Chapter 41 - Neurosurgery Flashcards Preview

Fiser Absite > Chapter 41 - Neurosurgery > Flashcards

Flashcards in Chapter 41 - Neurosurgery Deck (64):
1

What is neuropraxia?

No axonal injury (temporary loss of function)

2

What is axonotmesis?

Disruption of axon with preservation of axon sheath, will improve

3

What is neurotmesis?

Disruption of axon and axon sheath (whol enerve disrupted), may need surgery for recovery

4

What is the rate of regeneration of nerves?

1mm/d

5

What are the Nodes of Ranvier? What is the purpose?

Bare sections
Allow salutatory conduction

6

Release of ADH controlled by what?

Supraoptic nucleus of hypothalamus which descends into the posterior pituitary gland

7

What stimulates release of ADH?

In response to high plasma osmolarity
Leads to increased water absorption in collecting ducts

8

What are the manifestations of DI (low ADH)?

Increased urine output, decreased urine specific gravity, increased serum Na, increased serum osmolarity

9

When can DI occur?

ETOH, head trauma

10

Treatment for DI?

DDAVP, free water

11

What are the manifestations of SIADH (high ADH)?

Decreased urine output, concentrated urine, low serum Na, low serum osmolarity

12

When will SIADH occur?

With head injury

13

Treatment for SIADH?

Fluid restriction, diuresis; can give hypertonic saline if initial treatment fails

14

How do AV malformations present 50% of the time?

Hemorrhage

15

Treatment of AV malformation?

Resection if possible; can coil prior to resection

16

How do cerebral aneurysms present?

Bleeding, mass effect, seizures, infarcts

17

Where do cerebral aneurysms occur?

At branch points in artery, most in carotid or anterior circulation; most congenital

18

Cause of SDH?

Torn bridging veins

19

CT findings with SDH?

Crescent shape on head CT; conforms to brain

20

Cause of epidural hematoma?

Injury to middle meningeal artery?

21

CT findings with epidural?

Lens shape, pushes brain away

22

What is the cause of nontraumatic SAH?

Cerebral aneurysms and AVMs

23

Symptoms of SAH?

Nuchal rigidity, severe headache, photophobia, neurologic defects

24

Treatment for SAH?

Hypervolemia, calcium channel blockers

25

What lobe is most often affected by intracerebral hematoma?

Temporal lobe

26

Cerebral perfusion pressure = what?

MAP - ICP

27

Goal CPP?

>60-70

28

Treatment for head trauma and decreased CPP?

Elevate HOB, sedate/paralyze, moderate hyperventilation (Pco2 30-35), mannitol to decrease brain edema, may need craniectomy

29

When does maximum brain swelling occur after trauma?

48-72h

30

Symptoms of elevated ICP? Signs?

Stupor, headache, n/v, stiff neck
HTN, HR lability, slow respirations

31

What is Cushing's triad?

HTN, bradycardia, slow respiratory rate

32

What does dilated pupil after trauma indicate?

Ipsilateral temporal herniation onto 3rd cranial nerve

33

Symptoms of complete cord transection?

Areflexia, flaccidity, anesthesia, autonomic paralysis below the level of lesions

34

Signs of spinal shock?

Hypotension, normal or slow heart rate, warm extremities

35

Spinal shock can occur with what level of cord injury?

T5 and above (loss of sympathetic tone)

36

Treatment for spinal shock?

Fluids, phenylephrine (alpha-agonist)

37

What is anterior spinal artery syndrome?

Most commonly occurs with acutely ruptured cervical disc
Bilateral loss of motor, pain, and temperature sensation below the level of lesion (preservation of position-vibratory sensation and light touch)

38

What % of anterior spinal artery syndromes recover to ambulation?

10%

39

What is Brown-Sequard syndrome?

Hemisection of cord; most commonly due to penetrating injury
Loss of ipsilateral motor, contralateral pain and temp below level of lesion

40

What % of Brown-Sequard recover to ambulation?

90%

41

What is central cord syndrome?

Most commonly occurs with hyperflexion of C spine
Bilateral loss of motor pain and temperature sensation in upper extremities, lower extremities spared

42

What is cauda equina syndrome?

Pain and weakness in lower extremities due to compression of lumbar nerve roots

43

What tract carries pain and temp sensory neurons?

Spinothalamic tract

44

What tract carries motor neurons?

Corticospinal and rubrospinal tract tract

45

What nerve roots are generally afferent; carry sensory fibers?

Dorsal nerve roots

46

What nerve roots are generally efferent; carry motor neruon fibers?

Ventral nerve roots

47

The majority of adult brain tumors are supra or infratentorial? Children?

Adult: 2/3 supratentorial
Children: 2/3 infratentorial

48

What is the most common primary brain tumor? Most common subtype?

Glioma
Glioma multiforma

49

What is the #1 tumor with mets to the brain?

Lung

50

What is the most common brain tumor in children?

Medulloblastoma

51

What is the most common metastatic brain tumor in children?

Neuroblastoma

52

Where does an acoustic neuroma arise from? Symptoms?

From 8th cranial nerve
Hearing loss, unsteadiness, vertigo, nausea/vomiting

53

#1 tumor overall of the spine?

Neurofibroma

54

What type of tumors are most likely benign?

Intradural tumors

55

What lab tests are checked with paraganglionoma?

Metanephrine in urin, MIGB for extramedullary chromatin tissue

56

When is intraventricular hemorrhage seen in children?

In premies secondary to rupture of the fragile vessels in germinal matrix

57

Risk factors for IVH in children?

ECMO, cyanotic congenital heart disease

58

Treatment of IVH in children?

Ventricular catheter for drainage and prevention of hydrocephalus

59

What is a myelomeningocele?

Neural corde defect with herniation of spinal cord and nerve roots through defect in vertebra

60

Where is the most common location for myelomeningocele?

Lumbar region

61

Where is Wernicke's area? What is its function?

Speech comprehension
Temporal lobe

62

Where is Broca's area? What is its function?

Speech motor
Posterior part of anterior lobe

63

What is the diagnosis for a patient with pituitary adenoma, undergoing XRT, now in shock? Treatment?

Pituitary apoplexy
Steroids

64

What cells act as brain macrophages?

Microglial cells