Ch. 2 - Neurosurgical investigation Flashcards Preview

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

What is the flow of CSF circulation?

A

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
Q

Most common indications for LP

A

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

3
Q

Major contraindications for LP

A
  1. Clinical evidence of raised ICP

2. Local infection

4
Q

At what vertebral level do you perform LP?

A

Approximately L3/L4, below conus

5
Q

Common complications of LP

A

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

6
Q

Best imaging modality to diagnose a spinal tumor

A

MRI

7
Q

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

A

Spinal HA 2/2 low CSF pressure; avoid by:

  • lying flat 12hrs post LP
  • <20g needle, avoid multiple sticks
  • blood patch
  • hydration
8
Q

Causes of xanthochromic (yellowish) spinal fluid

A

Hemorrhage, jaundice, hemolytic disease

9
Q

Bacterial meningitis on LP?

A

PMNs, elevated protein, low glucose

10
Q

Parasitic infection on LP?

A

Eosinophilia

11
Q

Causes of elevated protein in CSF?

A

GBS, carcinomatosis, multiple myeloma, infection

12
Q

Mononuclear pleocytosis in CSF?

A

Viral meningitis, TB meningitis, acute demyelination

13
Q

Findings on CSF electrophoresis in multiple sclerosis

A

Stable oligoclonal band pattern over time

14
Q

Causes of intracranial calcification

A

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

Normal in pineal gland, choroid plexus, and falx

15
Q

Cerebral abscess appearance on CT

A

Ring-enhancing lesion

16
Q

What is bright on T1 MRI?

A

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

17
Q

What is bright on T2 MRI?

A

CSF is bright BUT on T2 FLAIR it is black

18
Q

SPECT/PET

A

Measures cerebral blood flow or cerebral metabolism

19
Q

What is an interference pattern in nerve conduction studies?

A

Voluntary muscle contraction producing motor unit potentials

20
Q

What type of EMG interference pattern is seen with neuropathy?

A

Reduced interference 2/2 diminished motor units

21
Q

What type of EMG interference pattern is seen with myopathy?

A

Normal interference pattern