Neuro diagnostics Flashcards
(19 cards)
More specific neuro tests: (6)
Name some specific blood tests used for neuro case work up. (5)
muscle enzyme creatine kinase (e.g. muscular dystrophies, inflammatory myopathies; CK helps differentiate neuropathic vs. myopathic processes)
bile acids for liver shunts
genetic tests
acetylcholine receptor antibodies for myasthenia
+ other antibody tests
PCR tests (like for toxoplasmosis which can cause neuro signs)
Polycythemia can cause seizures.
What to note in regard to catheters and paretic patients?
Catheterized bladders in paraparectic animals can be contaminated and give them bacterial cystitis which can even cause discospondylitis.
discospondylitis = inflammation of the intervertebral disc, adjacent vertebral endplates, and vertebral bodies
Describe Cerebrospinal fluid analysis:
- Inflammatory conditions related to the CNS (meningitis, encephalitis, myelitis)
- CNS-related tumours (e.g. lymphoma) though rarely!
Location options:
* atlanto-occipital puncture
* lumbar puncture
Under general anaesthesia.
- Needs to be examined in the laboratory within 1h!!
- color, protein, cell count, cytology, bacteriology, infectious disease antibodies, neoplastic cells
Contraindications for CSF sampling. (5)
- high risk of anaesthesia
- increased intracranial pressure
- active intracranial haemorrhage, coagulopathy
- large intracranial mass lesions, hydrocephalus, cerebral oedema
- atlantoaxial instability
What type of xrays for atlanto-axial instability?
in case of spinal instability, initially only lat views due to risk of internal decapitation or paralysis!
Describe myelography.
- helps identify compressive spinal cord diseases (e.g. disc prolapse, spinal arachnoid diverticul)
- injection of contrast medium into the subarachnoid space from the occipital or lumbar region, X-ray or CT scan
- general anaesthesia
- difficult, invasive technique
- iodine-based contrast agent
- 10-20% of patients seizures, worsening of neurological condition
Myelography isn’t done so much anymore since its invasive and we have better options these days like MRI and CT.
Why might you use U/S for neuro cases?
- hydrocephalus (open fontanelle)
- FNA/biopsy samples under guidance
Explain these:
* EEG (electroencephalography):
* EMG (electromyography):
* MNCV (motor nerve conduction velocity):
* BAER TEST (brainstem auditory evoked
response):
- EEG (electroencephalography): measures
the strength and frequency of changes in
neuronal potentials - EMG (electromyography): identify muscles
with nerve innervation disorders and assess
myopathies - MNCV (motor nerve conduction velocity):
stimulation of peripheral nerve, diagnosis
of peripheral neuropathies - BAER TEST (brainstem auditory evoked
potentials): sounds stimulate the auditory
apparatus, electrical activity is recorded via
electrodes placed on the skull
How do you decide the order of your diagnostics?
Follow the differential diagnoses ranked on
the basis of the VITAMIND!
* Basic diagnostic tests first, then advanced exams!
* Don’t do diagnostic tests “just in case”, be respectful of the owner’s financial possibilities!
what is a vermicular gait
resembling a worm in form or motion, serpentine
with vermicular gait, where is your problem localized to?
in bilateral peripheral vestibular disease
after bilateral total ear canal ablation
and lateral bulla osteotomy, you need to prescribe eye drops for a week. why?
During TECA-LBO surgery, the facial nerve (cranial nerve VII) runs very close to the surgical field and is often stretched, bruised, or even damaged during dissection.
If the facial nerve is affected, the patient can develop facial nerve paralysis, which commonly causes:
* Inability to blink normally (loss of palpebral reflex)
* Lagophthalmos (incomplete eyelid closure)
* Reduced tear production in some cases
dermoid sinus
A dermoid sinus is a congenital defect in animals, particularly seen in certain dog breeds like Rhodesian Ridgebacks, where an abnormal tube-like tract forms between the skin surface and deeper tissues such as the spinal cord or vertebrae.
It arises due to incomplete separation of the skin and neural tube during embryonic development. Dermoid sinuses can vary in depth and may become infected, leading to swelling, pain, or neurological signs if they involve the spinal cord.
Clinically, they often present as a small opening, lump, or tuft of hair along the midline of the back, especially over the neck or thoracic spine. Treatment typically involves surgical removal of the entire sinus to prevent infection or serious complications.
hereditary degenerative myelopathy
Hereditary degenerative myelopathy is a progressive, inherited spinal cord disease mainly affecting older dogs, especially breeds like German Shepherds, Boxers, and Pembroke Welsh Corgis.
It results from a genetic mutation (commonly in the SOD1 gene) that leads to degeneration of the white matter in the thoracolumbar spinal cord, causing loss of coordination, weakness, and eventually paralysis of the hind limbs.
The disease is painless but relentlessly progressive, and affected dogs eventually lose the ability to walk. Diagnosis is often made by ruling out other causes of neurologic dysfunction, supported by genetic testing. There is no cure, but physical therapy can slow progression and maintain quality of life for a time.
why turn a patient on its back to test a cranial nerve?
if no nystagmus seen in normal recumbancy, by irritating the vestibular system you may be able to provoke pathological nystagmus if its present.
specific gravity ref. range for CSF
typically around 1.004 to 1.007
increases with severe inflammation when proteins are high
A histiocytoma in dogs
is a common, benign skin tumor arising from Langerhans cells, which are immune cells found in the skin. It typically appears as a small, round, hairless, and rapidly growing nodule, often pink or red, and usually affects young dogs (under 3 years old), though it can occur at any age.
Histiocytomas are most commonly found on the head, ears, and limbs, and they often provoke little discomfort unless secondarily infected or traumatized.
Importantly, histiocytomas often regress spontaneously within a few weeks as the immune system recognizes and eliminates the tumor, although surgical removal may be recommended if the diagnosis is uncertain or the lesion becomes problematic.
common CSF finding in SRAM
high leukocytes (thousands per microL) with neutrophilic pleocytosis
normally CSF leukocyte count should be like 5 per microL
SRMA = steroid responsive meningitis arteritis
