INJURIES OF THE LOWER EXTREMITY下肢的神经损伤课件.ppt

NERVE INJURIES OF THE LOWER EXTREMITY STACY RUDNICKI, MD ASSOCIATE PROFESSOR OF NEUROLOGY Dermatomes of the Leg Root Innervation of the Leg Hip Flexion L 1, 2, 3 Knee Extension L 2, 3, 4 Foot Dorsiflexion L 4,5 Foot Plantar Flexion S1, 2 Knee Flexion L5, S1, S2 Hip Extension L5, S1, S2 Clinical Principles Detecting subtle weakness Get up from squat Quadriceps/Gluteus maximus Stand on tip toes Gastrocnemius/Soleus Stand on heels Tibialis Anterior Reflexes Knee Jerks - evaluates Quadriceps muscle Femoral Nerve Primarily L4 nerve root (also L2, L3) Ankle Jerk - evaluates Gastrocnemius muscle Tibial Nerve Primarily the S1 nerve root (also S2) CASE 1 History 20 yo college student involved in an MVA She suffers multiple pelvic fractures She complains of weakness and numbness of the right leg She is aware that her right foot is “dropped” relative to the left, and that she must lift her foot up higher to clear her toes Exam She has weakness of: Foot dorsiflexion Foot eversion Toe extension Strength is normal in: Foot plantar flexion Foot inversion Toe flexion There is just a hint of weakness in knee flexion SENSORY LOSS Localization Finding Muscle Nerve Root Involved Ft Dorsiflex TIB ANT FIB L4,5 Grt toe ext EHL FIB L5 Toe ext EDL, EDB FIB L4,5 Foot eversion FIB L, B FIB L4,5 Knee flex Mult TIB/Fib L5S1S2 Spared Foot plant flex GASTROC, TIB S1,2 SOLEUS Toe flex FDL/FDB TIB L5,S1 Foot inv POST TIB TIB L4,5 Localization Finding Muscle Nerve Root Involved Ft Dorsiflex TIB ANT FIB L4,5 Grt toe ext EHL FIB L5 Toe ext EDL, EDB FIB L4,5 Foot eversion FIB L, B FIB L4,5 Knee flex Mult TIB/Fib L5S1S2 Spared Foot plant flex GASTROC, TIB S1,2 SOLEUS Toe flex FDL/FDB TIB L5,S1 Foot inv POST TIB TIB L4,5 Common Fibular (Peroneal) Nerve Common Fib Short head BF Deep Fib Superficial Fib Fib Longus Tib Ant Fib Brevis EHL Fib Tertius EDB Differentiating b/w L5 radiculopathy and Fibular Neuropathy Mo