Holmes-Adie vs Argyll-Robertson pupil vs Pupil in Parinaud syndrome AIIMS PG Medical HY Topic

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  • Holmes-Adie or tonic pupil syndrome is a condition of unknown cause related to degeneration of nerve cells in the ciliary ganglion. The degeneration of short ciliary nerves, with subsequent collateral sprouting, results in predominance of accommodation elements in the innervation of the iris. It is more frequent in females and can be unilateral at first. Typically, the patient presents with blurred near vision, loss of knee and ankle jerks, and impaired sweating. The pupil is round and widely dilated; it reacts poorly to light but better to accommodation. The minimal reaction to accommodation or to light is probably related to partial reinnervation of parasympathetic fibers and slow inhibition of sympathetic fibers. The confirmation of the diagnosis is made by pupillary reaction to pilocarpine drops. Pilo-carpine is rapidly hydrolyzed by acetylcholine esterase and has no effect on the normal pupil. In Holmes-Adie syndrome, the denervated pupil with enzyme depletion allows the pilolo-constrictor effect to occur.
  • Argyll-Robertson pupil is classically seen in patients with neurosyphilis. The site of the lesion is thought to be in the rostral midbrain, injuring the supranuclear inhibitory fibers that affect the visceral oculomotor nuclei. The pupils are usually affected bilaterally and are irregularly miotic with variable iris atrophy. There is a decrease or absence of the pupillary light reaction with conservation of the near response in the presence of normal visual acuity. Epidemic encephalitis lethargica causes loss of convergence with parkinsonism. The patient’s pupils react to light but not to accommodation.
  • Parinaud syndrome results from a lesion in the dorsal rostral midbrain that interferes with the decussating light reflex fibers in the periaqueductal area. The syndrome is characterized by dilated fixed pupils to light, loss of upward gaze, defective convergence, skew deviation, light near dissociation (reaction to accommodation but not to light) and lid retraction

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