Autonomic

Horner's Syndrome

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Horner's Syndrome, Horner Syndrome, Sympathetic Ocular Ophthalmoplegia

  • Pathophysiology
  1. Paralysis of superior cervical Sympathetic Nerve
    1. Destructive lesion to superior cervical Ganglion
    2. Destruction in posterior retroparotid space
    3. Mediastinal tumor or superior Lung Mass
  2. Lesions interrupt sympathetic fibers
    1. Courses to the Carotid Artery (in petrous Temporal Bone) and then to the orbit
    2. First order Neuron injury
      1. Ipsilateral fibers from Hypothalamus, through pons and Medulla to the spinal cord C8-T2
    3. Second order Neuron injury (preganglionic sympathetic)
      1. Preganglionic sympathetic fibers from T1 to superior cervical Ganglion (C3-4)
    4. Third order Neuron injury (postganglionic sympathetic)
      1. Sweat Gland denervation (Anhidrosis) via fibers along the external Carotid Artery
      2. Long ciliary nerve denervation (Miosis) via fibers along the Internal Carotid Artery
        1. Follow Internal Carotid Artery to carotid plexus
        2. Through Cavernous Sinus (alongside CN 6)
        3. Follow CN 5 (ophthalmic branch) to eye
  3. Associated lesions
    1. Cranial Nerve 9
    2. Cranial Nerve 10
    3. Cranial Nerve 11
    4. Cranial Nerve 12
    5. Cranial Nerve 6
    6. Cranial Nerve 5
  4. Images
    1. EyePupillaryReaction.png
  • Causes
  1. Vascular
    1. Brainstem Stroke
    2. Cerebral Aneurysm
    3. Cervical Artery Dissection
  2. Neurologic Conditions
    1. Demyelinating Disease (e.g. Multiple Sclerosis)
    2. Infection (Encephalitis, Meningitis)
  3. Posterior retroparotid space mass
    1. Parotid Gland tumor
    2. Carotid body tumor
    3. Metastatic tumor
    4. Lymphoma
    5. Tuberculous Adenitis
  4. Mediastinal Mass
  5. Apical Lung Lesion (e.g. Pancoast Tumor)
  • Signs
  1. Mnemonic: Miosis, Ptosis, Anhidrosis
  2. All findings are unilateral
  3. Miosis
  4. Palpebral Ptosis (Incomplete)
    1. Contrast with complete Ptosis in levator paralysis
    2. Illusion of eyeball recession (No true enophthalmos)
  5. Absence of sweating (Anhidrosis) on face and neck