Table of Contents
What is Antidromic axon reflex?
An antidromic impulse in an axon refers to conduction opposite of the normal (orthodromic) direction. That is, it refers to conduction along the axon away from the axon terminal(s) and towards the soma.
How is axon reflex test done?
The technician will wipe the skin on your foot, leg and wrist with acetone. Four electrodes filled with acetylcholine are then placed on three areas of the leg and one on the wrist. The iontophoretic stimulators are turned on, and sweat responses are measured.
What stimulates the axon?
Electrical stimulation enhances peripheral axon regeneration. A single session of low-frequency electrical stimulation (1 h, 20 Hz) can enhance motor and sensory axon regeneration following epineurial suture repair (left) or when used as a conditioning stimulus prior to subsequent axotomy (right).
What is antidromic and orthodromic?
In an orthodromic study, the recording electrodes measure the action potential traveling in the physiologic direction. In an antidromic study, the recording electrodes measure the action potential traveling opposite the physiologic direction.
What is Chronaxie and Rheobase?
Chronaxie is the minimum time required for an electric current double the strength of the rheobase to stimulate a muscle or a neuron. Rheobase is the lowest intensity with indefinite pulse duration which just stimulated muscles or nerves.
What is SSR test?
Sympathetic skin response (SSR) is being used to assess the autonomic dysfunctions such as PD, spinal cord injury, and stroke. [5–7] It is a noninvasive paraclinical electrophysiological test, which is an assessment of sympathetic cholinergic psudomotor function.
How do you test for small fiber neuropathy?
Skin biopsy Skin biopsies are the most effective way to diagnose small fiber neuropathy. They’re only mildly invasive. During the procedure, the physician will remove several tiny skin samples, typically from the legs. The samples are then examined under a microscope for signs of small fiber neuropathy.
How do axons move?
Axonal materials are transported from the cell body to terminals and back by motor molecules that bind to cargo and move it along rail-like microtubule arrays at rates that vary from one to several hundred mm/day.
How do electrical signals travel down an axon?
Action potentials travel down a single neuron cell as an electrochemical cascade, allowing a net inward flow of positively charged ions into the axon. Within a cell, action potentials are triggered at the cell body, travel down the axon, and end at the axon terminal.
What is the main function of axon?
The function of the axon is to transmit information to different neurons, muscles, and glands.
What is the difference between orthodromic and antidromic conduction?
How can an axon generate an antidromic action potential?
Electrical stimulation of the central nervous system creates both orthodromically propagating action potentials, by stimulation of local cells and passing axons, and antidromically propagating action potentials, by stimulation of presynaptic axons and terminals.
What is chronaxie and its significance?
How is SSR test performed?
For recording the median nerve SSR, the active electrode was placed at the palm of the hand and the reference electrode at dorsum of the hand. For recording the tibial nerve SSR, the active electrode was placed at the sole of the foot and the reference electrode at the dorsum of the foot.
Where is GSR measured?
Palms, feet, fingers and shoulders are the most common locations to place the GSR electrodes because they have a high density of sweat glands.
What is the difference between peripheral neuropathy and small fiber neuropathy?
Small fiber neuropathy is considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain.