Brachial Plexus Injuries

Clinical Presentation

Clinical symptom onset may vary from acute to insidious, with shoulder or upper arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways described as “electric shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock-like” or a burning sensation. 

Traumatic plexopathies

• Trauma from injuries:
  • Open: knife or gunshot wounds Gunshot wounds Disruption of structural continuity of the body as a result of the discharge of firearms. Penetrating Chest Injury, animal bites
  • Closed: motorcycle/automobile accidents, falls from a height, hematomas
  • Manifestations correlate to the nerve(s) affected by the injury.
• Trauma from sports injuries: burner (also called stinger)
  • Caused by downward traction of the shoulder, involving the upper trunk of the brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region
  • Most often due to tackling
  • Manifests as transient numbness, paresthesias Paresthesias Subjective cutaneous sensations (e.g., cold, warmth, tingling, pressure, etc.) that are experienced spontaneously in the absence of stimulation. Posterior Cord Syndrome, or weakness in the arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy
  • Usually brief and self-limited; occasionally, recovery may take days to weeks
• Backpack palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies (also known as rucksack paralysis or cadet palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies):
  • Affects the upper trunk (C5–C6)
  • Presents after wearing a backpack or similar apparatus
  • Usually painless, due to stretch or compression Compression Blunt Chest Trauma of the nerve fibers Nerve Fibers Slender processes of neurons, including the axons and their glial envelopes (myelin sheath). Nerve fibers conduct nerve impulses to and from the central nervous system. Nervous System: Histology
  • Symptoms: 
    • Weakness of shoulder abduction Abduction Examination of the Upper Limbs and elevation
    • Weakness in extension Extension Examination of the Upper Limbs of the forearm Forearm The forearm is the region of the upper limb between the elbow and the wrist. The term “forearm” is used in anatomy to distinguish this area from the arm, a term that is commonly used to describe the entire upper limb. The forearm consists of 2 long bones (the radius and the ulna), the interosseous membrane, and multiple arteries, nerves, and muscles. Forearm: Anatomy, wrist, and fingers 
    • Some sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology loss in the same distribution
    • Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship recover fully in a few months.
• Obstetric brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region palsies:
  • Erb palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies:
    • More common than Klumpke palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies
    • Affects C5 and C6 nerve roots
    • Deformity Deformity Examination of the Upper Limbs: arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy hanging by the side, adducted, and medially rotated
  • Klumpke palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies:
    • Affects C8 and T1 nerve roots 
    • “Claw hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy” deformity Deformity Examination of the Upper Limbs: hyperextension at the metacarpophalangeal joints Metacarpophalangeal joints The articulation between a metacarpal bone and a phalanx. Examination of the Upper Limbs and flexion Flexion Examination of the Upper Limbs at the interphalangeal joints Interphalangeal joints Hand: Anatomy

Nontraumatic plexopathies

Neuralgic amyotrophy Neuralgic amyotrophy Mononeuropathy and Plexopathy (progressive wasting of muscle tissues):

• Inflammatory disorder of the brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region
• Also known as Parsonage-Turner syndrome Parsonage-Turner Syndrome Mononeuropathy and Plexopathy or idiopathic Idiopathic Dermatomyositis brachial plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy
• May affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment both children and adults
• Sudden onset of shoulder/upper arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways → progressive weakness and atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation

Hereditary brachial plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:

• Autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance 
• Characterized by painful, recurrent brachial plexopathies
• Features: short stature, hypotelorism, unusual skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions folds, creases on the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess
• Rare 

Neoplastic brachial plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:

• Presents with pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the shoulder/ axilla Axilla The axilla is a pyramid-shaped space located between the upper thorax and the arm. The axilla has a base, an apex, and 4 walls (anterior, medial, lateral, posterior). The base of the pyramid is made up of the axillary skin. The apex is the axillary inlet, located between the 1st rib, superior border of the scapula, and clavicle. Axilla and Brachial Plexus: Anatomy
• Types:
  • Primary: due to neurogenic tumors (e.g., schwannomas, neurofibromas)
  • Secondary: due to regional lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy causing nerve compression Compression Blunt Chest Trauma; most commonly due to breast and lung cancers
  • Paraneoplastic: due to demyelinating injury from antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions against the myelin sheath, associated with Hodgkin lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum
• C8 or T1 nerve root involvement:
  • Seen with Pancoast tumors (usually non–small cell lung carcinoma (NSCLC))
  • Sympathetic neurons Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. Nervous System: Histology run through the brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region over the lung apex.
  • Clinical symptoms: Horner syndrome Horner syndrome Horner syndrome is a condition resulting from an interruption of the sympathetic innervation of the eyes. The syndrome is usually idiopathic but can be directly caused by head and neck trauma, cerebrovascular disease, or a tumor of the CNS. Horner Syndrome ( ptosis Ptosis Cranial Nerve Palsies, miosis Miosis Pupil: Physiology and Abnormalities, and anhidrosis) due to an interruption of the cervical sympathetic chain supply to the eye

Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma-induced brachial plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:

• May not present until months or years after radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma
• Due to direct axonal damage, demyelination Demyelination Multiple Sclerosis, microvascular infarction, and fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans
• Risk ↑ with concurrent chemotherapy Chemotherapy Osteosarcoma

Thoracic outlet Thoracic Outlet Thoracic Outlet Syndrome syndrome ( TOS TOS Thoracic outlet syndrome (TOS) is a broad term used for a spectrum of syndromes related to the general region of the thoracic outlet, which involves the compression or irritation of elements of the brachial plexus, subclavian artery, or subclavian vein. Thoracic Outlet Syndrome):

• Due to compression Compression Blunt Chest Trauma of blood vessels and nerves as they pass between the clavicle Clavicle A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone. Clavicle Fracture and the 1st rib 
• Causes:
  • Accidents
  • Repetitive-use type of occupational injuries
  • Anatomic variants
  • Hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation of the scalene or pectoralis minor muscle in weight lifters and athletes
• Symptoms vary but may include:
  • Muscle weakness
  • Numbness
  • Ischemic changes
  • Edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema of the upper extremities
  • Venous thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus

Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus-related brachial plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:

• Not as common as lumbosacral plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy
• May be mononeuropathies of the ulnar and median Median After arranging the data from loWest to highest, the median is the middle value, separating the lower half from the upper half of the data set. Measures of Central Tendency and Dispersion nerves

Iatrogenic Iatrogenic Any adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment. Anterior Cord Syndrome plexopathies:

• Classic postoperative paresis Paresis A general term referring to a mild to moderate degree of muscular weakness, occasionally used as a synonym for paralysis (severe or complete loss of motor function). In the older literature, paresis often referred specifically to paretic neurosyphilis. ‘general paresis’ and ‘general paralysis’ may still carry that connotation. Bilateral lower extremity paresis is referred to as paraparesis. Spinal Disk Herniation:
  • Caused by traction or pressure during surgery
  • Presents with painless weakness and paresthesia
  • Recovery is rapid and complete.
• Post- median Median After arranging the data from loWest to highest, the median is the middle value, separating the lower half from the upper half of the data set. Measures of Central Tendency and Dispersion sternotomy Sternotomy Making an incision in the sternum. Cardiac Surgery plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:
  • Occurs after open-heart surgery 
  • Caused by injury to the anterior ramus C8 
  • Presents with hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy weakness, paresthesia, and pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the C8 dermatome Dermatome Spinal Disk Herniation
• Anesthetic block plexopathy Plexopathy Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. Mononeuropathy and Plexopathy:
  • Occurs after regional infraclavicular brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region blockade
  • Due to trauma from the infusion needle, hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception formation, or neurotoxicity from the local anesthetic
• Medial brachial fascial compartment syndrome Compartment Syndrome Compartment syndrome is a surgical emergency usually occurring secondary to trauma. The condition is marked by increased pressure within a compartment that compromises the circulation and function of the tissues within that space. Compartment Syndrome:
  • Occurs after puncture of the axillary or brachial artery Brachial Artery The continuation of the axillary artery; it branches into the radial and ulnar arteries. Cubital Fossa: Anatomy during procedures such as arteriography or axillary regional anesthetic blocks
  • Expanding hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception causes nerve compression Compression Blunt Chest Trauma of the median Median After arranging the data from loWest to highest, the median is the middle value, separating the lower half from the upper half of the data set. Measures of Central Tendency and Dispersion or ulnar nerves most commonly.