Hemodynamic Complications Common in Traumatic Brain Injury

Honolulu, Hawaii — A new study shows that cerebral arterial vasospasm (VSP) and intracranial hypertension are common outcomes of combat-related traumatic brain injury (TBI), so much so that its authors are recommending daily transcranial Doppler (TCD) monitoring to better recognize and manage these complications.

TCD ultrasound technology is portable and cost-effective, although dedicated and knowledgeable personnel are needed to properly administer the tests, according to the study's lead author, Alexander Razumovsky, PhD, director, Sentient NeuroCare Services, Hunt Valley, Maryland.

The research was presented here on February 6 at the International Stroke Conference (ISC) 2013.

Retrospective Evaluation

The study included 122 consecutive patients with TBI admitted to Walter Reed National Military Medical Center from October 1, 2008, to November 30, 2012, and identified through a computerized registry. Of these, 88 had sustained a penetrating injury and 34, a closed-head injury. The mean age of the cohort was 26.1 years, and the mean time from injury to hospital admission was 6.7 days.

Dr. Alexander Razumovsky

Researchers retrospectively evaluated the patients for TCD-determined incidence of posttraumatic cerebral vasospasm and intracranial hypertension. TCD recordings included pulsatility indices of the anterior and posterior circulation vessels and mean cerebral blood flow velocities (CBFV, in cm/s).

Mild, moderate, and severe vasospasm was considered present if mean CBFV was 100 to 139 cm/s, 140 to -199 cm/s, and greater than 200 cm/s, respectively.

The study found that mild, moderate, and severe VSP involving anterior circulation vessels was present in 71%, 42%, and 16% of patients, respectively. Mild, moderate, and severe VSP involving posterior circulation vessels was found in 57%, 32%, and 14% of patients, respectively.

Intracranial hypertension was recorded in 43% of the patient sample.

Eight patients (7%) underwent transluminal angioplasty for posttraumatic symptomatic vasospasm treatment.

According to Dr. Razumovsky, the study results suggest that TCD may help detect early signs of cerebral vasospasm and facilitate better management strategies, for example, determining urgent aggressive treatment and continuous invasive monitoring, where appropriate.

Surrogate Test

According to another study author, Rocco Armonda, MD, Colonel, Medical Corp, U.S. Army; director, cerebrovascular surgery and interventional neuroradiology, Walter Reed National Military Medical Center, a neurological examination "trumps all other means of monitoring." However, he said the Doppler test serves as a "surrogate" in cases where a good neurologic examination is not possible, including emergency situations.

"We're talking about the most severe brain injuries," with patients coming in comatose and with multiple traumas that could include orthopedic injuries and chest injuries and often heavily sedated, said Dr. Armonda.

He stressed that information from Doppler imaging "has to be used in context" and along with other appropriate measures and bedside tools. "The idea here is that it's not the tool that makes the difference; it's the therapy that the tool then helps define."

A limitation of the study was that it included only younger patients and that there are no established criteria for vasospasm in young people, said Dr. Razumovsky.

Very Select Group

Approached to comment, David T. Lackland, PhD, professor of epidemiology and neurosciences, Medical University of South Carolina, Charleston, said this was a "nice preliminary study" but because it was carried out on a "very, very select group of individuals," additional work needs to be done in other populations.

Larry B. Goldstein, MD, professor of neurology at Duke University Medical Center, Durham, North Carolina, had a few issues with the study. For one thing, the patient population was "difficult" because it was a mix of patients with closed-head and penetrating head injuries, he told Medscape Medical News. "Complications of those 2 can overlap but there are certainly differences."

As well, said Dr. Goldstein, it wasn't clear whether the patients in the study also had traumatic subarachnoid hemorrhage. "We know from other studies that traumatic subarachnoid hemorrhage carries a risk of vasospasm not too different from non-traumatic subarachnoid hemorrhage."

Dr. Razumovsky is a full-time employee of the private practice (Sentient NeuroCare Services) that currently is under contract with the Army Medical Department. Dr. Lackland and Dr. Goldstein have disclosed no relevant financial relationships.

International Stroke Conference (ISC) 2013. Abstract 53. Presented February 6, 2013.