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Surg Neurol 1991 ;35 :30-5

Transcranial Doppler Ultrasound Following Closed Head Injury : Vasospasm or Vasoparalysis? Camilo R . Gomez, M .D., F.A.C.A ., Robert J . Backer, M.D., and Richard D . Bucholz, M .D. Department of Neurology and Division of Neurological Surgery, St . Louis University Medical Center, St . Louis, Missouri

Gomez CR, Backer RJ, Bucholz RD . Transcranial Doppler ultrasound following closed head injury : vasospasm or vasoparalysis! Surg Neurol 1991 ;35 :30-5 . Nine patients suffering closed head injury were studied using transcranial Doppler ultrasound recording of the basal cerebral arteries . On admission, six patients had Glasgow Coma Scores of 7 or less, while three had initial scores of 8-10. Eight of the nine patients (82%) developed abnormally high mean velocities 0110 cm/s) in one or more vessels . The onset, duration, and amplitude of the altered flow velocities were somewhat different from those that are seen with vasospasm after aneurysmal subarachnoid hemorrhage, which tend to occur later . Cerebral angiography in one of the study patients confirmed the presence of vasospasm . Multivariate regression analysis showed a definite correlation between the velocities recorded, even when abnormally elevated, and concurrent pH and Pe„ i measurements (p = 0 .01, P2 = 0.23) . Although these results suggest that the cerebral vasculature retains its vasoreactivity following head injury, arguing against vasoparalysis, inconsistencies found in some of the patients lead us to think that both vasospasm and vasoparalysis may occur following head trauma but that they may have different temporal profiles . KEY WORDS :

Doppler ultrasound ; Trauma ; Vasoparalysis

Advances in ultrasound technology have opened a window to the noninvasive evaluation of intracranial circulation . Transcranial Doppler (TCD) sonography is a safe and reproducible technique that provides information on blood flow direction, velocity, and pulsatility in the basal cerebral arteries 12] . Normal values for the individual brain vessels are now well established, and reports documenting the usefulness of TCD sonography in assessing collateral circulation, detecting vasospasm after

Presented at the 57th Annual Meeting of the American Association of Neurologic Surgeons, Washington, D .C ., April 5, 1989. Addreu reprint requests to : Camilo R. Gomez, MD ., F.A .C .A ., Stroke Resource Center, Department of Neurology, 3635 Vista at Grand, St. Louis, Missouri 63110-0250. Received April 23, 1990 ; accepted August 7, 1990 . © 1991 by

Elsevier Science Publishing

Co., Inc .

subarachnoid hemorrhage, and monitoring the deterioration of cerebral blood flow to its cessation in patients considered brain dead exist in the literature [1,3-5,9-13] . We report the results of TCD examinations repeated in nine patients who suffered and survived closed head injuries . The findings are examined in light of previous and current knowledge regarding posttraumatic vasospasm and vasoparalysis .

Materials and Methods Patients Nine patients were evaluated using TCD monitoring following closed head injury . Table 1 summarizes their clinical characteristics . Patients with open or penetrating wounds were excluded . There were five women and four men, their ages ranging from 16 to 49 years (mean )4 years) . All of the subjects had admission Glasgow Coma Scores (GC Ss) of 8 or less . Six patients with GCS of 7 or less had ventricular catheters placed for intracranial pressure (ICP) monitoring . Five of them had elevations of ICP to 20 mm Hg or higher during the first week of hospitalization . These patients were treated with a combination of hyperventilation and osmotic diuresis . One patient with elevated ICP was treated with pentobarbital coma, begun within 24 hours of admission . Two patients underwent craniotomy upon presentation, one for subdural hematoma and one for a combined subdural and epidural hematoma .

Examination Technique Transcranial Doppler studies were performed using a standard technique with a 2-MHz range-gated, pulsed Doppler transducer connected to aTCD-dedicated spectral analyzer 12, 31 . Two instruments were utilized during the study, the TC2-64B (Eden Medical Electronics, Uberlingen, Federal Republic of Germany) and the Transpect (Medasonics, Mountain View, Calif .) . The transtemporal window was used for insonation of the middle cerebral arteries (MCAs) . Spectral analysis was performed by fast Fourier transform and displayed as veloci0090-3019/91/S3 .5o

M

17

19

18 16

49

17

37

18

32

Patient

J .L

V .K.L.

M. A. M .F .

V .K .O .

R.O.

G.B .

S .P.

B .W.

4

8 3

6

4

Admission GCS

6

7

10

14 9

7

8

Discharge GCS

180/150

120/100

80/(20

90/120

110/120

130/° 110//0

80/70

170/120

LMCA/RMCA Maximal mean velocity (cm/s)

11/13

4/1

11/3

11/4

6/6

1P' 12/9

3/3

6/6

LMCA/RMCA Postinjury day of maximal velocity

Large right frontal contusion, left frontal contusion, brain stein contusion, blood in the right sylvian fissure, intravenaicular hemorrhage .

Possibility of blood along the fats, otherwise normal Normal Right parietal contusion, left frontal contusion, small right frontal hematuma Inrraventricular hemorrhage, right temporal contusion, blood in the left sylvian fissure, small left frontoparietal contusion Right occipital and left frontal contusions Left subdural hematoma and left cerebral swelling Bifrontal contusions

Right parietal epidural/subdural hematuma

Admission CT findings

Vcntriculostomy for ICP monitoring Craniotomy for evacuation of subdural hemaroma Ventriculosromy for ICP monitoring Ventriculostomy for ICP monitoring

None

Craniotomy for evacuation of combined epidural/subdural hematuma . Ventriculostomy for ICP monitoring Ventriculostomy for ICP monitoring None Ventriculostomy for ICP monitoring

Operations/procedures

Abbreviations : F, female ; GCS, Glasgow Coma Score ; ICP, intracranial pressure ; LbfCA, left middle cerebral artery ; M, male ; RMCA, right middle cerebral artery . ° Unable to intonate.

M

F

M

M

F

F F

F

Sex

Age (years)

Table 1 . Patient Characteristics



32

Surg Neurol 1991 ;35 :30-5

ties in centimeters per second . Gosling's pulsari liry index (peak systolic velocity - end diastolic velocity/mean velocity) for each measurement was also calculated . Examinations were performed daily until the GCS improved to 13 or the neurological status remained stable for 72 hours, at which time the studies were obtained three times per week for 1 week and then weekly thereafter until discharge . Patients with abnormal flow velocities were studied daily until peak velocities were reached . After that point, they were examined three times per week until values returned to within normal ranges, at which time they were studied weekly . Additional studies were performed whenever the ICP rose higher than 25 mm Hg or the cerebral perfusion pressure (CPP) fell to less than 45 mm Hg . Bilateral carotid cerebral angiography was performed in one patient .

Data Analysis For the purposes of this report, data regarding age, sex, and race were entered into a data base, together with day (after injury), GCS, mean arterial blood pressure (MABP), ICP, CPP, pH, P o , and P,„_ at the moment of every TCD recording . The mean blood flow velocities (MBFVs) for each of these recordings were also entered . This data base was used as the basis for the statistical analysis . Simple regression coefficients were calculated for each of the variables in relationship to the MBFVs . Then, multivariate regression analysis was completed for all variables together and, finally, for a combination of those variables of importance in relation to vasomotor reactivity (age, pH, and Pc,,,) .

Results Timing of Abnormal Velocities Eight of the nine patients (82%) developed abnormally high MBFVs (110 cm/s) within the first 2 weeks following trauma . Of these, two had bilaterally increased MBFVs and five only unilateral . The average value of the maximal velocities for the MCA was 112 .4 cm/s (normal 65 ± 15 cm/s) . The time from injury to development of the abnormal velocities varied significantly . The distribution of this latency shows that the majority of the patients reached the peak MBFVs between 3 and 6 days after the injury . Of the remaining two cases, one had maximal MBFVs upon admission, and these decreased as the patient recovered . The last patient had been treated with pentobarbital coma until day 3 . After discontinuation of the barbiturate, the MBFVs began to increase, becoming clearly abnormal by day 7 and reaching a maximum by days 11-13 . Figure 1 shows the velocities of both MCAs of one of these patients (J .L .) in relationship to time . In the five patients with ICP monitors, the

Gomez et al

progressive rise in MBFVs was concurrent with the tall in ICP . The mean duration of altered MBFVs was 11 days (range 3-24 days) . Only one patient retained normal MBFVs throughout his hospitalization . Relationship to Intracranial Hemorrhage Review of the admission computed tomography (CT) scans suggested a relationship between the presence of intracranial hemorrhage and the development of abnormally elevated MBFVs . Although this was not statistically significant, it merits discussion . Only one patient had a normal CT scan upon admission . This is the same individual who recovered rapidly and whose MBFVs were maximal upon admission, decreasing to normal levels before discharge . A second patient had a normal CT scan, except for questionable blood along the falx, and never developed increased MBFVs . The rest of the patients had intracranial hematomas and contusions of various types, and abnormally high MBFVs . Correlation Results Multivariate regression analysis showed a definite relationship between the MBFVs and the age, GCS, MABP, ICP, pH, P0 ,, and P

Transcranial Doppler ultrasound following closed head injury: vasospasm or vasoparalysis?

Nine patients suffering closed head injury were studied using transcranial Doppler ultrasound recording of the basal cerebral arteries. On admission, ...
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