Request for GABA Quantitative Analysis – Desperately Seeking Help After MRS Exam in Georgia (Country)

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I’m reaching out with a humble request for help and guidance. I recently underwent a Magnetic Resonance Spectroscopy (MRS) exam on a Siemens Vida 3T scanner here in Georgia (the country). Unfortunately, the scanner was not equipped with MEGA-PRESS (SVS-EDIT), but the technician was kind enough to adjust the parameters to TE 68ms, TR 2000ms, and a frequency of 1500 Hz - NA was set to 1024. Basal Ganglia was scanned with a single voxel (left and right side at 20x20x20mm). I now have the .rda raw data file, but I’m struggling to find anyone here with the knowledge or capacity to analyze it.

I’ve been suffering from debilitating symptoms for as long as I can remember, and after countless consultations and tests, it’s suspected that a weak GABAergic system might be at the root of my struggles. Genetic markers, as well as a history of symptoms, point to GABA deficiency, and recent bloodwork shows low Taurine levels. I also underwent a previous MRS exam with a TE of 30ms, which revealed normal GLU/CR ratios across multiple brain regions, but the excitotoxicity I’m experiencing remains. My day-to-day life is significantly impacted by what appears to be low GABA activity, and I feel trapped by the limitations of the healthcare system here.

I’m desperately seeking someone who would be willing to perform a quantitative analysis of the data to help me understand what’s going on. I would, of course, be happy to compensate for your time and expertise. Having spent so long without answers, this analysis is a crucial step in finding a path forward, and I would be eternally grateful to anyone who might assist me in this process.

Thank you for taking the time to read this, and I truly hope someone here can offer a lifeline in what has been a very long and difficult journey.

Warm regards,

Timo

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Hi @tminx,

The majority of users on this forum are researchers in medical-related fields, but are not qualified (or permitted) to give any individual medical advice/opinions.

That said, I can comment on the technical aspect. By my understanding, you have regular PRESS data with similar sequence timings to those often used for MEGA-PRESS. However, the crucial element which makes MEGA-PRESS useful is the editing pulse, which allows us to isolate specific metabolites of interest which are otherwise buried under much stronger signals in the same part of the spectrum. Without that, it will not be possible to meaningfully assess GABA from the data.

Even with the best acquisition techniques and highly experienced radiographers, GABA estimates from individual spectra have a fair degree of uncertainty. The techniques are really useful in research contexts where this uncertainty can be averaged out across a number of subjects, but I would be very hesitant to draw any conclusions from a single measurement – even with the appropriate sequence.

There are relatively few contexts where clinically meaningful conclusions can be drawn from individual spectra (traumatic brain injury, hypoxia, certain tumour cases,…), and most of these involve substances which are much easier to measure than GABA.

So, I’m afraid for several reasons this data will not be able to give you an answer in terms of GABA levels. Sorry that this is not the response you were hoping for, and I wish you the best of luck finding a way forward.

Alex.

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