Neurosurgery, C75 P721-743 Flashcards
HEAD TRAUMA
What is the incidence?
P721
70,000 fatal injuries/year in the United
States, 500,000 head injuries per year
HEAD TRAUMA What percentage of trauma deaths result from head trauma? P721
50%
HEAD TRAUMA
Identify the dermatomes:
P721 (picture)
(see Picture)
HEAD TRAUMA
What is the Glasgow Coma
Scale (GCS)?
P721
GCS is an objective assessment of the
level of consciousness after trauma
HEAD TRAUMA
GCS SCORING SYSTEM
Eyes?
P721
Eye Opening (E) 4—opens spontaneously 3—opens to voice (command) 2—opens to painful stimulus 1—does not open eyes (Think: “4 eyes”)
HEAD TRAUMA
GCS SCORING SYSTEM
Motor?
P722
Motor Response (M) 6—obeys commands 5—localizes painful stimulus 4—withdraws from pain 3—decorticate posture 2—decerebrate posture 1—no movement (Think: 6-cylinder motor)
HEAD TRAUMA
GCS SCORING SYSTEM
Verbal?
P722
Verbal Response (V) 5—appropriate and oriented 4—confused 3—inappropriate words 2—incomprehensible sounds 1—no sounds (Think: Jackson 5 = verbal 5)
HEAD TRAUMA GCS SCORING SYSTEM What indicates coma by GCS score? P722
< 8 (Think: “less than eight—it may be
too late”)
HEAD TRAUMA GCS SCORING SYSTEM What does unilateral, dilated, nonreactive pupil suggest? P722
Focal mass lesion with ipsilateral
herniation and compression of CN III
HEAD TRAUMA GCS SCORING SYSTEM What do bilateral fixed and dilated pupils suggest? P722
Diffusely increased ICP
HEAD TRAUMA GCS SCORING SYSTEM What are the four signs of basilar skull fracture? P722
1. Raccoon eyes—periorbital ecchymoses 2. Battle’s sign—postauricular ecchymoses 3. Hemotympanum 4. CSF rhinorrhea/otorrhea
HEAD TRAUMA GCS SCORING SYSTEM What is the initial radiographic neuroimaging in trauma? P722
- Head CT scan (if LOC or GCS 15)
- C-spine CT
- T/L spine AP and lateral
HEAD TRAUMA GCS SCORING SYSTEM Should the trauma head CT scan be with or without IV contrast? P722
Without!
HEAD TRAUMA
GCS SCORING SYSTEM
What is normal ICP?
P722
5 to 15 mm H(2)O
HEAD TRAUMA GCS SCORING SYSTEM What is the worrisome ICP? P723
>20 mm H(2)O
HEAD TRAUMA GCS SCORING SYSTEM What determines ICP (Monroe-Kelly hypothesis)? P723
- Volume of brain
- Volume of blood
- Volume of CSF
HEAD TRAUMA
GCS SCORING SYSTEM
What is the CPP?
P723
Cerebral Perfusion Pressure = mean
arterial pressure—ICP (normal CPP is
>70)
HEAD TRAUMA
GCS SCORING SYSTEM
What is Cushing’s reflex?
P723
Physiologic response to increased ICP:
1. Hypertension 2. Bradycardia 3. Decreased RR
HEAD TRAUMA GCS SCORING SYSTEM What are the three general indications to monitor ICP after trauma? P723
- GCS 9
- Altered level of consciousness or
unconsciousness with multiple system
trauma - Decreased consciousness with focal
neurologic examination abnormality
HEAD TRAUMA
GCS SCORING SYSTEM
What is Kocher’s point?
P723 (picture)
Landmark for placement of ICP monitor
bolt:
HEAD TRAUMA GCS SCORING SYSTEM What nonoperative techniques are used to decrease ICP? P724
1. Elevate head of bed (HOB) 30 (if spine cleared) 2. Diuresis-mannitol (osmotic diuretic), Lasix®, limit fluids 3. Intubation (PCO2 control) 4. Sedation 5. Pharmacologic paralysis 6. Ventriculostomy (CSF drainage)
HEAD TRAUMA GCS SCORING SYSTEM What is the acronym for the treatment of elevated ICP? P724
“ICP HEAD”: INTUBATE CALM (sedate) PLACE DRAIN (ventriculostomy)/ PARALYSIS
HYPERVENTILATE TO PCO2 35 ELEVATE head ADEQUATE BLOOD PRESSURE (CPP 70) DIURETIC (e.g., mannitol)
HEAD TRAUMA GCS SCORING SYSTEM Can a tight c-collar increase the ICP? P724
Yes (it blocks venous drainage from
brain!)
HEAD TRAUMA GCS SCORING SYSTEM Why is prolonged hyperventilation dangerous? P724
It may result in severe vasoconstriction
and ischemic brain necrosis!
Use only for very brief periods
HEAD TRAUMA GCS SCORING SYSTEM What is a Kjellberg? (pronounced “shellberg”) P724
Decompressive bifrontal craniectomy
with removal of frontal bone frozen for
possible later replacement
HEAD TRAUMA GCS SCORING SYSTEM How does cranial nerve examination localize the injury in a comatose patient? P724
CNs proceed caudally in the brain stem
as numbered: Presence of corneal reflex
(CN 5 + 7) indicates intact pons; intact
gag reflex (CN 9 + 10) shows functioning
upper medulla (Note: CN 6 palsy is often
a false localizing sign)
HEAD TRAUMA GCS SCORING SYSTEM What is acute treatment of seizures after head trauma? P724
Benzodiazepines (Ativan®)
HEAD TRAUMA GCS SCORING SYSTEM What is seizure prophylaxis after severe head injury? P724
Give phenytoin for 7 days
HEAD TRAUMA GCS SCORING SYSTEM What is the significance of hyponatremia (low sodium level) after head injury? P725
SIADH must be ruled out; remember,
SIADH = Sodium Is Always Down Here
HEAD TRAUMA EPIDURAL HEMATOMA What is an epidural hematoma? P725
Collection of blood between the skull and
dura
HEAD TRAUMA
EPIDURAL HEMATOMA
What causes it?
P725
Usually occurs in association with a skull
fracture as bone fragments lacerate
meningeal arteries
HEAD TRAUMA EPIDURAL HEMATOMA Which artery is associated with epidural hematomas? P725
Middle meningeal artery
HEAD TRAUMA EPIDURAL HEMATOMA What is the most common sign of an epidural hematoma? P725
>50% have ipsilateral blown pupil
HEAD TRAUMA EPIDURAL HEMATOMA What is the classic history with an epidural hematoma? P725
LOC followed by a “lucid interval”
followed by neurologic deterioration
HEAD TRAUMA EPIDURAL HEMATOMA What are the classic CT scan findings with an epidural hematoma? P725 (picture)
Lenticular (lens)-shaped hematoma
Think: Epidural = LEnticular
HEAD TRAUMA EPIDURAL HEMATOMA What is the surgical treatment for an epidural hematoma? P725
Surgical evacuation
HEAD TRAUMA EPIDURAL HEMATOMA What are the indications for surgery with an epidural hematoma? P725
Any symptomatic epidural hematoma;
any epidural hematoma >1 cm
HEAD TRAUMA
SUBDURAL HEMATOMA
What is it?
P726
Blood collection under the dura
HEAD TRAUMA
SUBDURAL HEMATOMA
What causes it?
P726
Tearing of “bridging” veins that pass through the space between the cortical surface and the dural venous sinuses or injury to the brain surface with resultant bleeding from cortical vessels
HEAD TRAUMA SUBDURAL HEMATOMA What are the three types of subdurals? P726
1. Acute—symptoms within 48 hours of injury 2. Subacute—symptoms within 3 to 14 days 3. Chronic—symptoms after 2 weeks or longer
HEAD TRAUMA SUBDURAL HEMATOMA What is the treatment of epidural and subdural hematomas? P726
Mass effect (pressure) must be reduced;
craniotomy with clot evacuation is usually
required
HEAD TRAUMA SUBDURAL HEMATOMA What classic findings appear on head CT scan for a subdural hematoma? P726 (picture)
Curved, crescent-shaped hematoma
Think: sUbdural = cUrved
HEAD TRAUMA
TRAUMATIC SUBARACHNOID HEMORRHAGE
What is it?
P726
Head trauma resulting in blood below the
arachnoid membrane and above the pia
HEAD TRAUMA
TRAUMATIC SUBARACHNOID HEMORRHAGE
What is the treatment?
P726
Anticonvulsants and observation
HEAD TRAUMA
CEREBRAL CONTUSION
What is it?
P726
Hemorrhagic contusion of brain parenchyma
HEAD TRAUMA CEREBRAL CONTUSION What are coup and contrecoup injuries? P727
Coup—injury at the site of impact
Contrecoup—injury at the site opposite
the point of impact
HEAD TRAUMA
CEREBRAL CONTUSION
What is DAI?
P727
Diffuse Axonal Injury (shear injury
to brain parenchyma) from rapid
deceleration injury; 33% mortality;
long-term coma
HEAD TRAUMA CEREBRAL CONTUSION What is the best diagnostic test for DAI? P727
MRI
HEAD TRAUMA CEREBRAL CONTUSION What can present after blunt trauma with neurological deficits and a normal brain CT scan? P727
DAI, carotid artery injury
HEAD TRAUMA SKULL FRACTURE What is a depressed skull fracture? P727
Fracture in which one or more fragments
of the skull are forced below the inner
table of the skull
HEAD TRAUMA SKULL FRACTURE What are the indications for surgery? P727
1. Contaminated wound requiring cleaning and débridement 2. Severe deformity 3. Impingement on cortex 4. Open fracture 5. CSF leak
HEAD TRAUMA SKULL FRACTURE What is the treatment for open skull fractures? P727
- Antibiotics
- Seizure prophylaxis (phenytoin)
- Surgical therapy
HEAD TRAUMA SPINAL CORD TRAUMA What are the two general types of injury? P727
- Complete—no motor/sensory function
below the level of injury - Incomplete—residual function below
the level of injury
HEAD TRAUMA
SPINAL CORD TRAUMA
Define “spinal shock.”
P727
Loss of all reflexes and motor function,
hypotension, bradycardia
HEAD TRAUMA
SPINAL CORD TRAUMA
Define “sacral sparing.”
P728
Sparing of sacral nerve level: anal sphincter
intact, toe flexion, perianal sensation
HEAD TRAUMA SPINAL CORD TRAUMA What initial studies/ intervention are important? P728
1. ABCs—obtain airway and ventilate if needed 2. Maintain BP (IVF, pressors if refractory to fluids) 3. NG tube—prevents aspiration 4. Foley 5. High-dose steroids—proven to improve outcome if given 8 hours post injury 6. Complete cervical x-rays and those of lower levels as indicated by examination
HEAD TRAUMA SPINAL CORD TRAUMA What are the diagnostic studies? P728
Plain films, CT scan, MRI
HEAD TRAUMA SPINAL CORD TRAUMA What are the indications for emergent surgery with spinal cord injury? P728
Unstable vertebral fracture
Incomplete injury with extrinsic
compression
Spinal epidural or subdural hematoma
HEAD TRAUMA SPINAL CORD TRAUMA What is the indication for IV high-dose steroids with spinal cord injury? P728
Controversial: Blunt spinal cord injury with neurologic deficit (methylprednisolone: high-dose bolus [30 mg/kg] followed by continuous infusion [5.4 mg/kg] for 23 hours)
HEAD TRAUMA SPINAL CORD TRAUMA Have steroids been proven to help after PENETRATING spine injury? P728
No
HEAD TRAUMA SPINAL CORD TRAUMA Describe the following conditions: Anterior cord syndrome P728 (Picture)
Affects corticospinal and lateral
spinothalamic tracts, paraplegia, loss of
pain/temperature sensation, preserved
touch/vibration/proprioception
HEAD TRAUMA SPINAL CORD TRAUMA Describe the following conditions: Central cord syndrome P729 (Picture)
Preservation of some lower extremity
motor and sensory ability with upper
extremity weakness
HEAD TRAUMA SPINAL CORD TRAUMA Describe the following conditions: Brown-Séquard syndrome P729 (Picture)
Hemisection of cord resulting in
ipsilateral motor weakness and touch/
proprioception loss with contralateral
pain/temperature loss
HEAD TRAUMA SPINAL CORD TRAUMA Describe the following conditions: Posterior cord syndrome P729
Injury to posterior spinal cord with loss
of proprioception distally
HEAD TRAUMA SPINAL CORD TRAUMA How can the findings associated with Brown- Séquard syndrome be remembered? P729
Think: CAPTAIN Brown-Séquard = “CPT”: Contralateral Pain Temperature loss
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Jefferson’s fracture P729
Fracture through C1 arches from axial
loading (unstable fracture)
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Hangman’s fracture P729
Fracture through the pedicles of C2 from
hyperextension; usually stable
Think: A hangman (C2) is below stature of
President T. Jefferson (C1)
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Odontoid fracture P729
Fracture of the odontoid process of C2
view with open-mouth odontoid x-ray
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Priapism P729
Penile erection seen with spinal cord
injury
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Chance fracture P730
Transverse vertebral fracture
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Clay shoveler’s fracture P730
Fracture of spinous process of C7
HEAD TRAUMA SPINAL CORD TRAUMA Define the following terms: Odontoid fractures P730 (picture)
A: Type I—fracture through tip of dens B: Type II—fracture through base of dens C: Type III—fracture through body of C2
TUMORS GENERAL What is the incidence of CNS tumors? P730
≈1% of all cancers; third leading cause of
cancer deaths in people 15 to 34 years of
age; second leading cause of cancer
deaths in children
TUMORS GENERAL What is the usual location of primary tumors in adults/ children? P730
In adults, 66% of tumors are
supratentorial, ≈33% are infratentorial;
the reverse is true in children (i.e.,
≈66% infratentorial)
TUMORS GENERAL What is the differential diagnosis of a ringenhancing brain lesion? P730
Metastatic carcinoma, abscess, GBM,
lymphoma
TUMORS GENERAL What are the adverse effects of tumors on the brain? P730
- Increased ICP
- Mass effect on cranial nerves
- Invasion of brain parenchyma,
disrupting nuclei/tracts - Seizure foci
- Hemorrhage into/around tumor mass
TUMORS GENERAL What are the signs/symptoms of brain tumors? P730
- Neurologic deficit (66%)
- Headache (50%)
- Seizures (25%)
- Vomiting (classically in the morning)
TUMORS
GENERAL
How is the diagnosis made?
P731
CT scan or MRI is the standard
diagnostic study
TUMORS GENERAL What are the surgical indications? P731
- Establishing a tissue diagnosis
- Relief of increased ICP
- Relief of neurologic dysfunction
caused by tissue compression - Attempt to cure in the setting of
localized tumor
TUMORS GENERAL What are the most common intracranial tumors in adults? P731
Metastatic neoplasms are most common;
among primaries, gliomas are #1 (50%)
and meningiomas are #2 (25%)