Imaging and outcomes of fetal adrenal hemorrhage: A systematic review.

OBJECTIVE: To describe prenatal and postnatal imaging findings of fetal adrenal hemorrhage (FAH) and its associated perinatal outcomes, including frequency of postnatal surgical intervention. METHOD: A systematic literature review of seven electronic databases was conducted from inception until January 2022, with 2008 articles identified reporting prenatally identified fetal adrenal masses. Studies with confirmed FAH diagnosis were included. Quality and risk assessment were evaluated. RESULTS: Thirty-five studies, including 102 FAH cases, were analyzed. FAH was commonly described as cystic (28/90, 31%), anechoic (25/90, 28%), or mixed echogenic (14/90, 16%) on ultrasound. Outcome data were available for 65 cases (64%) of FAH: 9% (6/65) resolved prenatally, 35% (23/65) resolved postnatally, 34% (22/65) regressed in size after birth, and 22% (14/65) persisted postnatally. Overall, 25% (16/65) of cases underwent postnatal surgical intervention. Neuroblastoma was suspected in all 16 surgical cases. Only one case (1/16, 6%) confirmed a cystic hematoma with microscopic islets of neuroblastoma in situ on pathology. CONCLUSION: Prenatal diagnosis of FAH is challenging due to the significant heterogeneity of ultrasound findings. Final pathology did not support the need for surgical intervention. Persistent postnatal FAH warrants shared decision making for further management based on the clinical presentation.

Mirror syndrome: a systematic literature review.

OBJECTIVE: This study aimed to review the diagnostic criteria for mirror syndrome and describe its clinical presentation. DATA SOURCES: Databases from PubMed, Scopus, Cochrane Library, ClinicalTrials.gov, and CINAHL were inquired for case series containing ≥2 cases of mirror syndrome from inception to February 2022. STUDY ELIGIBILITY CRITERIA: Studies were included if they reported ≥2 cases of mirror syndrome and included case reports, case series, cohort studies, and case-control studies. STUDY APPRAISAL AND SYNTHESIS METHODS: The studies' quality and risk of bias were independently assessed. Data were tabulated using Microsoft Excel and summarized using narrative review and descriptive statistics. This systematic review was conducted according to the Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement. All eligible references were assessed. Screening of records and data extraction were independently performed, and a third author resolved disagreements. RESULTS: Of 13 citations, 12 studies (n=82) reported diagnostic criteria for mirror syndrome: maternal edema (11/12), fetal hydrops (9/12), placental edema (6/12), placentomegaly (5/12), and preeclampsia (2/12); 12 studies (n=82) described the clinical presentation of mirror syndrome as maternal edema (62.2%), hypoalbuminemia (54.9%), anemia (39.0%), and new-onset hypertension (39.0%); 4 studies (n=36) reported that hemodilution was present in all patients; 8 studies (n=36) reported the etiology of fetal hydrops, with the most common being structural cardiac malformations (19.4%), alpha thalassemia (19.4%), Rh isoimmunization (13.9%), and nonimmune hydrops fetalis (13.9%); and 6 studies (n=47) reported maternal complications, 89.4% of which were major: postpartum hemorrhage (44.7%), hemorrhage requiring blood transfusion (19.1%), intensive care unit admission (12.8%), heart failure (10.6%), pulmonary edema (8.5%), and renal dysfunction (8.5%). In 39 cases, the reported fetal outcomes were stillbirth (66.6%) and neonatal or infant death (25.6%). The overall survival rate among continued pregnancies was 7.7%. CONCLUSION: The diagnostic criteria of mirror syndrome differed considerably among studies. Mirror syndrome clinical presentation overlapped with preeclampsia. Only 4 studies discussed hemodilution. Significant maternal morbidity and fetal mortality were associated with mirror syndrome. Further research is warranted to elucidate the pathogenesis of mirror syndrome to better guide clinicians in identifying and managing the condition.

Correlations between specific patterns of spontaneous activity and stimulation efficiency in degenerated retina.

Retinal prostheses that are currently used to restore vision in patients suffering from retinal degeneration are not adjusted to the changes occurring during the remodeling process of the retina. Recent studies revealed abnormal rhythmic activity in the retina of genetic mouse models of retinitis pigmentosa. Here we describe this abnormal activity also in a pharmacologically-induced (MNU) mouse model of retinal degeneration. To investigate how this abnormal activity affects the excitability of retinal ganglion cells, we recorded the electrical activity from whole mounted retinas of rd10 mice and MNU-treated mice using a microelectrode array system and applied biphasic current pulses of different amplitude and duration to stimulate ganglion cells electrically. We show that the electrical stimulation efficiency is strongly reduced in degenerated retinas, in particular when abnormal activity such as oscillations and rhythmic firing of bursts of action potentials can be observed. Using a prestimulus pulse sequence, we could abolish rhythmic retinal activity. Under these conditions, the stimulation efficiency was enhanced in a few cases but not in the majority of tested cells. Nevertheless, this approach supports the idea that modified stimulation protocols could help to improve the efficiency of retinal prostheses in the future.

Pharmacological analysis of intrinsic neuronal oscillations in rd10 retina.

In the widely used mouse model of retinal degeneration, rd1, the loss of photoreceptors leads to rhythmic electrical activity of around 10-16 Hz in the remaining retinal network. Recent studies suggest that this oscillation is formed within the electrically coupled network of AII amacrine cells and ON-bipolar cells. A second mouse model, rd10, displays a delayed onset and slower progression of degeneration, making this mouse strain a better model for human retinitis pigmentosa. In rd10, oscillations occur at a frequency of 3-7 Hz, raising the question whether oscillations have the same origin in the two mouse models. As rd10 is increasingly being used as a model to develop experimental therapies, it is important to understand the mechanisms underlying the spontaneous rhythmic activity. To study the properties of oscillations in rd10 retina we combined multi electrode recordings with pharmacological manipulation of the retinal network. Oscillations were abolished by blockers for ionotropic glutamate receptors and gap junctions. Frequency and amplitude of oscillations were modulated strongly by blockers of inhibitory receptors and to a lesser extent by blockers of HCN channels. In summary, although we found certain differences in the pharmacological modulation of rhythmic activity in rd10 compared to rd1, the overall pattern looked similar. This suggests that the generation of rhythmic activity may underlie similar mechanisms in rd1 and rd10 retina.