Branchial and lumbosacral plexus Flashcards
Sequences
Initially T2 FSE with fat suppression and STIR
BUT NOW: 3D T2 sequences (SPACE) enhance contrast between nerves and muscles
Complete nerve root avulsion
Partial avulsion
Empty root sleeve, absence of ventral and dorsal roots
Reduced number of rootlets on MIP projection, missing ventral or dorsal root with absent or minimal abnormality
Branchial Plexus Components
C5-T1 Roots 3 Trunks (Superior, Middle, Inferior) 6 Divisions 3 Cords (Lateral, Posterior, Medial) Terminal Branches
Where are the roots and the trunks located?
Where are the trunks formed?
In the interscalenic space/triangle
In the interscalenic space
Describe the infraclavicular BP
Lateral cord = anterior divisions of UT and MT = Musculocutaneous and Median n.
Posterior cord= posterior divisions of the three trunks = Axillary and Radial n.
Medial cord = Continuation of IT= Ulnar and Median n.
Infraclavear - costo-clavicular space
Infraclavear - retropectoralis minor space
Divisions and cords
Distal cords and terminal branches
Imaging of Chronic Inflammatory Demyelinating Poliradiculoneuropathy
High signal and hypertrophic nerve roots with gradual normalization
Thoracic outlet syndrome
Fibrous band middle scalene muscle - first rib
Lumbosacral Plexus
Lumbosacral trunk
Lumbar plexus= T12 - L4
Sacral plexus= Ventral rami L4-L5 and S1-S4
The lumbosacral trank connects the lumbar and sacral plexuses
Femoral nerve
And signs of injury
L2-L3-L4
Psoas muscle -iliacus
Exits pelvis under the inguinal ligament
High signal, enlargement, muscle denervation
Lateral Femoral cutaneus nerve
L2-L3
Exits anterior superior iliac spine
Meralgia parestethica
Obturator nerve
L2-L4
Obturator foramen
Pudendal nerve
S2-S3-S4 Greater sciatic foramen between piriformis and coccygeus muscle Pudendal (Alock’s canal) Hardly identified NEUROVASCULAR BUNDLE
Sciatic nerve
L4-S3 roots
Greater sciatic foramen
Inferiorly piriformis muscle
At the lateral ischial tuberosity gives tibial and peroneal nerves
