P4‐140: Obsessive Compulsive Symptoms before Frontotemporal Dementia: A Review of Imaging Case Series
Bibliographic record
Abstract
Evidence shows that compared to healthy controls, obsessive compulsive disorder (OCD) patients have frontal brain hyperactivity and regional (white and grey matter) volume differences but not focal atrophy. Also, obsessive compulsive symptoms (OCs) occasionally precede (up to 27 years) the clinical diagnosis of Frontotemporal Dementia (FTD). This relationship may affect brain morphology and functionality. Understanding of the possible imaging differences may improve differential diagnosis. To examine the structural (MRI, CT) and functional (PET, SPECT)] imaging of case-reports currently published on manifestation of OCs prior to FTD. We hypothesis that these cases have a different neuroanatomical substrate in comparison to OCD alone, as presented in the literature. Individual-patient data were extracted from case-reports after systematic searches on PubMed (N=29) and EMBASE (N=84). Inclusion criteria consisted of cases OCs or OCD prior to clinical diagnosis of FTD, with imaging data. Twenty cases of OCD and OC prior to diagnosis of FTD that reported data on structural and/or on functional imaging were included in our analysis. Atrophy via MRI/CT was frequently reported in frontal lobe [FL: 16 cases (80%)], temporal lobe [TL: 14 cases (70%)], parietal lobe [PL: 2 cases (10%)], caudate nuclei [2 cases (10%)], and insular/amygdala [1 case]. These cases of OC/OCD prior to FTD predominantly reported symmetric presentation, 7 of the TL (50%), and 11 of the FL (69%) cases. The most common PET/SPECT observations were, 7 cases of TL hypometabolism (HM), 3 cases of TL hypoperfusion (HP), 7 cases of FL-HM, 6 cases of FL-HP, 2 cases of PL-HM, 1 case of occipital lobe-HM, and 1 caudate nuclei-HM. The lateralization presentation for these HM and HP were sporadic. In contrast to what is reported in the neuroimaging literature on OCD alone, our findings from the case-series of patients with OCs/OCD prior to FTD show abnormal brain imaging in terms of atrophy and hypo-function, with heterogeneous distribution and lateralization.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.010 | 0.011 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".