Disc prolapse involving L4 nerve root typically presents with: (Repeat)
Ans: D (Absent ankle jerk) Ref: Harrison's Principles of Internal Medicine, 18th ed.Explanation:Lumbosacral Radiculopathy--Neurologic Features (Sec Table 16}Neurologic ExaminationDeep Tendon ReflexesL4 Nerve Root (L3-4 disc): Patellar Reflex or Knee jerkSI Nerve Root (L5-SI disc): Achilles Reflex or Ankle jerkMotor ExamL4 Nerve Root (L3-4 disc): Ankle dorsiflexionL5 Nerve Root (L4-5 disc ): Great toe dorsiflexion (extensor haihicis longus)S1 Nerve Root (L5-S l disc): Ankle plantar flexion (gastrocnemius-soleus complex)Sensory ExamL4 Nerve Root (L3-4 disc): Medial malleolusL5 Nerve Root (L4-5 disc): Dorsal third metatarsophalangeal jointSI Nerve Root (L5-S1 disc): Lateral heelRadicular patterns by disc herniation typeCentral Disk herniationNerve root affected is ABOVE the discExample: Central L3 di.,c herniation causes findings above the L2-3 Nerve rootParacentral disk herniationNerve root affected is AT the discExample: Paracentral ' ' disc herniation causes findings at the L2-3 Nerve rootLateral disk herniationNerve root affected is BELOW the disc (foraminal effects) Table 16Examination FindingsLumbosacral Nerve RootsReflex AbsentSensoryMotorPain DistributionL2--Upper anterior thighPsoas (hip flexion)Anterior thighL3--Lower anterior thigh Anterior KneePsoas (hip flexion) Quadriceps (knee extension} Thigh adductionAnterior thigh, kneeL4Quadriceps (Knee reflex)Medial calfQuadriceps (knee extension) Thigh adduction Tibialis anterior (foot dorsiflexion)Knee medial calf Anterolateral thighL5 Dorsal surface- foot Lateral calfPeroneii (foot eversion) Tibialis anterior (foot dorsiflexion) Gluteus medius (hip Auction) Tne dorsiflexorsLateral calf dorsal foot, teral thigh,buttocksS1Gastrocnemius/soleus (Ankle reflex)Plantar surface-- foot Lateral aspect -footGastrocnemius/soleus (foot plantar flexion) Abductor hallucis (toe flexors) Gluteus maximus (hip extension)Bottom foot, posterior calf, posterior thigh, buttocksExample: Lateral L3 disc herniation causes findings at the L3-4 Nerve root
Weakness of hip flexion
Absent ankle jerk
Weakness of hip extension
Absent knee jerk
Thoracic and Lumbosacral Spine Injuries