Chapter 30 Medical Conditions of the Vertebral Column and Spinal Cord Flashcards
List DAMNIT V categories
D - Degenerative
A - Anomalous
M - Metabolic
N - Neoplasia, nutritional
I - Inflammatory, infectious
T - Toxic, traumatic
V - Vascular
6 finger rule
- Singlament
- Onset
- Progression
- Lateralising?
- Painful?
- Neurolocalisation
List 3 examples of metabolic conditions that may result in signs of SC dysfunction
Secondary hyperparathyroidism
Thiamine deficinecy
Hypervitaminosis A (cats)
Name 2 locations fo rCSF collection
Lumbar subarachnoid space
Cerebellomedullary cistern
What direction does CSF predominantly flow in
Rostro-caudal
How mcuh CSF (vol) can be safely collected
1 ml/5kg
At what specific site i slumbar CSF collection performed in dogs?
And in cats?
L5-L6 in dogs
L6-L7 in cats
What does xanthochromic CSF suggest
Xanthochromic = yellow (in greek)
Suggests previous subarachnoid haemorrhage
What is normal WBC level of CSF
An TP?
<5 x 10^6/L
TP at cerebellomedullary cistern <250 mg/L, at lumbar subarachnoid space <450 mg/L
What breed of dog is prone to fungal disco?
GSDs
Which type of antibody reflects primary (direct expose) and secondary (repeated/chronic infection) immune responses?
IgM = primary
IgG secondary
i.e elevated IgG may just represent previous exposure/vaccination. Do IgG antibody index to help distinguish
What antibody tet and result can be used to help diagnose SRMA ?
Serum and CSF IgA
(combined elevation in serum and CSF highly suggestive)
List 5 common mediacl disorders of vertebral column and spinal cord
- FCE
- HNPE
- Degenerative myelopathy
- Discospondylitis
- Meningomyelitis
What is degenerative myelopathy?
C/s
What is gene mutation responsible
Definitive dx?
CDM: Diffuse axonopathy associated with necrosis primarily in lateral and ventral funiculi –> axonal and myelin degeneration
C/s: UMN paresis and ataxia –> incontinence, thoracic limb involvement.
Gene mutation: Superoxide dismutase 1 (SOD1). Mis-sense mutation G-to-A transition (A-to-T in Bernese mountain dogs)
Dx: Histo. Presumtive with exluding other disorders thorugh imaging and CSF analysis, + SOD1 gene mutation analysis
Spinal cord histopathology from a 6-year-old Boxer with degenerative myelopathy.
A, Pallor and myelin degeneration (pale-staining areas of the white matter) are marked in the lateral and ventral funiculi at the level of the fifth thoracic spinal cord segment (Luxol fast blue stain with periodic acid–Schiff counterstain).
B, Myelin loss is seen predominantly in the lateral and ventral funiculi (stars) at the level of the eighth thoracic spinal cord segment (Luxol fast blue stain).
C, Dilated myelin sheaths that contain debris (arrows) are most numerous adjacent to the ventral median fissure (star) (Luxol fast blue stain with periodic acid–Schiff counterstain).
D, Multiple axons are absent or fragmented (arrows) and are surrounded by dilated myelin sheaths (Bielschowsky silver stain).
What is prognosis for dogs once dx CDM?
Any exceptions?
6-9 month
Corgis 19 months
Name 4 types of meningomyelitis
- Viral
- Bacterial
- Protozoal
- Idiopathic (SRMA, GME (or MUA as GME can only be dx on PM)
Which meninges are affected by SRMA
Leptimeninges (=arachnoid + pia)
At what age are dos usually affected by SRMA?
Breeds:
6-18 months
Beagle, Bernese, Boxer (BBB)
With SRMA, what other structures may be affected by arteritis
Mediastinum, thyroid, heart
What are the two types of SRMA?
Dx:
Acute and chronic
Dx:
- MRI = miningeal enhancement
- CSF = pleocytosis + elevated TP
-
Serum + CSF IgA!
- If both high then sens 91% spec 78%. N.B. IgA remains elevated so no use for monitoring
Gross and histopathologic lesions associated with steroid-responsive meningitis-arteritis.
A, Ventral surface of the caudal medulla with a leptomeningeal plaque (arrow).
B, High magnification (40×) views of the prolific arterial inflammation in the cervical spinal cord leptomeninges. Neutrophils are prominent. Note the thrombosis of the arteriole (left) and the fibrinoid degeneration of the blood vessel (right).
C, Transverse section of the cervical spinal cord—low-magnification view of an inflammatory plaque in the ventral leptomeninges (left arrow). In the two insets at higher magnification, note the advanced fibrinoid mural degeneration (right arrow) and the neutrophilic infiltration.
What is most common MRI finding in disseminated GME?
Multiple T2W and T2 FLAIR hyperintensities throughout the CNS white matter - typically infiltrative appearance and irregular margins.
Despite the predilection of the granulomatous meningoencephalomyelitis for white matter, MRI lesions often are distributed throughout both gray and white matter.
The lesions have variable intensity on T1-weighted images and have variable degrees of contrast enhancement.
Vasogenic edema in the white matter is commonly present on T2-weighted images and appears hyperintense to the neuroparenchyma. Although meningeal enhancement has been described it is not commonly apparent.
Ddx: Infectious meningoencephalomyelitis, CNS lymphoma, metastatic neoplasms
Magnetic resonance imaging (MRI) and histopathology of granulomatous meningomyelitis in a 6-year-old mixed-breed dog.
A, On the sagittal plane T2-weighted MRI of the lumbar vertebral column, there is a diffuse, intramedullary hyperintensity in the lumbar spinal cord (arrows) Histopathologically this hyperintensity is the result of granulomatous meningoencephalomyelitis.
B, Subgross transverse section of the lumbar spinal cord (taken from a section of spinal cord in the area of hyperintensity dorsal to L5 vertebra) shows intramedullary inflammation within the dorsal, right lateral, and ventral funiculi. Note the rare involvement of the right dorsal and ventral nerve rootlets (arrows).
C, Magnified view (box outline in B) at the level of the central canal depicting numerous perivascular, coalescing, inflammatory infiltrates within the spinal cord parenchyma typical of granulomatous meningoencephalomyelitis (40×; hematoxylin and eosin stain).
Comment on MRI
Transverse (A) and sagittal (B) plane T2-weighted magnetic resonance images of lumbar vertebral column in a dog with bacterial meningomyelitis and epidural empyema. Note the hyperintensity present on the sagittal (single arrow) image that is shown on the transverse images (double arrows) as marked hyperintensity in the epidural space. Cerebrospinal fluid analysis and culture disclosed marked neutrophilic pleocytosis and Gram-negative bacilli, respectively. The dog had a complete response to a 3-month course of antibiotics.
List 4 rdaiographic changes of disco
- End plate lysis
- IVD space narrowing
- Sclerosis
- Spondylosis
Radiograph and computed tomography (CT) scan of discospondylitis in a 6-year-old female, spayed Working Kelpie mix.
A, Lateral radiograph shows mild narrowing of the lumbosacral intervertebral disc space. The caudal endplate of the L7 vertebra and the cranial endplate of the sacrum do not appear lytic.
B, Transverse CT image (bone window) disclosing marked lytic changes (white arrows) within the sacrum consistent with discospondylitis. The dog responded completely to a 3-month course of antibiotics.
