Bassam Al-Fatly

Charité Universitätsmedizin Berlin | Charité · Department of Neurology with Chair in Experimental Neurology/BNIC

Hi FSL users,

any hint on how to use FSL topup on two phase encoded DTI scan each with 63 directions and 1 b0, the data is actually from PPMI dataset (PD patients) and am trying to correct for susceptibility distortion using topup. I know it can be used for one DTI scan and 2 b0 but have no experience with two scans!

Thanks in advance

Bassam

Surgical lesioning, like thalamotomy, is usually targeted using AC-PC coordinates. Does anyone know of thalamotomy coordinates in MNI space?

What are the causes of the artefact appearing in the second image (attached) before the mep wave?

Before we didn't encounter such artefact (first image).

Some pitfalls which could be related to the condition:

1. We are not grounding our devices (like TMS, 1902 amplifier or 1401 console).

2. Paste used for emg recording appear to break the signal throughout recording procedures or sometimes we are getting flat line when we attach the electrodes to the subject from the beginning. We tried to use more soluble gel like EEG paste, we achieve some recording but the artefacts appear larger and might even hide the mep.

NB. MEP sometimes get distorted by this initial artefacts which is getting bigger and annoying even if we use the original paste. We have changed our location to another building when the problem appeared. The problem of flat line when attaching the electrodes was already there before our location change, and we used to change couples of electrode until we get some reponse which could be unstable during the recording procedure)

Looking forward to hearing some helpful answers!

How we could trigger TMS pulse using CED SIGNAL software after an interval from a tone produced by the computer soundcard or an external speaker, or after giving a visual cue? Do we need a special software? or we can simply make SIGNAL software to produce a sound from soundcard and then trigger the pulse?

I was thinking of recording SEPs in patients with movement disorders. We are using CED signal software in our lab to register MEPs. It has been stated on the software website that it can be used for SEPs recording, however I don't know what are the requirements? are there any specific scripts that we should enter? or it is a matter of simply setting a protocol with electrical stimulation coming from our digitimer stimulator and recording 500-1000 frame of seps from the scalp?

Is there a way of single pulse electrical stimulation through DBS electrodes after they have already attached to the pulse generator? or, the only way is to stimulate through the externalized electrode immediately after surgical operation in the period before the electrode will get attached to the pulse generator? are there any pulse generators capable of doing single pulse? Medtronic ones are able to produce 3Hz stimulation as the lowest stimulation frequency. 

I know this might seem difficult in the sense of how to predict when the subject will start imagination, but: How can I trigger TMS stimulus with the beginning of the process of imagining a movement in order to secure effects on MEP outcome parameters changes? I heard that we can train the subject to imagine the movement when he will hear some kind of sound! When should I apply TMS pulse, at the beginning or during sustained state of the imagined movement?