Cervical plexus is formed from the ___________ rami from which spinal nerves?
Ventral
C1-C4
Brachial plexus is formed from the ___________ rami from which spinal nerves?
Ventral
C5-T1
Cervical nerve roots exit through the intervertebral foramen ______________ the corresponding vertebral body above
Are the nerves in the cervical plexus sensory or motor?
C1 is motor only
C2-C4 are both sensory and motor
Phrenic nerve is motor/sensory/both and is made up of which ventral roots?
Both motor and sensory
C3, C4, C5
Which cranial nerve comes out superior to C1?
CN XII – hypoglossal nerve
What is the ansa cervicalis?
Loop of nerves that are part of the cervical plexus
Ansa cervicalis is made up of a superior root and inferior root. The superior root is aka __________________ and the inferior root is aka _________________
Descending hypoglossus
Descending cervicalis
The ansa cervicalis is made up of fibers from the ________________
Hypoglossal nerve and the cervical plexus nerves
Cervical plexus can be damaged by any operation where?
Posterior to the sternocleidomastoid muscle
What structures does the ansa cervicalis innervate?
All infrahyoid muscles except the thyrohyoid muscle
What is the punctum nervosum?
The area where the rami of C2, C3, and C4 emerge from posterior of SCM muscle
What is Erb’s point?
The point where C5 and C6 nerve roots join
What does injury to Erb’s point do?
Erb’s palsy or Erb’s palsy plus
What determines whether a baby will have Erb’s palsy or Erb’s palsy plus?
Erb’s palsy is damage to C5 and C6
Erb’s palsy plus is damage to C5, C6, and C7
Waiter’s tip arm is related to which condition?
Erb’s palsy plus
In _____________________, baby’s arm hangs at the side with hand rotated medially
Erb’s palsy plus
What causes Horner’s Syndrome?
Damage to C5-T1
What are the symptoms of Horner’s syndrome?
Partial ptosis of upper eyelid
Anhidrosis
Miosis
What muscles does Erb’s palsy affect?
Biceps brachii
Brachialis
Coracobrachialis
Brachioradialis
Deltoid
What is scalenus anticus syndrome?
Compression of anterior scalene on brachial plexus
Upper cervical spine does what movements?
Rotational movements
Lower cervical spine does what movements?
Flexion/extension
Spondylotic disease most commonly occurs where in the spine?
Lower cervical spine
What does this show?
Spondylolisthesis
Radiculopathy vs plexopathy
Radiculopathy affects nerve root
Plexopathy affect nerves of a plexus distal to the root
What is the most common type of radiculopathy?
Compressive
What are examples of compressive radiculopathies?
Cervical spondylosis
Disc herniation
What are examples of non-compressive radiculopathies?
Diabetes
Autoimmune diseases
What does this MRI show?
Posteriorly herniated discs
Cervical spine imaging is usually normal in ___________________ radiculopathy and abnormal in ___________________ radiculopathy
Non-compressive
Compressive
What is the most frequently affected nerve root of a cervical radiculopathy?
C7
What is the spurling maneuver? What does a positive test look like?
Extend and rotate neck to the side of pain, then apply downward pressure on the head
Positive if there is limb pain or paresthesia produced
What is the preferred initial test to diagnose cervical radiculopathy?
MRI
What is the gold standard for making the diagnosis of cervical radiculopathy, specifically foraminal compression?
CT myelography
What does this image show?
Spondylosis (lipping of vertebral bodies)
Ulnar nerve is derived from branches of the ________________ cord in the brachial plexus
Medial
Radial nerve is derived from branches of the _________________ cord in the brachial plexus
Posterior
Median nerve is derived from branches of the _________________ cord in the brachial plexus
Medial and lateral
Musculocutaneous nerve is derived from branches of the _________________ cord in the brachial plexus
Lateral
Musculocutaneous nerve motor or sensory?
Motor above the elbow
Sensory below the elbow
Axillary nerve is derived from branches of the ________________ cord in the brachial plexus
Posterior
Long thoracic nerve comes from which spinal nerves?
C5-C7
Which nerves are sometimes accidentally injured during a mastectomy?
Long thoracic nerve and thoracodorsal nerve
Thoracodorsal nerve is derived from branches of the ________________ cord in the brachial plexus
Posterior
Lower subscapular nerve is derived from branches of the ________________ cord in the brachial plexus
Posterior
Upper subscapular nerve is derived from branches of the ________________ cord in the brachial plexus
Axillary nerve is made of fibers from which spinal nerves?
C5 and C6
Musculocutaneous nerve is made of fibers from which spinal nerves?
C5-C7
Median nerve is made of fibers from which spinal nerves?
C6-T1
Radial nerve is made of fibers from which spinal nerves?
C5-C8
Ulnar nerve is made of fibers from which spinal nerves?
C7-T1
A: roots
B: trunks
C: divisions
D: cords
Posterior dislocation of the shoulder affects which nerve?
Axillary nerve
The musculocutaneous nerve penetrates which muscle?
Coracobrachialis
Upper and lower subscapular nerves come from the _____________ cord of the brachial plexus
Posterior
Thoracodorsal nerve comes from the _______________ cord of the brachial plexus
Posterior
Explain why the thoracodorsal nerve is also known as the middle subscapular nerve
Because it is in the middle between upper and lower subscapular nerves
Brachial plexus is located between which muscles?
Middle and anterior scalenes
What are common plexopathies affecting brachial plexus? (5)
Scalene syndrome
Cervical rib syndrome
Costoclavicular syndrome
Hyperabduction syndrome
Backpack paralysis
Define the risk factors for a brachial plexus palsy
A large maternal weight gain
Maternal diabetes (baby high birth weight)
Multiparity (twins/triplets)
Breech position
Which nerves contribute to the waiter’s tip deformity in Erb’s palsy plus?
Suprascapular nerve
Musculocutaneous nerve
Axillary nerve
Neonatal brachial plexus palsies are caused by…
Baby’s shoulder getting stuck under mother’s pubic symphysis and this stretches the brachial plexus
Klumpke palsy results from…
Injury to C8 and T1
Klumpke palsy affects mostly which muscles?
Intrinsic muscles of the hand (thenar, hypothenar, and interossei muscles)
True or false. Horner’s syndrome is sometimes seen with Klumpke palsy
True
In Klumpke palsy, if _______________ are severely affected, you can see a clawhand deformity
Lumbricals
Erb’s palsy and Klumpke palsy are both caused by injury to the brachial plexus, Erb’s is caused by injury to ______________ and Klumpke is caused by injury to ______________
C5 and C6
C8 and T1
What are the most common neoplasms leading to brachial plexopathy?
Breast and lung cancer
The most common symptom of neuralgic amyotrophy is ________________
Winging of the scapula
Neuralgic amyotrophy is caused by…
Damage to the long thoracic nerve
Neuralgic amyotrophy is aka __________________
Brachial plexus neuropathy
Hereditary neuralgic amyotrophy mode of inheritance
Autosomal dominant
Hereditary neuralgic amyotrophy is characterized by ____________________
Recurrent brachial plexopathies
What are the symptoms of hereditary neuralgic amyotrophy?
Short stature
Small face
Hypotelorism (close eyes)
What is paresthesia?
Burning or prickling sensation
What is a fasciculation?
A muscle twitch
What is thoracic outlet syndrome?
Blood vessels or nerves in the space between clavicle and first rib (thoracic outlet) are compressed
What are the two forms of thoracic outlet syndrome?
True neurogenic
True vascular
What are the clinical findings in a patient with thoracic outlet syndrome?
Reduced ulnar and medial antebrachial cutaneous sensory response but normal median sensory response
Reduces ulnar and median motor response
What plexus is most often involved in diabetic-related plexopathy?
Lumbosacral plexus
How is medial brachial fascial compartment syndrome caused?
Puncture of axillary or brachial artery causing hematoma
What nerves are most affected in median brachial fascial compartment syndrome?
Median and ulnar nerve
What is scalene syndrome?
Neurovascular compression of interscalene space and brachial plexus
What is cervical rib syndrome?
Cervical rib compresses interscalene space and brachial plexus
What is costoclavicular syndrome?
Narrowing of space between first rib and clavicle causing compression of brachial plexus
What is hyperabduction syndrome?
Compression of brachial plexus by pectoralis minor muscle and coracoid process when arm is raised above head
Lumbosacral plexus is formed by the ventral rami of which spinal nerves?
L1-S4
The lumbar plexus is formed by which spinal nerves?
L1-L4
The lumbar plexus divides into anterior and posterior branches within which muscle?
Psoas major
What happens to the lumbar plexus in the psoas major muscle?
Divides into anterior and posterior branches
What is the main difference between anterior and posterior branches of the lumbar plexus?
Anterior branches become the obturator nerve
Posterior branches become the femoral nerve
The sciatic nerve is made from the ____________ segments of the lumbosacral plexus
L4-S3
What is piriformis syndrome?
Sciatic nerve compressed by piriformis
What is cauda equina syndrome?
Damage to the cauda equina below the end of the spinal cord
Sensory disturbance involving the anterior/medial thigh and medial leg typically represents ___________________ injury
Lumbar plexus
Lumbosacral trunk and upper sacral lesions result in ______________
Drop foot
Sensory disturbance involving the leg, dorsum of the foot, posterior thigh, and perineum suggests _________________ injury
Lumbosacral trunk or sacral plexus
How is Patrick’s test performed?
Hip is externally rotated with knee flexed 90 degrees and placed on top of the opposite knee
What diseases are being screened for with Patrick’s test?
Hip or sacroiliac disease
How is the straight leg test performed?
Patient’s extended leg is passively raised with foot dorsiflexed (patient should not help)
What diseases are being screened for with the straight leg test?
Radiculopathy due to disc herniation
What imaging is best to use for lumbosacral plexopathy?
MRI and EMG (electromyography)
What is radiation plexopathy?
Lumbosacral plexopathy occurring months to years after pelvic irradiation
What is myokymia?
Quivering of a few muscles insufficient to move a joint
What are the clinical findings in a patient with myokymia?
Tissue fibrosis
Microinfarction of axons
Myokymia is common in which condition?
Radiation plexopathy
What are the most common types of peripartum plexopathies?
Intrapartum and postpartum lumbosacral plexopathies
Peripartum plexopathies present with which symptoms?