🧠🔦The Neurologic Exam🔦🧠
These are the 6 parts of the neurologic exam
What are
1)mentation/behavior
2) gait/posture
Hands on component below
3) cranial nerves
4) postural reactions
5) reflexes
6) palpation/sensation
In this type of lesion the animal will have a head tilt, intention tremor, dysmetria, absent menace and other vestibular signs. The animal will have intact visual tracking and blink reflexes, with a poor menace. but intact PLR and blink
cerebellar lesion
In this lesion, will have ipsilateral eye, lip, ear droop, +/- blink.
myencephalon/medulla lesion
CN 7 specifically
These are the advanced diagnostics for neurology
Imaging: myelogram, CT, MRI
CSF analysis
electrodiagnostics: EEG
Define seizure, cluster, status epilepticus and pharmacoresistant/refractory epilepsy ***
epilepsy- ongoing reccurent sx condition. is a symptom not a diagnosis.
cluster-two or mor seizures within 24 hours
status epilepticus-sx lasting longer than 5 minutes or 2 or more sx without full recovery to normal in between.
refractory/pharmacoresistant epilepsy: failure to achieve freedom from seizures despite adequate trials of two (or more) well tolerated AEDs
this is the difference between level of mentation and quality of mentation
-Level of mentation (RAS system in the brainstem or forebrain), how aware animal is [normal (BAR), obtunded, stuporoous, comatose)
-quality of mentation (forebrain)-how awake or alert, dementia confusion, or other inappropriate behavior (might appear very bright and awake but are acting strangly, or personality change)
In this lesion the animal will have ipsilateral blind mydriasis, poor menace with intact palpebral. PLR no direct, or consensual with the one eye. intact consensual from other eye
Diencephalon lesion (CN2)
In this lesion you look for a 2 engine gait. Thoracic N-> absent LMN, pelvic n. to increased, UMN
C6-T2, spinal cord lesion
radiography advantages and disadvantages?
advantages: low cost, readily available, rules out many easier to diagnose dxs. and make sure to look for metastasis in chest and belly
disadvantages: poor soft tissue detail (unable to see CNS). not an absolute to rule out for neoplasia, infections, trauma. also hard to see convincing evidence of disc herniation. Low diagnostic yield in many neuro cases.
These are the components of the seizure and these are the classifications of them
components Pre-ictal, ictal and post-ictal
focal, generalized or unknown.
whole body-generalized. generalized or focal is motor manifestation (tonic-colic, atonic, myoclonic)
These are types of postural abnormalities that can be seen
These are types of gait abnormalities
posture-head tilt (vestibular lesion), head turn (forebrain, cerebral/thalamic), pleurosthotonus (head and body turn, forebrain). spine-kyphosis (dorsal curvature), lordosis (ventral curvature), scoliosis (lateral curvature), torticollis, opisthotonus (dorsal extension of the neck), neck pain, decerebrate rigity (rostral brain stem)m decrebellate rigidity (cerebellar lesion), schiff-sherrignton posture (thoracolumbar lesion), plantigrade or palmigrade limbs, tail carriage
gait-lameness, weakness, ataxia
In this type of lesion the animal will be obtunded, dementia, confusion, compulsive pacing, head turn, contralateral blindness with normal pulpils and PLRs
cerebrothalamic lesion
myelencephalon/medulla lesion
specifically cn 12
this is diagnostic is with spinal radiographs or CT obtained following injection or radiopaque contrast agent into subarachnoid space.
2)this is collected prior to injecting contrast agent.
3) advantages and disadvantages.
myelography. non-ionic iodinated, water soluble contrast agents are used.
Collect CSF prior to injection contrast agent. then CSF is collected after myelogram will be abnormal for over 1 week.
advantages: easily and rapidly visualize the shape/outline of the spinal cord vs. radiographs. low cost.
disadvantages: invasive (meningitis, seizures, deterioration of signs) limited diagnostic information
these are essential principles of seizure management
first manage client expectations.
for when starting medications: consider the dxs, consider the seizures "kindling phenomena", consider the pt
start meds if 2 or more seizures in 6 months, if accelerated, if episode clustered or status epilepticus, or underlying dx
consider the medication and pt. and the effectiveness of medication. impact of the cost. are the meds working? check blood levels is he getting the drug. etc.
** This is the difference between withdrawl vs deep pain vs voluntary motor control
Animals can have reflexes and withdrawl without voluntary motor or cons. pain =umn lesion.
an animal with absent withdrawl with intact conscious pain sensation +/- voluntary motor: LMN lesion.
reflexes tell lesion localization. motor and pain sensation tell you how bad
In this lesion the animal will have a dropped jaw if bilateral. masticatory m. wasting can also be seen.
Metencephalon/pons lesion, CN5
in this lesion reflexes are intact are in all 4 limbs. long strides, wobbly. Can have tetraparesis, or plegia with CP deficits and general propioceptive ataxia
C1-C5 lesion
1) this description is used for CT. Good for these dxs
2) advantages and disadvantages
MRI is good to see this? and then advantages and disadvantages
1) attenuation. IVDD, lumbosarcral, neoplasia, bone trauma. but cannot identify all disc dx
2) advantages: superior soft tissue contrast compared to rads. less cost. quicker than mri. disadvantages: limited soft tissue detail and can miss lesions in CNS, more expensive and less available than rads.
spinal cord and intervertebral discs, foramen magnum herniation. advantages: superior soft tissue compared to any other modality. best modality to visualize CNS. avoid risk associated with myelogram. disadvantages: more expensive and less available, requires general anesthesia and longer anesthesia.
these are most common anticonvulsants used in veterinary medicine
Very fast-onset, short duration to stop a seizure interupts: diazepam, midazolam, lorazepam. fast onset, short duration preventive short term
slower onset longer duration to make seizures as mild and infrequent as possible. preventive long time: phenobarbital, potassium bromide, levetiracetam/keppra, zonisamide/zonegram
pheno most common med. hepatic major.
bromide do not use in cats. metabolism kidneys
These are segmental reflexes tested
they test?
thoracic: biceps, triceps, withdrawl. pelvic: patellar gastrognemious, cranial tibial, withdrawl
LMN to front: biceps, triceps, patellar
cranial tibial, gastrocnemius branch of sciatic n.
In this lesion, ipsilateral mydriasis and ventrolateral strabismus. good navigation and menace. PLR-no direct. consensual to other side is present. Absent consenal from other eye.
Mesencephalon/midbrain lesion
CN3
With a lesion in this region, the animal can have varying degrees of floppy/stiff gait. loose limbed with palm grade/plantigrade gait
Polyneuropathy, neuromuscular dx
1) This is a high risk procedure if done incorrectly. performed after imaging
2) this is used for PNS dx to check for function of muscle and nerve
1) cerebrospinal fluid collection
2) electrodiagnostic. like EEG, BAER
these are some differentials for episodes that look like seizures but are not true seizures
Syncope-cardioresp.
tremors-cerebellar, neurromusuclar, basal ganglia
muscle spasms-usually neuromuscular
dystonia-basla ganglia, cerebrum cerebellum
behavior/compuslive-non epiletptic forebrain
narcolepsy, cataplexy, rem sleep disorders,
feline hyperestheia syndrome
neuromyotona=neuromuscular