Lucid Interval and Acute Subdural Hematoma

To the Editor.—  In his recent article "Acute Subdural Hematoma With a Lucid Interval" (240:2284,1978), Volker K. H. Sonntag, MD, states that the occurrence of a lucid period in patients with acute subdural hematoma "has not been stressed in any of the recent stories published" and implies that it is uncommon. However, several recent studies have shown that a lucid interval occurs in patients with acute subdural hematoma. In a series cited by the authors, Jamieson and Yelland¹ reviewed 553 cases of surgically treated traumatic subdural hematomas and found that a lucid interval occurred in 13% of the patients. They compared this with the 12% incidence of lucid interval in their earlier review of extradural hematomas.² Richards and Hoff³ reviewed 100 surgical patients with acute subdural hematoma; 37% had a lucid interval. Therefore, although a lucid interval after head trauma is classically associated with epidural hematoma, it