Hey ClosetCHer,

Good questions...  Long time no see...

For starters, oxygen therapy is only an abortive and not a preventative...  Moreover, the term rebound headache, actually Medication Overuse Headache (MOH), doesn't technically apply to the results of oxygen therapy as the term relates to continued, frequent and increased doses of headache pharmaceuticals, i.e., ergotamine, triptans, opioids and combination medications in particular with analgesics.

The ICHD defined MOH as a secondary headache, with the aim of emphasizing excessive drug intake as the basis of this form of headache.

What you're experiencing with oxygen therapy is an interesting phenomenon where the frequency of CH increases over a period of time if oxygen is the primary escape abortive then decreases.

We ran a pilot study of oxygen therapy at flow rates that support hyperventilation in 2007 and 2008 with seven CHers from here at CH.com.  They collected abort times and pain levels for every abort for a period of 8 weeks each. 

All seven had a green light from their PCP or neurologist to participate.  In all, these seven participants collected abort data on 366 CH aborts with this method of oxygen therapy.

Many of you may have seen one of my posts with the primary graphic that depicts the results of this pilot study illustrated below.

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

What many of you may not have seen was the change in CH frequency over the 8-week period.

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or

All seven pilot study participants experienced a similar response pattern but participant #4's response was the most exaggerated.  As you can see the weekly frequency of his CH had doubled by the end of the second week using this method of oxygen therapy and tripled by the end of the 4th week where it started to drop.

What is also interesting was the time to abort and maximum pain level at each abort dropped steadily throughout the 8-week period.

I shared this data with the Head of pulmonology at Swedish Medical Center here in Seattle.  He checked with a cardiologist and came back with a possible explanation for the shape of this curve... 

Vascular Toning - The initial increase in CH frequency may be due to the smooth muscles lining arteries and capillaries adjusting to the frequent exercise of vascular constriction and dilation associated with the use of this method of oxygen therapy.  Then, after continued use, these muscles become stronger, i.e., toned up... so constrict faster and stay constricted longer after end of therapy.

Finally, I'd suggest getting back on the anti-inflammatory regimen if you haven't already done so.  I'd also stay on it year round.  This saves a lot of pain and the health benefits are too good to pass up.

You were one of the first CHers here at CH.com to start this regimen in early 2011 and I recall several PMs and posts discussing what to do next.

There have been a few changes to this regimen since then.  The first is a 3-month course of vitamin B 50.  Take a tablet a day for 3 months.   After that, the Kirkland brand 50+ Mature Multi has sufficient amounts of the seven B vitamins to prevent any deficiencies.

Benadryl, (Diphenhydramine) has proven effective in jump-starting this regimen if there's been no favorable response after 10 days of use.  An allergic reaction will trigger a flood of histamine that can and will make nearly every CH preventative ineffective.

Dypenhydramine is a first-generation antihistamine that crosses the blood brain barrier to block H1 histamine receptors at the genetic level. This helps prevent a reaction triggered by histamine that results in a flood of calcitonin gene-related peptide (CGRP) that has been found elevated during the pain phase of cluster and migraine headaches.  It triggers neurogenic inflammation and the pain we experience as CHers.

A week to 10 days of Benadryl (Diphenhydramine) taking 25 mg in the am and 25 mg in the pm.  Be careful not to drive while taking Benadryl as it will make you drowsy.  If you need to drive during the day, taking 50 mg in the evening is just as effective.

Trauma and surgery can also trigger inflammation and an immune response that consumes vitamin D3 and its metabolites. 

Viral and bacterial infections also trigger an immune response.  In either of the above cases, I take a 50,000 IU vitamin D3 loading dose for a couple days then double my maintenance dose for at least two weeks.

Take care and please keep us posted.

V/R, Batch