Ch. 2 - Neurosurgical investigation Flashcards Preview

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Flashcards in Ch. 2 - Neurosurgical investigation Deck (21)
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1

What is the flow of CSF circulation?

Choroid plexus (0.4 mL/min) -> lateral ventricles -> interventricular foramen -> 3rd ventricle -> aqueduct of Sylvius -> 4th ventricle -> foramen of Luschka/Magendie -> subarachnoid space -> arachnoid villi of dural sinuses (superior sagittal sinus)

2

Most common indications for LP

Infection, subarachnoid hemorrhage, MS, Guillan-Barre, neoplastic disease, myelography

3

Major contraindications for LP

1. Clinical evidence of raised ICP
2. Local infection

4

At what vertebral level do you perform LP?

Approximately L3/L4, below conus

5

Common complications of LP

Worsening brain herniation/spinal cord compression, injury to neural structures, HA, backache, infection, implantation of epidermoid tumor

6

Best imaging modality to diagnose a spinal tumor

MRI

7

Most common complication of LP? How do you avoid it?

Spinal HA 2/2 low CSF pressure; avoid by:
- lying flat 12hrs post LP
- <20g needle, avoid multiple sticks
- blood patch
- hydration

8

Causes of xanthochromic (yellowish) spinal fluid

Hemorrhage, jaundice, hemolytic disease

9

Bacterial meningitis on LP?

PMNs, elevated protein, low glucose

10

Parasitic infection on LP?

Eosinophilia

11

Causes of elevated protein in CSF?

GBS, carcinomatosis, multiple myeloma, infection

12

Mononuclear pleocytosis in CSF?

Viral meningitis, TB meningitis, acute demyelination

13

Findings on CSF electrophoresis in multiple sclerosis

Stable oligoclonal band pattern over time

14

Causes of intracranial calcification

Meningiomas, craniopharyngioma, ependymoma, aneurysm, AVMs, and oligodendroglioma

Normal in pineal gland, choroid plexus, and falx

15

Cerebral abscess appearance on CT

Ring-enhancing lesion

16

What is bright on T1 MRI?

Fat is bright, CSF is black - good for detail of anatomic structures

17

What is bright on T2 MRI?

CSF is bright BUT on T2 FLAIR it is black

18

SPECT/PET

Measures cerebral blood flow or cerebral metabolism

19

What is an interference pattern in nerve conduction studies?

Voluntary muscle contraction producing motor unit potentials

20

What type of EMG interference pattern is seen with neuropathy?

Reduced interference 2/2 diminished motor units

21

What type of EMG interference pattern is seen with myopathy?

Normal interference pattern