TRANSCRANIAL DOPPLER DIAGNOSIS OF CEREBRAL VASOSPASM FOLLOWING SUBARACHNOID HEMORRHAGE - CORRELATION AND ANALYSIS OF RESULTS IN RELATION TO THE AGE OF PATIENTS

A retrospective analysis was undertaken to determine whether cerebral vasospasm following subarachnoid haemorrhage (SAH) correlates with the age of patients. For at least 3 weeks after bleeding 80 subjects underwent very close follow-up with clinical examination and transcranial Doppler records of the blood velocities within the basal cerebral arteries. Firstly a correlation between measured maximal mean blood flow velocities and age was made. Secondly, according to their age and the maximum of recorded mean velocitites (v), the patients were divided into groups as follows: age 55 years or less, age more than 55 years; and maximum velocity vl < 90 cm/s, 90 cm/s < v2 < 120 cm/s, 120 cm/s < v3 < 160 cm/s, v4 > 160 cm/s. There was a significant correlation of the measured maximum mean velocities and the age of the patients (r = -0.525, p < 0.01). With regard to the velocity groups there was a significant (chi-squared statistic for contingency tables, p < 0.01) difference between both age-groups: 32% (n = 18) of the younger fell into group v4 with maximum mean velocities of more than 160 cm/s, but none of the older had such. Vice versa, 63% (n = 15) of the older compared with only 14% (n = 8) of the younger fell into group vl with maximum mean velocities of less than 90 cm/s. Clinical follow-up also depicted differences between both age groups. 13 of 18 younger patients with maximum mean velocities > 160 cm/s exhibited symptomatic vasospasm with a delayed neurological deficit. This typical course did not occur in the older age group. We conclude from this analysis that the increase of blood velocity in the basal cerebral arteries following subarachnoid haemorrhage depends on the age of the patient. Furthermore, young patients will be more prone to a delayed ischaemic deficit. On the other hand, older patients may also suffer ischaemic deficits following subarachnoid haemorrhage but often without measurable vasospasm according to transcranial Doppler criteria and without the typical delayed appearance.