The clinical significance of isolated traumatic subarachnoid hemorrhage.

BACKGROUND: Mild traumatic brain injury is a clinical diagnosis predicated on a patient's neurologic status and encompasses a variety of pathologies on computed tomography. We wondered whether isolated traumatic subarachnoid hemorrhage (iSAH) without other intracranial pathologic diagnosis is a more benign form of minor head injury that does not warrant extensive (and expensive) observation and follow-up. METHODS: This is a retrospective review of patients identified prospectively via a trauma registry during a period of 7 years, who had the computed tomographic finding of iSAH on admission scan and a Glasgow Coma Scale (GCS) score of 13 or greater. RESULTS: There were 478 patients identified, with a mean age 61 years, and 223 were male. Median Injury Severity Score (ISS) was 10 (range, 9-48), and the distribution was 415, 54, and 12 for those with GCS score of 15, 14, and 13, respectively. In-hospital follow-up imaging in nine patients demonstrated increased pathologic findings, but subsequent imaging showed stable or decreasing blood, and none experienced a neurologic decline or underwent a neurosurgical procedure.Among those with no other injuries (ISS = 9, n = 118) patients spent a mean of 2.0 (95% confidence interval, 1.1-2.9) days in intensive care unit and 4.9 (95% confidence interval, 3.9-6.0) days in hospital. The likelihood of discharge home was significantly related to age (p < 0.0001), ISS (p < 0.01), and admission GCS (p < 0.01) (stepwise logistic regression), but not progression of SAH.At 6-week follow-up, one patient (0.2%) developed bilateral chronic subdurals requiring drainage, without neurologic sequela. CONCLUSION: In this largest reported series to date of iSAH in the setting of mild traumatic brain injury, the finding seems to be benign and can likely be managed without routine follow-up imaging or intensive care unit admission in the absence of other significant trauma. LEVEL OF EVIDENCE: Epidemiologic/prognostic study, level III; therapeutic study, level IV.

Survey of the h index for all of academic neurosurgery: another power-law phenomenon?

OBJECT: The h index is a recently developed bibliometric that assesses an investigator's scientific impact with a single number. It has rapidly gained popularity in the physical and, more recently, medical sciences. METHODS: The h index for all 1120 academic neurosurgeons working at all Electronic Residency Application Service-listed training programs was determined by reference to Google Scholar. A random subset of 100 individuals was investigated in PubMed to determine the total number of publications produced. RESULTS: The median h index was 9 (range 0-68), with the 75th, 90th, and 95th percentiles being 17, 26, and 36, respectively. The h indices increased significantly with increasing academic rank, with the median for instructors, assistant professors, associate professors, and professors being 2, 5, 10, and 19, respectively (p < 0.0001, Kruskal-Wallis; all groups significantly different from each other except the difference between instructor and assistant professor [Conover]). Departmental chairs had a median h index of 22 (range 3-55) and program directors a median of 17 (range 0-62). Plot of the log of the rank versus h index demonstrated a remarkable linear pattern (R(2) = 0.995, p < 0.0001), suggesting that this is a power-law relationship. CONCLUSIONS: A survey of the h index for all of academic neurosurgery is presented. Results can be used for benchmark purposes. The distribution of the h index within an academic population is described for the first time and appears related to the ubiquitous power-law distribution.

Hydrogel coil-related delayed hydrocephalus in patients with unruptured aneurysms.

OBJECT: Because of high recanalization rates associated with wide-necked intracranial aneurysms treated with bare platinum coils, hydrogel coils (HydroCoil, MicroVention, Inc.) have been developed. Hydrogel coils undergo progressive expansion once exposed to the physiological environment of blood and increase overall aneurysm filling. METHODS: The authors retrospectively reviewed their series of patients with unruptured aneurysms treated between 1998 and 2006 and who underwent placement of bare platinum and hydrogel coils for cerebral aneurysms. They examined the incidence of delayed hydrocephalus as related to coil type. In a subgroup of patients in which preand postprocedure CT and MR imaging studies were available, the authors quantitatively analyzed the ventricular size change after hydrogel coils were placed. RESULTS: Four of 29 patients treated with hydrogel coils developed symptomatic hydrocephalus 2-6 months after the intervention compared with 0 of 26 treated with bare platinum coils alone. The difference in ventricular size between the subgroups in which pre- and postprocedure imaging was performed was found to be statistically significant (p < 0.05). All 4 HydroCoil-treated patients in whom hydrocephalus developed required placement of a shunt. CONCLUSIONS: A 14% incidence (95% confidence interval 3.9-31.7%) of hydrocephalus in patients with unruptured aneurysm undergoing embolization with hydrogel coils was discovered. This incidence is much higher than previously reported. The mechanism by which hydrogel coils may induce hydrocephalus remains poorly understood.

Relation among aneurysm size, amount of subarachnoid blood, and clinical outcome.

OBJECT: The authors of recent reports have suggested that smaller aneurysms are associated with more extensive subarachnoid hemorrhage (SAH), which could potentially presage poor outcome in patients harboring these lesions. The authors reviewed their clinical experience to determine if this theory has a basis in truth. METHODS: The authors undertook a retrospective review of a consecutive series of patients with aneurysmal SAH. Computed tomography scans and angiograms were studied to establish SAH scores and aneurysm size. RESULTS: One hundred thirty-three patients were treated during a 2-year period (January 2003-December 2004). There were 101 female and 32 male patients whose mean age was 56.7 years. The location distribution of aneurysms that bled was as follows: anterior communicating artery (56 cases), posterior communicating artery (34 cases), middle cerebral artery (21 cases), posterior circulation (16 cases), and paraclinoid region (six cases). The mean aneurysm size was 6.2 mm (range 2-26 mm). The mean SAH score was 18.3 (not normally distributed, p < 0.01, D'Agostino-Pearson test). One hundred three patients underwent surgical exploration and placement of an aneurysm clip, 21 underwent deployment of a coil, and two underwent both therapies; seven patients died prior to intervention. No correlation was found between aneurysm size and SAH score (r(s) = -0.023, p = 0.8) or between small aneurysm size and poor Glasgow Outcome Scale score (p = 0.13). In fact, the trend was the opposite. The SAH score did, however, correspond strongly with the admission Hunt and Hess grade (p < 0.0001), indicating the strong correlation between grade and volume of intracranial blood. Outcome was best explained in the multivariate analysis by the following factors: admission Hunt and Hess grade, age, and clinical vasospasm (p < 0.0001) with the proportion of cases correctly classified as 79.7%. CONCLUSIONS: Evaluation of the results in the present clinical series suggests that there is no relation between aneurysm size and volume of subarachnoid blood. The volume of cisternal blood correlates with Hunt and Hess grade but is not an independent determinant of outcome. Outcome is related to the following triad of well-established clinical factors: Hunt and Hess grade, age, and clinical vasospasm.

Surgical management of acute epidural hematomas.

INDICATIONS FOR SURGERY: An epidural hematoma (EDH) greater than 30 cm3 should be surgically evacuated regardless of the patient's Glasgow Coma Scale (GCS) score. An EDH less than 30 cm3 and with less than a 15-mm thickness and with less than a 5-mm midline shift (MLS) in patients with a GCS score greater than 8 without focal deficit can be managed nonoperatively with serial computed tomographic (CT) scanning and close neurological observation in a neurosurgical center. TIMING: It is strongly recommended that patients with an acute EDH in coma (GCS score < 9) with anisocoria undergo surgical evacuation as soon as possible. METHODS: There are insufficient data to support one surgical treatment method. However, craniotomy provides a more complete evacuation of the hematoma.