brainstem → thalamus, basal ganglion, cortex, & limbic) Behavior can be erratic and bizarre.

Etiology: drug intoxication, metabolic disorders, nervous system diseases, other

Manifestations (fluctuating): confusion, restlessness, focus/attention/vigilance problems, delusions, hallucinations, perseveration

infratentorial herniation

Shift of cerebellar tonsils