Cases with Minor Head Trauma: Estimation of Cerebral Autoregulation in an Acute Period

Semenyutin V.B., Bersnev V.P., Aliev V.A., Mustafaev B.S.

Polenov Research Neurosurgical Institute, Saint Petersburg, Russia

 

Prevention of complications in an acute period of craniocerebral trauma (CCT) is greatly dependent on understanding mechanisms of head injury. A state of cerebral circulation is an important constituent of these mechanisms. First of all, it concerns cerebral autoregulation (CA). It has been demonstrated, that severe head trauma leads to marked disturbances of CA up to its failure. However, information on its state in minor head trauma is discrepant, being a cause of rather ineffective prognostication of outcomes in this category of cases.

The study goal has been estimation of CA in cases with acute minor craniocerebral trauma for prognostication of treatment results.

Material and Methods. We examined 30 cases in an acute period of CCT. Their age varied from 17 up to 55 years. CCT severity was assessed on the basis of the Glasgow Coma Scale. Then all the cases were divided into 3 groups: patients with minor (the score of 13-15), moderate (the score of 8-12) and severe (the score of less than 8) head trauma. Linear blood flow velocity (BFV) in major intracranial arteries and systemic blood pressure (BP) were monitored on the 1st-3rd day after trauma with applying Multi DOP X (DWL, Germany) and Finapres-2300 (Ohmeda, USA). A cuff test with calculating RoR index and cross-spectral analysis with determining a phase shift (PS) between spontaneous oscillations of BFV and CBP within the range of Meierís waves were used for CA velocity estimation.

Results. There was no reliable intergroup difference in BFV and BP. Mean values of RoR (30.3±3.6 %/s) and PS (1.06±0.35 rad) were indicative of normal CA in cases with minor CCT. RoR (15±20 %/s) and PS (0.49±0.99 rad) tended to decrease in 3 cases with moderate CCT. Considerable reduction of RoR (5.3±4.2 %/s) and PS (0.41±0.28 rad), being an indication of marked disturbances of CA, were revealed in 6 cases with severe CCT (p<0.05). RoR and PS (r = 0.65 and r = 0.75, respectively) correlated with a degree of trauma severity. Mean values of RoR and PS (35.2±4.3 %/s and 1.24±0.24 rad, respectively), watched in 14 cases (67%) with minor CCT and a smooth course of the disease, were reliably higher (p<0.001) in comparison with 7 patients (33%) with signs of persistent hypertension (20.3±3.2 %/s and 0.80±0.27 rad, respectively), which demanded additional treatment correction.

Conclusion. Thus, CA velocity (according to RoR and PS data) can be used as a criterion of prognosticating treatment results in an acute period of minor CCT.