Cortical spreading depolarization (CSD) is recognized as a cause of transient neurological symptoms (TNS) in various clinical entities. Although scientific literature has been flourishing in the field of CSD, it remains an underrecognized pathophysiology in clinical practice. The literature evoking CSD in relation to subdural hematoma (SDH) is particularly scarce. Patients with SDH frequently suffer from TNS, most being attributed to seizures despite an atypical semiology, evolution, and therapeutic response. Recent literature has suggested that a significant proportion of those patients’ TNS represent the clinical manifestations of underlying CSD. Recently, the term Non-Epileptical Stereoytpical Intermittent Symptoms (NESIS) has been proposed to describe a subgroup of patients presenting with TNS in the context of SDH. Indirect evidence and recent research suggest that the pathophysiology of NESIS could represent the clinical manifestation of CSD. This review should provide a concise yet thorough review of the current state of literature behind the pathophysiology of CSD with a particular focus on recent research and knowledge regarding the presence of CSD in the context of subdural hematoma. Although many questions remain in the evolution of knowledge in this field would likely have significant diagnostic, therapeutic, and prognostic implications.

Background: Current opinions regarding the use of dexamethasone in the treatment of chronic subdural hematomas (CSDH) are only based on observational studies. Moreover, the use of corticosteroids in asymptomatic or minimally symptomatic patient with this condition remains controversial. Here, we present data from a prospective randomized pilot study of CSDH patients treated with dexamethasone or placebo. Methods: Twenty patients with imaging-confirmed CSDH were recruited from a single center and randomized to receive dexamethasone (12 mg/day for 3 weeks followed by tapering) or placebo as a conservative treatment. Patients were followed for 6 months and the rate of success of conservative treatment with dexamethasone versus placebo was measured. Parameters such as hematoma thickness and clinical changes were also compared before and after treatment with chi-square tests. Adverse events and complications were documented. Results: During the 6-month follow-up, one of ten patients treated with corticosteroids had to undergo surgical drainage and three of ten patients were treated surgically after placebo treatment. At the end of the study, all remaining patients had complete radiological resolution. No significant differences were observed in terms of hematoma thickness profile and impression of change; however, patients experienced more severe side effects when treated with steroids as compared with placebo. Dexamethasone contributed to many serious adverse events. Conclusions: Given the small sample size, these preliminary results have not shown a clear beneficial effect of dexamethasone against placebo in our patients. However, the number of secondary effects reported was much greater for corticosteroids, and dexamethasone treatment was responsible for significant complications.

Background: Recurrence of chronic subdural haematomas (CSDHs) after surgical drainage is a significant problem with rates up to 20%. This study focuses on determining factors predictive of haematoma recurrence and presents a scoring system stratifying recurrence risk for individual patients. Methods: Between the years 2005 and 2009, 331 consecutive patients with CSDHs treated with surgery were included in this study. Univariate and multivariate analyses were performed searching for risk factors of increased post-operative haematoma volume and haematoma recurrence requiring repeat drainage. Results: We found a 12% reoperation rate. CSDH septation (seen on computed tomogram scan) was found to be an independent risk factor for recurrence requiring reoperation (p=0.04). Larger post-operative subdural haematoma volume was also significantly associated with requiring a second drainage procedure (p<0.001). Independent risk factors of larger post-operative haematoma volume included septations within a CSDH (p<0.01), increased pre-operative haematoma volume (p<0.01), and a greater amount of parenchymal atrophy (p=0.04). A simple scoring system for quantifying recurrence risk was created and validated based on patient age (< or ≥80 years), haematoma volume (< or ≥160cc), and presence of septations within the subdural collection (yes or no). Conclusion: Septations within CSDHs are associated with larger post-operative residual haematoma collections requiring repeat drainage. When septations are clearly visible within a CSDH, craniotomy might be more suitable as a primary procedure as it allows greater access to a septated subdural collection. Our proposed scoring system combining haematoma volume, age, and presence of septations might be useful in identifying patients at higher risk for recurrence.