Risk factors for the development of post-traumatic cerebral vasospasm

Post-traumatic vasospasm is a well-recognized sequela of head injury. The risk factors associated with post-traumatic vasospasm have not been well defined. We studied 119 consecutive patients with head injury to determine the risk factors for post-traumatic vasospasm.

Twenty-nine (27.1%) patients were excluded from the study because of poor insonation (n = 12) or a hospital stay of less than 72 hours (n = 17). Seventy (77.8%) of 90 patients suffered severe head injury. Sixteen (17.8%) patients sustained moderate head injury and four (4.4%) patients sustained mild head injury. All patients were monitored with transcranial Doppler (TCD) ultrasonography daily.

Post-traumatic vasospasm was detected in 32 (35.6%) of 90 patients. Among these patients, 29 (90.6%) had severe head injury, and three (9.4%) had moderate head injury. None of the patients with mild head injury suffered post-traumatic vasospasm. In most cases, the onset of post-traumatic vasospasm began on the fifth day and lasted 1 to 9 days. In 8 (25%) patients, post-traumatic vasospasm began within the first three days of the head injury. Among 32 patients with post-traumatic vasospasm, 10 (31.2%) patients had mild vasospasm, 20 (65.5%) had moderate vasospasm, and 2 (6.3%) had severe post-traumatic vasospasm. Clinical deterioration was documented in two (2.5%) patients.

Development of post-traumatic vasospasm correlated only with severe subarachnoid hemorrhage on initial computed tomographic scan. There was an increased incidence of post-traumatic vasospasm in patients with epidural hematomas, subdural hematomas, and intracerebral hemorrhages. The Glasgow Coma Scale (GCS) score on admission was inversely related to the development of post-traumatic vasospasm. In most cases, the period of vasospasm was short and clinical deterioration was rare. Probably, two varieties of post-traumatic vasospasm exist, one that lasts a shorter time and does not correlate with the presence of SAH, and a second that correlates with the presence of SAH, lasts longer, and resembles aneurysmal vasospasm.