Figure 1 shows that the average age of our patients was 34.86 years with a range from 2 months to 78 years.

The range from 40 to 49 years was the most represented with 25.92%.

The males were most represented with 70.37%.

Patients were seen for varying reasons and impaired consciousness was the most frequent reason for consultation, 51.87% of patients were received in the emergency department, followed by headaches with 22.22% of cases (6 patients). Psychomotor agitation, convulsive seizures, functional impotence of the limbs and continuity solutions represent 25.91% of cases (7 patients).

In 77.78% of cases, our patients were transferred from other medical structures and only 22.22% of patients consulted directly for their care.

The average time to consult our patients is 359.1 hours (14.96 days) with extremes between 3 minutes and 5760 hours (8 months).

It can be seen in Table 1 that the average Glasgow score was 11, with extremes between 15 and 3. We observed a clear predominance of patients with a Glasgow score between 10 and 14 with 40.74% of cases (11 patients) followed by those with a Glasgow score of 15 (25.92% of cases).

Table 2 shows that Brain CT scan was performed in 81.48% of cases (22 patients), unlike brain MRI with only 3.70% of cases.

The average consultation time is 16.84 hours with extremes between 1 and 68 hours.

Oedematohemorrhagic contusions were the predominant lesions in our study with 33.33% of cases followed by subarachnoid hemorrhages with 18.51% of cases.

In the majority of cases, the time taken to perform TCD was more than 7 hours with 61.53% of cases ( Figure 2 ).

The average time to complete TCD was 17.23 hours, with extremes between 1 and a half hours and 72 hours.

In our series, there was a clear majority of patients with a PI greater than 1.20 (92.59% of cases). An adjusted Odd ratio (Ora) greater than 1 in both cases (11.18 and 9.15), suggesting a potential association between a high PI and a factor studied.

However, the 95% confidence intervals (CI: 0.65 - 3.99 and 0.58 - 3.86) include 1, indicating that the association was not statistically significant. The value of p = 0.1562 confirms the absence of a significant difference.

Thus, although the elevated PI may be a potential risk factor (OR > 1), the results are not statistically significant and do not allow a definitive conclusion to be made ( Table 3 ).

Since cell (0.0) creates division by zero, the OR is infinite (∞). This means that all patients with a positive PI also had a positive CT scan, while no patient with a negative PI had a positive CT scan. Infinite OR indicates a perfect association between a positive PI and a positive CT ( Table 4 ). This means that in this sample, no patients with a negative PI had a positive CT scan, which is a very strong result but potentially biased by the small sample size.

The confidence interval cannot be calculated directly because of the null values, which points to a lack of statistical robustness. In conclusion, it seems that the pulsatility index is a very good indicator of the CT result, but this conclusion should be interpreted with caution, especially because of the small sample size and the risk of selection bias. The significant p-value (p < 0.05) suggests that this association is not due to chance, but to a high level of, but a study with a larger sample size is needed to obtain more usable values.

SENSITIVITY: TP/(TP + FN) = 7/7 + 0 = 1(100%) of positive individuals were predicted to be positive.

SPECIFICITY: TN/(TN + FP) = 2/2 + 0 = 1 (perfect test). The specificity of the middle cerebral pulsatility index is 100% for patients with CT (+).

FALSE NEGATIVE RATE: 1 – sensitivity = 1 – 1 = 0% of cases. The false negative rate found was zero.

FALSE POSITIVE RATE: 1 – specificity = 1 − 1 = 0% of cases. The false positive rate of the middle cerebral artery pulsatility index is zero (n = 0).

THE POSITIVE PREDICTIVE VALUE: TP/TP + FP = 21/21 + 0 = 1 (100%). In our series, the positive predictive value of the middle cerebral artery pulsatility index is 1 (100%).

THE NEGATIVE PREDICTIVE VALUE: TN/TN + FN = 2/2 + 0 = 2/2 = 1 = 100%. In our series, the negative predictive value of the S100 beta protein assay dosed before 6 hours is 10%.

Table 5 shows that the average time for PS 100 beta dosing is 15.24 hours, with extremes between 1.15 and 48 hours. The mean value of the PS 100 beta dosage is 0.25 with extremes between 0.05 and 1.27. There is no significant difference between the values of PS 100 beta that PI could be a risk factor (OR > 1). The mean value of the S100 protein was 0.25 with extremes between 0.05 and 1.27. There was no significant difference between the S100 beta protein (OR > 1) values, probably due to the small sample size.

There is a difference in sensitivity and specificity depending on the time taken to assay the S100 beta protein (less than or greater than 6 hours) ( Table 6 ).

(TN = True Negative, FP = False Positive)

The specificity of PS 100 beta is 100% for patients dosed between 3 and 6 hours with a clear predominance of patients before 3 hours.

The false negative rate in the S100 beta protein assay is 13%.

The false positive rate in the S100 beta protein assay before 3 hours is zero (n = 0).

(TP = True Positive, FP = False Positive)

In our series, the positive predictive value of the S100 beta protein assay dosed before 6 hours is 1 (100%).

In our series, the negative predictive value of the S 100 beta protein assay dosed before 6 hours is 10%.

(TN = True Negative, FN = False Negative)

The management was generally medical with a surgical performance rate of 11.11% of cases (3 patients).

In 55.55% of cases, as shows Table 7 , the evolution was satisfactory compared to a death rate of 45.45% of cases. The average length of hospitalization is 116.96 hours with extremes between 4 and 288 hours (12 days). There was no significant difference between the S100 beta protein values (OR > 1).

In our series, 37.03% of patients presented complications, Secondary brain injury of systemic origin was the most frequent with 25.92% of cases (6 patients) followed by cardiorespiratory arrest with 7.41% of cases (4 patients) ( Table 8 ).

In our series, there is no particular variation in the value of the S100 beta protein as a function of the Glasgow score, unlike the value of the pulsatility index (PI) ( Table 9 ).

1) Glasgow score and mortality:

2) Pulsatility Index (PI) and Glasgow:

3) S100 beta protein (PS 100 β):

Table 10 shows that a Glasgow score ≤ 9 is a major risk factor for death in this population. The high pulsatility index in these patients suggests impaired cerebral blood flow. A larger sample size is needed to refine these results and obtain a usable confidence interval. The very low p-value (p < 0.001) indicates that this association is highly significant and not due to chance. However, the sample is too small to obtain an interpretable OR with a realistic confidence interval. Depending on the Glasgow, we subdivide patients into 2 risk groups:

This study highlights specificity and proportional positive predictivity values between the PS 100 beta before 3 hours (sometimes before 6 hours) and the transcranial Doppler PI despite the small difference in sensitivity ( Table 11 ). Overall, the combination of tests in brain-injured patients is very promising in diagnosing severity.

It can be seen in Table 12 that among the factors of poor prognosis of the patients received we have age (young adult), patients transferred, long consultation time, low Glasgow, mean PS 100 beta values of 0.24; multiple CT scans, hyperglycemia, long hospitalization, ACSOS, cardiorespiratory arrest, ...

Assay in biological fluids (blood, CSF) revealed an increase in the concentrations of the S-100B protein during different pathologies. This increase can have two origins [3] .:

Transcranial Doppler non-invasively measures the velocity of red blood cells in the large arterial trunks of the brain. This measurement is easily obtained in the middle cerebral arteries, which account for 70% of the flow of internal carotid arteries [5] .

For Walae E. Abdel-Ghaffar et al. in 2019, the main finding of the study was that the S100B protein measured on day 3 after acute stroke was significantly correlated with short-term functional change on day 14, as determined by MRS and NIHSS scores, with a high sensitivity of 91% and a specificity of 80%, as shown by the ROC curve. The S100B protein at day 1 was not significantly correlated [8] . In line with their study, Wunderlich et al. found that serum concentrations and S100B protein kinetics are highly predictive of early neurobehavioral outcomes in patients after acute stroke, and that S100B protein concentrations at days 2 and 4 after acute stroke can provide valuable information on neurological status and functional impairment upon discharge from acute hospital care. Neurological status was assessed by NIHSS at admission, on days 1 and 4 in the stroke unit, on day 10, and at the hospital discharge. These results are consistent with the present study in terms of the importance of the correlation between S100B day 3 and short-term functional outcome [12] .

The SENSITIVITY is 1 (100%) of positive individuals were predicted to be positive. The specificity of the middle brain pulsatility index is 100% for patients with MDD (+) and the false negative rate found was zero.

The false positive rate of the middle cerebral artery pulsatility index is zero (n = 0). The positive predictive value of the middle cerebral artery pulsatility index is 1 (100%) and the negative predictive value of the S 100 beta protein assay measured before 6 hours is 10%.

Classification of Patients According to the Pulsatility Index (PI)

This table shows how patients can be classified based on Middle Cerebral Artery Pulsatility Index and Cranio-cerebral Trauma severity levels

This table shows how patients can be classified based on the PI of ACM and the severity levels of TCE.

Conversely, patients with a Glasgow 15 have a low PI (0.33), indicating better cerebral perfusion. In contrast to the PI, the value of the PS-100 β does not show a trend according to the Glasgow score.