Right anterior insula ASL hypoperfusion as a diagnostic biomarker of prodromal and mild dementia with Lewy bodies: preliminary evidence using a Bayesian approach.

Identifying and validating a biomarker with high specificity in early-stage dementia with Lewy bodies (DLB) using a feasible method is crucial to enhance the current suboptimal diagnostic procedure. Previous research revealed abnormalities, including hypoperfusion in the right anterior insular cortex at group level, in prodromal DLB. Exploring hypoperfusion of the right anterior insula, at an individual-level and assessing its relevance as a potential imaging biomarker in early DLB, has, to our knowledge, not been investigated. Our preliminary study aims to assess the feasibility of the technique and to provide a methodological framework for further investigation. We assessed the feasibility and accuracy of the hypoperfusion of the right anterior insula per arterial spin labelling magnetic resonance imaging (ASL-MRI) as a diagnostic biomarker in early DLB and provided rough estimates of its sensitivity and specificity. Defining the region of interest based on previous research, we established the biomarker as the hypoperfusion of the right anterior insula. Discriminative and analytical performances were assessed in comparison to a control group of treatment-resistant depression patients. Bayesian diagnostic reasoning was employed to assess the biomarker diagnostic usability in early DLB in two scenarios: healthy elderly controls and mild cognitive impairment. Additionally, we updated probabilities by integrating data from the Mayo-clinic cognitive fluctuations scale and real-time quaking-induced conversion (RT-QuIC) α-synuclein data. Lastly, a whole-brain perfusion analysis of DLB patients was conducted to identify further brain regions with discriminative abilities. We successfully replicated the right anterior insular hypoperfusion (RAI-Hypo) in all DLB patients at the individual level. The overall sensitivity of the biomarker was 96%, and the specificity was 92%. Bayesian testing revealed the biomarker's highest performance in early-stage DLB with cognitive fluctuations, showcasing a diagnostic potential associated with a high precision and moderate accuracy. In a cognitively non-impaired population, the RAI-Hypo showed a limited usability and lacked in selectivity to qualify as a screening tool. The exploratory whole-brain analysis revealed perfect discriminative capacities in the bilateral anterior insulae and the left inferior parietal lobule. Further studies are needed to confirm our preliminary results. If performance is maintained in subsequent studies and is compared to a more suitable control population, the proposed biomarker may be eventually sufficient to discriminate early-stage DLB from non-DLB.

Images: Sleep-related painful erection with concomitant hypnic headache.

Sleep-related painful erection (SRPE) is a parasomnia defined by the repetition of painful erections during rapid eye movement (REM) sleep. Hypnic headache (HH) is a primary headache occurring exclusively at night, often during REM sleep. We report the observation of a 33-year-old man with simultaneous SRPE and HH. Physical examination was normal. Comprehensive urological and endocrine explorations excluded other organic differential diagnoses. Polysomnography revealed several awakenings in REM, due to SRPE and concurrent HH. Medication by baclofen at bedtime seemed to have resulted in a decrease in SRPE episodes, confirmed by polysomnography, but at the cost of excessive daytime sleepiness, and was discontinued by the patient. Caffeine intake at bedtime was proposed, but the patient was reluctant because he was concerned about worsening insomnia. At 9-month follow-up, the patient had accepted his medical condition and was coping with both SRPE and HH. He felt reassured and wished no "overmedicalization." To our knowledge, the coexistence of both conditions has not yet been reported, yet their frequencies might be underestimated. We hypothesize a common underlying pathophysiology with a possible dysfunction of the vascular control and/or the autonomic nervous system and that could involve the hypothalamus. Somnologists should be aware of SRPE, potentially overlapping with HHs. SRPE should be considered in case of sleep-maintenance insomnia. Patient reassurance seems to be central in the care process of SRPE. CITATION: Moreau A, Monnier L, Medde A, Bourgin P, Ruppert E. Images: sleep-related painful erection with concomitant hypnic headache. J Clin Sleep Med. 2024;20(5):837-839.

Early use of high efficacy therapies in pediatric forms of relapsing-remitting multiple sclerosis: A real-life observational study.

BACKGROUND: Pediatric forms of multiple sclerosis are more active than those in adults. Yet, the effectiveness of different therapeutic approaches is not well studied in this population. Our objective was to compare the effectiveness of the early use of high efficacy therapies (HETs) with the effectiveness of moderate efficacy therapies (METs) in children with MS. METHODS: This observational study included patients diagnosed with pediatric MS, at 4 hospital centers in France, during a 10-year period. METs included: interferon ß-1a, glatiramer acetate, dimethyl fumarate, teriflunomide; HETs included: fingolimod, natalizumab, ocrelizumab, alemtuzumab. The primary endpoint was the occurrence of a new relapse, the secondary endpoint was EDSS worsening. RESULTS: Sixty-four patients were included in the analysis (80% women; mean age 15.5 years, 81% treated with MET) with a median follow-up of 22.5 months. At baseline, 52 patients were on MET (interferon ß-1a, glatiramer acetate, dimethyl fumarate, teriflunomide) and 12 patients were on HET (natalizumab, ocrelizumab). The cumulative probability of being relapse-free at 6.5 years was 23.3% on MET, vs 90.9% on HET (p = 0.013). The cumulative probability of no EDSS worsening did not differ between the 2 groups. CONCLUSION: Patients starting with METs had much higher clinical disease activity than those starting early with HETs. Rapid initiation of more aggressive treatment may allow better disease control; however, the data on EDSS worsening are not conclusive.