Ancillary Diagnostic Tests for Neurological Patients Patient ...
Transcript of Ancillary Diagnostic Tests for Neurological Patients Patient ...
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Ancillary Diagnostic Tests forNeurological Patients
Patient Evaluation
� Signalment� History� Physical and Neurological Exams� Localization of Lesion� Differential diagnosis� Diagnostic plan� Diagnosis/Prognosis� Treatment/Evaluate
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Minimum Database
� CBC� Chemistry
• Bile acids• Cholinesterase
� Urinalysis� Chest and
abdominal radiographs
� Abdominal ultrasound
� Heartworm test� Fecal
Ancillary Neurologic Tests
� Electrodiagnostics• EEG• EMG• BAER
� CSF tap & analysis• Cells & protein• Cholinesterase• Titers
� Radiographs• Skull or spine• Myelography• CT scan• MRI
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Electrodiagnostics
� EEG• Measures electrical
activity of the outer 3 mm of the cerebral cortex
• Normal activity is low amplitude, fast waves
EEG -- Normal
� The normal EEG shows primarily Beta wave activity (15-30 Hz) with low amplitude (5-15 V)
� The EEG is normal in Idiopathic Epilepsy, except during a seizure.
Left Occipital
Right Occipital
Left Frontal
Right Frontal
Left Side
Right Side
Occipitals
Frontals
Left Parietal
Right Parietal50 :V 1 second
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EEG -- Encephalitis
� In active encephalitis, the EEG show high-amplitude, slow- waves with spikeactivity.
Left Occipital
Right Occipital
Left Frontal
Right Frontal
Left Side
Right Side
Occipitals
Frontals
Left Parietal
Right Parietal50 :V 1 second
Electrodiagnostics
� EMG• Evaluates the LM
Unit– Spinal nerve– Neuromuscular
junction– muscle
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Electrodiagnostics
� EMG• Needle EMG looks
for abnormal spontaneous potentials– Fibrillation
potentials– Fasciculation– Complex repetitive
potentials
Electrodiagnostics
� EMG• Motor conduction
velocity– Measured from
several locations along the nerve
– Disstance/Time delay for response
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Electrodiagnostics
� EMG• F wave
– Indication of integrity of the axons
– Measured at 2 sites
– proximal– distal
Electrodiagnostics
� EMG• Repetitive Nerve
Stimulation– Decremental in
Myasthenia gravis and OP intoxication
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Electrodiagnostics
� EMG• Spinal Evoked
Potential– Acute spinal trauma– Chronic spinal cord
disease
Electrodiagnostics
� BAER• Evaluation of
auditory system in the ear and brainstem
• Same instrument as for EMG
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BAER
� Deafness in puppies• Particularly useful
in unilateral disease
BAER
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Cerebrospinal Fluid tap
� Routinely done on most neurological patients
� Collection from the cisterna magna (cerebellomedullary cistern) or L4-L5 lumbar space
Cerebrospinal Fluid Analysis
� Analyze• RBC and WBC cell
number• Cytology• Protein
� Abnormalities• Increased types of
cells• Increased protein• Increased pressure
� Titers for infectious disease• Species specific
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Cerebrospinal Fluid Titers
� Viral• Canine Distemper
� Bacterial • Lyme
� Protozoal• Toxoplasmosis• Neospora
� Rickettsial• RMSF• Ehrlichia
� Fungal• Aspergillus• Cryptococcus
� Viral• FeLV• FIV• F
IP� Protozoal
• Toxoplasmosis� Fungal
• Cryptococcus
DogDog CatCat
Neuroradiology
� Plain X-rays of head and vertebrae• Bone fractures, infection, neoplasia
� Myelogram-compressive and expanding spinal cord lesions
� CT and MRI lesions of the head or vertebrae
� CT better for bone; MRI better for soft tissue
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When all else fails…
Look at the patient!!!Look at the patient!!!
CNS Neoplasia
Today’s FrontierToday’s Frontier
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CNS Neoplasia- -Dogs
� Common Types• Meningioma• Astocytoma• Oligodendroglioma• Choroid plexus
papilloma• Lympoma• Neuroectodermal
tumors• Metastatic tumor
CNS Neoplasia- -Dogs
� Dog has 1-18 months average survival time• 1-3 with nothing• 6-9 with surgery• 12-18 with
radiation treatment� All tumors are
invasive (malignant)
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CNS Neoplasia- -Cats
� Most common is meningioma
� Usually extra-axial and benign
� Seen in aged cats� Present with
depression and dementia
Treatment
� Prednisolone (0.25-0.5 mg/kg q12h)• Treats secondary
effects• Cover with
gastroprotectants� Chemotherapy� Radiation therapy
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Chemotherapy
� Lomustine• 60 mg/M2 given• Monitor CBC
weekly• If WBC and
platelets okay in 5 weeks, then give 80 mg/M2
• Repeat every 5-8 weeks
� Procarbazine• 2-4 mg/kg/day for
1 week, then 4-6 mg/kg/day
• Monitor CBC• Continue as long as
WBC levels are > 4000/µl & platelet count is > 100,000/µl
Treatment
� Diet• Low carbohydrate
� Supplements• Antioxidants &
membrane stabilizers� Herbal medications
• Western• Traditional Chinese
medicine
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Radiosurgery (3D radiation therapy)
� McKnight Brain Institute at UF
� High, single dose radiotherapy
� 5 arcs of radiation provide sphere of death• Based upon the
focal size and tissue treated
Radiosurgery- -MRI
� Tumors are identified with MRI
� Fusion studies are performed
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Radiosurgery- -Bite plate
� A molded “bite plate” is made for the patient and secured in position
� Can be taken off and re-applied for later treatment
Radiosurgery- -3D alignment
� Special orientation system is applied to bite plate before CT scan
� Infrared cameras are used to align device for radiosurgery
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Radiosurgery- -CT scan
� Fusion CT scan is obtained is bite-plate and alignment guide in place
� CT guided biopsy is obtained for tissue type
Image fusion snapshots
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Radiosurgery- -Treatment plan
� Fused MRI and CT images provide target
� Provides anatomic detail of MRI with precision of CT
� Tumor margins outlined with combined spheres of radiation
Treatment plan
� Treatment plan generated & evaluated in transverse, dorsal and sagittal planes
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Radiosurgery- -Treatment
� Treatment is applied with LINAC unit at UFBI
� Cost of radiosurgery• procedure is around
$3000.00 • plus workup &
conventional surgery