Outcome differences between spontaneous and traumatic chronic subdural hematoma: a comparative analysis using modified Nakaguchi CT classification

Abstract

Aims
This study aimed to compare the clinical presentation, radiology, surgical management, and outcomes between spontaneous and traumatic CSDH.


Materials and methods

A prospective cohort of 63 patients with radiological confirmed CSDH was enrolled over six months and categorized by etiology into spontaneous (
n
 = 32) and traumatic (
n
 = 31) groups. It was classified according to a modified Nakaguchi system and later consolidated into three membrane-based categories for clinical relevance. Functional outcomes were assessed using the Glasgow Outcome Scale–Extended (GOS-E), and recurrence was monitored for 4–6 weeks. Statistical analyses included logistic and ordinal regressions, Kruskal-Wallis tests, and repeated-measures ANOVA.



Results

Patients in the spontaneous group had significantly lower odds of presenting with unilateral weakness (OR = 0.200,
p
 = 0.003) and worse post-operative outcomes (OR = 0.242,
p
 = 0.005). Spontaneous cases more often showed separated types; traumatic case, low complexity types. Multinomial regression confirmed etiology as a significant predictor of radiological presentation. No significant association was found between CT type and short-term outcome or recurrence. The presence of neoplastic lesions significantly impacted outcomes in spontaneous cases (
p
 = 0.017), while other comorbidities did not. Surgical approach did not significantly differ by etiology, and recurrence rates remained low in both groups.



Conclusion
CSDH etiology significantly influences clinical and radiological patterns and short term outcomes presentation, CT appearance, and functional outcomes. Radiological subtype and surgical technique did not predict recurrence, suggesting a multifactorial process requiring individualized care.