In October 2022, we ran a blog post called “PSSD Patients Needed for Small Fibre Neuropathy Investigation”. It’s worth reading to get some background on the situation before continuing with this post.
We had connected with a neurology department in Sheffield, UK, with the aim of recruiting several patients with post-SSRI sexual dysfunction (PSSD) who could be tested for small fibre neuropathy (SFN) with a skin biopsy. If the investigation was successful, we were going to write up the results for publication in a medical journal.
Since running the blog post, we have been liaising with several PSSD sufferers who contacted us to apply for the testing. Unfortunately, some problems have occurred that may stop the study going ahead.
Trying to persuade GPs to arrange investigations into PSSD can be very challenging, and this adds to an already difficult situation for sufferers. The original plan was for Professor Healy to make the referrals, thereby removing the need to have any interaction with a GP. However, after starting to recruit patients, we were told that GP referrals would be required. This delayed the project, but several patients have now managed to get referred.
We’ve been told that several other people with PSSD attempted to circumvent the process that we had set up, and tried to persuade the neurologist involved to accept them by contacting him directly and pleading their case. This wasn’t helpful and it caused some unnecessary friction in the process. There were limited places available and we wanted to make sure that those taking part were the most suitable and didn’t have anything in their medical history or clinical presentation that could potentially undermine the results. The work being done was ultimately for the benefit of all PSSD sufferers, not just those being referred.
We hoped that the testing would have been done by now, but we’ve now been informed that the neurology department is waiting for permission from the hospital management to accept referrals for patients who don’t fit the standard picture of small fibre neuropathy – in other words the PSSD patients. We were not aware of this, and it may mean that the testing can’t go ahead.
Given the problems with Sheffield, we think that another NHS hospital will have the same restrictions, so there seems little point in switching to a different NHS hospital.
Another idea might be to find somewhere that can carry out the testing privately, but this is likely to be very expensive. Even if we could use money from the PSSD Research Fund, the cost may be prohibitive.
Getting a lot of individual results from different places might not be useful either, as different clinics likely to things slightly differently. Ideally we need everyone to go to the same place.
If you can find anywhere or anyone who might be able to carry out skin biopsies for small fibre neuropathy, please let us know and we’ll try to contact them. We’ll need their email address.
One positive – one negative
Some further news is that we’ve had results from two people with PSSD who recently had a skin biopsy for SFN.
The first case was negative ie. epidermal nerve fibre density was within the normal range for the person’s age. This person’s case is very convincing for PSSD, so it’s difficult to know what this means and how it fits into the overall picture given that so many of the Finnish PSSD group reported abnormal results. Epidermal nerve fibre densities can vary in different people, so it’s difficult to draw any firm conclusions without more data.
The second person had nerve conduction tests. This type of testing was mentioned in the original blog post linked above. It predominantly assesses large nerve fibres which are used in motor function and isn’t really suitable for investigating small fibre neuropathy. However, the neurologist noted that while the motor function results were normal, a sensory abnormality was found. The person is going to be referred for more testing which may include skin biopsy.
We’ll continue to keep you updated, so please stay tuned to the blog.
Additional Note March 10
Another option that may be as good as skin biopsy tests done around the ankle – is Corneal Confocal Microscopy which has been mentioned in RxISK posts before.
Some people have already had CCM tests and these have shown up as positive. Anyone who has a positive test has a small fibre neuropathy.
CCM abnormalities may also have some linkage to the many visual abnormalities that SSRIs and related drugs can cause. These abnormalities often only show after treatment stops – so they overlap with PSSD – see Antidepressants and Vision Problems.
See also Antidepressants Sex and Thermal Thresholds for more about Quantitative Sensory Threshold Testing. CCM and QST are likely as sensitive as SFN biopsies.