Subdural Tension on the Brain in Patients with Chronic Subdural Hematoma Is Related to Hemiparesis but Not to Headache or Recurrence.
BACKGROUND
Hemiparesis is a major symptom of chronic subdural hematoma (CSDH). Its severity does not always correlate with hematoma size. The authors analyzed hematoma thickness, pressure, and tension to clarify the mechanism of hemiparesis in CSDH patients.


METHODS
A burr-hole surgery was performed on 124 CSDHs in 102 patients. Hematoma thickness and midline shift were measured by computed tomography, and hematoma pressure was measured in surgery. According to Laplace law, tension was calculated as follows: (half the hematoma thickness × hematoma pressure)/2. Student t test and Pearson correlation coefficient (r) were applied in statistical analysis of findings.


RESULTS
Motor weakness was identified in 76.5% of our cases. Tension was strongly related to hemiparesis (r = -0.747, P < 0.01), whereas hematoma thickness (r = -0.458, P < 0.01) and pressure (r = -0.596, P < 0.01) were moderately correlated. Mean age of 14 patients (13.7%) with headache was much younger than those without headache (P < 0.01). Stronger midline shift (P < 0.01) and greater ratio of midline shift to hematoma thickness (P < 0.01) were statistically correlated with headache. Recurrence was recognized in 8 patients (7.8%), and stronger midline shift (P < 0.05) and greater ratio of midline shift to hematoma thickness (P < 0.05) were statistically associated with recurrence.


CONCLUSIONS
Tension is the most influencing factor to hemiparesis in CSDH patients. This study also elucidates the mechanism for quick recovery from hemiparesis after surgery in that tension on the motor cortex is decreased immediately by drainage.
['Tomita|Yusuke|Y|', 'Yamada|Shoko Merrit|SM|', 'Yamada|Shokei|S|', 'Matsuno|Akira|A|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D003399:Craniotomy D005260:Female D006261:Headache D020200:Hematoma, Subdural, Chronic D006801:Humans D008297:Male D008875:Middle Aged D009044:Motor Cortex D010291:Paresis D011312:Pressure D012008:Recurrence D013355:Subdural Space D014057:Tomography, X-Ray Computed
Tension Chronic subdural hematoma Hemiparesis Thickness Pressure Laplace law