"brain fog" studies part 4

G and M have already provided great information on this topic, but I will add my 2 cents.  My reading of this literature is that in treatment naive patients, there is a decrease in cognitive efficiency over the course of IFN therapy for most patients (see Kraus et al 2005 for one of the better studies looking at this).  Whether this decrease results in clinically significant cognitive impairment has not been well studied and whether the deficits persist for a certain percentage of patients post-treatment (as in the case of your patient) is not known.  As Geoffery pointed out, however, your patient's case is confounded in that respect since he is still HCV positive and about 1/3 of HCV patients exhibit mild cognitive deficits (see Huckans et al., 2009 JINS for a really nice recent study on this topic).  The only "contradictory" data I have seen involves patients who are being re-treated - aka treatment non-responders - who do not seem to show a significant decrease over the course of re-treatment (Fontana et al., 2007).  It is possible these patients have already experienced cognitive effects of treatment during their first round and are not susceptible to further declines during re-treatment.  There is also a selection bias in these groups since these are the patients who usually were able to tolerate treatment well enough the first time to feel brave enough to undergo it again.  It is not an easy course of treatment.

We completed a recent review of this topic (Perry W et al., 2008) that talks about possible mechanisms.  The one my group in San Antonio has been studying is the effect of chronic immune activation - specifically cytokines.  Below is the abstract from our recently published article on this topic.

Hope this has been helpful,
Robin Hilsabeck

Cognitive efficiency is associated with endogenous cytokine levels in patients with chronic hepatitis C, Journal of Neuroimmunology 221 (2010) 53-61.

Robin C. Hilsabeck, Gregory M. Anstead, Amy L. Webb, Anastasio Hoyumpa, Paul Ingmundson,
Steve Holliday, Qiong Zhang, Angela M. Casas, Marci Jovel, Stephen L. Stern

The etiology of cognitive dysfunction in chronic hepatitis C (CHC) infection is unknown. Among the
possibilities is cytokine activation, which has been associated with cognitive dysfunction in other chronic
conditions. The purpose of this study was to investigate the relationship between endogenous IFN-α, IL-6,
and TNF-α and cognitive functioning in CHC patients. Seventy-eight veterans with CHC underwent cognitive
testing and measurement of serum cytokines. In patients with detectable IFN-α, higher levels of IL-6 and
TNF-α were related to poorer cognitive functioning. Findings suggest CHC patients with immune responses
characterized by elevated IFN-α may be at risk for cognitive difficulties.

[Marcia2202]

Thanks so much for posting this. I have just spend two mornings in a row at the hospital, because of post interferon cognitive, concentration and memory problems. I always feel like I am in some kind of a haze. I finished a 32 week treatment 1 year ago and am SVR.

The funny thing is that I passed their test with flying colors. I was told that I was very much above average, even though the tests were conducted in Danish, which is definitely not my 1st language. So far they could not find anything 'wrong' with me. I still have to do a CT-scan, but they doubt they will find something on it.

I was told that they have many patients (post chemo and post depression), who have the same symptoms and they cannot find any anomalies. She suggested that the technology to measure neural functions for this does not exist, even though one might possibly be able to in 10 or 20 years.

So what can one do to get back on track? Healthy diet, adequate supplements, exercise. Exercise seems to be an important factor to boost overall brain function. Brain exercises are also good, but they only train in the certain areas one trains.

I asked about lymph drainage and was told that whatever helps you to be better physically, will most probably help your brain too.  I had told her about an episode some years ago where I had quick silver poisoning from taking out too many fillings in a very short period of time. I was going around with 'brain fog' for several weeks, had some lymph drainage treatments to flush out the toxins and the fog went away.

So now I am planning on trying that again, who knows if it will help some.