What is light-near dissociation?

Description. Light-near dissociation (LND) is a pupillary sign that occurs when the pupillary light reaction is impaired while the near reaction (accommodative response) remains intact.

What causes light-near dissociation?

Philadelphia-The five most important causes of light-near dissociation are deafferented pupils, midbrain lesions, Argyll-Robertson pupils, aberrant regeneration of the third nerve, and tonic pupils. “The lesion in these patients is located in the pretectal nuclei and ganglion cell axons as they enter the midbrain.

What causes Argyll Robertson pupil?

Argyll Robertson pupil is found in late-stage syphilis, a disease caused by the spirochete Treponema pallidum. Neurosyphilis occurs due to an invasion of the cerebrospinal fluid (CSF) by the spirochete which likely occurs soon after the initial acquisition of the disease.

What is dorsal midbrain syndrome?

The dorsal midbrain (Parinaud’s) syndrome is characterized by a supranuclear vertical gaze paresis (upward more than downward), lid retraction, convergence-retraction nystagmus, pupillary light-near dissociation, and pseudoabduction deficits caused by excessive convergence tone.

How do you test near response?

The near response pupil test measures the pupil’s response to a near target. 4 This test will be performed in a room with normal lighting. Your healthcare provider will ask you to look at a distant object, then move a small object or card in front of your eyes.

How do you test Argyll Robertson pupil?

A clinician can diagnose the Argyll Robertson pupil through a thorough evaluation of symptoms, conduction of a physical exam, and discussion of past medical history. The examination will typically show a light-near dissociation, in which the pupil focuses quickly on a near object but doesn’t respond to bright light.

What is reverse Argyll Robertson pupil?

Inverse Argyll Robertson Pupil (IARP), absence of pupillary constriction to near stimuli with retention of pupillary light reflex, has rarely been described. Chrousos and colleagues (1985) reported a child with absence of complete near reflex triad.

How is Adie syndrome treated?

Doctors may prescribe reading glasses to compensate for impaired vision in the affected eye, and pilocarpine drops to be applied 3 times daily to constrict the dilated pupil. Thoracic sympathectomy, which severs the involved sympathetic nerve, is the definitive treatment for excessive sweating.

What does Adies mean?

: a neurological disorder that is characterized especially by an abnormally dilated pupil, absent or diminished light reflexes of the eye, abnormal visual accommodation, and usually impaired reflex activity of the arms or legs, that typically occurs between the ages of 20 to 50 and most commonly affects women, and that …