Sections Flashcards
A measurement of the speed of conduction of an electrical impulse through a nerve
Nerve Conduction velocity
Mechanism of nerve conduction velocity test
Two electrodes are placed on the nerve:
- One electrode stimulates the nerve with a mild electrical impulse
- Another electrode records the resulting electrical activity
The NCV is then calculated by measuring the distance between the electrodes and the time it takes for electrical impulses to travel between electrodes
Factors affecting NCV
- Myelin Sheath (myelinated neurons have higher NCV)
- Diameter (the higher the diameter, the higher the NCV)
- Temperature (The higher the temp, the higher the NCV)
A technique widely used for pain relief and refers to the delivery of electrical currents through the skin to activate peripheral nerves
Transcutaneous Electrical Nerve Stimulation (TENS)
TENS mechanism
Activity in large diameter low threshold mechanoreceptive (touch-related) nerve fibers could inhibit the transmission of action potentials from small diameter higher threshold nociceptive (pain-related) fibers.
Most commonly used imaging modalities for visualizing peripheral nerves
Ultrasound and MRI
Type of peripheral nerve imaging that allows dynamic imaging
Ultrasound
Imaging modalities used in direct structure visualization of CNS
X-ray, CT, MRI
Imaging modalities used in recording of metabolic activity of CNS
fMRI, PET scan
A system for assessing spinal motion using video x-ray, uses a special motion support platform to optimize alignment and range of motion
VMA (Vertebral Motion Analysis)
An imaging modality that provides cross-sectional images of bony and soft tissue elements of the vertebral column, uses an x-ray based on the degree to which a tissue attenuates the x-ray beam (grey scale)
Computed Tomography (CT)
Primary imaging method for the vertebral column
MRI
The only method to show an intrinsic abnormality of the spinal cord substance
Magnetic Resonance Imaging (MRI)
Imaging modalities that are central to neuroimaging
CT and MRI
An imaging modality that is good for diagnosing hemorrhage and calcification, excellent for emergency situations
CT
An imaging modality that maps the brain’s white matter tracts (Fiber Tractography)
Diffusion Tensor Imaging (DTI)
An imaging modality that is used in studying diseases involving white matter, changes in brain structure with age and for surgical planning
Diffusion Tensor Imaging (DTI)
An imaging modality that maps brain activity by detecting changes in blood flow
Functional MRI (fMRI)
A functional imaging technique that shows how the brain works by detecting metabolic or chemical activity, rather than just its structure
PET scan
Two imaging modalities used in pre-surgical planning
fMRI and DTI
Focuses on structural information of white matter
DTI
Focuses on functional and metabolic information of the brain
fMRI
Most used imaging modality for cranial nerve evaluation
- MRI
- CT
- High-resolution ultrasound (for superficial nerves)
Used for assessing electrical activity of the brain
- EEG
- EC0G
- Single-neuron recordings
