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Suico LE radiculopathies, plexopathies, and entrapment
Terms in this set (53)
What is the most common lumbosacral nerve root involved in a lower extremity radiculopathy?
Uncommon causes of herniated discs/radiculopathies
H - Herpes zoster
I - Inflammatory: TB, Lyme disease, HIV, sarcoidosis, syphilis, cryptococcus
M - Metastasis
A- Arachnoiditis: myelogram, surgery, steroids, anesthesia
D - Diabetes mellitus
A - Abscess
M - Mass: meningioma, neurofibroma, leukemia, lipoma, cysts, hematoma
Far lateral disc herniations tend to affect the nerve root...
Central herniations tend to affect the nerve root...
- Pt in a flexed seated position with arms behind back. Examiner passively raises leg to full knee extension with ankle dorsiflexion
- Test considered positive if pain radiates into ipsilateral limb
- Only considered positive if they have the SAME radicular pain down the leg. Does not mean positive if down a different radicular path or in back.
Straight leg raise test
- Patient is laying supine
- Examiner passively raises leg (hip flexion) with full knee extension
- Test considered positive if pain radiates into ipsilateral limb
Neural tension signs
Provocative maneuvers. SLR and slump test
Clinical presentation of L4 nerve root radiculopathy
- Reduced patellar tendon reflex
- Weakness in knee extension, ankle dorsiflexion (tibialis anterior)
- Numbness/parasthesia in anterolateral thigh and medial ankle
Clinical presentation of L5 nerve root radiculopathy
- Reduced hamstring reflex
- Weakness in hallux extension.
- Numbness/parasthesia in posterolateral thigh/calf and dorsal foot
Clinical presentation of S1 nerve root radiculopathy
- Reduced achilles tendon reflex
- Weakness in plantar flexion
- Numbness/parasthesia in posterior thigh/calf and lateral ankle
L1-L2/L2-L3/L3-L4 HND muscles involved
Posterolateral L4-L5 HND muscles involved
Posteriolateral L5-S1 HND muscles involved
What is the most common disc herniation?
S2/S3/S4 HND muscles involved
Look more at spinal stenosis. Cauda equina syndrome can affect it too. UMN syndroms. Bowel and urinary dysfunction, abductor hallucis, abductor digiti quinti
Should examine at least 5 peripheral muscles and paraspinals. Need findings in 2 separate muscles innervated by 2 separate nerves with a common nerve root
Nerve that connects lumbar plexus to sacral plexus. Originates from L4
Where does the lumbar part of the plexus lie?
Embedded between and in the paraspinal quadratus lumborum and psoas muscles
Nerve fibers originating from ventral rami of L1, L2, L3 & L4
Nerve fibers origination from ventral rami of L4, L5, S1, S2, S3 & S4
Anterior division of lumbar plexus
Posterior division of lumbar plexus
Anterior division of sacral plexus
Posterior division of sacral plexus
Common fibular nerve
What are the most common cause of non-traumatic lumbosacral plexopathy?
Direct neoplastic extensions
- Colorectal, uterine, prostate, ovarian
- More proximal -> lumbar plexus
Distant neoplastic extensions
- Breast, sarcoma, thyroid and testicular
- Sacral plexus
Characteristics of neoplasm and not radiation
Weakness, leg edema, pain
- Compression of the plexus as it passes through the iliopsoas muscle
- Iatrogenic - heparin
- Abdominal, back or groin pain
- Grey Turner's syndrome
- Acute, unilateral back pain
- Look for unexplained anemia
- Confirm w/ CT
What nerves/plexuses are often involved with obstetric causes of plexopathies?
Lumbar plexus or femoral nerve
What can IV injections cause?
Vasospasms of lumbar plexus
- AKA Diabetic Amyotrophy
- Anterior thigh pain and proximal leg weakness (quads)
- Severe aching or burning and lancinating pain
- Diminished or absent patella reflex
- May see muscle wasting
What improves with blood sugar control?
Diabetic amyoptrophy, NOT peripheral neuropathy
What nerves are commonly involved with trauma to the LSP?
Usually sciatic nerve. Common fibular > gluteal > tibial > obturator
What are UMN signs?
Clonus and babinski signs
If you see increased tone and hyperreflexia, what is the more likely etiology?
UMN, not plexopathy
Neuropathic pain meds
Lateral femoral cutaneous nerve entrapment
- L2 and L3 nerve roots -> posterior division of lumbar plexus
- AKA meralgia parasthetica
- Purely sensational. Usually from pregnancy, tight clothing
- Exacerbated with sitting, driving, hip extension or flexion
Femoral nerve root entrapment can present as what?
Femoral nerve root entrapment
- L2-L4 nerve roots (posterior division of lumbar plexus)
- Injury from trauma, fracture, retroperitoneal hematoma, tumor, inguinal ligament compression, or cardiac catheterization
- Most common = iatrogenic from abdominal or pelvic surgery
- Complaints: Weakness of knee extension (quads), knee instability, decreased sensation over whole anterior thigh and medial leg
- Hip flexion weakness if above inguinal ligament
What is the largest branch of the lumbar plexus?
Sciatic nerve root entrapment
- L4-S3: posterior division of lumbosacral plexus
- Etiology: hip trauma, hip replacement, injection, hematoma, pelvic fracture, penetrating wounds, or a gravid uterus
- Piriformis Syndrome - at the pelvic outlet as nerve runs inferior or through this muscle
What innervates the pectineus?
Femoral and obturator nerves
What innervates the adductor magnus?
Sciatic (tibial portion) and obturator nerves
What innervates the biceps femoris?
Sciatic nerve (tibial portion) and sciatic nerve (peroneal portion)
If the piriformis is hypertonic, what can it compress?
The sciatic nerve
Tibial nerve route
L4, L5, S1, and S2 (S3) roots -> sciatic nerve -> branches at the popliteal fossa to finally form tibial nerve -> under flexor retinaculum -> medial plantar, lateral plantar and calcaneal nerves
Tibial nerve entrapment
- TARSAL TUNNEL
- Compression underneath flexor retinaculum
- Intrinsic foot weakness
- Perimalleolar pain, numbness and paresthesias reproduced by ankle inversion
- Positive Tinel's
- Heel sensation spared
Common peroneal nerve route
L4-S2 roots -> Sciatic nerve -> peroneal nerve
-> winds around the fibular head -> into the deep and superficial portions
What does the superficial peroneal nerve innervate?
Medial cutaneous nerve
Lateral cutaneous nerve
Deep peroneal nerve innervates...
Extensor digitorum longus
Extensor hallucis longus
Extensor digitorum brevis
First dorsal interossei
Dorsal distal cutaneous nerve
Common peroneal neuropathy/entrapment
- Most common site of this nerve injury is at the fibular head
- Etiology: Compression from prolonged leg crossing, weight loss, poor positioning during surgery, poor cast application, prolonged squatting position (strawberry pickers' palsy) and metabolic disorders such as diabetes
- Involve all muscles supplied by the deep and superficial branches of common peroneal nerve (short head of the biceps femoris is spared)
- Complaints of weakness of the dorsiflexors (TA, EDL, EHL). Foot drop or foot slap and Steppage Gait
- Sensory loss may be noted
What causes foot drop?
- L4-L5 radiculopathy: ankle dorsiflexion, eversion, inversion
- Peroneal neuropathy: Tibialis anterior, 1st and 2nd toe web space numbuess
- ALS: pure motor neuron disease, mixed UMN and LMN findings
- NOT lumbosacral plexopathy
THIS SET IS OFTEN IN FOLDERS WITH...
Suico gait mechanics
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