Shifted phase of EEG cross-frequency coupling in individuals with Phelan-McDermid syndrome.

BACKGROUND: Phelan-McDermid Syndrome (PMS) is a rare condition caused by deletion or mutation of the SHANK3 gene. Individuals with PMS frequently present with intellectual disability, autism spectrum disorder, and other neurodevelopmental challenges. Electroencephalography (EEG) can provide a window into network-level function in PMS. METHODS: Here, we analyze EEG data collected across multiple sites in individuals with PMS (n = 26) and typically developing individuals (n = 15). We quantify oscillatory power, alpha-gamma phase-amplitude coupling strength, and phase bias, a measure of the phase of cross frequency coupling thought to reflect the balance of feedforward (bottom-up) and feedback (top-down) activity. RESULTS: We find individuals with PMS display increased alpha-gamma phase bias (U = 3.841, p < 0.0005), predominantly over posterior electrodes. Most individuals with PMS demonstrate positive overall phase bias while most typically developing individuals demonstrate negative overall phase bias. Among individuals with PMS, strength of alpha-gamma phase-amplitude coupling was associated with Sameness, Ritualistic, and Compulsive behaviors as measured by the Repetitive Behavior Scales-Revised (Beta = 0.545, p = 0.011). CONCLUSIONS: Increased phase bias suggests potential circuit-level mechanisms underlying phenotype in PMS, offering opportunities for back-translation of findings into animal models and targeting in clinical trials.

Development of Neural Response to Novel Sounds in Fragile X Syndrome: Potential Biomarkers.

Auditory processing abnormalities in fragile X syndrome (FXS) may contribute to difficulties with language development, pattern identification, and contextual updating. Participants with FXS (N = 41) and controls (N = 27) underwent auditory event-related potentials during presentation of an oddball paradigm. Data was adequate for analysis for 33 participants with FXS and 27 controls (age 4-51 y, 13 females [FXS]; 4-54 y, 11 females [control]). Participants with FXS showed larger N1 and P2 amplitudes, abnormal lack of modulation of P1 and P2 amplitudes and P2 latency in response to oddball stimuli ) relative to controls: Females with FXS were more similar to controls. Participants with FXS showed a marginal speeding of the P2 latency, suggesting potentiation to oddball stimuli rather than habituation. Participants with FXS showed a heightened N1 habituation effect compared to controls. Gamma power was significantly higher for participants with FXS. Groups did not differ on mismatch negativity. Both controls and participants with FXS showed similar developmental trajectories in P1 and N1 amplitude, P2 latency, and gamma power, but not for P2 amplitude. One month retest analyses performed in 14 participants suggest strong test-retest reliability for most measures. Individuals with FXS show previously demonstrated increased response amplitude and high frequency neural activity. Despite an overall normal developmental trajectory for most measures, individuals with FXS show age-independent but gender-dependent decreases in complex processing of novel stimuli. Many markers show strong retest reliability even in children and thus are potential biomarkers for clinical trials in FXS.

Correlation of Clinicohaematological Parameters in Paediatric Dengue: A Retrospective Study.

Dengue is one of the arthropod-borne (arbo) viral diseases transmitted by female mosquito Aedes aegypti. Dengue fever has a wide spectrum of clinical presentation ranging from flu-like illness to severe complicated stage of dengue hemorrhagic fever leading to mortality. This was a retrospective study conducted in a tertiary care hospital in Coastal Karnataka, South India, to know the correlation between the clinical presentation and haematological parameters in the paediatric cases presented with dengue symptoms. A total of 163 paediatric cases who presented fever and dengue-like illness were included in the study. Of which, 69 were confirmed dengue patients. Critical analysis showed that there was a significant difference in the haematological parameters like total leucocyte count, percent differential leucocyte count, and platelets count, in the erythrocyte sedimentation rate (P < 0.05 to 0.0001). Additionally, when compared to nondengue patients, even the liver function and renal function parameters were significantly deranged (P < 0.05 to 0.0001). Stratification based on NS1, IgG, and IgM showed significant alterations in the haematological, hepatic, and renal parameters. With respect to the treatment a small percentage of patients, that is, 8% (4 patients), required platelet transfusion as their counts went below 20,000/µL. Two patients succumbed to their illness while three required ICU stay.