Neuro Flashcards
What is the difference between arousal and awareness? In what parts of the brain do they arise?
- Arousal
- vegetative function
- brainstem and RAS (diencephalon)
- Awareness
- cognitive and affective function
- cortex
What is included in a neuro exam for a possible coma patient?
- C = level of consciousness
- O = Ocular motility and pupils
- M = Motor response
- A = Airway and breathing
What does fruity breath signify in a possible coma patient?
Diabetic ketoacidosis
What does fishy breath signify in a possible coma patient?
Hepatic failure
What does musty breath signify in a possible coma patient?
Renal failure
If the patient has a hemispheric lesion, where will the eyes and head deviate?
Toward lesion
If the patient has a brainstem lesion, where will the eyes and head deviate?
Away from the lesion
If the patient’s pupils are in a mid-position and non-reactive, where is the lesion?
Midbrain
If the patient’s pupils are dilated on one side and non-reactive, where is the lesion?
CN III paralysis
If the patient’s pupils are small but reactive, where is the lesion?
Pontine
If the patient’s pupils are pinpoint but reactive, what is the cause?
Opiate intoxication
In the oculocephalic reflex, if the patients head is moved to one side, where should the eyes move?
To the opposite side (to stay focused on the same thing)
In the oculovestibular reflex, cold water in the ear should cause the eyes to move where? Warm water?
COWS: Cold water = Opposite; Warm water = Same
Cold water = nystagmus to opposite side
Warm water = nystagmus to same side
What part of the brain is responsible for inducible reflex lateral eye movements?
Pons and midbrain
If a patient lacks inducible reflex eye movements with the doll’s eye maneuver but has preserved pupillary reactivity, what is the likely diagnosis?
Drug intoxication
If patient presents with decerebrate rigidity (extended arms and legs), where is the lesion located?
upper brainstem (between red nucleus and vestibular nucleus)
Midbrain or pontine level
If the patient presents with decorticate rigidity (extended legs and flexed arms), where is the lesion located?
- level of diencephalon or above
- hemispheres
- internal capsule
- thalamus
Where is the lesion if an unconscious patient presents with small reactive pupills, full conjugate lateral eye movements, and an appropriate motor response?
Early diencephalic
Where is the lesion if an unconscious patient presents with small reactive pupills, full conjugate lateral eye movements, and decorticate rigidity?
Late diencephalic
Where is the lesion if an unconscious patient presents with midposition, fixed pupills, dysconjugate lateral eye movements, and decerebrate rigidity?
Midbrain
Where is the lesion if an unconscious patient presents with midposition, fixed pupills, absent lateral eye movements, and lack of a motor response?
Pons or Medulla
What are the possible causes of Cheyne-Stokes respiration?
- Definition
- Hyperpnea alternating with apnea
- Causes:
- Diffuse bilateral cerebral hemispheric dysfunction
- Diencephalic dysfunction
- CHF
What are the possible causes of central neurogenic hyperventilation?
- Definition
- sustained rapid and deep hyperpnea
- Cause:
- Lower midbrain or pons lesion
What is the cause of Apneustic breathing?
- Definition:
- end inspiratory pause alternating with end expiratory pause
- Cause
- Lwr pontine lesion
What is the cause of Ataxic breathing?
- Definition
- irregular breathing pattern
- Cause:
- Medullary lesion
What is invaded/ destroyed in a supratentorial lesion? What are some causes?
- Damage to diencephalon
- Causes:
- cerebral hemorrhage
- tumor
- Encephalitis
What is compressed in a subtentorial lesion? What are some causes?
- Compresses
- midbrain-pontine reticular formation
- Causes
- Pontine or cerebellar hemorrhage
- Infarction
- Tumor
What size lesion does a CT detect? What type of lesion is best visualized? What is the advantage over an MRI?
- Size
- >5mm
- Type of lesion
- best for acute hemorrhage
- Advantage
- faster than MRI
What size lesion does an MRI detect? What can prevent a patient from being able to get an MRI?
- Lesion
- 1-2 mm
- Exclusion
- people with metallic objects like pacemakers, aneurysm clip
What is the treatment for raised intracranial pressure from a brain tumor?
IV steroids
What is the treatment for diabetic ketoacidosis?
Insulin
What is the treatment for opiate overdose?
Naloxone
What is the treatment for benzodiazepine overdose?
Flumazenil
What is the treatment for ETOH abuse?
Thiamine
What is the treatment for hepatic encephalopathy?
Lactulose
What is a vegetative state?
- Arousal without awareness
- Termed persistant after 4 weeks
- Vegetative after:
- 3 months (non-traumatic)
- 12 months (traumatic)
What is a locked-in state?
- Patient is awake and aware
- Reactive pupils
- Preserved voluntary vertical eye movements and blinking only
- Otherwise paralyzed
What is Brain Death?
- Irreversible damage that leaves the brain incapable of maintaining homeostasis of body
- Unperceptie/Unresponsive to pain (Cortex)
- Unreactive pupils (Midbrain)
- Absent reflex eye movements (Pons)
- Apnea (Medulla)
Patient reports severe headache with maximal intensity at onset (“thunderclap headache”) and neck stiffness. What is the diagnosis? What is the cause?
- Diagnosis
- Subarachnoid hemorrhage
- Cause
- Ruptured aneurysm (most common)
- Ruptured AVM
What is the cause of subdural hematomas?
Tearing of bridging veins from trauma
Patient describes a headache following head trauma. They had a period of lucidity then deteriorating mental status. What is the diagnosis? What is the likely cause?
- Diagnosis:
- Epideral Hematoma
- Cause:
- Damage to middle meningeal artery
- Imaging
- Convex (like a lens)
- b/c expansion stops at skull sutures
- Convex (like a lens)
What is shown?
Epidural Hematoma
- Convex shape (like a lens)
- b/c expansion stops at skull sutures
How can you tell the difference between an epidural hematoma and a subdural hematoma via imaging? Why does this occur?
- Epidural
- Convex in shape (like a lens)
- b/c expansion stops at skull sutures
- Convex in shape (like a lens)
- Subdural
- Concave in shape
- expansion not limited by sutures
- Concave in shape