1) Describe the general approach to and interpretation of nerve conduction studies, including motor and sensory studies of peripheral nerves, and clinical electromyography
2) Describe the demographics, risk factors, etiology, pathophysiology, diagnosis, general progression and prognosis of Amyotrophic Lateral Sclerosis (ALS), Guillain–Barré Syndrome (GBS), Postpolio Syndrome (PPS), neuropathies, and brachial plexus injuries
3) Differentiate among signs and symptoms and impairments related to lower motor neuron pathology versus upper motor neuron pathology
4) Discuss the medical management of common symptoms found in individuals with motor neuron and neuropathy disorders
5) Design a physical therapy intervention program with appropriate goals and outcomes for the individual with motor neuron or neuropathy disorders
6) Discuss the current knowledge of degeneration and regeneration phenomena of nerve and muscle
This chapter focuses on diseases and disorders that affect neurons. Common to each of these disorders are changes in the way muscles are activated and nerves convey information. This may involve disruption in sensory afferents, lower or upper motor neurons, or all of these. Diagnosis of these conditions typically involves electrophysiologic testing, so we will begin this chapter with an introduction to these measures.
Electrophysiologic testing employs a variety of approaches to evaluate the function of the nervous system. This is also referred to as electrodiagnostic testing, but in a certain sense that is a misnomer. The results of these tests must always be correlated with other clinical findings and would never be diagnostic on their own. This is why the term electrophysiologic testing is more appropriate.
CASE A, PART I
Mr. Posner is a 40-year-old, married, father of two children, ages 7 and 9 who worked as the Chief Financial Officer at an insurance company. He was in good health until 6 months ago when he began to experience difficulty using his left hand for writing, typing on a computer keyboard, cutting food, handling utensils, and buttoning his shirts. He also noticed that his walking was slower and his legs sometimes felt “heavy and tired,” after going up a flight of stairs. Mr. Posner went to a neurologist, who ordered a variety of tests, including electrophysiologic testing.
Usually, the focus of attention for electrophysiologic testing is on the peripheral nervous system, but there are approaches to measure central nervous system function, as well. Nerve Conduction Studies (NCS) in the peripheral nervous system are most useful for detecting reduced conduction velocity due to damage to the myelination of the nerves.1 Clinical Electromyography (EMG) using needle electrodes within the muscles is the most reliable way to determine whether the axons themselves are injured.1 Needle EMG can also allow for relatively specific testing of nerve root levels to aid in the diagnosis of radiculopathy.2-5 Overall, the clinical reasoning used to interpret results from NCS and EMG studies mimics the clinician’s ...