Neuro Flashcards
What antibiotics penetrate the BBB?
3rd gen cephalosporins
Fluoroquinolones
Metronidazole
Chloramphenicol
Trimethoprim
Sulfonamides
What is the max amount of CSF you can take and what are normal cell and proteins amounts?
1 ml/5 kg
Cell counts <5 cell/uL
Protein <25 mg/dL (cisterna, <45 mg/dL (lumbar)
What structures show normal contrast enhancement on MRI?
Meninges, choroid plexus, pituitary glands, pharyngeal mm. Should not normally cross the BBB.
What electrodiagnostic study can help diagnosis myasthenia gravis and botulism, and what are the findings?
Repetitive nerve stimulation
MG= >10% decremental response
Bot= facilitation (increased amplitude and AUC with higher stimulation rates)
What do the M wave, F wave, and H reflex assess?
M= distal motor nerve conduction velocity
F= proximal motor nerve, ventral nerve root and ventral grey horn
H= sensory and motor, sensory fibers proximal to the electrode, alpha motor neuron, polyneuropathies, spinal cord
What are the surgical options for dorsal stabilization of AA luxation?
- AA wiring
- Nuchal ligament technique
- Dorsal cross-pinning + PMMA
- Kishigami AA tension band
What are the surgical options for ventral stabilization of AA lunation?
- Transarticular screws/pins
- Pins + PMMA
- Screws + PMMA
- Ventral plating
What are the angle for screw/pin placement for AA lux?
Transarticular pins are at 40 deg mediolateral and 20 deg ventrodorsal, aim for alar notch. Pins in caudal axis are 30deg mediolateral
What are the grades of nerve injury?
Grade 1: neurapraxia= interruption in function but normal structure, reversible
Grade 2: axonotmesis= axon disrupted, wallerian degeneration distally, recover after weeks
Grade 3: neurotmesis= axon/ endometrium disrupted
Grade 4: neurotmesis= axon/endoneurium/perineurium disrupted
Grade 5: neurotmesis= entire nerve severed
Treatment options for Cervical IVDD
Conservative (40% recurrence)
Ventral Slot/Slanted ventral slot (90-100% recover; 70% for large dog with IVDP)
Dorsal Laminectomy (100%)
Hemilaminectomy (80%)
Fenestration (33%)
Treatment options for Wobblers
Static: Decompression
Ventral Slot (Inverted Cone)
Dorsal Lam (continuous)
Dorsal Hemilam
Dynamic: Distraction-Stabilization.
Pins + PMMA
Screw-bar + PMMA
Locking plate
Discectomy + PMMA plug or cortical graft
Cervical disc arthroplasty
Treatment options for LS/CES
Dorsal laminectomy +/- partial discectomy, +/- foraminotomy
Distraction and Stabilization +/- graft or cage/Interbody device
Pins/screws + PMMA
Dorsal crosspinning/lag screws across zyga joints
SOP
Pedicle screw-rod fixation
Treatment options for vertebral fractures
Pins/screws + PMMA (C, TL, LS)
Screw Bar + PMMA (C)
ESF (TL)
Pedicle screw/rod (LS)
Locking plates (C, TL, LS)
Spinous process stabilization (Thoracic)
Auburn spinal plate
Lumbar plate
Spinal stapling/segmental fixation
What are the angles for pin placement in the cervical vertebrae?
Ventral stabilization. Enter at midline of caudoventral body. 35 degrees dorsolateral (45 for C7).
If C2: spinous process –> dorsal techniques, if body –> ventral.
Body: cranial and caudal body, 40 deg lateral, can cross AA joint to increase stability (like AA lux).
Always ventral stabilization before dorsal decompression
What are the angles for pin placement for LS stabilization?
Transarticular for CES: 30-45 deg, base of L7 spine –> zyga joints –> ilial wing
For fracture:
L7 pedicles: enter caudal to base of cranial articular process –> ventral and slightly craniomedial
Sacrum: enter caudal to cranial articular surface of sacrum –> ventral or engage ilium (aim for tuber sacrale)
What are the angles for pin placement for TL fractures?
Thoracic: enter at accessory process/tubercle of rib
Lumbar: enter at base of transverse and accessory
Both: 30-60 deg lateral to medial
30 if exiting midbody
60 if exiting lateral body
24 for T5-9 (Schmitt study)
Want them to diverge dorsally.
What is the pin placement technique?
- Pilot holes through cis cortex
- Probe down to transcortex (ensure no breach, look at angle)
- Pilot hole through trans cortex
- Measure, blunt the pin and determine number of exposed threads needed
- Insert pin with low speed, high torque drill
Name the ligaments of the dens, which is most important?
Apical (dens to basioccipital)
Transverse (holds dens ventral)
Alar ligaments*** x2 (dens to occipital bone )
Treatment options for nerve injury
Neurotization (nerve transfer or rein nervation)
Reconstruction (end-to-end neurorrhaphy)
Preimplantation of rootlets –> cord
Conservative treatment for IVDD
Rest and pain meds
Acupuncture (70% helpful)
Chemonucleolysis with chondrotinase ABC (90% improve, 80% excellent)
Types Dorsal laminectomies
Funkquist A: removes spinous process, laminae, articular process, 50% of pedicle
Funkquist B: leaves the articular process and pedicles
Modified: remove laminae, spinous processes and caudal articular processes, undercut the pedicles
Dorsal lam + hemi –> 75% of spinal cord exposed
Signs of IVDE on rads
Narrowing/wedging of the disc space *highest sensitivity
Increased articular process overlap
Mineralized material superimposed over the intervertebral foramen/vertebral canal
Reduced intervertebral foramen diameter
Complications of myelography. How to decrease risk
Seizures
Myelopathy/Deterioration (30% dobies)
Apnea
Subarachnoid hemorrhage
Meningitis
Arrhythmias
Death
Max dose of 8 ml by LUMBAR. (Higher risk with big does and cisternal punctures
Signs of IVDE on CT
Loss of epidural fat opacity surrounding the spinal cord
Visible spinal cord compression
* Compressive material is typically hyperattenuating (hemorrhage + mineral)
Mineral-dense material within the vertebral canal
Material within epidural space consistent with hemorrhage density
