Electrodiagnostic Testing & Biofeedback

This set of flashcards includes 75 questions and answers derived from lecture notes on Electrodiagnostic Testing & Biofeedback, covering key concepts, definitions, and clinical applications related to EMG/NCS.

What does ENMG stand for?

Electroneuromyography.

What are two types of electrophysiologic testing mentioned in the notes?

EMG (Electromyography) and NCS (Nerve Conduction Study).

What is one of the primary objectives of this course?

Familiarization with the scope of electrophysiologic testing.

What role do PTs play in electrophysiologic evaluation?

They perform EMG/NCS as part of patient evaluation.

Which practice act recognizes EMG/NCS services performed by PTs?

KRS 327.

What has been the history of EMG service provision by PTs?

PTs have been safe providers for more than 50 years.

What is the rationale for electrophysiologic testing?

Helps assist in diagnosis and prognosis regarding neuromuscular function.

What is an extension of the neuro-musculoskeletal examination?

Electrophysiologic testing.

What does EMG and NCS provide about the muscle-nerve complex?

A better snapshot of the motor unit.

What are the typical sites for upper extremity entrapment?

Median nerve, ulnar nerve, radial nerve.

What are the classic nerve injury categories according to Seddon?

Neurapraxia, Axonotmesis, Neurotmesis.

What does the term neuropraxia refer to?

Focal injury with preservation of axon continuity.

What is Axonotmesis?

Injury of axons with rapid degeneration of distal axon stump.

What type of EMG findings may occur with Axonotmesis after 9-14 days?

Fibrillations and positive sharp waves.

What signifies Neurotmesis in nerve injuries?

Injury to axons and connective tissue with no reinnervation.

What are common symptoms of discogenic pain caused by herniated nucleus pulposus?

Intense pain in legs brought on by walking.

What is the primary goal of rehabilitation according to the notes?

Optimization of motor control.

Which kind of nerve injury is indicated by reduced insertional activity?

Chronic denervation.

What does the term 'all-or-none' depolarization refer to?

A principle where nerve fibers and motor units respond fully or not at all.

What is the normal range for motor unit action potential duration?

3 to 12 milliseconds.

How is a nerve conduction study (NCS) performed?

By stimulating a nerve and recording the detected impulse response.

What is the significance of EMG in evaluating muscles?

To assess whether muscles are normally, partially, or completely innervated.

What are the findings at rest indicative of denervation in EMG?

Spontaneous potentials, positive sharp waves, fibrillations.

What factors can influence NCS results?

Age, temperature, and anatomical anomalies.

What does a reduction in amplitude on NCS typically indicate?

An axonal issue.

What is an example of a common upper extremity nerve entrapment?

Carpal Tunnel Syndrome (Median nerve).

What does the term 'H-reflex' denote in nerve testing?

A monosynaptic reflex response used to assess spinal and nerve function.

What should be examined in relation to EMG testing principles?

Muscles above and below the suspected site.

What does an increased amplitude in EMG indicate?

Potential muscle action or increased muscle recruitment.

What type of injury might cause muscle fiber atrophy?

Axonal degeneration due to nerve injury.

What type of components are included in instrumentation for EMG studies?

Pick-up electrodes, preamplifiers, amplifiers, recording mechanisms.

What are typical symptoms of Myasthenia Gravis in repetitive stimulation testing?

A drop in muscle action potentials.

What is a common result of nerve conduction studies in cases of demyelination?

Slowed latency.

What is the main advantage of electrophysiologic testing according to the notes?

Aiding diagnosis and management of neuromuscular conditions.

What does a normal EMG reveal about muscle innervation?

That the muscle is normally innervated.

What can be assessed by comparing findings in both upper and lower limbs in EMG?

Differences in nerve function and pathology.

What clinical question can EMG help answer regarding muscle abnormalities?

Is the muscle innervated, and if so, to what degree?

What type of response implies axon injury in an EMG?

Fibrillation potentials.

What is the effect of radial nerve entrapment at the spiral groove?

Saturday night palsy symptoms.

What is the outcome when nerve conduction studies indicate absent H-reflex?

Possible diagnosis of lumbar spinal stenosis.

What defines segmental demyelination?

Abnormalities in conduction velocity due to myelin sheath issues.

What is the primary cause of pain in acute nerve root infections?

Mechanical and chemical forces acting on nociceptors.

Which nerve is affected in Kiloh-Nevin Syndrome?

Anterior interosseus nerve (a branch of median nerve).

What does synaptic transmission depend on?

Neurotransmitter release and receptor interaction.

What does spinal stenosis commonly lead to in clinical symptoms?

Pain, possibly radiating to the lower extremities.

What are the expected EMG findings for normal motor units?

Polyphasic motor unit action potentials.

What is a favorable indication regarding surgical intervention in EMG findings?

Positive evidence of nerve root damage preoperatively.

In assessing nerve injuries, what does a muscle respond to during EMG?

Electrical stimulation.

What is a common complication of neuropraxia?

Temporary loss of motor function.

What is the role of Schwann cells in nerve regeneration?

They help in repair and remyelination.

What would an increased duration in MUP indicate?

Axonal sprouting or regeneration efforts.

What is the relationship between EMG findings and nerve damage severity?

Higher severity typically correlates with abnormal EMG findings.

What features define the motor unit anatomy?

Anterior horn cell, nerve root, peripheral nerve.

How does temperature affect nerve conduction studies?

Lower temperatures can slow conduction velocity.

What does banding or atrophy in EMG indicate?

Chronic denervation or myopathy.

What can cause a 'focal slowing' in nerve conduction studies?

Demyelination or remyelination as injury resolves.