Shape/Volume of the Superior Lateral Ventricle After ECT: New MRI Study

Out on PubMed, from researchers in the Netherlands, is this study:

Shape and volume changes of the superior lateral ventricle after electroconvulsive therapy measured with ultra-high field MRI.

Nuninga JO, Mandl RCW, Siero J, Nieuwdorp W, Heringa SM, Boks MP, Somers M, Sommer IEC.Psychiatry Res Neuroimaging. 2021 Sep 3;317:111384. doi: 10.1016/j.pscychresns.2021.111384. Online ahead of print

The abstract is copied below:The subventricular zone (SVZ) of the lateral ventricles harbors neuronal stem cells in adult mammals. Rodent studies report neurogenic effects in the SVZ of electroconvulsive stimulation. We hypothesize that if this finding translates to depressed patients undergoing electroconvulsive therapy (ECT), this would be reflected in shape changes at the SVZ. Using T1-weighted MR images acquired at ultra-high field strength (7T), the shape and volume of the ventricles were compared from pre to post ECT after 10 ECT sessions (in patients twice weekly) or 5 weeks apart (controls) using linear mixed models with age and gender as covariates. Ventricle shape significantly changed and volume significantly decreased over time in patients for the left ventricle, but not in controls. The decrease in volume of the ventricles was associated to a decrease in depression scores, and an increase in the left dentate gyrus, However, the shape changes of the ventricles were not restricted to the neurogenic niche in the lateral walls of the ventricles, providing no clear evidence for neurogenesis as sole explanation of volume changes in the ventricles after ECT.

Keywords: ECT; Neurogenesis; Neuroplasticity; Shape analysis; Subventricular zone.

The pdf is here.

And from the text:

Given that ECT induces a generalized seizure and that it is associated with widespread changes in the brain, neuroplastic effects are not necessarily limited to the hippocampus. With respect to neurogenesis, the lateral walls of the ventricles (subventricular zone; SVZ) are also capable of generating new cells (Weickert et al., 2000; Weissleder et al., 2016), although it is unclear to what extent this is possible throughout adulthood in humans (Alvarez-Buylla and Garcı́a-Verdugo, 2002; Han-sen et al., 2010; Lim and Alvarez-Buylla, 2016; Qui ̃nones-Hinojosa et al., 2006). To investigate whether ECT stimulates neurogenesis in the SVZ, we analyzed the shape of the ventricles in a group of patients with a depressive disorder undergoing ECT. A small control group was also scanned twice to test whether any changes found were due to scanner drift. In the present study, we explore changes in the volume and shape of the ventricles and hypothesize that if neurogenesis takes place in the SVZ, this would be reflected in a change in the shape of the lateral walls of the ventricle; the location of the SVZ.

We investigated the effects of ECT on the volume and shape of the lateral ventricles. The  main  finding is  that both  the  volume of  the ventricle and its shape significantly change over time within individuals receiving ECT, but not in controls. The volume decrease in both right and left ventricle correlated with the decrease in severity of depression within subjects. The changes in shape did not pertain solely to the areas containing the subventricular zone (SVZ), making neurogenesis as the            sole explanation of volumetric changes in the ventricle unlikely.                                

Here is yet another volumetric (and stereometric?) neuroimaging study with a an interesting finding. Demonstrating the volume decrease in the ventricles is novel, and it is especially significant that it correlates with clinical improvement. The cellular basis of the observed changes remains debated.The study is small (16 patients and 5 controls) and, of course needs to be replicated.

For readers interested in the neurogenesis theory of mechanism of action of ECT, and the ECT neuroimaging literature as a whole, this paper is worth a full and careful read, ~15 minutes.