Tarc: Neuro Imaging And Diagnostics Flashcards by laura knight

Clinical signs nd pathogenesis of hydrocephalus

congential (more common dogs) or acquired
domed head shape
open fontanel
diverging strabismus
blindness with absent menace OU
ataxia and v postural reactions
> on imaging
thin cortex w/ greatly distended lateral ventricles

How well did you know this?

Not at all

Perfectly

Best diagnostic modalities for diagnosing hydrocephalus?

MRI
CT
0 Ultrasound

How well did you know this?

Not at all

Perfectly

Tx hydrocephalus?

> medical 
- low dose GCs
- acetazolamide
- omeprazole
- mannitol (emergency) 
> surgical
- ventriculoperitoneal shunt placement

How well did you know this?

Not at all

Perfectly

What breeds hav ^ risk of hydrocephalus?

toy breeds with brachycephalic skulls

How well did you know this?

Not at all

Perfectly

How long after ventriculoperitoneal shunt sx are clinical signs likely to improve?

4 months

How well did you know this?

Not at all

Perfectly

WHat proportion of animals are likely to develop shun complications following surgery for hydrocephalus?

25%~

How well did you know this?

Not at all

Perfectly

What radiographic abnormalities indicate IVDD?

^ opactiy over intervertebral foramen
mineralisation of intervertebral disks
narrowed intervertebral disk space
spondylosis

How well did you know this?

Not at all

Perfectly

What is the intervertebral disk made up of?

annulus fibrosus

- nucleus pulposus

How well did you know this?

Not at all

Perfectly

What is the SC surrounded by?

Epidural fat

How well did you know this?

Not at all

Perfectly

What 3 planes can CT/MRI be taken in?

transverse
median/sagittal
dorsal

How well did you know this?

Not at all

Perfectly

How can a cervical vertebrae e identified on MRI?

Only vertbrae to contain BVs

How well did you know this?

Not at all

Perfectly

What are the 2 types of IVDD?

> type 1 (Hansen) EXTRUSION
- chondroid degeneration 
- extrusion of degenerate nucleus 
- acute -> spinal cord trauma (contusion and/or compression)
> type 2 (Hansen) PROTRUSION 
- fibroid degeneration 
- protrusion of hypertrophied annulus > chronic compression of SC
- may still present acutely

How well did you know this?

Not at all

Perfectly

Tx IVDD?

> thoracolumbar spine: Hemilaminectomy
- removal of half the lamina, articular facet joint and pedicle allowing access to vertebral canal from a lateral approach
cervical spine: Ventral slot
- slot burred though the centre of the disk and adjecent vertebral endplates to gain access to vertebral canal from ventral aproach

How well did you know this?

Not at all

Perfectly

Can radiographs dx disk disease?

No, but can indicate disk diseas

- myelography needed for dx

How well did you know this?

Not at all

Perfectly

Where is the most common space for IVDD?

T13- L1

How well did you know this?

Not at all

Perfectly

What is present above the disk hat -> asymetrical signs of IVDD?

longitudinal ligament along dorsal aspect of annulus fibrosus

How well did you know this?

Not at all

Perfectly

WHERE IS CONTRAST INJECTED FOR A MYELOGRAM?

SUBARACHNOID SPACE

How well did you know this?

Not at all

Perfectly

What is decision to go to surgery for IVDD based upon?

Study These Flashcards

pain
progression
deep pain/neuro deficits severity

Ddx for a chronic progressive asymmetrical painful forebrain dz. What about if ^ cellularity (mononuclear cells) found on CSF tap

Study These Flashcards

> Neoplastic
- supretentorial tumours cause pain d/t ^ICP
infectious/inflam
with CSF findings > GME (magnitude and type of pleiocytosis will vary in this condition)

Histo findings associated with GME

Study These Flashcards

mononuclear inflammatory cells
located perivascularly (around the BVs)
> macroscopically brownish lesions seen in the white matter (enlarged sie of brain w/ oedema and inflammatory focus)

What is SRMA?

Study These Flashcards

steroid responsive meningitis arteritis
(acute, progressive, symmetircal, painful)
inflamamtory cells (mainly neutrophils) within meninges and around BVs and nerve roots
young dogs commonly
may be febrile
usually neurologically normal
cervical hyperaesthesia (+- spine)
risk of haemorrhage into vertebral canal

What is GME?

Study These Flashcards

granulomatous meningioencephalitis

- a type of MUA (meningitis of unknown origin)

What would a population of small, mature lymphocytes on CSF tap indicate?

Study These Flashcards

inflmmation - MUA

How si GME dx confirmed?

Study These Flashcards

PME

Tx MUA?

Cytarabine

What would a CSF tap of marked pleiocytosis, predominanty neutrophils give as Ddx?

- SRMA (no and type of pleiocytosis may vary in this condition) - infectious - neoplasia (eg. meningiomia) - IVDD (can -> neutrophilic pleiocytosis)

How do nerves respond to damage?

SWELL!

Ddx for spinal ataxia in the horse

- CVM/S - EHV1 - EDM - trauma - migrating parasites - EPM (foreign imports) - ryegrass staggers

Clinical signs of EHV1 infection?

- ascending paresis/ataxia - systemic signs: pyrexia, depression - bladder incontinence, tail paresis - urine scalding - occasionally cranial nerve signs

Pathogenesis of EHV1?

> transmission - inhalation: aerosolised infective droplets - fomites: hands, water, eeed > viral replication in nasal epitheliem and shedding in nasal secretions - within 2hrs - usually for 7d, up to 14d in immunologically naive horses

Which part of the SC does EHV1 mostly affect?

- grey matter (vasculitis and thrombosis -> sharply demarcated haemorrhage)

What causes the clinical signs of EHV?

result of vascular compromise (extent of neuro deficit correlates to haemorrhage)

How can EHV1 be diganosed?

> IHC - vial antigen in endothelial cells and myocytes surrounding BVs - first detected @6-8d post infection

Pathogenesis of EHV1

- endotheliotopic - dissemination to uterus, lung or CNS, then to endothelium - vasculitis and thrombo-ischaemia (peripheral vasculitis (limb oedema), SC vasculitis, immune complex deposition) - some strains more liekly to be associated with neuro form of dz

What codes of practice hsould be consulted for appropriate measures around EHV1 disease?

HBLB

Tx EHV1

Look up

Management of an EHV1 outbreak?

Look up

How can good quality standing radiographs of the cervical spine be judged?

Ventrolateral processes should be perectly aligned

What boney changes are ofen seen in older horses? Are these pathological?

- articular face changes @ C5-C7 common in adult healthy horses - NOT neurological

What radiographic signs may indicate Opathology of the spine?

> subjective - spinal canal aligment - OA of articular processes - caudal epiphyseal flare (ski ramping) > objective = intRAvertebral ratios (more senstiive and specific in young horses) - measure minimum canal diameter (perpendicular to canal floor) and maximum vertebral physis diameter (perpendicula to canal floor) - calculate ratio (canal/physis) to adjust for distance of radiograph from xray machine and size of horse - if

If ratio of

No not necessarily

Pathogenesis of CVM/S. What are the 2 types?

> neuro signs d/t progressive SC compression > 2 main types of osseus malformation/stenosis - type 1: dynamic (flexion C3-C5, extension C5-C7, young animals) - type 2: absolute (osseus changes in vertebrae -> SC compression, older horses @ C5-7, O changes in articular process joints (facets) d/t congenital OCD?)

How may the location of the lesion be determined at PME with CVMS?

> Wallerian degeneration - ascending tracts cranial to the lesions and descedning tracts caudal to the lesion degenerate - white and grey matter changes at site of lesion

Outline the flow of CSF

- produced choroid plexus of lateral ventricles - flows into 3rd ventricle then 4th - exits via arachnoid villi to the lymphatics

Tarc: Neuro Imaging And Diagnostics Flashcards

(44 cards)