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© 2014 Realief™ Neuropathy Centers

Overview

Realief™ Therapy for Peripheral Neuropathy

Social and Economic Impact Lesson 1: Anatomy and Physiology

Learning Objectives

Central Nervous System

Peripheral Nervous System

Somatic Nerves

Autonomic Nerves

Impulse Transmission

Nerve Roots

Progress Check

Lesson 2: Pathophysiology

Learning Objectives

Peripheral Neuropathy

Symptoms of Neuropathy

Patterns of Neuropathy

Causes of Neuropathy

Progress Check

Lesson 3: Clinical Workup

Learning Objectives

Medical History

Physical Examination

Sensory Tests

ReflexTesting

Neurological Assessments

Progress Check

Lesson 4: Treatment Options

Learning Objectives

Pharmacologic Therapy

Alternative Therapies

Progress Check

Module 1: Peripheral Neuropathy Index

Module1•Index


This self-study module provides information about the peripheral nervous system, the underlying causes of peripheral neuropathy, and conventional approaches to neuropathy treatment.

•Comprehensive training Study the illustration, read the content, review the Key Concept, and complete the Checkpoint before moving to the next screen.

•Quick review Study the illustration, review the Key Concept, and complete the Checkpoint.

•Progress check Complete the progress check at the end of each lesson. The answers are provided, so you can assess your mastery of objectives and decide whether to review content or move on to the next lesson.

The key concept allows you to review what you’ve learned or take a fast path through content.

The checkpoint allows you to quickly check your understanding. Answers are provided.

Module 1: Peripheral Neuropathy Instructions

Key Concept

Checkpoint

Module1•Instructions

Key Concept

Checkpoint


Peripheral neuropathy is a progressive disorder of the peripheral nervous system. Symptoms include pain, tingling, numbness, pins and needles sensations, and increased sensitivity.

•Neuropathysymptomsusuallystartinthehandsor feet and progress to the arms and legs. The symptomsaremildatfirst,butgraduallybecomemore debilitating. Over time, nerve dysfunction leads to muscle weakness and loss of balance.

•Realief™ Therapy is a new, clinically proven laser therapy that is safe, comfortable, non-invasive, and drug free. It relieves peripheral neuropathy symptoms, restores more normal nerve function, and improves quality of life.

•Thismoduledescribes:- Normal nerve function - Nerve dysfunction and the development of

peripheral neuropathy- Clinical assessments and tests used to

characterize peripheral neuropathy- Conventional therapies and their limitations

•Module2describeslaserprinciplesandtheRealieftherapeutic laser. Module 3 describes how to use the Realief System.

Peripheral neuropathy is a disorder of the nervous system that progresses from the hands or feet to the arms or legs.

Overview Realief™ Therapy for Peripheral Neuropathy

Key Concept

Checkpoint

Module1•Overview

Realief Therapy is a new, clinically proven therapy that uses a _______ .

therapeutic laser

therapeutic needles

Key Concept

Checkpoint


The social and economic impact of peripheral neuropathyissignificant.

• TheU.S,NationalHealthandNutritionExamination Survey estimates that 14.8% of individuals older than 40 have neuropathy. This estimate increases to 28.5% in individuals over 40 with diabetes. Though estimates vary, it is likely that millions of diabetics have mild to severe peripheral nerve damage.

•Patientswithneuropathyusehealthcareservicesmore often and spend more on those services. In 2003, the estimated annual cost of treating diabetic neuropathy and its complications were almost 11 billion dollars and accounted for about 27% of the total costs of diabetes.

•Peripheralneuropathyisassociatedwithasubstantially poorer quality of life (QOL) in terms of physical and social function. Neuropathy can affect the ability of patients and their caregivers to work, adding loss of income to direct medical costs.

The most common underlying causeofneuropathyintheU.S.is diabetes.

The estimated annual cost of treating diabetic neuropathy is 11 _________ dollars.

million billion

PathophysiologySocial and Economic Impact


After completing this lesson, you should be able to

•Identifytheprincipalstructuresofthecentralnervous system (CNS) and describe their function.

•Describehowtheperipheralnervoussystem(PNS) is organized.

•Distinguishbetweenvoluntary(somatic)andinvoluntary (autonomic) nerve functions.

Anatomy and PhysiologyLearning Objectives

Module1•Lesson1•Screen 1 of 9

Key Concept

Checkpoint


The central nervous system (CNS) controls and coordinates all body functions. It consists of the brain and spinal cord.

• Thebrain interprets incoming neural signals and sends out neural instructions. It regulates conscious perceptions, enabling a healthy adult to willfully initiate and terminate activities such as walking, speaking, and urinating.

• Thespinal cord is a bundle of nerves that runs through the vertebral column (spine). It transmits neural signals between peripheral body structures and the brain.

• Thespinalcordalsoservesasthereflex center, bypassing communication with the brain to allow fast reactions when required. Example: The withdrawalreflexpullsbackyourlegwhenyoustepbarefootonathistle.Theextensorreflexsimultaneously stabilizes the other leg so you don’t lose your balance.

Peripheral refers to body structures outside the central nervous system.

The brain and spinal cord control and coordinate all body functions.


Anatomy and PhysiologyCentral Nervous System

Neural messages from peripheral structures are sent to the brain via the _______ .

spinal cord

extensorreflex

Key Concept

Checkpoint


The peripheral nervous system (PNS) is a network of nerves that connects the CNS to peripheral structures.

• Thirty-one pairs of spinal nerves emerge from the spinal cord to innervate the right and left sides of the body.

8 pairs of cervical (neck) nerves supply the neck, upper extremities, and diaphragm

12 pairs of thoracic (chest) nerves supply the organs of the trunk, including the heart, lungs, kidneys, liver, and stomach

5 pairs of lumbar (lower back) nerves supply the lower extremities

5 pairs of sacral (base of spine) nerves supply the pelvic organs, including the genitals and bladder

1 pair of coccygeal (tailbone) nerves supplies the small region over the coccyx

• Peripheralnervesarearrangedalongband-likeareasof skin, called dermatomes, innervated by a single nervepairorspinalcordsegment.Dermatomesserveas a reference for clinicians evaluating spinal nerve root function.

Spinal nerves exit the spine via openings called the intervertebral foramen. The spinal cord is shorter than the spine, so the lower eleven nerve pairs hang down like hairs. They are called the cauda equina, which means horse’s tail.

The peripheral nervous system includes thirty one pairs of spinal nerves.

Peripheral nerves are arranged along band-like areas of skin called ______________ .

foramen

dermatomes


Anatomy and PhysiologyPeripheral Nervous System

Key Concept

Checkpoint


Twelve cranial nerve pairs emerge from the brain and brainstem.

Cranial nerve Innervation I Olfactory nose (smell)

II Optic eye (vision)

III Oculomotor eyelid / eyeball (movement)

IV Trochlear eye (movement)

V Trigeminal face, mouth (chewing)

VI Abducens extrinsic eye muscle

VII Facial face / tongue / gums (expression, tears, taste)

VIII Vestibulocochlear inner ear (hearing, balance)

IX Glossopharyngeal throat / back of tongue (taste, blood pressure)

X Vagus vocal cords / thorax / abdomen (blood pressure, heart rate, digestion)

XI Spinal accessory throat / shoulders / head / neck (swallowing, movement)

XII Hypoglossal tongue (movement)

The peripheral nervous system includes twelve pairs of cranial nerves.

The cranial nerve that regulates the heart rate is the _______ .

vagus

optic

Anatomy and PhysiologyPeripheral Nervous System


Key Concept

Checkpoint


Somatic nervesregulatevoluntaryandreflexiveactivity.

• Thesomaticnervoussystem(SNS)communicateswith the CNS via sensory nerves. These nerves enable the body to interact with the external environment via motor nerves.

• Sensory nerves transmit sensations from neural receptors in body tissue. Sensations of touch, pressure, and temperature from the skin inform the CNS of changes outside the body (exteroception).

Sensations of tension from muscles, tendons, and joints inform the CNS of the body’s position in space (proprioception). Example: Healthy adults can walk without looking at their feet because they sense the position of their feet relative to the ground.

Sensations of pain inform the CNS of harmful stimuli (nociception).

• Motor nerves transmit signals from the CNS to skeletal (voluntary) muscles, permitting voluntary andreflexive muscle contractions.

Note that motor and sensory signals travel along different neural pathways. Afferentfiberscarrysensory information toward the CNS. Efferent fiberscarrymotorinformation away from the CNS. (Afferents arrive, efferents exit.)

The somatic nervous system regulates voluntary and reflexiveactivityviasensoryand motor nerves.

Sensory afferent nerves transmit sensations __________ the CNS.

away from

toward

Anatomy and PhysiologySomatic Nerves


Key Concept

Checkpoint


Autonomic nerves regulate involuntary activity.

• Theefferent(motor)componentoftheautonomicnervous system (ANS) is divided into sympathetic and parasympathetic nerves. Sympathetic nerves stimulate activityandallowthebodytorespondtostresses(fightorflight).Parasympatheticnervesinhibit activity and allow the body to restore energy (rest and digest).

Example: As you jog, sympathetic nerves increase the heartrate,dilatethearteries,andincreasebloodflowrela-tive to your body’s increasing need for oxygen. As you end your jog, parasympathetic nerves slow the heart rate, constrictthearteries,andreducebloodflowrelativetothedecreasing need for oxygen.

• The ANS is classically described as the visceral motor sys-tem because it innervates the internal organs (viscera), in-cluding the heart, lungs, blood vessels, bladder, and so on. Theafferent(sensory)fibersoftheANStransmitvisceralpain sensations from glands, blood vessels, and mucous membranes.

• The enteric nervous system (ENS) is a subdivision of the ANS that regulates the gastrointestinal tract (stomach andintestines)andinfluencesdigestiveprocesses.Itnor-mally communicates with the CNS, but in nerve injury, the ENS functions independently.

Sympathetic nerves are distributed to all parts of the body.Parasympatheticnervesaregenerallyconfinedtothe head, neck, and body cavities.

The autonomic nervous system regulates involuntary activity via sympathetic and parasympathetic nerves.

Sympathetic nerves _________activity.

stimulate

inhibit

Anatomy and PhysiologyAutonomic Nerves


Key Concept

Checkpoint


Neurons (nerve cells) are specialized for rapid communication.

• Neuronsarecomposedofacellbody,axons,anddendrites. Axons transmit neural impulses away from a cell body. Dendrites receive impulses. Neurons communicate at synapses – gaps between the axon of one neuron and the dendrite of the next neuron. Communication at the synapses is mediated by neurotransmitters, chemicals that allow the neural impulses to travel across a synapse.

• Aperipheral nerve is much like an electric cable. Axonsarethefibersthattransmitneuralimpulses.Each axon is insulated by a sheath of connective tissue, which keeps the impulse from leaving the axon. The insulated axons are arranged in bundles, called fascicles, and enclosed in a protective outer layer of strong connective tissue.

The outermost layer of a nerve includes the blood vessels – called the vasa nervorum – that carry oxygen and nutrients to nerve tissue.

• Someaxonsareinsulatedbyamyelin sheath, formed by Schwann cells. Large-diameter, heavily myelinated axons conduct motor, touch, and proprioceptive impulses rapidly. Small-diameter, thinly myelinated or unmyelinated axons conduct pain, temperature, and autonomic impulses slowly.

Note that axons are myelinated in segments, called internodes.

Neural messages travel along the axons of a nerve cell and are received by the dendrites of the next nerve cell.

Large, heavily myelinated axons transmit motor, touch, and proprioceptive impulses ______ .

slowly

rapidly

Anatomy and PhysiologyImpulse Transmission


Key Concept

Checkpoint


The nerve roots of the spinal cord are the only sites at which motor and sensory nerves are separated.

• Most(30of31)spinalnervesarisefromrootlets,which converge to form ventral (anterior) and dorsal (posterior) roots. The ventral root carries motor fibers; the dorsal root sensory fibers.

• Astherootsemergefromthespinalcord,theyuniteto form a mixed spinal nerve that immediately divides into ventral and dorsal branches (called rami). The rami carry both motor and sensory nerves, as do all subsequent branches of the peripheral nervous system.

• ClustersofcellbodiesoutsidetheCNSarecalledganglia. The nerves that control the arms and legs are arranged in an elaborate network called a nerve plexus. Example: The brachial plexus innervates the arm; the lumbrosacral plexus innervates the leg.

The peripheral nerve refers to the part of the spinal nerve distal to the nerve root and plexus.

Distal refers to structures farthest from a point of

reference; proximal to structures nearest the point of reference. Anterior refers to the front of a body structure; posterior to the back.

The dorsal and ventral roots are the only sites at which motor and sensory nerves are separated.

The ventral root carries _______fibers.

motor

sensory

Anatomy and PhysiologyNerve Roots



1. Identify spinal nerve pairs by dragging the correct label to the illustration.

sacral cervical coccygeal thoracic lumbar

cervical

thoracic

lumbar

sacral

coccygeal

2. Match the nerve to its function. Nerve

a. sensory

b. motor

c. sympathetic

d. parasympathetic

e. enteric

Nerve function

d. inhibits involuntary activity (rest and digest)

a. transmits sensations

c.stimulatesinvoluntaryactivity(fightorflight)

e.influencesdigestion

b. permits voluntary muscle contractions

Anatomy and PhysiologyProgress Check 1




•Defineperipheralneuropathy.

•Listsymptomsassociatedwithsensory,motor,and autonomic nerve damage.

•Discusstheunderlyingetiologies(causes)ofperipheral neuropathy.

• Discussthesocialandeconomicimpactofperipheral neuropathy.

PathophysiologyLearning Objectives


Key Concept

Checkpoint


Peripheral neuropathy is a disorder of the peripheral nervous system caused by damage to the myelin sheath, axon, or cell body.

• Segmental demyelination is the disintegration of one or more segments of the myelin sheath. Loss of myelin distorts or interrupts impulse conduction.

The myelin may regrow during the healing process, but the newly formed myelin segments are shorter than normal and the new myelin sheath is thinner.

•Axon degeneration is primary destruction of the axon, with secondary destruction of the myelin sheath.Damagemayoccuratafocal point along the nerve, or generally affect the cell body (neuronopathy) or its axon (axonopathy). Cutting or crushing injuries may separate the axon from the cell body (Wallerian degeneration).

Axons are able to regenerate if the cell body remains intact, but the process is slow. The loss of neural signals to muscle tissue, called denervation, can lead to muscle dysfunction, called myopathy.

Myocytes are muscle cells.

Peripheral neuropathy is a nerve disorder caused by damage to the myelin, axons, or cell body.

Axon degeneration can lead to ______________ of muscle tissue.

regeneration

denervation

PathophysiologyPeripheral Neuropathy


Key Concept

Checkpoint


Neuropathy symptoms provide clues to the type of nerve damage.

• Damagetolarge-diameter, myelinated sensory nerves may cause numbness, parasthesia (pins- needles sensation), stocking-glove numbness (sensation of wearing thin stockings and gloves), loss of proprioception (balance),orlossofreflexes.

• Damagetosmall-diameter, thinly myelinated or unmyelinated sensory nerves may cause pain, burning, or cold sensations or hypersensitivity to light touch.

• Motor nerve damage may cause muscle weakness (most common), paralysis, cramps, twitching (fasciculations), or wasting (atrophy).

•Autonomic nerve damage may impair respiration, blood pressure control, bladder or bowel control, digestion, swallowing, sweating, sexual function, and other involuntary and reflexivefunctions.Thedamagemaybecomelife-threatening and require emergency treatment.

• Nerve root damage is associated with shooting pains that radiate along the dermatome of the affected root. Chronic damage can lead to loss of reflexesandmuscularatrophy.

Neuropathy symptoms provide clues to the type of nerve damage.

Loss of pain and temperature sensations indicates injury to _______________ nerves.

sensory

autonomic

PathophysiologySymptoms of Neuropathy


Key Concept

Checkpoint


More than 100 neuropathic conditions have been described, each with its own set of symptoms, pattern of development, and etiology (underlying cause).

• Nervedamagemayaffect: – One nerve (mononeuropathy)– Multiple nerves (polyneuropathy) – Multiple isolated nerves (multifocal

mononeuropathy)– Nerve plexus (plexopathy)– Nerve root (radiculopathy)

• Polyneuropathysymptomsoftendevelopinadistal to proximal pattern:theystartinthelongestnervesin the distal extremities (feet or legs); then ascend slowly or rapidly. For some neuropathies, symptoms develop symmetrically (on both sides of the body). In others, symptoms develop asymmetrically (on one side of the body).

• Peripheralneuropathymaybe:– Acquired via physical trauma, metabolic

disorders, toxin exposure, or systemic disease – Inherited via genetic conditions – Idiopathic (of unknown cause)

Broad categories of neuropathy and examples of common underlying causes are described on the next few pages.

More than 100 neuropathic conditions have been described, each with its own etiology, pattern of development, and symptoms.

Polyneuropathy symptoms often occur in a ___________pattern.

proximal to distal

distal to proximal

Polyneuropathy:symmetricdistalto proximal pattern

Plexopathy:asymmetricupper left extremity

PathophysiologyPatterns of Neuropathy


Key Concept

Checkpoint


Traumatic/compression neuropathies are caused by accidents, falls, sports injuries, or repetitive stress.

• Physical trauma can lacerate, crush, compress, or stretch nerves, sometimes so forcefully they partially or completely detach from the spinal cord (called avulsion). Healing may be complicated by discontinuity or misalignment of neural axons.

• Repetitivestresscanentrapanervewithinits anatomic compartment. In carpal tunnel syndrome,forexample,edema(fluidretention)compresses the median nerve at the wrist. Nerve entrapment is the most common cause of mononeuropathy.

Other sites of entrapment are the ulnar nerve at the elbow, radial nerve in the arm, peroneal nerve behind the knee, tibial nerve at the ankle (tarsal tunnel), and interdigital nerves in the toes.

• Nerveinjurycanalsooccurwithexternal pressure from casts, braces, splints, crutches, or sustained use of a tourniquet during surgery. Prolonged compression of blood vessels reduces the blood supply to nerve tissue, causing temporary numbness or permanent nerve damage.

•Disc herniation occurs when an intervertebral disc protrudes out of its normal anatomic location. Herniation, which is most common at the L4 or L5 (lumbar) level of the spinal cord, may compress nerve roots and cause radiculopathy.

Traumatic and compression neuropathies are caused by physical injury, repetitive stress, or external pressure.

Nerve entrapment is the most common cause of __________ .

mononeuropathy

radiculopathy

PathophysiologyCauses of Neuropathy


Compression radiculopathy

Key Concept

Checkpoint


Metabolic neuropathies are caused by diseases that impair the body’s ability to breakdown and distribute nutrients and process waste.

• Diabetes mellitus results in chronically high blood glucose levels, diffuse vascular damage, andreducedbloodflow.Diabeticneuropathyhasmany patterns. The most common is symmetric polyneuropathy that begins with distal sensory loss (stocking, then glove numbness). Motor nerve deficitsmayoccur,butaretypicallylessevident.

• Theendocrine system consists of glands that release hormones directly into the blood stream. Hormonal imbalances slow metabolism, cause edema, and lead to nerve compression. Overproduction of growth hormones can cause acromegaly, the gradual enlargement of bones and joints and subsequent nerve compression.

• Nutritional deficiencies as a cause of neuropathy mayoccurwithinsufficientintakeofaparticularvitamin, such as the B vitamins (B1 B6, B12,), Vitamin E, niacin, or thiamine.

• Kidney failure results in toxic levels of urea that lead to vascular damage. Neuropathy symptoms develop symmetrically and may include muscle cramps, loss of distal sensations, and diminished deeptendonreflexes.Chronic liver disease and thyroid dysfunction cause chemical imbalances that can damage nerves.

Metabolic neuropathies are caused by diseases that impair the body’s ability to use nutrients.

Diabeticneuropathymaybeginwith loss of sensation in the _____________ extremities.

distal

proximal



Key Concept

Checkpoint


Toxic neuropathies are caused by exposure to industrial or environmental chemicals, biologic toxins, or therapeutic drugs.

• Anumberofchemotherapy,seizure,antiviral,and antibiotic drugs are associated with axon damage. Examples include cisplatin, taxol, and vincristine sulfate for cancer; isoniazid for tuberculosis.

• Excessive alcohol use may contribute to direct nerve injury or lead to thiamine (B1)deficiencyand nutritional neuropathy.

• Industrial toxins include heavy metals (arsenic, lead, mercury, thallium) and chemical solvents.

• Neurotoxinsdamagethesensory nerves. Toxic neuropathy is associated with tingling, numbness, or sharp pain, which may worsen with increased exposure. It usually develops symmetrically.

Toxic neuropathies are caused by exposure to chemicals, biologic toxins, or therapeutic drugs.

Neurotoxins damage _________nerves.

motor

sensory


Key Concept

Checkpoint


Autoimmune neuropathies are caused by diseases that elicitaninflammatoryresponseinnerves,nerveroots,orautonomic ganglia.

• Guillain-Barre syndrome (acuteinflammatorydemyelinating polyradiculoneuropathy) is an autoimmune disease that affects motor, sensory, and autonomic nerves. Guillan-Barre neuropathy often follows a viral illness. It is characterized by muscle weakness that starts in the legs and spreads to the arms, a condition called ascending paralysis. Muscle weakness progresses rapidly.

• Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) affects sensory, motor, and in rare cases autonomic nerves. CIDP follows a course of remissions and relapses, with evidence of recurrent demyelination and remyelination. (Research indicates that demyelination / remyelination occur more often than once thought.)

• Vasculitis (inflamedbloodvessels)hardensandnarrowsblood vessels, thereby compromising the blood supply to nerve tissue. Vasculitis, along with other vascular disorders and blood diseases, may lead to multifocal mononeuropathy.

Inflammation is the vascular response to a foreign substance that invades the body. The immune system produces antibodies to destroy the invading substance and ward off infection. In autoimmune diseases, the body produces antibodies that destroy its own tissue.

Inflammatoryneuropathiesare caused by diseases that elicitaninflammatoryresponsein nerves, nerve roots, or autonomic ganglia.

Guillain-Barre neuropathy is characterized by __________muscle weakness.

ascending

descending



Key Concept

Checkpoint


Infectious polyneuropathies are caused by viral or bacterial diseases.

• HIV(humanimmunodeficiencyvirus)damagesthe central and peripheral nervous systems. Distinctneuropathysymptomsareassociatedwith each stage of the disease.

• Herpes viruses remain latent in sensory ganglia until reactivated years later. The varicella zoster (chicken pox) virus may erupt as herpes zoster (shingles), causing painful blisters and sensory loss most commonly in the thoracic dermatomes.

Cytomegalovirus (CMV) causes gastrointestinal infections in HIV patients and sensory loss primarily in the lumbrosacral dermatomes.

Herpes simplex causes blisters around the mouth (HSV1) or genitals (HSV2). Epstein Barr, which is transmitted via saliva, causes infectious mononucleosis and may damage nerve roots.

• Lyme disease can cause neuropathy within a few weeks of bacterial infection from a tick bite.

• Peripheralneuropathyincancer patients may result from nerve compression by the tumor, toxicityofchemotherapy,nutritionaldeficiencies,or metabolic disorders. In some cases, neuropathyisthefirstsignofcancer.

Infectious polyneuropathies are caused by viral or bacterial diseases.

Infectious polyneuropathies may be caused by viruses that remain latent in ___________until they reactivate.

sensory ganglia

muscle tissue



Key Concept

Checkpoint


Hereditary neuropathies are caused by genetic defects present at birth.

• Charcot-Marie-Tooth (CMT) causes progressive muscular atrophy. Symptoms typically appear in children or young adults. They include distal muscle weakness, atrophied calf muscles (skinny calves), foot deformities (high arch), foot drop (inability to hold the foot horizontally, and a slapping gait.

• Friedreich’s ataxia (FA) causes coordination problems (ataxia),includingdifficultywalkingandspeaking.Most people develop scoliosis (spine curvature). FA can also cause sensory problems, including loss of sensationandtendonreflexes.Symptomsappearbetweentheagesof5and15.Patientsareconfinedtowheelchair within 20 years of symptom onset.

Hereditaryneuropathiesareclassifiedasmotor-sensory (HMSN) or sensory–autonomic (HSAN). Further divisions intosubtypesidentifyaspecificdefect.CMT,forexample,isclassifiedasHMSN1inpatientswithnerveenlargement;HSM2 in patients without nerve enlargement.

CMT is the most common inherited neuropathy, affectingabout2.6millionpeopleintheUnitedStates. FA affects about 1 in every 50,000 people.

Hereditary neuropathies are caused by gene defects.

Charcot-Marie-Tooth neuropathy is characterized by progressive____________________ .

coordination problems

muscular atrophy


Charcot-Marie-Tooth (high arch) Friedreich’s ataxia (scoliosis)



1. Match the nerve damaged to the associated set of symptoms.

Nerve damaged Symptoms a. motor nerve c. pain and temperature sensations,

oversensitivity

b. large, myelinated sensory nerve d. impaired respiration, bladder control, blood pressure control, digestion

c. small, unmyelinated sensory nerve

a. muscle weakness, muscle atrophy, cramps, twitching

d. autonomic nerve b. numbness, parasthesia, loss of balance

2. Select each statement that accurately characterizes peripheral neuropathy.

√ Nerve entrapment may lead to compression neuropathy at the wrist, knee, elbow, foot, or upper arm.

√Diabetesisthemostcommonunderlyingcauseofneuropathy.

√Discherniationasacauseofradiculopathyismostcommonatthelumbarlevel.

Polyneuropathies commonly develop in a proximal to distal pattern.

√ Neuropathyresultsinapoorqualityoflifeintermsofphysicalandsocialfunction.

√ Toxicneuropathiestypicallyaffectsensorynerves.

Guillan-Barre neuropathy is characterized by proximal to distal muscle weakness.

PathophysiologyProgress Check 2




•Discusstheimportanceofthepatientinterviewincharacterizing peripheral neuropathy.

• Describethesensory,reflex,andneurologicalassessments used to evaluate nerve function.

Clinical WorkupLearning Objectives


Key Concept

Checkpoint


A thorough medical history allows the clinician to characterize peripheral neuropathy and decide which diagnostic tests are needed.

• Duringtheinitialpatient interview, the clinician gathers information about family history, medical conditions, occupation, possible toxin exposure, symptoms, treatments tried, and quality of life.

• Symptom informationincludes:

Severity:1-10painscale(seeFigure)

Onset:suddenorgradual

Quality:numbness,burning,tingling,sharppain

Pattern:focalordiffuse;symmetricorasymmetric,distal or proximal

Exacerbating conditions:hotorcold,movingorresting, sitting or standing, compression from braces, use of medications or supplements.

• Quality of life (QOL): Patients may report loss of mobility, balance, coordination, or sleep as well as social isolation, depression, impotency, and decreased self esteem.

Symptoms are subjective patient complaints. Quality of life assessments are a subjective indicator of overall well-being.

A thorough medical history is thefirststepincharacterizingperipheral neuropathy and deciding which diagnostic tests are needed.

The pain scale provides _______________ information about symptom severity.

objective

subjective


Clinical Workup Medical History

Key Concept

Checkpoint


The physical exam helps localize the area of damage and distinguish between muscle and nerve damage.

Duringthephysicalexam,theclinicianmay:

• Palpate (feel) arterial pulses at multiple sites inthearmsandlegs.Diminishedpulsesareasignofdecreasedbloodflowandpossiblenervecompression.Pulsesarecheckedatthesearteries:tibial (lower leg), dorsalis pedis (top of foot), brachial (upper arm), radial (wrist), ulnar (elbow).

• PerformaTinel’s test by percussing (lightly tapping) over a nerve to elicit a tingling sensation along the nerve. A positive Tinel’s test - distal tingling upon percussion - is a sign of an irritated nerve. The sites checked are the carpal tunnel (wrist and hand), tarsal tunnel (foot and ankle), andfibularhead(belowknee).

• Visuallyinspect muscles for signs of atrophy (wasting), hypertrophy (enlargement) or fasciculations (twitching).

• Check fine muscle movementsviafinger,hand,or foot tapping. These tests reveal subtle motor deficitsthatmaynototherwisebedetected.

• Test the strength of individual muscle groups to assess patterns of weakness and localize the area of damage.

The physical exam helps to localize the area of damage and distinguish between muscle and nerve damage.

Diminishedarterialpulsesareasignofdecreasedbloodflowand possible _____________ .

oversensitivity

nerve compression

Arterial pulse evaluation Tinel’s test


Clinical Workup Physical Examination

Key Concept

Checkpoint


Sensory tests measure the patient’s sensitivity to external stimuli and reveal the extent of nerve damage. The area of sensory loss, measured by pinprick and vibration tests, is usually greater than the area of reported symptoms.

• Poorvibration sensitivity, poor pressure sensitivity or poor balance suggest damage to larger, more heavily myelinated nerves.

Pressure sensitivity istestedwithamonofilament(plasticfiber)calibratedtobendtopressure.Individuals with normal sensitivity can usually feel pressure at 1 gram of force.

Vibration sensitivity is tested by placing a vibrating tuning fork on the skin and asking patients to indicate if they can feel the vibration.

Balance is tested with a series of stances or steps.

• Poortemperature sensitivity, pinprick (pain) sensitivity, or touch hypersensitivity suggest damage to smaller, less myelinated nerves.

Temperature sensitivity is tested with a piece of cold metal; pinprick sensitivity with a safety pin or Wartenburg pinwheel; and hypersensitivity with a cotton swab or light touch.

• Joint position sense is tested by moving the patient’sfingersandtoesupanddownandaskingthem to report the direction of movement.

Sensory tests measure the patient’s sensitivity to external stimuli and reveal the extent of nerve damage.

The area of sensory loss to vibration and pinprick is usually ___________ than the area of reported symptoms.

greater

less


Clinical Workup Sensory Tests

Key Concept

Checkpoint


A reflex hammer is used to assess deep tendon reflexreactions.

• Deep tendon reflexes are tested at the biceps (C5, C6), brachioradialis (C6), triceps (C7), knee (L4), and achilles tendon (S1). Reflexesareratedaccordingtothefollowingscale:

0absentreflex1+ hypoactive (trace) reflex 2+ normal reflex3+ hyperactive with nonsustained clonus (involuntary muscle contractions) 4+ hyperactive with sustained clonus

Diminishedreflexesareasignofmuscle,sensory neuron, or lower motor neuron (PNS) damage.Hyperactivereflexesareanindicationof upper motor neuron (CNS) damage. A rating of 1+ or 2+ is considered normal unless there is a dramatic difference between the right and left sides or between the arms and legs.

• Theplanter reflex is tested by stroking the sole of the foot from heel to toe. An abnormal response, called Babinski’s sign, occurs when the big toe moves up and the other toes fan out. The presence of Babinski’s sign after age two suggests upper motor neuron (CNS) damage.

Deeptendonreflexesaretestedat the biceps, brachoradialis, triceps, knee, and achilles tendon.

Diminisheddeeptendonreflexesare a sign of _________dysfunction.

PNS

CNS

Deeptendonreflextesting Plantarreflextesting


Clinical Workup Reflex Testing

Key Concept

Checkpoint


Neurological assessments allow the clinician to determine the nature and extent of neuropathy.

• Electromyography (EMG) uses a needle electrode to measure the electrical activity of muscles at rest and during contraction. It helps distinguish between nerve and muscle damage.

• Anerve conduction velocity (NCV) test uses patch electrodes to measure the strength and speed of neural signals. Slower than normal transmission suggests myelin sheath damage. Reduced signal strength suggests axon degeneration.

• Nerve biopsy involves examining a sample of nerve tissue for abnormalities. Biopsy is used conservatively as it is invasive and can cause further damage.

• Aneurological CT scan provides cross-sectional x-ray images (slices) that may reveal the underlying causeofneuropathy:vascularirregularities,tumor,herniated disc, spinal stenosis (narrowing).

• AnMRI provides cross-sectional radio wave images (slices) to determine if nerve compression or muscle damage are present.

• Aquantitative sudomotor axon reflex test (QSART) measures skin temperature, resting sweat output, and electrically stimulated sweat output. Low sweat output suggests an ANS disorder. A QSART may be used when NCV tests are normal.

Neurological tests are used to assess the nature and extent of neuropathy.

Reduced signal strength on a nerve conduction test suggests degeneration of the _________ .

myelin sheath

axon

Electromyography (EMG) Nerve conduction velocity (NVC) test


Clinical Workup Neurological Assessments


1. Selecteachstatementthatcorrectlydescribestheclinicalfindinginperipheralneuropathy.

√ Poorvibrationsensitivitysuggestsdamagetolarge,heavilymyelinatedfibers.

√Poorpinpricksensitivitysuggestsdamagetosmall,lessmyelinatedfibers.

The presence of Babinski’s sign in adults is a sign of normal nerve function.

√ Hyperactivedeeptendonreflexesmaybeduetouppermotorneuron(CNS)dysfunction.

A patient’s reported symptoms are likely to match the area of sensory loss.

A positive Tinel’s test is a sign of normal nerve function.


Clinical Workup Progress Check 3



•Listthegoalsofperipheralneuropathytreatment.

• Discussthebenefitsandlimitationsofpharmacologic therapy for peripheral neuropathy.

• Discussthebenefitsandlimitationsofalternativetreatments for peripheral neuropathy.

Treatment Options Learning Objectives


Key Concept

Checkpoint


The goals of peripheral neuropathy treatment are to 1) manage the underlying cause, 2) relieve symptoms, and 3) provide supportive patient care.

• Patient participation is essential for successful management of peripheral neuropathy. Patients may receive instruction about lifestyle habits that promote health and prevent nerve damage. Examples:smokingcessation,exercise,footcare,vitamin supplements, avoiding repetitive motions

Consultations with dieticians, physical therapists, occupational therapists, chiropractors, or massage therapists may be recommended to help patients cope with progressive disability.

The goals of neuropathy treatment are to manage the underlying condition, relieve symptoms, and provide supportive patient care.

The most important factor in successful neuropathy treatment is ______________ .

massage therapy

patient participation

Treatment OptionsGoals of Therapy



Pharmacologic therapy requiresatrialanderrorprocesstofindaneffectivedruganddosage.Drugsare typically used to help neuropathy patients tolerate pain. A major limitation is drug side effects and adverse reactions, which may affect quality of life or result in lack of patient compliance. The drugs marked with an asterisk (*) in this table are recommended most often.

Agent Action / Effect Side effects / Adverse reactions

Anticonvulsants * Pregabalin (Lyrica®) * Gabepentin (Neurontin®) Oxacarbazine (Trileptal®) Topiramate (Topamax®) Lamotrigine (Lamictal®)

May quiet sensations of tingling, burning, and pain by disrupting transmission of neural signals.

Drowsiness,dizziness,nausea,vomiting, double vision, low white blood cell count, liver damage, depression

Note:Whitebloodcellsfightinfection

Antidepressants Duloxitene(Cymbalta®) * Amytriptyline (Elavil®) Nortriptyline (Pamelor®) * Venlafaxine (Effexor®)

May interfere with chemical processes associated with pain.

Drowsiness,dizziness,lowbloodpressure, decreased appetite, urinary retention, constipation

Opiates Oxycodone CR (Oxycontin®) Fentanyl(DuragesicTransdermal System®) Methadone(Dolophine®)

May relieve acute pain. Dizziness,stomachupset,shortness of breath, insomnia, urinary retention, constipation, addiction, withdrawal effects

Topical Medications Lidocaine patch Capsaicin (Zostrix®)

May provide temporary pain relief in patients with focal neuropathy.

Lidocaine may cause rash at patch site.Capsaicin, a component of chile peppers, causes stinging upon skin contact.

NSAIDS(nonsteroidalanti-inflammatorydrugs)arenon-narcoticanalgesics(painkillers).NSAIDS,includingaspirinandibuprofen,mayrelieveinflammation,butareusuallyineffectiveforneuropathy pain.

Treatment OptionsPharmacologic Therapy


Key Concept

Checkpoint


An alternative therapy is one that has not been sufficientlyscientificallydocumentedoridentifiedassafeandeffectiveforaspecificcondition.Likedrugs,alternatives are used primarily to treat neuropathy pain.

• Acupuncture is the insertion of thin, sterile needles into the skin along lines, called meridians. Proponents claim that stimulation of acu-points near nerves releases endorphins, which, along with other neurotransmitters, block pain signals.

• Biofeedback involves the use of electric sensors to measure body processes and provide auditory and visual feedback. A therapist then trains the patient to use methods such as relaxation to reduce symptom severity. In time, the patient learns to control symptoms without feedback.

• Transcutaneous electrical nerve stimulation (TENS) involves the delivery of electrical impulses via skin electrodes to increase blood flowandblockpainsignals.

• Lowlevellight therapies, such as Anodyne® Infrared Therapy are used to increase blood circulation and reduce pain and stiffness. While effectivefortreatingsuperficialconditions,theselasers are not designed to penetrate through body tissue to deeper structures, such as nerves.

Alternative therapies are used primarily to relieve neuropathy pain.

Low level light therapies are most effective for treating _____________ conditions.

superficial

deep

Acupuncture Biofeedback

Treatment OptionsAlternative Therapies



1. Select each statement that correctly describes current options for treating peripheral neuropathy.

Opiatesaretherecommendedfirstlinetreatmentforneuropathypain.

√ A lidocaine patch may relieve pain in patients with focal neuropathy.

√ The anticonvulsants, Lyrica® and Neurontin®, may quiet pain by disrupting neural signals.

√ Biofeedback may involve the use of relaxation to reduce symptom severity.

√ Acupuncture is thought to release endorphins that block pain signals.

Light therapies, such as Anodyne, restore normal sensation.

Treatment OptionsProgress Check 4


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