Hi FS experts,

I was wondering if someone could help me get the following issue resolved.

Thanks.

---------- Forwarded message ---------
From: Martin Juneja <mj70481@gmail.com>
Date: Fri, Dec 8, 2023 at 11:03 AM
Subject: Case-controls study !
To: Freesurfer support list <freesurfer@nmr.mgh.harvard.edu>

Hello FreeSurfer experts,

In my case-control study, I have a dataset of 5 healthy controls (HCs) and one patient (PAT). I was wondering if there is any way to perform GLM for PAT > HCs on brain morphometry data.

When I tried to follow instructions from here: MailScanner has detected a possible fraud attempt from "secure-web.cisco.com" claiming to be https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/GroupAnalysis, the mri_glm fit command gives me the following error:

Class Size and Means of each Continuous Variable

1 HC 5 24.2000 0.6000

2 Tumor 1 50.0000 1.0000

ERROR: Class Tumor has 1 members. With 2 variables and using DODS, you need at least 3 members

It seems at-least three subjects are required in the Tumor category - because I have age and sex covariates in my fsgd file.

I was wondering if there is any way to still perform the above GLM analysis or any other alternatives available to compare HCs vs one PAT.

Thanks!