1017 - Not All That Hallucinates is the Brain: A Case of Vitreous Floaters Mistaken for Post-TBI Hallucinations

Thursday, February 19, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

AP

Ashton Purtle-Smith, MD

Resident Physician
UAMS
Conway, Arkansas, United States

Co-Author(s)

RG

Rani Gardner, MD, BIM

Division Chief, Program Director, Associate Professor
UAMS
Little Rock, Arkansas, United States

Submitter(s)

AP

Ashton Purtle-Smith, MD

UAMS
Conway, Arkansas, United States

Case Diagnosis: Vitreous floaters presenting as hallucinations after traumatic brain injury

Case Description: A 68-year-old male with recovering from a moderate TBI presented to physiatry clinic reporting recurrence of post traumatic hallucinations characterized by persistent dancing "shadowy figures" in his vision. His case manager expressed concern for hallucinations as a neuropsychiatric sequela of brain injury. Patient with initial visual hallucinations after acute injury but had resolution of symptoms with time and short course of olanzapine. The patient described the recurrent visual phenomena as consistent in size and shape to prior hallucination but rather than discreet image was just seeing the shadow of his previous hallucination. The symptoms are most noticeable upon awakening or when turning off lights at night when in bed. Ophthalmologic evaluation revealed sizeable vitreous floaters. Given his altered perceptual processing after TBI, the floaters were misinterpreted as hallucinations.

Discussions: Hallucinations are a well-recognized complication of TBI, but ocular pathology may mimic or contribute to these symptoms. Vitreous floaters are a common, benign condition, yet in patients with brain injury, altered perception and interpretation can result in their being reported as hallucinations. Floaters can be prominent at night due to pupil dilation and contrast in low light. Misdiagnosis could lead to unnecessary psychiatric evaluation or treatment. This case highlights the need for a broad differential diagnosis, interdisciplinary collaboration, and consideration of ophthalmologic causes when evaluating hallucinations in TBI patients.

Conclusions: What appears to be a neuropsychiatric symptom can sometimes have a simple, physical origin. The brain's attempt to make sense of altered sensory input, like floaters, can lead to misinterpretations that mimic serious psychiatric conditions. Careful history-taking and ophthalmologic assessments are critical to distinguish true hallucinations from misinterpreted visual disturbances, ensuring accurate diagnosis and appropriate management.