What’s the value of the Pupillary Light Reflex (PLR) or Swinging Penlight Test?
360 Neuro Health
We believe in multidisciplinary connections, knowing that working together increases access to meaningful content.
The Pupillary Light Reflex (PLR) is an incredibly complex physiological process that involves multiple neurological pathways, providing valuable insights into autonomic, midbrain, and central brain functions. Additionally, a mobile pupil has been found to enhance visual performance by affecting depth of focus and optical abnormalities. This means that studying pupil responses can also have practical applications in improving vision and optimizing visual performance.
??CLINICAL TAKEAWAYS:
? If one pupil is consistently larger than the other (anisocoria), it warrants further evaluation. A sudden onset of anisocoria indicates an acute neurological event.
? Pupils constrict due to parasympathetic activity and dilate due to sympathetic activity.
? Monitoring pupillary changes during position changes helps assess ANS function.
? A sluggish or absent PLR is of significant concern for impaired neurological function, especially if the pupil remains fixed and dilated (mydriasis) during the PLR test.
? If you see a poor response to the PLR test, compare their pupil response to the light versus viewing a near target or a convergence test. Poor response to the PLR test but constriction with viewing a near target (accommodation) is referred to as Light-Near Dissociation, which can occur with neurosyphilis, diabetic neuropathy, lesions in the midbrain, or can occur with a benign condition.
? Bilateral pinpoint pupils (miosis) may respond to the PLR test, but excessive constriction can occur from opioid use, brainstem dysfunction, neurological conditions, or some medications.
? In concerns of ANS dysfunction, assess the PLR in supine to standing. An abnormal PLR in standing (compared to a normal response in supine) may appear as a sluggish constriction, asymmetry, or a fixed and dilated pupil. These findings suggest ANS dysfunction.
PURPOSE:
To assess pupil constriction with exposure to direct light.
领英推荐
INDICATIONS:
Assessment of the PLR is useful for identifying a relative afferent pupillary defect (RAPD) due to dysfunction anywhere along the afferent pupillary pathway. The clinician can provide a quick, inexpensive analysis of the patient’s pupillary response to light.
EQUIPMENT:
Penlight with pupil size measurements (millimeters) and distant target. Optional: a distinct target for near-target testing.
TIME REQUIRED:
Less than 2 minutes.
SET-UP:
INSTRUCTIONS:
For interpretation and additional considerations, grab your copy of the Dizziness and Balance Assessments & Treatments – A Clinical Guide for Healthcare Professionals | 1st Edition today! Click here to learn more.