Chapter 75 / Neurosurgery 727
What are coup and	Coup—injury at the site of impact
contrecoup injuries?	Contrecoup—injury at the site opposite
		the point of impact
What is DAI?	Diffuse Axonal Injury (shear injury
	to brain parenchyma) from rapid
	deceleration injury; 33% mortality;
	long-term coma
What is the best diagnostic	MRI
test for DAI?
What can present after blunt	DAI, carotid artery injury
trauma with neurological
deficits and a normal brain
CT scan?
SKULL FRACTURE
What is a depressed skull	Fracture in which one or more fragments
fracture?	of the skull are forced below the inner
	table of the skull
What are the indications for	1.	Contaminated wound requiring
surgery?		cleaning and débridement
	2.	Severe deformity
	3.	Impingement on cortex
	4.	Open fracture
	5.	CSF leak
What is the treatment for	1.	Antibiotics
open skull fractures?	2.	Seizure prophylaxis (phenytoin)
	3.	Surgical therapy
SPINAL CORD TRAUMA
What are the two general	1.	Complete—no motor/sensory function
types of injury?		below the level of injury
	2.	Incomplete—residual function below
		the level of injury
Define “spinal shock.”	Loss of all reflexes and motor function,
	hypotension, bradycardia

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Define “sacral sparing.”	Sparing of sacral nerve level: anal sphinc-
	ter intact, toe flexion, perianal sensation
What initial studies/	1. ABCs—obtain airway and ventilate if
intervention are important?		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

What are the diagnostic studies?

What are the indications for emergent surgery with spinal cord injury?

What is the indication for IV high-dose steroids with spinal cord injury?

Plain films, CT scan, MRI

Unstable vertebral fracture Incomplete injury with extrinsic

compression

Spinal epidural or subdural hematoma

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)

Have steroids been proven to help after PENETRATING spine injury?

Describe the following conditions:

Anterior cord syndrome

No

Affects corticospinal and lateral spinothalamic tracts, paraplegia, loss of pain/temperature sensation, preserved touch/vibration/proprioception

Central cord syndrome

Brown-Séquard syndrome

Posterior cord syndrome

How can the findings associated with BrownSéquard syndrome be remembered?

Define the following terms: Jefferson’s fracture

Hangman’s fracture

Chapter 75 / Neurosurgery 729

Preservation of some lower extremity motor and sensory ability with upper extremity weakness

Hemisection of cord resulting in ipsilateral motor weakness and touch/ proprioception loss with contralateral pain/temperature loss

Injury to posterior spinal cord with loss of proprioception distally

Think: CAPTAIN Brown-Séquard

“CPT”: Contralateral Pain Temperature loss

Fracture through C1 arches from axial loading (unstable fracture)

Fracture through the pedicles of C2 from hyperextension; usually stable

Think: A hangman (C2) is below stature of President T. Jefferson (C1)

Odontoid fracture	Fracture of the odontoid process of C2
	(view with open-mouth odontoid x-ray)
Priapism	Penile erection seen with spinal cord
	injury

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Chance fracture	Transverse vertebral fracture
Clay shoveler’s fracture	Fracture of spinous process of C7
Odontoid fractures	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	1% of all cancers; third leading cause of
CNS tumors?	cancer deaths in people 15 to 34 years of
	age; second leading cause of cancer
	deaths in children

What is the usual location of primary tumors in adults/ children?

What is the differential diagnosis of a ringenhancing brain lesion?

What are the adverse effects of tumors on the brain?

In adults, 66% of tumors are supratentorial, 33% are infratentorial; the reverse is true in children (i.e.,66% infratentorial)

Metastatic carcinoma, abscess, GBM, lymphoma

1.Increased ICP

2.Mass effect on cranial nerves

3.Invasion of brain parenchyma, disrupting nuclei/tracts

4.Seizure foci

5.Hemorrhage into/around tumor mass

What are the signs/symptoms of brain tumors?

1.Neurologic deficit (66%)

2.Headache (50%)

3.Seizures (25%)

4.Vomiting (classically in the morning)

		Chapter 75 / Neurosurgery 731
How is the diagnosis made?	CT scan or MRI is the standard
	diagnostic study
What are the surgical	1.	Establishing a tissue diagnosis
indications?	2.	Relief of increased ICP
	3.	Relief of neurologic dysfunction
		caused by tissue compression
	4.	Attempt to cure in the setting of
		localized tumor
What are the most common	Metastatic neoplasms are most common;
intracranial tumors in adults?	among primaries, gliomas are #1 (50%)
	and meningiomas are #2 (25%)
What are the three most	1.	Medulloblastomas (33%)
common in children?	2.	Astrocytomas (33%)
	3.	Ependymomas (10%)
GLIOMAS
What is a glioma?	General name for several tumors of
	neuroglial origin (e.g., astrocytes,
	ependymal, oligodendrocytes)

What are the characteristics of a LOW-grade astrocytoma?

What is the most common primary brain tumor in adults?

What are its characteristics?

Nuclear atypia, high mitotic rate, high signal on T2 weighted images, nonenhancing with contrast CT scan

Glioblastoma multiforme (GBM) (Think: GBM Greatest Brain Malignancy)

Poorly defined, highly aggressive tumors occurring in the white matter of the cerebral hemispheres; spread extremely rapidly

What is the average age of onset?

What is the treatment?

What is the prognosis?

Fifth decade

Surgical debulking followed by radiation

Without treatment, 90% of patients die within 3 months of diagnosis; with treatment, 90% die within 2 years

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MENINGIOMAS

What is the layer of	Arachnoid cap cells
origination?
What are the risk factors?	Radiation exposure
	Neurofibromatosis type 2
	Female gender
What are the associated	Psammoma bodies (concentric
histologic findings?	calcifications), whorl formations
	(“onion skin” pattern)
What is the histologic	Brain parenchymal invasion
malignancy determination?
What is the peak age of	40 to 50 years
occurrence?
What is the gender ratio?	Females predominate almost 2:1
What is the clinical	Variable depending on location; lateral
presentation?	cerebral convexity tumors can cause focal
	deficits or headache; sphenoid tumors
	can present with seizures; posterior fossa
	tumors with CN deficits; olfactory groove
	tumors with anosmia
What is the treatment?	Preoperative embolization and surgical
	resection
CEREBELLAR ASTROCYTOMAS
What is the peak age of	5 to 9 years
occurrence?
What is the usual location?	Usually in the cerebellar hemispheres;
	less frequently in the vermis
What are the signs/	Usually lateral cerebellar signs occur:
symptoms?	ipsilateral incoordination or dysmetria
	(patient tends to fall to side of tumor) as
	well as nystagmus and ataxia; CN deficits
	are also frequently present, especially in
	CNs VI and VII

What are the treatment and prognosis?

Chapter 75 / Neurosurgery 733

Completely resectable in 75% of cases, which usually results in a cure; overall 5-year survival rate exceeds 90%

MEDULLOBLASTOMA

What is the peak age of	First decade (3 to 7 years)
occurrence?
What is the cell of origin?	External granular cells of cerebellum
What is the most common	Cerebellar vermis in children; cerebellar
location?	hemispheres of adolescents and adults
What are the signs/	Headache, vomiting, and other signs of
symptoms?	increased ICP; also usually truncal ataxia
What are the treatment and	Best current treatment includes surgery
prognosis?	to debulk the tumor, cranial and spinal
	radiation, and chemotherapy; 5-year
	survival rate is 50%
PITUITARY TUMORS
What is the most common	Prolactinoma
pituitary tumor?
What is the most common	Bitemporal hemianopsia (lateral visual
presentation of a	fields blind)
prolactinoma?