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Flashcards in Neurosurgery Deck (195):
1

What is the incidence of head trauma?

70,000 fatal injuries per year in US (500,000 head injuries)

2

What percentage of trauma deaths result from head trauma?

50%

3

What is the Glasgow Coma Scale?

Objective assessment of the level of consciousness after trauma

4

What does unilateral, dilated, nonreactive pupil suggest?

Focal mass lesion with ipsilateral herniation and compression of CN III

5

What do bilateral fixed and dilated pupils suggest?

Diffusely increased ICP

6

What are the 4 signs of basilar skull fracture?

1. Raccoon eyes (periorbital ecchymoses)
2. Battle's sign (postauricular ecchymoses)
3. Hemotympanum
4. CSF rhinorrhea or otorrhea

7

What is the initial radiographic neuroimaging in trauma?

1. Head CT (if LOC or GCS

8

Should the trauma head CT be with or without IV contrast?

Without

9

What is normal ICP?

5-15 mmH2O

10

What is the worrisome ICP?

> 20 mmH2O

11

What determines ICP?

1. Volume of brain
2. Volume of blood
3. Volume of CSF

12

What is the CPP?

Cerebral Perfusion Pressure:
CPP = MAP - ICP

13

What is Cushing's reflex?

Physiologic response to increased ICP:
1. Hypertension
2. Bradycardia
3. Decreased RR

14

What are the 3 general indications to monitor ICP after trauma?

1. GCS

15

What is Kocher's point?

Landmark for placement of ICP monitor bolt

16

What nonoperative techniques are used to decrease ICP?

ICP HEAD:
Intubate
Calm (sedate)
Place drain (ventriculostomy), Paralysis
Hyperventilation to PCO2 = 35
Elevate head
Adequate blood pressure (CPP > 70)
Diuretic (e.g. mannitol)

17

Can a tight c-collar increase the ICP?

Yes (it blocks venous drainage from brain)

18

Why is prolonged hyperventilation dangerous?

It may result in severe vasoconstriction and ischemic brain necrosis

19

What is a Kjellberg?

Decompressive bifrontal craniectomy with removal of frontal bone frozen for possible later replacement

20

How does cranial nerve examination localize the injury in a comatose patient?

CNs proceed caudally in the brain stem as numbered.
(Presence of corneal reflex and gag reflex indicates intact pons and medulla, respectively.)

21

What is acute treatment for seizures after head trauma?

Benzodiazepines

22

What is seizure prophylaxis after severe head injury?

Phenytoin for 7 days

23

What is the significance of hyponatremia after head injury?

SIADH must be ruled out

24

What is an epidural hematoma?

Collection of blood between the skull and dura

25

What causes an epidural hematoma?

Usually occurs in association with a skull fracture as bone fragments lacerate meningeal arteries

26

Which artery is associated with epidural hematomas?

Middle meningeal artery

27

What is the most common sign of an epidural hematoma?

> 50% have ipsilateral blown pupil

28

What is the classic history with an epidural hematoma?

LOC, followed by a lucid interval, followed by neurologic deterioration

29

What are the classic CT findings with an epidural hematoma?

Lenticular hematoma

30

What is the surgical treatment for an epidural hematoma?

Surgical evacuation

31

What are the indications for surgery with an epidural hematoma?

Any symptomatic epidural hematoma or hematoma > 1 cm

32

What is a subdural hematoma?

Blood collection under the dura

33

What causes a subdural hematoma?

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

34

What are the 3 types of subdural hematomas?

1. Acute: symptoms within 48 hours
2. Subacute: symptoms with 3-14 days
3. Chronic: symptoms after 2 weeks or longer

35

What is the treatment for epidural and subdural hematomas?

Craniotomy with clot evacuation is usually required

36

What are classic CT findings with a subdural hematoma?

Curved, crescent-shaped hematoma

37

What is traumatic subarachnoid hemorrhage?

Head trauma resulting in blood below the arachnoid membrane and above the pia

38

What is the treatment for subarachnoid hemorrhage?

Anticonvulsants and observation

39

What is a cerebral contusion?

Hemorrhagic contusion of brain parenchyma

40

What are coup and contrecoup injuries?

Coup: injury at the site of impact
Contrecoup: injury at the site opposite the point of impact

41

What is DAI?

Diffuse Axonal Injury:
Shear injury to brain parenchyma from rapid deceleration.

42

What is the best diagnostic test for DAI?

MRI

43

What can present after blunt trauma with neurological deficits and a normal brain CT?

DAI, carotid artery injury

44

What is a depressed skull fracture?

Fracture in which one or more fragments of the skull are forced below the inner table of the skull

45

What are the indications for surgery after a skull fracture?

1. Contaminated wound requiring cleaning and debridement
2. Severe deformity
3. Impingement on cortex
4. Open fracture
5. CSF leak

46

What is the treatment for open skull fractures?

1. Antibiotics
2. Seizure prophylaxis
3. Surgical therapy

47

What are the 2 general types of spinal cord injuries?

1. Complete: no motor/sensory function below the level of injury
2. Incomplete: residual function below the level of injury

48

What is spinal shock?

Loss of all reflexes and motor function, hypotension, bradycardia

49

What does "sacral sparing" mean?

Sparing of sacral nerve level: anal sphincter intact, toe flexion, perianal sensation

50

What initial studies/interventions are important in spinal cord injuries?

1. ABCs
2. Maintain BP (IVF, pressers if refractory to fluids)
3. NG tube (prevents aspiration)
4. Foley
5. High-dose steroids
6. Complete cervical XRs and those of lower levels as indicated by exam

51

What are the diagnostic studies for spinal cord injury?

X-rays, CT, MRI

52

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

Unstable vertebral fracture; incomplete injury with extrinsic compression; spinal epidural or subdural hematoma

53

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

Controversial: Blunt spinal cord injury with neurologic deficit (methylprednisolone: high-dose bolus followed by continuous infusion for 23 hours)

54

Have steroids been proven to help after penetrating spine injury?

No

55

What is anterior cord syndrome?

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

56

What is central cord syndrome?

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

57

What is Brown-Sequard syndrome?

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

58

What is posterior cord syndrome?

Injury to posterior spinal cord with loss of proprioception distally

59

What is a Jefferson's fracture?

Fracture through C1 arches from axial loading (unstable)

60

What is a hangman's fracture?

Fracture through the pedicles of C2 from hyperextension (usually stable)

61

What is an odontoid fracture?

Fracture of the odontoid process of C2 (view with open-mouth odontoid XR)

62

What is a Chance fracture?

Transverse vertebral fracture

63

What is a clay shoveler's fracture?

Fracture of the spinous process of C7

64

What is a type I odontoid fracture?

Fracture through tip of dens

65

What is a type II odontoid fracture?

Fracture through base of dens

66

What is a type III odontoid fracture?

Fracture through body of C2

67

What is the incidence of CNS tumors?

1% of all cancers

68

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

Adults: 66% are supratentorial
Children: 66% are infratentorial

69

What is the differential diagnosis of a ring-enhancing brain lesion?

Metastatic carcinoma, abscess, GBM, lymphoma

70

What are the adverse effects of tumors on the brain?

1. Increased ICP
2. Mass effect on cranial nerves
3. Invasion of brain parenchyma, disrupting nuclei/tracts
4. Seizure foci
5. Hemorrhage into or around tumor mass

71

What are the signs and symptoms of intracranial tumors?

1. Neurologic deficit
2. Headache
3. Seizures
4. Vomiting (classically in the morning)

72

How is the diagnosis of intracranial tumor made?

CT, MRI

73

What are the surgical indications with intracranial tumors?

1. Establishing a tissue diagnosis
2. Relief of increased ICP
3. Relief of neurologic dysfunction caused by tissue compression
4. Attempt to cure in the setting of localized tumor

74

What are the most common intracranial tumors in adults?

Metastatic neoplasms are most common.
Primary: Glioma (50%) , meningioma (25%)

75

What are the 3 most common intracranial tumors in children?

1. Medulloblastoma (33%)
2. Astrocytoma (33%)
3. Ependymoma (10%)

76

What is a glioma?

General name for several tumors of neuroglial origin (e.g. astrocytes, ependymal, oligodendrocytes)

77

What are the characteristics of low-grade astrocytoma?

Nuclear atypia, high mitotic rate, high signal on T2 weighted images, non-enhancing with contrast on CT

78

What is the most common primary brain tumor in adults?

Glioblastoma multiforme (GBM)

79

What are the characteristics of GBM?

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

80

What is the average age of onset with GBM?

5th decade

81

What is the treatment for GBM?

Surgical debunking followed by radiation

82

What is the prognosis for GBM?

Without treatment: >90% die within 3 months
With treatment: 90% die within 2 years

83

What cell of origin in meningiomas?

Arachnoid cap cells

84

What are the risk factors for meningioma?

Radiation exposure, neurofibromatosis type 2, female

85

What are the associated histologic findings with meningioma?

Psammoma bodies (concentric calcifications), whorl formations (onion-skin pattern)

86

What is the histologic malignancy determination with meningiomas?

Brain parenchymal invasion

87

What is the peak age of occurrence for meningioma?

5th decade

88

What is the clinical presentation of meningioma?

Variable depending on location:
Lateral cerebral convexity: focal deficits or headache.
Sphenoid: seizures.
Posterior fossa: CN deficits.
Olfactory groove: anosmia.

89

What is the treatment for meningioma?

Preoperative embolization and surgical resection

90

What is the peak age for cerebellar astrocytoma occurrence?

5-9 years

91

What is the usual location for cerebellar astrocytomas?

Cerebellar hemispheres, less frequently in the vermis

92

What are the signs and symptoms of cerebellar astrocytoma?

Ipsilateral incoordination or dysmetria (patient tends to fall to side of tumor) as well as nystagmus and ataxia.
CN deficits (especially VI and VII).

93

What is the treatment for cerebellar astrocytoma?

Completely resectable in 75% of cases

94

What is the peak age for medulloblastoma?

3-7 years

95

What is the cell of origin in medulloblastoma?

External granular cells of cerebellum

96

What is the most common location for medulloblastoma?

Cerebellar vermis in children.
Cerebellar hemispheres of adolescents and adults.

97

What are the signs and symptoms of medulloblastoma?

Headache, vomiting, and other signs of increased ICP.
Usually truncal ataxia.

98

What is the treatment for medulloblastoma?

Surgery to debulk tumor, cranial and spinal radiation, chemotherapy

99

What is the prognosis for medulloblastoma?

5-year: > 50%

100

What is the most common pituitary tumor?

Prolactinoma

101

What is the most common presentation of a prolactinoma?

Bitemporal hemianopsia (lateral visual fields blind)

102

What are the blood prolactin levels with a prolactinoma?

> 300 mg/L (> 100 mg/L is abnormal)

103

What is the medical treatment for prolactinoma?

Bromocriptine

104

What is the surgical treatment for prolactinoma?

Trans-sphenoidal resection of the pituitary tumor

105

What is the treatment for a recurrent prolactinoma after surgical resection?

XRT

106

What are the usual causes of subarachnoid hemorrhage?

Trauma; ruptured berry aneurysm; arteriovenous malformations

107

What is a berry aneurysm?

Saccular out-pouching of vessels in the circle of Willis, usually at bifurcations

108

What is the usual location of a berry aneurysm?

Anterior communicating artery (30%), posterior communicating artery, middle cerebral artery

109

What medical disease increases the risk of berry aneurysms?

Polycystic kidney disease and connective tissue disorders

110

What is an arteriovenous malformation?

Congenital abnormality of the vasculature with connections between the arterial and venous circulations without interposed capillary network

111

Where do brain AVMs occur?

>75% are supratentorial

112

What are the signs and symptoms of subarachnoid hemorrhage?

"Worst headache of life", meningismus, LOC, N/V, photophobia

113

What comprises the workup of subarachnoid hemorrhage?

Head CT, LP (not necessary if CT is definitive), arteriogram

114

What are the possible complications of subarachnoid hemorrhage?

1. Brain edema leading to increased ICP
2. Rebleeding (most common in the first 24-48 hour)
3. Vasospasm (most common cause of morbidity and mortality)

115

What is the treatment for brain vasospasm?

Nimodipine (CCB)

116

What is the treatment for brain aneurysms?

Surgical treatment by placing a metal clip on the aneurysm.
Also, balloon occlusion, coil embolization.

117

What is the treatment for AVMs?

Preoperative embolization (reduce size), followed by surgical resection.
If inaccessible, radiosurgery is effective for AVMs

118

What is intracerebral hemorrhage?

Bleeding into the brain parenchyma

119

What is the etiology of intracerebral hemorrhage?

Hypertension and atherosclerotic disease (Charcot-Bouchard aneurysms).
Also, coagulopathy, AVMs, amyloid angiopathy, bleeding into tumor, trauma.

120

Where do intracerebral hemorrhages occur?

66% in basal ganglia (most commonly putamen)

121

What is the usual presentation of intracerebral hemorrhage?

66% present with coma.
Large putamen bleeding classically presents with contralateral hemiplegia and hemisensory deficits, lateral gaze preference, aphasia, and homonymous hemianopsia.

122

What is the associated diagnostic study for intracerebral hemorrhage?

CT

123

What are the surgical indications for intracerebral hemorrhage?

CN III palsy, progressive alteration of consciousness

124

What is the prognosis for intracerebral hemorrhage?

Poor, especially with ventricular or diencephalons involvement

125

What is lumbar disc herniation?

Extrusion of the inner portion of the intervertebral disc (nucleus pulposus) through the outer annulus fibrosis, causing impingement on nerve roots exiting the spinal canal

126

Which nerve is affected in lumbar disc herniation?

Nerve exiting at the level below (e.g. an L4-L5 disc impinges on the L5 nerve exiting between L5-S1)

127

Who is affected by lumbar disc herniation?

Middle-aged and older individuals

128

What is the usual cause of lumbar disc herniation?

Loss of elasticity of the posterior longitudinal ligaments and annulus fibrosis as a result of aging

129

What are the most common sites of lumbar disc herniation?

L5-S1 (45%)
L4-L5 (40%)

130

What is the usual presenting symptom for lumbar disc herniation?

Low back pain

131

What are the signs of L5-S1 herniation?

Decreased ankle jerk reflex; weakness of plantar flexors in foot; pain in back/midgluteal region to posterior calf to lateral foot; ipsilateral radiculopathy on straight leg raise

132

What are the signs of L4-L5 herniation?

Decreased biceps femoris reflex; weak extensors of foot

133

What are the signs of L3-L4 herniation?

Decrease or absence of knee jerks; weakness of the quadriceps femoris; pain in lower back/buttocks; pain in lateral thigh and anterior thigh; pain in hip/groin region to posterolateral thigh, lateral leg, and medial toes

134

How is the diagnosis of lumbar disc herniation made?

CT, CT myelogram, MRI

135

What is the treatment for lumbar disc herniation?

Conservative: bed rest, analgesics
Surgical: partial hemilaminectomy and discectomy

136

What are the indications for emergent surgery for lumbar disc herniation?

1. Cauda equina syndrome
2. Progressive motor deficits

137

What is caudal equina syndrome?

Herniated disc compressing multiple S1, S2, S3, S4 nerve roots, resulting in bowel or bladder incontinence, saddle anesthesia over buttocks and perineum, low back pain, sciatica

138

What is sciatica?

Radicular or nerve root pain

139

What is cervical disc disease?

Same pathology as lumbar disc her nation, except in the cervical region.
The disc impinges on the nerve exiting the canal at the same level of the disease.

140

What are the most common sites of cervical disc disease?

C6-C7 (70%)
C5-C6 (20%)
C7-T1 (10%)

141

What are the signs and symptoms of C7 disease?

Decreased triceps reflex and strength; weakness of forearm extension; pain from neck, through triceps and into index and middle finger

142

What are the signs and symptoms of C6 disease?

Decreased biceps and brachioradialis reflex; weakness in forearm flexion; pain in neck, radial forearm, and thumb

143

What are the signs and symptoms of C8 disease?

Weakness in intrinsic hand muscles; pain in 4th and 5th fingers

144

How is the diagnosis of cervical disc disease made?

CT, MRI

145

What is the treatment for cervical disc disease?

Anterior or posterior discectomy with fusion PRN

146

What are the symptoms of central cervical cord compression from disc fragments?

Myelopathic syndrome with LMN signs at level of compression and UMN signs distally

147

What is Spurling's sign?

Reproduction of radicular pain by having the patient turn his head to the affected side and applying axial pressure to the top of the head

148

What is the etiology of spinal epidural abscess?

Hematogenous spread from skin infections is most common.
Also, distant abscesses or infections, UTIs, postoperative infections, spinal surgery, epidural anesthesia.

149

What is the commonly associated medical condition with spinal epidural abscess?

Diabetes

150

What are the 3 most common sites of spinal epidural abscesses?

1. Thoracic
2. Lumbar
3. Cervical

151

What is the most common organism in spinal epidural abscesses?

Staph aureus

152

What are the signs and symptoms of spinal epidural abscesses?

Fever; severe pain over affected area and with flexion/extension of spine; weakness can develop, ultimately leading to paraplegia

153

How is the diagnosis of spinal epidural abscess made?

MRI

154

Which test is contraindicated with spinal epidural abscess?

LP (risk of seeding CSF with bacteria)

155

What is the treatment fro spinal epidural abscess?

Surgical drainage and appropriate antibiotic coverage

156

What is the prognosis for spinal epidural abscess?

If severe neurologic deficits preoperatively, little recovery.
15-20% fatal.

157

What is hydrocephalus?

Abnormal condition consisting of an increased volume of CSF along with distention of CSF space.

158

What are the 3 general causes of hydrocephalus?

1. Increased production of CSF
2. Decreased absorption of CSF
3. Obstruction of normal flow of CSF

159

What is the normal daily CSF production?

500 mL

160

What is the normal volume of CSF?

150 mL

161

What is communicating hydrocephalus?

Unimpaired connection of CSF pathway from lateral ventricle to subarachnoid space

162

What is noncommunicating hydrocephalus?

Complete or incomplete obstruction of CSF flow within or at the exit of the ventricular system

163

What are the specific causes of hydrocephalus?

Congenital malformations; aqueductal stenosis; myelomeningocele; tumors obstructing CSF flow; inflammation causing impaired absorption of fluid; subarachnoid hemorrhage; meningitis; choroid plexus papilloma (increased CSF production)

164

What are the signs and symptoms of hydrocephalus?

Sings of increased ICP (HA, N/V, ataxia, increasing head circumference)

165

How is the diagnosis of hydrocephalus made?

CT, MRI, measurement of head circumference

166

What is the treatment for hydrocephalus?

1. Remove obvious offenders
2. Perform bypass obstruction with ventriculoperitoneal or ventriculoatrial shunt

167

What is the prognosis for hydrocephalus if untreated?

50% mortality.
Survivors show decreased IQ, ataxia, paraparesis, visual deficits

168

What are the possible complications of treatment of hydrocephalus?

1. Blockage or shunt malfunction
2. Infection

169

What is hydrocephalus ex vacuo?

Increased volume of CSF spaces from brain atrophy, not from any pathology in the amount of CSF absorbed or produced

170

What is a shunt series?

Series of XRs covering the entire shunt length looking for shunt disruption or kinking to explain malfunction of shunt

171

What is the incidence of neural tube defects?

1/1000 births

172

What are the race/gender demographics for neural tube defects?

More common in whites and females

173

What is spina bifida occulta?

Defect in the development of the posterior portion of the vertebrae

174

What are the signs and symptoms of spina bifida occulta?

Usually asymptomatic, though it may be associated with other spinal abnormalities.
Usually found incidentally on XRs.

175

What is the most common clinically significant neural tube defect?

Myelomeningocele

176

What is a myelomeningocele?

Herniation of nerve roots and spinal cord through a defect in the posterior elements of the vertebra.
The sac surrounding the neural tissue may be intact, but more commonly is ruptured and therefore exposes the CNS to the external environment.

177

What are the 3 most common sites for myelomeningocele?

1. Lumbar region
2. Lower thoracic region
3. Upper sacral region

178

What are the signs and symptoms of myelomeningocele?

Variable from mild skeletal deformities to a complete motor/sensory loss.
Bowel/bladder function is difficult to evaluate, but often is affected and can adversely affect survival.

179

What is the treatment for myelomeningocele?

If open, patients are operated on immediately

180

What is the prognosis for myelomeningocele?

2-year: 95% survival with surgery (25% without)

181

Which vitamin is though to lower the rate of neural tube defects in utero?

Folic acid

182

What is craniosynostosis?

Premature closure of one or more of the sutures between the skull plates

183

What is the incidence of craniosynostosis?

1/200 births

184

What are the types of craniosynostosis?

Named for closed suture (e.g. sagittal, coronal lambdoid, etc.)

185

How is the diagnosis of craniosynostosis made?

Physical (ridges along fused sutures and lessened suture mobility).
X-rays (lack of lucency along fused suture).

186

What are the indications for surgery for craniosynostosis?

Cosmetic, as cranial vault with continue to deform with growth.
Increased ICP.

187

What is the timing of surgery for craniosynostosis?

Usually 3-4 months of age.
Earlier surgery increases the risk of anesthesia.
Later surgeries are more difficult because of the worsening deformities and decreasing malleability of skull.

188

What is the operative mortality with craniosynostosis?

189

What is the most common bacteria causing post-neurosurgery meningitis?

Staph aureus

190

What classically presents as the "worst headache of life"?

Spontaneous subarachnoid hemorrhage

191

What classically has a lucid interval?

Epidural hemorrhage

192

What is the most common location of a hypertensive intracerebral hemorrhage?

Putamen

193

What is a 3rd-nerve palsy?

1. Diplopia
2. Ptosis
3. Mydriasis

194

What is Millard-Gubler syndrome?

Pons infarction:
1. CN VI palsy
2. CN VII palsy
3. Contralateral hemiplegia

195

What is syringomyelia?

Central pathologic cavitations of the spinal cord