Peripheral Nerve Disorders Flashcards
3 types of nerve injury
neuropraxia
axonotmesis
neuromesis
Neuropraxia = focal damange to fibers, sheath remains in tact = least severe
Axonotmesis = more severe, injury to the axon but recovery can happen (full revoery probably wont but some)
Neuromesis = complete disruption of the axon = need surgery or no receovery
Bells Palsy
- etiology
- symptoms
Etiology
- LMN lesions of the facial nerve (CN VII)
- can be reactive VZV or HSV or lyme
- inflammation of facial nerve inhibits cn innervations
Risk Factors
- immunocomp.
- pregnant
- hypertension
- sarcoid
- lyme
Symptoms
- sudden onset of facial paresis; usually unilateral
- stiff feeling of face
- ear pain
- drooping eyelid
- taste issues
- unilatera facial drop with loss of forehead wrinkles
Bells v stroke
Diagnosis
Bells
- LMN
- so you lose all innervation to taht side
- maneing the forehead wrinkles are gone too
Stroke
- UMN lesion of one side of the brain
- so you lose innervation from that side to contralat. face
- but you still have ipsilateral innervation of the forehead
Diagnosis
- can be clincial with right signs and symptoms
- ensure youve rule out eberything else as the cause
- can get labs to do this
- imaging can be done if you : suspect a central lesion or if there is bilateral paresis
Bells Palsy
Treatment
Treatment
- most recover spontaneously
- give steroids; either a prednisone with taper or prednisolone
- eye care while the lid wont close : tape at night or lube it up
- if lyme = doxycycline
- if HSv/VZV= acyclovir
good prognosis:most recovery in like 2 weeks
unless…
- 60+, complete faical weakness and hypertension = then worse
Trigeminal Neuralgia
Etiology and Pathology
Etiology
- brief episodes of intense facial fain anywehre in the trigem. facial distribution (V1, V2, V3)
- common in females in middle age
Patho
- etopic generation of AP’s in the sensory fibers of CNV
- can be a result of compression to the nerve (blood vessel or tumor) which can lead to the demyleination of the nerve fibers
Trigeminal Neuralgia
Symptoms
Symptoms
- extreme pain: in the trigem. distribution that can last secondes to minutes
- can be culster episodes; like in weeks
- no sensory loss!!! just pain
- can be bought on by chewing, smiling. etc.
Diagnosis
- imaging: not normally needed for a dx –> could do MRI to r/o MS
Treatment
- initital treatment is carbamazepine : continue med and then taper (watch agranulocytosis)
- alternative medications include….
- oxarbazepine
- lamotragine, phenytonin, topieramate, etc.
Brachial Plexus Injury
etiology
Symptoms
diagnosis
treatemetn
Etiology & Symptoms
- common in collision sports
- acute onset of parasthesias int he upper arm (circumfrential – not a single nerve pattern)
- motor symptoms possible; less commong but happen days/weeks after injury
- always r/o a c-spine injury
Diagnosis
- monitor serially over 24 hours and then every few days to see if motor symptoms develop
- new symptoms = refer to specialist
- +/- MRi, EMG and NCS
Treatment
- can return to play within 14 minutes if symptoms resolve; but still need reevaluation
neonatal Brachial Plexus Injury
- “waiters tip” Erb’s Palsay
Thoracic Outlet Syndrome
Etiology
- compression of brachial plexus or subclavian vessesl between shoulder and first rib
- can be due to extra rib, abnormal C7 process or a band that traps them
- this is usually a vascualr issue not neurologic
Symptoms
- vague: minics ulnar nerve compression with parasthesias of little finger and ring finger
- achy pain that can extend into the neck and shoulder (worse with overhead activity)
- swelling/discoloration = vascular
- assign for mass in supraclavicualr region : auscultate too for bruits
Signs
- EAST test: elevated arm stress test: abduct arms uprighta t 90 degerees
- if this reproduces symptoms = postive test
- adson’s maneuver : p.. standing with the arm abducted, extended then turn neck to th side (try to compress the area) & get pulse and comapred to otehr side
Diagnosis
- can get radiography to look for rib issues or chest xray for tumor
- not really any stuides to do
Treatment
- nonsurgical management with thearpy
- nsaids to relax
Axillary Nerve Injury
Etiolog y
- passes through quadrangle space and can become injured
- dislocation, fracture, compression (crutches), overhead movements etc.
Symptoms
- arm fatigue with overhead activities
- parasthesiad and numbess in axillary distrubution (lateral deltoid)
- weakness to abduct and externally rotate arm
Diagnosis
- clinically usually: can do MRI if unclear presenataion
Treatment
- conservative
Long Thoracic Nerve Injury
Etiology
- acute shoulder injry or repetitive injury (tennis, baseball)
Symptoms
- diffuse shoulder or neck pain worse with overhead
- see scapular winging and weakness with forward elevation
Diagnosis
- no need for imaging: could should deinneravtion
Treatment
- conservative with ROM exercises
Spinal Accessory Nerve INjury
Etiology
- trap trauam or shoulder dislocation or neck surgery
Symptoms
- shoulder pain and weakness (CN XI)
Diagnosis
- asymmetric shoulders, unable to shrug
- weak forward elevation of arm
Treatment
- therapy
Radial Nerve Injury: Spiral Groove
“Saturday night palsy”
Etiology
- radial nerve gets compresses in teh sprail groove of humerus = parasthesiad and “wrist drop”
- weak brachioradialis
Treatment
- resolve on own or therapy
Radial nerve Injury: at Elbow
Radial Tunnel Syndrome
Posterior Interosseous Injury
Radial Tunnel Syndrome: superfiscal raidal nerve branch
- difficult to pronate
- the point of max. tenderness is taht the anterior radial neck, not at the tendon origing: just a little lower
Posterior Inerosseous Injury
- pain with extension of the middle finger
- hand weakenss and wrist extensor weakness
Treatment = therapy, splinting and pain managemetn
Median Nerve Injury @ Elbow: Pronator Syndrome
ETiology
- pronator teres compresses the median nerve: giving carpel tunnel like syndrome
Symptoms
- parasthesias in thumb and first two fingers with achy forearm activity
- normal sensation in fingers and forearm
- loss sensation over the thenar eminence
- negative phalen and tinnerls (so its not carpel tunnel)
Diagnosis - iamging not neeede: but MRI could should hypertrophy or lesion
Treatment
- modificaion of activity
- steroif innjection or split
Cubital Tunne Syndrome: Ulnar NErve Injury at Elbow
Etiology
- nerve sits superfiscally: with prolonger flexion the following occurs
Symptoms
- parathesias at 4th and 5th fingers
- eblow pain radiation to hand
- sensory loss
- issues with grip strength
Treatmen t
- padding at the eblow
- extension splinting
