Migraine is commonly comorbid with insomnia; both disorders are linked to functional disturbance of the default mode network (DMN). Evidence suggests that DMN could be segregated into multiple subnetworks with specific roles that underline different cognitive processes. However, the relative contributions of DMN subnetworks in the comorbidity of migraine and insomnia remain largely unknown. This study sought to identify altered functional connectivity (FC) profiles of DMN subnetworks in the comorbidity of migraine and insomnia. Direct group comparisons with healthy controls, followed by conjunction analyses, were used to identify shared FC alterations of DMN subnetworks. The shared FC changes of the DMN subnetworks in the migraine and insomnia groups were identified in the dorsomedial prefrontal and posteromedial cortex subnetworks. These shared FC changes were primarily associated with motor and somatosensory systems, and consistently found in patients with comorbid migraine and insomnia. Additionally, the magnitude of FC between the posteromedial cortex and postcentral gyrus correlated with insomnia duration in patients with comorbid migraine and insomnia. Our findings point to specific FC alterations of the DMN subnetwork in migraine and insomnia. The shared patterns of FC disturbance may be associated with the underlying mechanisms of the comorbidity of the two disorders.

Purpose Permanent nerve damage after corticosteroid injection has been suggested when symptoms of median nerve injury (MNI) are irreversible. We assess the outcomes of MNI and their association with ultrasonography (US)-guided hydrodissection and the following corticosteroid injection for symptomatic carpal tunnel syndrome (CTS). Methods US-guided hydrodissection and the following corticosteroid injections were administered to 126 CTS patients. Occurrence of MNI, clinical data, and post-hydrodissection findings were evaluated. Post-hydrodissection findings included vascular injury during hydrodissection, altered echogenicity, reduced flattening ratio, and increased cross-sectional area of the MN at the inlet of the carpal tunnel (MN-CSA-Inlet) on ultrasonography after hydrodissection. The relevance of MNI with respect to these clinical data and findings was determined. The outcome was rated using Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores. Results Nine patients suffered MNI (incidence, 7.1 %) but improved significantly at follow-up. Clinical data and vascular injury during hydrodissection, altered echogenicity, and reduced flattening ratio after hydrodissection were unrelated to prolonged transient MNI (p > 0.05). MNI was significantly associated with increased CSA (p = 0.005). A CSA increase > 2 mm² after hydrodissection yielded the greatest performance (0.979) for MNI in the receiver operating characteristic analysis. Decreases in BCTQ scores after injection did not differ significantly between groups with and without MNI (p > 0.05). Conclusion MNI during hydrodissection may be reversible. MNI is indicated by an increase in MN-CSA-inlet immediately after hydrodissection. Ziel Eine permanente Nervenschädigung nach Kortikosteroid-Injektion wird angenommen, wenn die Symptome der N.-medianus-Schädigung (MNI) irreversibel sind. Wir beurteilten den Outcome der MNI und dessen Zusammenhang mit der ultraschallgesteuerten Hydrodissektion (US) und anschließenden Kortikosteroid-Injektion bei symptomatischem Karpaltunnelsyndrom (CTS). Methoden Bei 126 CTS-Patienten wurde eine US-gestützte Hydrodissektion mit darauffolgender Kortikosteroid-Injektion durchgeführt. Das Auftreten von MNI, die klinischen Daten und die Befunde nach der Hydrodissektion wurden ausgewertet. Zu den Post-Hydrodissektionsbefunden gehörten eine Gefäßverletzung während der Hydrodissektion, eine veränderte Echogenität, ein verringerter Abflachungsquotient (flattening ratio) und eine Zunahme der Nervenquerschnittsfläche am Eingang des Karpaltunnels (MN-CSA-Inlet) in der Sonografie nach Hydrodissektion. Die Bedeutung der MNI in Bezug auf diese klinischen Daten und Befunde wurde ermittelt. Der Outcome wurde mittels „Boston-Carpal-Tunnel-Syndrome-Questionnaire“ (BCTQ) beurteilt. Ergebnisse 9 Patienten litten an MNI (Inzidenz 7,1 %), zeigten jedoch bei der Nachuntersuchung eine signifikante Verbesserung. Die klinischen Daten und die Gefäßverletzung während der Hydrodissektion, die veränderte Echogenität und der verringerte Abflachungsquotient nach der Hydrodissektion standen nicht in Zusammenhang mit einer länger anhaltenden transienten MNI (p > 0,05). MNI war signifikant mit zunehmender CSA assoziiert (p = 0,005). Eine CSA-Zunahme > 2mm² nach Hydrodissektion erbrachte in der ROC-Analyse die beste diagnostische Leistungsfähigkeit (0,979) für MNI. Der Abfall der BCTQ-Scores nach der Injektion unterschied sich nicht signifikant zwischen den Gruppen mit und ohne MNI (p > 0,05). Schlussfolgerung Die MNI während der Hydrodissektion ist möglicherweise reversibel. MNI wird durch eine Zunahme des MN-CSA-Inlets direkt nach der Hydrodissektion angezeigt. Received: 19 September 2018 Accepted: 23 February 2020 Publication Date: 30 June 2020 (online) © Georg Thieme Verlag KG Stuttgart · New York

Background and Objectives: Although the ultrasound-guided technique is used in caudal epidural injections, severe complications can happen if ultrasound cannot identify the occurrence of intravascular injection. To determine intraepidural and intravascular injection during caudal epidural injections, we used power Doppler ultrasonography (PDU) when injecting medications into the epidural space. Materials and Methods: This is a retrospective study that enrolled a total of 277 patients with refractory low back pain or degenerative disc from January 2019 to December 2019. The injectate flow of caudal epidural injections was examined with the assistance of PDU and confirmed by fluoroscopy. Four flow patterns were identified by PDU in our study: the “Earthworm sign,” the “Patch sign,” the ”Tubular sign” and the “Absent flow sign.” The accuracy of PDU in identifying intraepidural and intravascular injections was determined by fluoroscopy images recorded during each injection. Results: We evaluated 277 patients (mean age, 68.6 ± 13.2 years; 106 men). The “Patch sign” showed a sensitivity of 88.76% and a specificity of 80% in predicting epidural injection without intravascular injection. The “Earthworm sign” demonstrated a sensitivity of 70% and a specificity of 100% in detecting intravascular injection. The “Tubular sign” showed a specificity of 100% and a sensitivity of 9.4% in predicting successful epidural injection. The absence of a flow signal showed a sensitivity of 1.87% and a specificity of 90% in predicting successful epidural injection. Conclusions: Ultrasound-guided caudal epidural injection can accurately determine intraepidural and intravascular injections with the assistance of PDU and is thus a good alternative technique to fluoroscopy-guided caudal epidural injection.