Electromyography (EMG) - Revision history

Wdoyon at 23:17, 17 January 2022

2022-01-17T23:17:28Z

← Older revision		Revision as of 18:17, 17 January 2022
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	Electromyography involves the recording of electrical activity from muscle fibers. ~~EMG serves as an important diagnostic tool to monitor nerve root function and motor neuron activity. The lower~~ motor neurons that exit the spinal cord form nerve roots. These nerve roots are at risk for injury during spinal ~~surgeries~~. Lower motor neurons generate action potentials during voluntary movement, when electrically stimulated, and in response to disease or injury. Electromyography can detect these changes in electric potential.		Electromyography involves the recording of electrical activity from muscle fibers. Lower motor neurons that exit the spinal cord and brainstem form nerve roots. These nerve roots are at risk for injury during different types of surgeries, such as a spinal decompression. Lower motor neurons generate action potentials during voluntary movement, when electrically stimulated, and in response to disease or injury. Electromyography can detect these changes in electric potential. EMG serves as an important diagnostic tool to monitor nerve root function and motor neuron activity.
	==The Neuromuscular Junction==		==The Neuromuscular Junction==
	Lower motor neurons from the anterior horn of the spinal cord and from the motor nuclei in the brainstem send axonal projections to the periphery where they form synaptic connections with multiple muscle fibers. This interface between an axon terminal of the motor neuron and a single muscle fiber is known as the neuromuscular junction or motor end plate. The lower motor neurons release acetylcholine as a neurotransmitter. Acetylcholine binds to nicotinic acetylcholine receptors located on the cell membrane (or sarcolemma) of the muscle fiber, a process that can lead to depolarization and muscle contraction.		Lower motor neurons from the anterior horn of the spinal cord and from the motor nuclei in the brainstem send axonal projections to the periphery where they form synaptic connections with multiple muscle fibers. This interface between an axon terminal of the motor neuron and a single muscle fiber is known as the neuromuscular junction or motor end plate. The lower motor neurons release acetylcholine as a neurotransmitter. Acetylcholine binds to nicotinic acetylcholine receptors located on the cell membrane (or sarcolemma) of the muscle fiber, a process that can lead to depolarization and muscle contraction.

Wdoyon at 23:02, 17 January 2022

2022-01-17T23:02:20Z

← Older revision		Revision as of 18:02, 17 January 2022
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	Electromyography is the recording of electrical activity from muscle fibers ~~and~~ serves as an important diagnostic tool to monitor nerve root function and motor neuron activity. ~~Motor~~ neurons generate action potentials during voluntary movement, when electrically stimulated, and in response to disease or injury. ~~An electromyograph~~ can detect these changes in electric potential.		Electromyography involves the recording of electrical activity from muscle fibers. EMG serves as an important diagnostic tool to monitor nerve root function and motor neuron activity. The lower motor neurons that exit the spinal cord form nerve roots. These nerve roots are at risk for injury during spinal surgeries. Lower motor neurons generate action potentials during voluntary movement, when electrically stimulated, and in response to disease or injury. Electromyography can detect these changes in electric potential.
	==The Neuromuscular Junction==		==The Neuromuscular Junction==
	Lower motor neurons from the anterior horn of the spinal cord and from the motor nuclei in the brainstem send axonal projections to the periphery where they form synaptic connections with multiple muscle fibers. This interface between an axon terminal of the motor neuron and a single muscle fiber is known as the neuromuscular junction or motor end plate. The lower motor neurons release acetylcholine as a neurotransmitter. Acetylcholine binds to nicotinic acetylcholine receptors located on the cell membrane (or sarcolemma) of the muscle fiber, a process that can lead to depolarization and muscle contraction.		Lower motor neurons from the anterior horn of the spinal cord and from the motor nuclei in the brainstem send axonal projections to the periphery where they form synaptic connections with multiple muscle fibers. This interface between an axon terminal of the motor neuron and a single muscle fiber is known as the neuromuscular junction or motor end plate. The lower motor neurons release acetylcholine as a neurotransmitter. Acetylcholine binds to nicotinic acetylcholine receptors located on the cell membrane (or sarcolemma) of the muscle fiber, a process that can lead to depolarization and muscle contraction.

Wdoyon: /* Intraoperative Monitoring */

2022-01-17T22:44:20Z

Intraoperative Monitoring

← Older revision		Revision as of 17:44, 17 January 2022
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	==Intraoperative Monitoring==		==Intraoperative Monitoring==
	Spontaneous EMG activity is ~~widely~~ used to monitor ~~spinal cord and~~ spinal nerve root function ~~during~~ spinal ~~surgeries~~.		Spontaneous EMG activity is used to monitor spinal nerve root function for surgeries in which the spinal and cranial nerve roots are at risk for injury.
	#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar and sacral surgeries. The technique is sometimes used for thoracic pedicle screws, but there tends to be lower threshold values ~~just~~ because the pedicle is smaller~~; therefore screw~~ testing is not as reliable in the thoracic region.		#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar and sacral surgeries. The technique is sometimes used for thoracic pedicle screws, but there tends to be lower threshold values because the pedicle bone is smaller. Screw testing is not as reliable in the thoracic region.
	#Peripheral Nerves. Peripheral nerves, such as the recurrent laryngeal nerve (RLN), which is a branch of the Cranial Nerve X, are monitored to identify if the surgeon violating on the nerve during dissection. In addition to spontaneous EMG recordings, the surgeon will use triggered stimulation to probe the tissue at the surgical site. If the tip of the stimulator is near the nerve, the triggered stimulus will elicit a cMAP.		#Peripheral Nerves. Peripheral nerves, such as the recurrent laryngeal nerve (RLN), which is a branch of the Cranial Nerve X, are monitored to identify if the surgeon violating on the nerve during dissection. In addition to spontaneous EMG recordings, the surgeon will use triggered stimulation to probe the tissue at the surgical site. If the tip of the stimulator is near the nerve, the triggered stimulus will elicit a cMAP.
	#Brachial Plexus		#Brachial Plexus

Wdoyon: /* Peripheral Nerves */

2020-06-06T20:47:00Z

Peripheral Nerves

← Older revision		Revision as of 15:47, 6 June 2020
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	==Peripheral Nerves==		==Peripheral Nerves==
	EMG recordings from upper and lower extremity musculature are used to monitor the peripheral motor nerves that arise from the spinal cord. ~~Each~~ spinal nerve exits above the ~~vertebrae~~ to which it corresponds. For example, cervical spinal nerve 5 (C5) exits ~~above cervical vertebrae 5~~. The motor neurons form a ventral nerve root as they exit the spinal cord. Together with the dorsal (sensory) root, this bundle of fibers is called a spinal nerve root. There are 31 spinal nerve roots.		EMG recordings from upper and lower extremity musculature are used to monitor the peripheral motor nerves that arise from the spinal cord. A spinal nerve exits above the vertebra to which it corresponds. For example, cervical spinal nerve 7 (C7) exits between C6-7. There is no C8 vertebra; therefore, the C8 spinal nerve, which exits between C7-T1, is an exception. The motor neurons form a ventral nerve root as they exit the spinal cord. Together with the dorsal (sensory) root, this bundle of fibers is called a spinal nerve root. There are 31 spinal nerve roots.

	==Cranial Nerves==		==Cranial Nerves==

Wdoyon: /* Anesthesia and Other Factors */

2019-12-04T03:27:54Z

Anesthesia and Other Factors

← Older revision		Revision as of 22:27, 3 December 2019
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	==Anesthesia and Other Factors==		==Anesthesia and Other Factors==
	#Anesthesia Methods		#Anesthesia Methods. EMG activity is not affected by gas anesthesia.
	#Muscle Relaxants		#Muscle Relaxants
	#Temperature		#Temperature
	#Tourniquet		#Tourniquet
	#Others		#Others

	==References==		==References==

Wdoyon: /* Intraoperative Monitoring */

2019-12-04T03:26:12Z

Intraoperative Monitoring

← Older revision		Revision as of 22:26, 3 December 2019
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	==Intraoperative Monitoring==		==Intraoperative Monitoring==
	Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function during spinal surgeries.		Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function during spinal surgeries.
	#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar surgeries.		#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar and sacral surgeries. The technique is sometimes used for thoracic pedicle screws, but there tends to be lower threshold values just because the pedicle is smaller; therefore screw testing is not as reliable in the thoracic region.
	#Peripheral Nerves. Peripheral nerves, such as the recurrent laryngeal nerve (RLN), which is a branch of the Cranial Nerve X, are monitored to identify if the surgeon violating on the nerve during dissection. In addition to spontaneous EMG recordings, the surgeon will use triggered stimulation to probe the tissue at the surgical site. If the tip of the stimulator is near the nerve, the triggered stimulus will elicit a cMAP.		#Peripheral Nerves. Peripheral nerves, such as the recurrent laryngeal nerve (RLN), which is a branch of the Cranial Nerve X, are monitored to identify if the surgeon violating on the nerve during dissection. In addition to spontaneous EMG recordings, the surgeon will use triggered stimulation to probe the tissue at the surgical site. If the tip of the stimulator is near the nerve, the triggered stimulus will elicit a cMAP.
	#Brachial Plexus		#Brachial Plexus

Wdoyon: /* Intraoperative Monitoring */

2019-12-04T03:20:17Z

Intraoperative Monitoring

← Older revision		Revision as of 22:20, 3 December 2019
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	==Intraoperative Monitoring==		==Intraoperative Monitoring==
	Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function ~~for~~ spinal ~~decompressions and fusions~~.		Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function during spinal surgeries.
	#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar surgeries.		#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar surgeries.
	#Peripheral Nerves		#Peripheral Nerves. Peripheral nerves, such as the recurrent laryngeal nerve (RLN), which is a branch of the Cranial Nerve X, are monitored to identify if the surgeon violating on the nerve during dissection. In addition to spontaneous EMG recordings, the surgeon will use triggered stimulation to probe the tissue at the surgical site. If the tip of the stimulator is near the nerve, the triggered stimulus will elicit a cMAP.
	#Brachial Plexus		#Brachial Plexus
	#Dorsal Rhizotomy		#Dorsal Rhizotomy

Wdoyon: /* Peripheral Nerves */

2019-09-30T02:18:18Z

Peripheral Nerves

← Older revision		Revision as of 21:18, 29 September 2019
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	==Peripheral Nerves==		==Peripheral Nerves==
	EMG recordings from upper and lower extremity musculature are used to monitor the peripheral nerves that arise from the spinal cord.		EMG recordings from upper and lower extremity musculature are used to monitor the peripheral motor nerves that arise from the spinal cord. Each spinal nerve exits above the vertebrae to which it corresponds. For example, cervical spinal nerve 5 (C5) exits above cervical vertebrae 5. The motor neurons form a ventral nerve root as they exit the spinal cord. Together with the dorsal (sensory) root, this bundle of fibers is called a spinal nerve root. There are 31 spinal nerve roots.

	==Cranial Nerves==		==Cranial Nerves==

Wdoyon: /* Cranial Nerves */

2019-09-29T01:42:59Z

Cranial Nerves

← Older revision		Revision as of 20:42, 28 September 2019
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	Both spontaneous and electrically stimulated EMG recordings are used to monitor the cranial nerve function in a variety of surgical procedures. Electrically stimulated EMG activity is helpful for identifying the location of the nerves in the tissue. With this information, the surgeon can avoid that area and the possibility of injuring the nerve.		Both spontaneous and electrically stimulated EMG recordings are used to monitor the cranial nerve function in a variety of surgical procedures. Electrically stimulated EMG activity is helpful for identifying the location of the nerves in the tissue. With this information, the surgeon can avoid that area and the possibility of injuring the nerve.
	#Cranial Nerve VII. The facial nerve (CN VII) is at risk during surgeries such as a parotidectomy and middle ear cases (e.g., tympanoplasty, stapedectomy, etc.). The facial nerve has four main branches that are most often monitored for EMG activity. The Temporal Branches innervate the muscles above the eyes, including the frontalis, orbicularis oculi and corrugator supercilii. The Zygomatic Branches innervate the orbicularis oculi, underneath the eyes. The Buccal branches innervate the muscles of the upper mouth and cheeks. The Marginal Mandibular Branch innervates the mentalis around the chin. The Cervical Branch is a fifth branch of the facial nerve, which innervates the platysma near the throat, but this branch is not normally monitored for EMG activity.		#Cranial Nerve VII. The facial nerve (CN VII) is at risk during surgeries such as a parotidectomy and middle ear cases (e.g., tympanoplasty, stapedectomy, etc.). The facial nerve has four main branches that are most often monitored for EMG activity. The Temporal Branches innervate the muscles above the eyes, including the frontalis, orbicularis oculi and corrugator supercilii. The Zygomatic Branches innervate the orbicularis oculi, underneath the eyes. The Buccal branches innervate the muscles of the upper mouth and cheeks. The Marginal Mandibular Branch innervates the mentalis around the chin. The Cervical Branch is a fifth branch of the facial nerve, which innervates the platysma near the throat, but this branch is not normally monitored for EMG activity.
	#Cranial Nerve III, IV and VI. CN III, VI and VI innervate the extraocular muscles, which control the movements of the ~~eye~~ and upper ~~eyelid~~. The levator palpebrae superioris controls the upper ~~eyelid~~. The superior rectus, inferior rectus, medial rectus, lateral rectus, inferior oblique and superior oblique control the movement of the ~~eye~~ from side to side and up and down. These muscles would be monitored for EMG activity in cases involving the resection of a brain tumor, for example.		#Cranial Nerve III, IV and VI. CN III, VI and VI innervate the extraocular muscles, which control the movements of the eyes and upper eyelids. The levator palpebrae superioris controls the upper eyelids. The superior rectus, inferior rectus, medial rectus, lateral rectus, inferior oblique and superior oblique control the movement of the eyes from side to side and up and down. These muscles would be monitored for EMG activity in cases involving the resection of a brain tumor, for example.
	#Other Cranial Nerves		#Other Cranial Nerves

Wdoyon: /* Intraoperative Monitoring */

2019-09-28T21:35:04Z

Intraoperative Monitoring

← Older revision		Revision as of 16:35, 28 September 2019
Line 19:		Line 19:

	==Intraoperative Monitoring==		==Intraoperative Monitoring==
	Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function for spinal decompressions and fusions. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar surgeries~~, for example~~.		Spontaneous EMG activity is widely used to monitor spinal cord and spinal nerve root function for spinal decompressions and fusions.
	~~#Pedicle screws~~		#Pedicle screws. Electrically triggered EMG recordings are an important technique for evaluating pedicle screw placement in lumbar surgeries.
	#Peripheral Nerves		#Peripheral Nerves
	#Brachial Plexus		#Brachial Plexus