Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury.

A unique coagulopathy often manifests following traumatic brain injury, leading the clinician down a difficult decision path on appropriate prophylaxis and therapy. Conventional coagulation assays-such as prothrombin time, partial thromboplastin time, and international normalized ratio-have historically been utilized to assess hemostasis and guide treatment following traumatic brain injury. However, these plasma-based assays alone often lack the sensitivity to diagnose and adequately treat coagulopathy associated with traumatic brain injury. Here, we review the whole blood coagulation assays termed viscoelastic tests and their use in traumatic brain injury. Modified viscoelastic tests with platelet function assays have helped elucidate the underlying pathophysiology and guide clinical decisions in a goal-directed fashion. Platelet dysfunction appears to underlie most coagulopathies in this patient population, particularly at the adenosine diphosphate and/or arachidonic acid receptors. Future research will focus not only on the utility of viscoelastic tests in diagnosing coagulopathy in traumatic brain injury, but also on better defining the use of these tests as evidence-based and/or precision-based tools to improve patient outcomes.

Minimally invasive lateral transpsoas approach for spinal discitis and osteomyelitis.

We present a series of patients with discitis and osteomyelitis who were surgically treated via a minimally invasive lateral transpsoas approach to the lumbar spine. Surgical treatment for spinal discitis and osteomyelitis presents challenges because of comorbidities that are common in patients undergoing this procedure. A retrospective review found six patients who met strict operative criteria including instability, intractable pain, neurological deficit, and disease progression. All patients were non-ambulatory before surgery because of intractable back pain. The patients underwent standard lateral minimally invasive surgery using either the extreme lateral interbody fusion (NuVasive, San Diego, CA, USA) or direct lateral interbody fusion (Medtronic Sofamor Danek, Memphis, TN, USA) system. The patients underwent debridement with a discectomy and partial or complete corpectomy, with polyetheretherketone or titanium cage placement. Two patients had additional posterior fixation with percutaneous pedicle screws, and none had immediate perioperative complications. The postoperative CT scans demonstrated satisfactory debridement and hardware placement. All patients experienced significant pain improvement and could ambulate within a few days of surgery. So far, the 1 year follow-up data have demonstrated stable hardware with solid fusion and continued pain improvements. One patient demonstrated hardware failure secondary to refractory infection, 2 months postoperatively, and required additional posterior decompression and debridement with pedicle screw fixation. The lateral transpsoas approach permits debridement and fixation coupled with percutaneous pedicle screw fixation to further stabilize the spine in a minimally invasive fashion. Due to the significant comorbidities in this patient population, a minimally invasive approach is a suitable surgical technique. A close follow-up period is necessary to detect early hardware failure which may necessitate more extensive treatment.

An analysis of 88 patients with diffuse and "benign" perimesencephalic subarachnoid hemorrhage.

BACKGROUND AND STUDY AIMS: Perimesencephalic subarachnoid hemorrhage (PMSAH) was previously defined as a variant of subarachnoid hemorrhage (SAH) associated with a relatively benign clinical presentation and better outcomes than aneurysmal SAH. However, several prior studies have shown complications associated with PMSAH including vasospasm and hydrocephalus, and the need for follow-up imaging. We therefore reviewed our experience to further characterize the clinical consequences of PMSAH. MATERIALS AND METHODS: Eighty-eight consecutive patients who sustained spontaneous intracranial SAH and whose cerebral angiograms did not show any obvious source for SAH were retrospectively studied to characterize their prognosis and outcome based on SAH pattern. Glasgow Coma Scale and Hunt-Hess scores on admission, the incidence of vasospasm or hydrocephalus, the need for an external ventricular drain, and shunt dependence, along with Glasgow outcome score (GOS) at discharge and follow-up, were used to draw comparisons between perimesencephalic and diffuse SAH patient populations. RESULTS: Patients with perimesencephalic SAH differed statistically (p < 0.05) from patients with diffuse SAH in regard to age, Hunt-Hess score on presentation, hospital length of stay, GOS at discharge, and incidence of hydrocephalus, angiographic vasospasm, and clinical vasospasm. CONCLUSION: Our data demonstrate that although the patients with perimesencephalic SAH fared better than those with diffuse SAH, their outcomes were worse than those of similar patients with PMSAH who have been previously reported in the literature.

Radiographic and clinical outcome of syringomyelia in patients treated for tethered cord syndrome without other significant imaging abnormalities.

OBJECT: The surgical management of patients with symptoms of tethered cord syndrome (TCS) who lack significant radiographic abnormalities is controversial. One potential MRI marker for TCS is a spinal cord syrinx or syringomyelia. Alternatively, a syrinx may be a benign and incidental finding. In this report the authors evaluated a highly selected cohort of patients with symptoms of TCS with minimal radiographic abnormalities other than syringomyelia. They analyzed clinical and radiographic outcomes after tethered cord release (TCR). METHODS: A retrospective review of data from 16 children who met the study inclusion criteria was performed. All patients had been surgically treated at Riley Hospital for Children in Indianapolis, Indiana, between 2006 and 2011. All children had clinical symptoms of TCS as well as available pre- and postoperative MRI data. RESULTS: The most common presentation (12 [75%] of 16 patients) was urinary dysfunction, defined as symptoms of urgency or incontinence with abnormal urodynamic studies. Clinical follow-up data were available in 11 of these 12 patients. All 11 had improvement in symptoms at an average follow-up of 17 months. Seven (87.5%) of 8 patients presenting with back or leg pain had improvement. Three patients had progressive scoliosis; 2 had stabilization of the curve or mild improvement, and 1 patient had worsening deformity. Radiographic follow-up data were obtained an average of 14.5 months after surgery. Twelve patients (75%) had stable syringomyelia after TCR. Four patients showed improvement, with 2 having complete radiographic resolution. CONCLUSIONS: Highly selected patients with symptoms of TCS did very well clinically. Patients with abnormal urodynamic studies, pain, and gait disturbances showed a high rate of symptomatic improvement. However, a smaller percentage of patients had radiographic improvement of the syrinx. Therefore, the authors suggest that the decision to perform TCR should be based on clinical symptoms in this population. Symptomatic improvement was not necessarily related to radiographic resolution of the syrinx.

Acute, monocular vision loss from Rathke's cleft cyst.

Rathke's cleft cysts are benign, non-neoplastic sellar lesions that are often asymptomatic. The rare patient with symptoms may present with pituitary dysfunction, headache, or visual problems. Visual deficits are generally consistent with a chiasmal syndrome as associated with other sellar lesions. Therefore, the most commonly described deficit is bitemporal hemianopsia. We describe a 16-year-old female patient who presented with rare, rapidly progressing monocular blindness without signs of apoplexy or hemorrhage. She had complete return of vision after surgical decompression. The rapid loss and recovery of vision suggest that ischemic factors, rather than deformation of the optic apparatus, contributed to her symptoms. The relevant literature is reviewed.

Cyst-ventricle stent as primary or salvage treatment for posterior fossa arachnoid cysts.

OBJECT: The optimal treatment of symptomatic posterior fossa arachnoid cysts is controversial. Current options include open or endoscopic resection, fenestration, or cyst-peritoneal shunt placement. There are potential drawbacks with all options. Previous authors have described stenting a cyst into the ventricular system for supratentorial lesions. The current authors have used a similar strategy for posterior fossa cysts. METHODS: The authors performed a retrospective review of 79 consecutive patients (1993-2010) with surgically treated intracranial arachnoid cysts. RESULTS: The authors identified 3 patients who underwent placement of a stent from a posterior fossa arachnoid cyst to a supratentorial ventricle. In 2 patients the stent construct consisted of a catheter placed into a posterior fossa arachnoid cyst and connecting to a lateral ventricle catheter. Both patients underwent stent placement as a salvage procedure after failure of open surgical fenestration. In the third patient a single-catheter cyst-ventricle stent was stereotactically placed. All 3 patients improved clinically. Two patients remained asymptomatic, with radiographic stability in a follow-up period of 1 and 5 years, respectively. The third patient experienced initial symptom resolution with a demonstrable reduction of intracystic pressure. However, he developed recurrent headaches after 2 years. CONCLUSIONS: Posterior fossa cyst-ventricle stenting offers the benefits of ease of surgical technique and a low morbidity rate. It may also potentially reduce the incidence of shunt-related headaches by equalizing the pressure between the posterior fossa and the supratentorial compartments. While fenestration is considered the first-line therapy for most symptomatic arachnoid cysts, the authors consider cyst-ventricle stenting to be a valuable additional strategy in treating these rare and often difficult lesions.

Analysis of the risk of shunt failure or infection related to cerebrospinal fluid cell count, protein level, and glucose levels in low-birth-weight premature infants with posthemorrhagic hydrocephalus.

OBJECT: Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. METHODS: A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. RESULTS: Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. CONCLUSIONS: Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

Diagnostic and prognostic testing to evaluate coronary artery disease in patients with diabetes mellitus.

Coronary artery disease (CAD) continues to be the most common cause of morbidity and mortality in patients with diabetes mellitus (DM). In recent years, the strategies for treatment of CAD in DM have undergone much evolution. Currently, all patients with DM, regardless of symptoms or diagnosed CAD, are treated aggressively for CAD risk factor reduction. In this clinical climate, the ability to specifically identify patients with disease that will benefit from more aggressive and invasive therapies remains a challenge. In this article we review the current literature on diagnostic and prognostic utility of conventional non-invasive modalities for assessment of CAD in patients with DM, as well as on novel and emerging methods for CAD risk stratification.

A unique experiment in neurological surgery: intracerebral injection of antitoxin for tetanus.

The discipline of neurological surgery was considered primarily "hopeless" and, at best, experimental in the late 19th century. Harvey Cushing's efforts during his initial uncharted voyage through the surgery of the human cranium were rudimentary and exploratory. A direct review of his available patient records from early in his career provides the opportunity to look back at Cushing as a physician-scientist, uncovering work that demonstrates that he was at the forefront of neurosurgical intervention in avenues that have been largely overlooked. The authors present Cushing's notes pertaining to a case of tetanus. This case represents the intersection of neurosurgery and tetanus treatment in Dr. Cushing's intracerebral injection of antitoxin to treat generalized tetanus.

Spinal accessory nerve cavernous malformation.

We present the first reported case of a spinal accessory nerve cavernous malformation. A 54-year-old Caucasian male presented with a several-year history of progressive, vague bilateral upper and lower extremity paresthesias and pain. MRI of the spine revealed a heterogenously enhancing mass in the dorsal aspect of the spinal canal at the level of the atlas with mild spinal cord compression. The lesion was resected and upon gross and histologic examination it was a cavernous malformation embedded within a branch of the spinal accessory nerve. Post-operatively, the patient had no complications and some improvement in his symptoms. To our knowledge, this is the first report of a patient with a spinal accessory nerve cavernous malformation, and this should be considered in the differential of lesions in the craniocervical region.

Circumferential fixation with craniofacial miniplates for a cervical spine injury in a child.

Unstable pediatric cervical spine injuries present significant challenges in terms of fixation. Given the smaller cervical vertebral bodies in the preschool-aged population, commercially available pediatric cervical fixation instrumentation may be unsuitable because of the inappropriately large size of the screws and plates. The authors describe a 2-year-old girl who sustained an unstable C6-7 distraction injury during a motor vehicle accident. Because of the small size of her vertebral bodies, standard cervical spine instrumentation was not feasible, and posterior wiring alone was believed to be insufficient because of the complete distraction of all 3 spinal columns. The patient was taken to the operating room where craniofacial plates with an inherent locking mechanism were used to circumferentially stabilize the cervical spine. Follow-up examination 6 months postoperatively demonstrated stable cervical spine alignment and fusion with no evidence of the failure of either the anterior or posterior hardware. The use of craniofacial miniplates with an intrinsic locking mechanism represents a superior alternative for both anterior and posterior cervical fixations when spinal instrumentation is needed in the pediatric age group.