INTRODUCTION
Although spontaneous intracerebral haematoma (ICH) accounts for approximately 10-15% of all acute cerebrovascular diseases1, its importance stems from the generally severe neurological deficits it causes and its often grave prognosis2.
To develop therapeutic strategies for patients with spontaneous ICH, we need to be able to predict their evolution particularly during the very acute stage (<24 hours after stroke onset)3. Several studies have focused on early survival after spontaneous ICH, and on the identification of its prognostic factors4-7 but some used only univariate analysis which fails to account for interaction among prognostic factors4-6, and other suggested a highly sophisticated model to predict outcome for routinely clinical purposes7.
Based on initial clinical and brain CT findings, our aim was to determine: (1) The predictors of 30-day mortality in ICH patients, (2) The prognostic factors that determine the probability of favorable functional outcome in patients who survive the acute stage of ICH.
METHODS
Data were collected from 67 consecutive patients admitted to the stroke unit of the Neurology Department of Tanta University hospital over a period of six months and who have met the following inclusion criteria:
1. Admission within less than 24 hours of stroke onset.
2. CT scan of the brain demonstrating non-traumatic ICH.
3. Supratentorial site.
Thirty-eight patients (56.7%) were males and 29 (43.3%) were females. The age ranged between 34 and 80 (mean 53.5±10.19) years.
All patients were evaluated neurologically and clinically on admission and all variables were uniformly assessed. The level of consciousness was evaluated according to the (GCS)8. CT scan of the brain was performed within 24 hours of admission.
The following clinical variables were considered as potential prognostic factors suitable to influence the 30-day mortality and functional outcome: 1) patient's age, 2) gender, 3) mean arterial pressure (MAP) on admission, 4) level of consciousness on admission, 5) presence of gaze palsy and 6) pupillary abnormality. The following CT scan findings were also taken into account 1) haematoma location "site" 2) haematoma side, 3) haematoma size "volume" 4) midline shift "displacement on CT scan > 5mm" and 5) intraventricular extension (IVE) of the haematoma.
The total volume of parenchymal haematoma was calculated at bed side on CT films using ABC /2 formula9 (where the CT slice with largest area of the haematoma was identified and the largest diameter (A) of the haematoma on this slice was measured using the centimeter scale on the CT scan. The largest diameter 90° to A on the same slice measured next (B). Finally the approximate number of 10-mm slices on which ICH was seen was calculated (C). A, B and C were then multiplied and the product divided by 2 which yielded the volume of parenchymal haematoma in cubic centimeters).
Spontaneous ICH was classified on CT scan as deep (including putaminal and thalamic bleeds) or lobar. The haematoma was considered lobar, if was situated in the subcortical white matter, wholly outside the basal ganglia and thalamus, deep if the haematoma contacted these structures.
All patients were conservatively treated by a standard therapeutic protocol used in our stroke unit. The mortality rate was calculated 30 days following the stroke onset, whereas the survivors were evaluated for 2 months and their functional outcome then was classified according to the Rankin disability scale10 into the following grades (1=no significant disability-despite symptoms able to carry out all usual duties and activities, 2= slight disability- unable to carry out all previous activities, but able to look after own affairs without assistance, 3= moderate disability- requiring some help, but able to walk without assistance, 4= moderately severe disability- unable to walk without assistance and unable to attend to own bodily needs, 5= severe disability- bed ridden, incontinent and requiring constant nursing care and attention). Surviving patients' outcome at the end of 2 months was then classified into satisfactory "Rankin 1, 2 and 3" or unsatisfactory " Rankin 4 and 5".
Statistical Analysis:
The statistical analysis was performed by univariate methods (x2 or Fisher exact probability test or t-test as appropriate) to correlate the patients' outcome and each potential prognostic factor. Then multiple logistic regression "multivariate" analysis was used to estimate the probability of a given outcome in an individual patient as a function of that patient's prognostic factor.
Outcome was expressed as 1) alive at 30 days versus dead at 30 days and 2) satisfactory outcome "Rankin 1-3" at 2 months versus unsatisfactory outcome "Rankin 4 and 5" at 2 months. Value of p < 0.05 was considered significant.
RESULTS
Among the 67 studied ICH patients, putaminal location was the site of preference (46.2%), lobar location was the second in frequency (28.4%) whereas thalamic location constituted the remaining (25.4%)
Arterial hypertension, the main vascular risk factor of spontaneous ICH, was present in (83.8%) of patients. 26.7% of our hypertensive patients had their haematoma in the lobar location, whereas the rest (73.3%) had their haematoma within the deep locations.
The 30-day mortality rate was 11 deaths (16.42%), two patients died from non-neurological causes after one month, one patient died with bronchopneumonia and the other with renal failure and were included in the unsatisfactory outcome group at 2 months.
Regarding the 56 surviving patient after one month, 41 (73.21%) had a satisfactory functional outcome "Rankin 1-3" and 15 (26.79%) had unsatisfactory functional outcome "Rankin 4-5" at the end of the 2-months follow up period.
Univariate statistical analysis (Table 1) showed that patients age (P=0.0001), low admission GCS (P=0.00001), high admission MAP (P=0.005), gaze palsy (P=0.001), pupillary abnormality (P=0.003), ICH size (P-0.00001), IVE of the haematoma (P=0.01) and midline shift (P=0.04) to be significantly associated with 30-day mortality. On the other hand, gender (P=0.861), haematoma site (P=0.669) and haematoma side (P=0.47) were not significant. According to the results of univariate analysis, eight potential prognostic factors (patient's age, admission GCS, admission MAP, ICH site, ICH size, ICH side, IVE of the haematoma and midline shift) were selected for multivariate analysis by logistic regression. The results are presented in (Table 2) and showed that admission GCS (P=0.014) and ICH size (P=0.04) were the only significant independent predictors of 30-day mortality independent predictors of 30-day mortality among our patients.
Using the same statistical model, univariate analysis found that a satisfactory outcome "Rankin 1-3" at 2 months to be inversely correlated with old age (P=0.00001), low admission GCS (P=0.0001), high admission MAP (P=0.002), ICH size (P=0.,0001), and the presence of IVE of the haematoma (P=0.01), and midline shift (P=0.001) whereas gender (P=0.942), presence of gaze palsy (P=0.14), presence of pupillary abnormality (P=0.24), ICH site (P=0.899), and ICH side (P=0.724) were not significant (Table 3).
In multivariate analysis, age (P=0.01), admission GCS (P=0.04), and ICH size (P=0.03), were significant independent predictors of functional outcome (Table 4).
Moreover, our study revealed by univariate analysis (Table 5), that the prognostic role of IVE of the haematoma is particularly related to the haematoma site, showing its significant adverse effect on the 2-months functional recovery of patients with lobar haematoma (P=0.02), in contrast to its insignificant effect on patients with both putaminal (P=0.32), and thalamic (P=0.37) locations.
In support to the above data, our study revealed also by univariate analysis (Table 6) a significant relationship between haematoma volume and IVE only for patients with lobar haematoma (P<0.05), whereas in both putaminal and thalamic locations, such relationship was lacking (P>0.05) in each.