Intracerebral Hemorrhage in Cocaine Users
Background and Purpose— Cocaine is a cause of intracerebral hemorrhage (ICH), but there are no large studies that have characterized the location, pathology, and outcome of patients with cocaine-associated ICH.
Methods— We performed a retrospective analysis of all patients admitted to our stroke service from 2004 to 2007 who had nontraumatic ICH and urine drug screens positive for cocaine and compared them with similar patients who had negative drug screens for cocaine.
Results— We identified 45 patients with cocaine-associated ICH and 105 patients with cocaine-negative ICH. There were no significant differences in age or gender, but there was a significantly higher incidence of black patients in the cocaine-positive group. Cocaine-associated ICH patients had higher admission blood pressures, significantly more subcortical hemorrhages, and higher rates of intraventricular hemorrhage compared to patients with cocaine-negative ICH. Cocaine-positive patients had worse functional outcome, defined as modified Rankin Scale score >3 at the time of discharge (OR, 4.90; 95% CI, 2.19–10.97), and were less likely to be discharged home or to inpatient rehabilitation. Patients with cocaine-associated ICH were nearly 3-times more likely to die during their acute hospitalization when compared to cocaine-negative patients.
Conclusion— Recent cocaine ingestion is associated with hemorrhages that occur more frequently in subcortical locations, have a higher risk of intraventricular hemorrhage, and have a poor prognosis compared to patients with cocaine-negative, spontaneous ICH.
Intracerebral hemorrhage (ICH) is an uncommon central nervous system complication of cocaine use. Whereas previous case series have suggested that the etiologies for ICH in cocaine users include rapid increases in blood pressure,1 aneurysmal rupture,1–3 and vasculitis,4–6 these studies have been limited by small sample size. To our knowledge, no large, systematic studies have characterized the pathology and prognosis of patients with cocaine-associated ICH. We compared the demographics, location, and outcome of cocaine-associated ICH with cocaine-negative, spontaneous ICH in patients admitted to our stroke center.
Subjects and Methods
We conducted a retrospective chart review of all ICH patients admitted to our stroke service from 2004 to 2007 for whom cocaine was marked as an exposure on admission. Recent exposure was defined as a positive urine drug screen for cocaine metabolites at the time of hospital presentation. Other substances of abuse were also captured. A control group was also collected, consisting of all patients who presented to our service with nontraumatic, spontaneous ICH during the same time frame in which a urine drug screen was obtained and found to be negative for cocaine. All patients admitted to our stroke service with spontaneous ICH undergo a urine drug screen if they are younger than 50 years old, have no history of hypertension or dementia, report a history of illicit drug use, or have a history of substance abuse. Baseline demographics, admission blood pressure, NIHSS scores, Glasgow Coma Scale, ICH scores (Glasgow Coma Scale, age >80 yr, infratentorial origin, ICH volume >30 mL, presence of intraventricular blood), echocardiogram reports, neuroimaging results, urine drug screen results, and various laboratory measurements (creatine kinase, troponin, glucose levels) were collected.
All patients had frequent vital sign monitoring, including an ECG and 24 hours of telemetry. Cardiac and cerebrovascular imaging and lipid and glucose levels were obtained as part of routine practice. Early outcomes were evaluated at hospital discharge using the modified Rankin Scale score and discharge disposition. ICH characteristics, results of cardiac and vascular imaging, and outcomes in ICH patients with negative toxicology screens were compared to patients with positive toxicology for cocaine metabolites admitted to our stroke service during the same time period. We also report the incidence of untreated hypertension, blood pressure at initial presentation, evidence of chronic hypertension (defined as left ventricular hypertrophy on echocardiography), and cardiac sources of emboli. The primary outcome of interest was the modified Rankin Scale score at discharge. Poor outcome was defined as a discharge modified Rankin Scale score of 4 to 6.
Statistical analyses were performed using SPSS 15.0 (SPSS Inc). Continuous variables were reported as mean±SD when the distribution was normal and median with range for non-normal distributions. The modified Rankin Scale score and NIHSS were reported as the median with interquartile range. Categorical variables were analyzed using χ2 and Fisher exact tests when appropriate.
Of 3241 stroke patients admitted to our stroke service during the study period, 132 (4.1%) tested positive for cocaine metabolites on urine drug screen. Of those patients, 45 (34%) had ICH. Of the 45 cocaine-positive ICH patients, 6 tested positive for other illicit drugs (5 for marijuana, 1 for marijuana and amphetamines). They were included in the analysis. During the same time period, 105 patients were identified who had a spontaneous ICH and were found to have a negative urine drug screen for cocaine metabolites. Table 1 depicts the baseline demographics of cocaine-positive vs cocaine-negative ICH patients. Compared to ICH patients who denied a history of polysubstance use and were found to have a negative urine drug screen, cocaine-positive patients presenting with ICH were more likely to be black (69% vs 44%) and less likely to be Hispanic (11% vs 28%; P=0.022). There was no significant difference in median age, gender, baseline hypertension, or rate of untreated hypertension. Patients using cocaine had a significantly higher median admission diastolic blood pressure (121 [100–126] vs 110 [107–141]); P=0.024) and showed a trend toward higher median systolic blood pressure (216 [158–241] vs 204 [154–228]; P=0.066). Cocaine-positive patients presented with more severe ICH (NIHSS 18 [8–25] vs 13 [6–20]; P=0.014; Table 2). Whereas the median ICH volume in cocaine users (18 mL) was larger than that of noncocaine users (12 mL), this difference was not statistically significant (P=0.329). The median ICH score was significantly higher in cocaine-positive patients (2 [1–3] vs 1 [0–2]; P<0.0001; Table 2).
Although an unequal distribution of brain stem hemorrhage was noted in the cocaine-positive group, as shown in Table 2 (20% vs 5%), use of cocaine was not directly correlated with ICH location (r=.007; P=0.9) or with ICH volume (r=0.08; P=0.3). Cocaine use was, however, found to directly correlate with the occurrence of intraventricular hemorrhage (IVH; r=0.30; P<0.0001). Among patients with ICH associated with cocaine, they were nearly 4-times more likely to have IVH compared to ICH patients who did not have a recent cocaine exposure (OR, 3.84; 95% CI, 1.81–8.17; P<0.0001). Approximately half (24/45) of the cocaine-positive patients with ICH had an arteriogram (CTA, MRA, or digital subtraction angiography); 2 of the 24 patients had an arteriovenous malformation (8.3%) and 1 patient had findings consistent with Moya Moya syndrome (4.2%). None was found to have vasculitis.
Cocaine-positive patients had worse functional outcome at the time of discharge on modified Rankin Scale score (5 [4–6] vs 3 [2–5]; P<0.0001; Figure) and were less likely to be discharged home or to inpatient rehabilitation (31% vs 62%; P=0.002; Table 3). Patients with cocaine-associated ICH were nearly 3-times more likely to die during their acute hospitalization when compared to cocaine-negative patients (OR, 2.71; 95% CI, 1.18–6.25; P=0.017). After controlling for variables that were significantly different between the 2 groups, such as NIHSS on admission, Glasgow Coma Scale, IVH, and ventriculostomy, cocaine use remained a significant independent predictor of poor outcome (OR, 3.21; 95% CI, 1.03–10.01; P=0.044).
To our knowledge, this study involves the largest series of patients with cocaine-associated ICH and presents an opportunity to better-understand the demographics, pathophysiology, location, and outcome of cocaine-related ICH. Consistent with previous studies of cocaine users, we found a male predominance and higher proportion of blacks as compared to other ethnic groups.7 The age of our cohort (range, 33–69) is consistent with previous studies but includes some of the oldest patients ever to be reported and is in accordance with previous work showing that the elderly use cocaine and have central nervous system complications.8
In contrast to previous studies reporting a lobar location, cocaine-associated ICH in our cohort was predominately subcortical.9 There was a significantly higher incidence of brain stem ICH in cocaine-positive patients when compared with cocaine-negative patients. In agreement with other studies,1 hypertension may have contributed to the underlying pathology in patients with cocaine-associated ICH, given the high admission blood pressure and lesion location. The rate of vascular malformations in our cohort of cocaine users was lower than rates previously cited.3,10 This may be confounded by the fact that only half of our patients underwent angiographic imaging. However, our findings are in agreement with small studies that found no evidence for vascular anomalies as the predominant cause of cocaine-associated ICH.11–13 Therefore, cocaine-related ICH may not be a necessary indication for angiography in patients with preexisting hypertension and subcortical ICH. However, the literature suggests that a lobar location in patients with cocaine-related ICH may be associated with an arteriovenous malformation or an aneurysm.14,15 For those patients who did undergo angiography in our study, there was also no evidence for vasculitis, another purported pathology for cocaine-associated ICH.5 No other etiologies were found in our patients, including bleeding diatheses or coagulopathies.
The clinical presentation of cocaine-associated ICH in our sample was more severe than cocaine-negative ICH, as measured by admission neurological deficits on the NIHSS score and the ICH score. Cocaine-positive hemorrhages had a substantially higher rate of intraventricular extension, leading to higher ICH scores. The risk of mortality doubled in cocaine-positive patients when compared with cocaine-negative patients. The high morbidity and mortality rate may be attributable to a combination of factors, including brain stem location, IVH, and chronic hypertension; however, we cannot exclude the possibility that the intrinsic pharmacokinetic properties of the cocaine itself may also contribute to higher morbidity and mortality in ICH. Worse prognosis in cocaine users could also be related to socioeconomic factors, outside of the direct action of the cocaine, such as poor general medical care including suboptimal compliance with, or access to, antihypertensive therapy.
There was a higher rate of death in cocaine users who had IVH when compared to patients with noncocaine IVH, although this result did not prove statistically significant. Small sample size may be preventing us from detecting a significant association between IVH and outcome, but previous studies have already shown that IVH is an independent predictor of worse outcome.16 We investigated further the high rate of IVH in cocaine-associated ICH and found there was a moderate correlation between cocaine use and the occurrence of IVH. Previous work has shown that volume and location of the hemorrhage are associated with the likelihood of intraventricular extension;16 however, there was no correlation in this study between cocaine use and hemorrhage location or between cocaine use and hematoma volume. The underlying mechanisms that predispose cocaine exposure to lead to IVH remains unclear and will require further investigation.
This study has several limitations, including its retrospective nature and lack of angiographic studies for all patients. Not all of our patients with spontaneous hemorrhage undergo a urine drug screen, which may result in a sampling or selection bias when comparing cocaine-positive with cocaine-negative patients. The proven cocaine-negative group limited the age of the patients studied because not all elderly patients undergo a toxicology screen at our center, but this age cut-off makes it unlikely that other etiologies of spontaneous hemorrhage, such as amyloid angiopathy, was a predominant cause in the cocaine-negative patients. Because the average age was slightly older than 50 years in the cocaine-negative controls, there may be inherent bias regarding which patients older than 50 years undergo a toxicology screen. Do not resuscitate status on admission was not captured; therefore, we cannot rule out the possibility of a self-fulfilling prophecy accounting for worse outcomes in the cocaine-positive patients. In addition, we did not collect the type of cocaine used, quantity used, route of administration, or frequency of use, which previous reports have suggested may affect the likelihood of having ICH vs ischemic stroke.10 Because we focused only on ICH, we cannot comment on the etiologies of subarachnoid hemorrhage after cocaine use. Patients with large arteriovenous malformations, apparent on baseline CT scan, would have been admitted to our neurosurgery service; thus, the rate of underlying vascular anomalies in this cohort may be underrepresented.
In summary, recent cocaine ingestion is associated with large, subcortical ICH, often with intraventricular extension and high morbidity and mortality rates. The severity of cocaine-related ICH, in comparison with spontaneous ICH not associated with cocaine, may be attributable, in large part, to the occurrence of IVH and brain stem location, but further studies are needed to substantiate this possibility. The mechanisms of cocaine-induced IVH also require further study.
Sources of Funding
This work was supported by AHA Award 0475008N (S.I.S.), NIH training grant T32NS04712, and P50 NS044227.
- Received November 14, 2009.
- Accepted December 17, 2009.
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