The VA Acknowledged a Strong Link Between Tinnitus and Sleep Apnea — But Wrongly Dismissed It

In this case, the Board of Veterans’ Appeals (BVA) conceded that there’s a strong correlation between the veteran’s tinnitus and his obstructive sleep apnea (OSA)—but denied the claim by arguing there’s no causation. That decision fails to recognize how modern science, law, and VA precedent treat the connection between correlation and causation.

Under the Law, Veterans Only Need to Show a Medical Link—Not Prove Absolute Cause

According to 38 C.F.R. § 3.310, a veteran is entitled to service connection for a secondary condition if it is either:

1. Caused by a service-connected disability, or
2. Aggravated (made worse) by it.

In Wallin v. West (1998), the Court clarified what’s required to win a secondary service connection claim:

• A current diagnosis (e.g., OSA)
• A service-connected disability (e.g., tinnitus)
• A medical link (nexus) between the two

Once that medical link is shown, the burden shifts to the VA to explain why it isn’t enough.

Let’s be clear: Merriam-Webster defines nexus as “a causal link.” The veteran doesn’t need to show the only cause—just a contributing link backed by medical evidence.

Medical Articles and Expert Opinions Can Prove That Link

In Sacks v. West, the Court said that medical treatises, especially when combined with expert opinions, can establish causation—as long as they provide objective, peer-reviewed support. And even without an accompanying medical opinion, published studies can still prove a causal link when they show a “generic relationship with a degree of certainty.”

Here, the veteran did provide both:

• Multiple peer-reviewed studies
• An Independent Medical Opinion (IMO) by a qualified doctor
• Clear evidence showing a strong connection between tinnitus and sleep apnea, especially in the veteran population

These meet the Court’s standards from both Wallin and Sacks.

Scientific Evidence Treats Strong Association as Evidence of Causation

The VA examiner acknowledged a strong association between tinnitus and sleep apnea—but dismissed it, stating “association is not causation.” That’s scientifically inaccurate.

In fact, association is often the starting point for proving causation—especially in public health and epidemiology. The U.S. Surgeon General uses a well-established framework for determining when an association becomes evidence of cause. The book Chance Encounters outlines the Surgeon General’s criteria:

1. Strength of association — large differences between groups
2. Strong research design
3. Timing — the cause happens before the effect
4. Consistency across studies
5. Biological plausibility — a mechanism explains how the cause leads to the effect
6. Coherence with other known facts

The veteran’s studies meet all these:

• The research is VA-authored, reducing bias claims
• The studies involved millions of veterans, with sound control groups
• The association between tinnitus and sleep apnea is statistically significant
• The studies were published in high-impact peer-reviewed journals
• Tinnitus predates sleep apnea in the timeline
• More exposure (e.g., more deployments) increases risk of OSA
• The data is consistent across multiple locations and studies
• The biological mechanism is clear: tinnitus disrupts REM sleep, and disrupted REM is known to contribute to OSA

The Board Must Treat This Link the Same Way It Treats Obesity

It’s important to note: the VA regularly accepts obesity as a cause of OSA based only on statistical association. If that standard is good enough for obesity, it must also apply to tinnitus—especially since tinnitus is more prevalent and more strongly linked to OSA in the veteran population.

Yet the Board failed to explain why it treated tinnitus differently. If science and law say strong associations can equal causation, and the evidence here meets all the scientific and legal standards, then the nexus is sufficient.

Legal Precedents Support This Argument

• Tobin v. Derwinski (1991): Even if a condition (like arthritis) wasn’t caused by service, it is still compensable if service-connected conditions made it worse.
• Allen v. Brown (1995): Any increase in severity due to a service-connected condition qualifies for compensation—even if that condition didn’t cause the problem in the first place.

This means that if tinnitus aggravated the veteran’s sleep apnea even slightly, the veteran is entitled to compensation.

Conclusion: The VA Is Holding the Veteran to an Improper Standard

The veteran:

• Provided clear, peer-reviewed scientific studies
• Obtained a credible medical opinion
• Met the legal standards for secondary service connection
• Showed a strong, plausible, and well-supported connection between tinnitus and sleep apnea

The VA cannot claim that association alone is enough for obesity but not enough for tinnitus—especially when the science behind tinnitus’s role is equally (if not more) compelling in veterans.

At a minimum, this case merits further medical review and a reconsideration under the correct legal and scientific standards. The veteran has met his burden under § 3.310, Wallin, and Allen, and is entitled to the benefit of the doubt.