VNG Report Interpretation — K L Makhijani, Male, 85 yrs | 17-Apr-2026

1. SACCADES

• Horizontal saccades — velocity and precision are normal. Latency of ~349 ms is slightly prolonged (normal <250–280 ms), which is common in elderly individuals.
• Vertical saccades — markedly reduced velocity (especially right eye at 47.8 °/s; normal >150 °/s) and very poor precision (21%). This is abnormal and suggests possible central involvement (brainstem/cerebellar pathways), though age-related slowing of vertical saccades must also be considered in an 85-year-old.

2. SMOOTH PURSUIT

• Gains below 0.7–0.8 are considered reduced. Most values here are below normal, indicating bilateral impairment of smooth pursuit.
• The left eye shows particularly poor pursuit (rightward: 0.45, upward: 0.29), which may reflect asymmetric gaze control.
• Reduced smooth pursuit is a non-localizing finding in the elderly — it can be age-related, or point to central (cerebellar/cortical) pathology when significantly asymmetric or associated with other abnormalities.

3. OPTOKINETIC (OKN) TEST

• Left-to-right OKN gain is normal (~0.73–0.74).
• Right-to-left OKN gain is reduced (~0.47–0.52), suggesting directional asymmetry.
• Vertical OKN (top-to-bottom, bottom-to-top) is severely deficient or absent — the bottom-to-top direction shows no measurable response. This vertical OKN asymmetry/absence is a marker of central (brainstem/cerebellar) dysfunction.
• An OKN asymmetry (better in one direction) with intact fixation suppression would further support a peripheral localization, but vertical OKN loss points more centrally.

4. SPONTANEOUS NYSTAGMUS (in Light & Dark)

• No spontaneous nystagmus recorded in either light or dark conditions.
• This is a normal finding and argues against an active unilateral peripheral vestibular lesion at the time of testing.

5. GAZE TEST (Centre, Left, Right, Up, Down)

• All gaze positions: no nystagmus measured (all values show "–").
• Normal finding — no gaze-evoked nystagmus in any direction, making direction-changing gaze nystagmus (a central sign) absent.

6. POSITIONAL TESTING

Dix-Hallpike — Right

• Sit-head-right, supine head ext. right, return to sit: no nystagmus — negative right Dix-Hallpike.

Dix-Hallpike — Left ⚠️

• Pure geotropic/ageotropic horizontal nystagmus → suggests horizontal canal BPPV (HC-BPPV)
• Mixed horizontal + vertical nystagmus → raises concern for posterior canal BPPV or central positional nystagmus
• The nystagmus here has components in both planes, warranting careful clinical correlation.

McClure-Pagnini (Supine Roll) Test

Head Position Tests (Yaw/Pitch/Roll)

OVERALL IMPRESSION

1. Positional nystagmus consistent with BPPV — the left posterior canal and/or right horizontal canal are the most likely affected structures based on the Dix-Hallpike and McClure-Pagnini patterns.
2. Central oculomotor signs (markedly abnormal vertical saccades, reduced smooth pursuit, absent vertical OKN) — these require correlation with clinical examination and neuroimaging (MRI brain/posterior fossa), especially given the patient's age of 85.
3. No caloric test results are included in this report — caloric data would be essential to evaluate unilateral peripheral weakness and complete the VNG interpretation.

• Bithermal caloric testing (if not performed) to assess canal paresis
• Clinical bedside Dix-Hallpike with observation for torsional nystagmus character (latency, fatigability, direction) to differentiate posterior canal BPPV from central positional vertigo
• MRI brain with attention to posterior fossa / cerebellum, given the central oculomotor findings in an 85-year-old
• Canalith repositioning maneuver (Epley for posterior canal, or Barbecue roll for horizontal canal BPPV) if BPPV is clinically confirmed

Sit-to-Stand Dizziness — Clinical Significance

What is happening physiologically?

"Such persons, on rising abruptly from a recumbent or sitting position, experience a swaying type of dizziness, dimming of vision, and spots before the eyes that last for several seconds. The patient is forced to stand still and steady himself by holding onto a nearby object." — Adams and Victor's Principles of Neurology

Important: This symptom is NOT captured by VNG

Causes to Consider in This 85-Year-Old

What Should Be Done

1. Lying-to-standing BP and HR measurement (orthostatic vitals) — measure at 1 and 3 minutes after standing. This is the single most important next step.
2. Full medication review — identify and taper/stop offending drugs if safe to do so.
3. Hydration assessment — check for dehydration.
4. Cardiac auscultation — rule out aortic stenosis (common in elderly with exertional/positional dizziness).

• ECG (arrhythmia, conduction disease)
• Blood glucose (hypoglycemia)
• CBC, electrolytes, renal function, TSH
• Echocardiogram if cardiac cause suspected

• Non-pharmacological first: adequate hydration, compression stockings, slow deliberate rising, head-of-bed elevation at night, small frequent meals
• Review and reduce antihypertensives, diuretics, or other contributing drugs
• Pharmacological options (if refractory): fludrocortisone or midodrine — use cautiously in elderly

Putting It All Together