February 21, 2026

Cerebro Clinical Literature Review

Binocular Symptom Provocation (Convergence / NPC) in Uninjured vs TBI

Document control

Doc ID: CEREBRO-CRU-LIT-BINOC-NPC
Version: v0.1 (clinical review)
Audience: clinical leadership, research, regulatory stakeholders (FDA-facing)

Abstract

Binocular dysfunction—particularly vergence impairment and increased near point of convergence (NPC) distance—is frequently reported after concussion/mild TBI and is captured clinically through symptom provocation paradigms such as the Vestibular/Ocular Motor Screening (VOMS). VOMS combines structured ocular tasks with immediate patient-reported symptoms (headache, dizziness, nausea, fogginss) and includes NPC measurement across three trials. Evidence supports VOMS utility for concussion evaluation, while normative NPC cutoffs vary by population and method, motivating distribution-based interpretation. Objective eye-tracking studies demonstrate that disconjugate (*refers to eye movements where the two eyes move independently or in opposite directions, rather than together (conjugate) eye movements* can be detected algorithmically and associate with both concussion and structural TBI.

1. Clinical background: why binocular provocation matters in TBI

Oculomotor and binocular control are distributed across cortical, cerebellar, and brainstem networks; traumatic injury can disrupt these systems, yielding symptoms such as diplopia, headaches with near work, dizziness, and visual intolerance. VOMS was developed to rapidly screen vestibular and ocular motor impairments via symptom provocation and includes convergence (NPC) as a core domain.

2. VOMS as the reference clinical framework

2.1 Structure

VOMS consists of brief assessments across multiple domains and records HDNF symptoms (0–10) at baseline and after each item.