Neuro

• Innervation of Biceps Muscle

  Musculocutaneous nerve
• Nerve Roots of Biceps Muscle

  C5, C6
• Innervation of Triceps Muscle

  Radial Nerve
• Nerve roots of Triceps Muscle

  • Lateral Head: C6
  • Long Head: C7
  • Medial Head: C8
• Innervation of Brachioradialis Muscle


  Radial Nerve
• Nerve roots of Brachioradialis Muscle


  C5, C6
• Innervation of Deltoid Muscle

  Axillary nerve
• Nerve roots of Deltoid Muscle

  C5, C6
• Innervation of Wrist Extensor Muscles

  Radial Nerve (all extensors in arm are radial n.)
• Thumb innervation


  Median nerve
• Pinky innervation


  Ulnar nerve
• Triceps Reflex Nerve Roots

  C6 & C7
• Biceps Reflex Nerve Roots


  C5 & C6
• Brachioradialis Nerve Roots


  C5 & C6
• Patellar Reflex Nerve Roots

  L3 & L4
• Ankle Reflex Nerve Roots

  L5, S1
• Innervation of Gastrocnemius


  S1, S2
• Innervation of Quadriceps


  Femoral nerve (L2-L4)
• Checkerboard sensory & checkerboard motor fallout

  • Brainstem Lesion (Face = ipsilateral sensory motor/, arms & legs have contralateral sensory/motor fallout, Face always affected on side of lesion)
• Horizontal Gaze Palsy


  Due to pontine lesion affecting CNVI nucleus or stroke causing a lesion on contralateral cerebral hemisphere (frontal eye fields)

  
• Vertical Gaze Palsies


  Commonly results from midbrain lesions, usually infarct & tumour

  
• Upward Gaze Palsies


  • Pupils may be dilated & vertical nystagmus occurs during upward gaze

  
• Physiology of Upward Gaze

  Upward & downward gaze depends on input from fibre pathways that ascend from vestibular system through MLF on both sides to 3rd & 4th cranial nerve nuclei

  
• Parinaud Syndrome


  Vertical gaze palsy. Dorsal midbrain syndrome, on upward vertical gaze palsy that may result from pineal tumour that compresses the midbrain

  
• Characteristics of Parinaud Syndrome

  • Impaired Upward gaze
  • Lid retraction (Coller's sign)
  • Downward gaze preference (setting sun sign)
  • Convergence retraction nystagmus
  • Dilated pupils that respond poorly to light BUT can respond to accommodation (light-near dissociation)

  
• Ischaemic Brainstem Stroke


  Cerebral hypoxia -> ischaemia -> infarction