Forniceal deep brain stimulation rescues hippocampal memory in Rett syndrome mice

Deep brain stimulation (DBS) has improved the prospects for many individuals with diseases affecting motor control, and recently it has shown promise for improving cognitive function as well. Several studies in individuals with Alzheimer disease and in amnestic rats have demonstrated that DBS targeted to the fimbria-fornix^1-3, the region that appears to regulate hippocampal activity, can mitigate defects in hippocampus-dependent memory^3-5. Despite these promising results, DBS has not been tested for its ability to improve cognition in any childhood intellectual disability disorder (IDD). IDDs are a pressing concern: they affect as much as 3% of the population and involve hundreds of different genes. We hypothesized that stimulating the neural circuits that underlie learning and memory might provide a more promising route to treating these otherwise intractable disorders than seeking to adjust levels of one molecule at a time. We therefore studied the effects of forniceal DBS in a well-characterized mouse model of Rett Syndrome (RTT), which is a leading cause of intellectual disability in females. Caused by mutations that impair the function of MeCP2⁶, RTT appears by the second year of life, causing profound impairment in cognitive, motor, and social skills along with an array of neurological features⁷; RTT mice, which reproduce the broad phenotype of this disorder, also show clear deficits in hippocampus-dependent learning and memory and hippocampal synaptic plasticity^8-11. Here we show that forniceal DBS in RTT mice rescued contextual fear memory as well as spatial learning and memory. In parallel, forniceal DBS restored in vivo hippocampal long-term potentiation (LTP) and hippocampal neurogenesis. These results indicate that forniceal DBS might mitigate cognitive dysfunction in RTT.

Rectal and bladder dose reduction with the addition of intravaginal balloons to vaginal packing in intracavitary brachytherapy for cervical cancer

PURPOSE

The use of intravaginal Foley balloons in addition to conventional packing during high-dose-rate (HDR) tandem and ovoids intracavitary brachytherapy (ICBT) is a means to improve displacement of organs at risk, thus reducing dose-dependent complications. The goal of this project was to determine the reduction in dose achieved to the bladder and rectum with intravaginal Foley balloons with CT-based planning and to share our packing technique.

METHODS AND MATERIALS

One hundred and six HDR-ICBT procedures performed for 38 patients were analyzed for this report. An uninflated Foley balloon was inserted into the vagina above and below the tandem flange separately and secured in place with vaginal packing. CT images were then obtained with both inflated and deflated Foley balloons. Plan optimization occurred and dose volume histogram data were generated for the bladder and rectum. Maximum dose to 0.1, 1.0, and 2.0 cm(3) volumes for the rectum and bladder were analyzed and compared between inflated and deflated balloons using parametric statistical analysis.

RESULTS

Inflation of intravaginal balloons allowed significant reduction of dose to the bladder and rectum. Amount of reduction was dependent on the anatomy of the patient and the placement of the balloons. Displacement of the organs at risk by the balloons allowed an average of 7.2% reduction in dose to the bladder (D0.1 cm(3)) and 9.3% to the rectum (D0.1 cm(3)) with a maximum reduction of 41% and 43%, respectively.

CONCLUSIONS

For patients undergoing HDR-ICBT, a significant dose reduction to the bladder and rectum could be achieved with further displacement of these structures using intravaginal Foley balloons in addition to conventional vaginal packing.

Management of infections complicating the orbitocranial approaches: Report of two cases and review of literature

BACKGROUND

The orbitocranial approaches are now indispensible for treating lesions of the skull base, providing access to lesions in the anterior and middle cranial fossae, as well as the upper clivus and anterior brainstem. The management of infectious complications of the orbitocranial approaches, however, has evaded the literature.

CASE DESCRIPTION

We present two cases of patients who underwent orbitocranial approach whose clinical course was complicated by wound infection and osteomyelitis. One patient was treated with antibiotics and then had a custom implant placed for cranioplasty. The other case was managed with removal of bone and wire-mesh cranioplasty.

CONCLUSION

Management of orbitocraniotomy infections can be difficult due to the complex geometry of the flap and to cosmetic considerations. Once the infection involves the bone, the bone can be replaced after cleaning or discarded and a cranioplasty performed. Cranioplasty can be performed with wire-mesh or a custom implant made by computer-assisted modeling.

Impact of surgical methodology on the complication rate and functional outcome of patients with a single brain metastasis

OBJECT Brain metastases are the most common intracranial neoplasms and are on the increase. As radiation side effects are increasingly better understood, more patients are being treated with surgery alone with varying outcomes. The authors previously reported that en bloc resection of a single brain metastasis was associated with decreased incidences of leptomeningeal disease and local recurrence compared with piecemeal resection. However, en bloc resection is often feared to cause an increased incidence of postoperative complications. This study aimed to answer this question. METHODS The authors reviewed data from patients with a previously untreated single brain metastasis, who were treated with resection at The University of Texas M.D. Anderson Cancer Center (1993-2012). Data related to the patient, tumor, and methods of resection were obtained. Discharge Karnofsky Performance Scale (KPS) scores and 30-day postoperative complications were noted. Complications were considered major when they persisted for longer than 30 days, resulted in hospitalization or prolongation of hospital stay, required aggressive treatment, and/or were life threatening. RESULTS During the study period, 1033 eligible patients were identified. The median age was 58 years, 83% had a KPS score greater than 70, and 81% were symptomatic at surgery. Sixty-two percent of the patients underwent en bloc resection of their tumor, and 38% underwent piecemeal resection. There were significant differences between the 2 groups in terms of preoperative tumor volume, tumor functional grade, and symptoms at presentation, among others. The overall complication rates were 13% for patients undergoing en bloc resection and 19% for patients undergoing piecemeal resection (p = 0.007). The incidences of major complications and neurological complications were also significantly different. There was a trend in the same direction for major neurological complications, although it was not significant. Among patients undergoing piecemeal resection of tumors in eloquent cortex, 24% had complications (13% had major, 18% had neurological, 9% had major neurological, and 13% had select neurological complications; 4% died within 1 month of surgery). Among those undergoing en bloc resection of such tumors, 11% had complications (6% had major, 8% had neurological, 4% had major neurological, and 4% had select neurological; 2% died within 1 month of surgery). The differences in overall, major, neurological, and select neurological complications were statistically significant, but 1-month mortality and major neurological complications were not. In addition, within subcategories of tumor volume, the incidence of various complications was generally higher for patients undergoing piecemeal resection than for those undergoing en bloc resection. CONCLUSIONS The authors' results indicate that postoperative complication rates are not increased by en bloc resection, including for lesions in eloquent brain regions or for large tumors. This gives credence to the idea that en bloc resection of brain metastases, when feasible, is at least as safe as piecemeal resection.

Predictors of outcome in civilians with gunshot wounds to the head upon presentation

OBJECT

Prediction of outcome from initial presentation after a gunshot wound to the head (GSWH) is essential to further clinical decision making. The authors' goals are to report the survival and functional outcomes of these patients, to identify prognostic factors, and to propose a scoring system that can predict their outcome.

METHODS

The records of 199 patients admitted with a GSWH with dural penetration between 1990 and 2008 were retrospectively reviewed. The inclusion criterion was a CT scan available for review. Patients declared brain dead on presentation were excluded, which yielded a series of 119 patients. Statistical analysis was performed using a logistic regression model.

RESULTS

Fifty-eight (49%) of the 119 patients died. Twenty-three patients (19%) had a favorable outcome defined as a 6-month Glasgow Outcome Scale (GOS) score of moderate disability or good recovery, 35 (29%) had a poor outcome (GOS of persistent vegetative state or severe disability), and 3 (3%) were lost to follow-up. Significant prognostic factors for mortality were age older than 35 years, nonreactive pupils, bullet trajectory of bihemispheric (excluding bifrontal), and posterior fossa involvement compared with unihemispheric and bifrontal. Factors that were moderately associated with higher mortality included intracranial pressure (ICP) above 20 mm Hg and Glasgow Coma Scale (GCS) score at presentation of 3 or 4. Upon multivariate analysis, the significant factors for mortality were bullet trajectory and pupillary response. Variables found to be significant for good functional outcome were admission GCS score greater than or equal to 5, pupillary reactivity, and bullet trajectory of unihemispheric or bifrontal. Factors moderately associated with good outcome included age of 35 years or younger, initial ICP 20 mm Hg or lower, and lack of transventricular trajectory. In the multivariate analysis, significant factors for good functional outcome were bullet trajectory and pupillary response, with age moderately associated with improved functional outcomes. The authors also propose a scoring system to estimate survival and functional outcome.

CONCLUSIONS

Age, pupils, GCS score, and bullet trajectory on CT scan can be used to determine likelihood of survival and good functional outcome. The authors advocate assessing patients based on these parameters rather than pronouncing a poor prognosis and withholding aggressive resuscitation based upon low GCS score alone.

Simultaneous spectrophotometric determination of celecoxib and diacerein in bulk and capsule by absorption correction method and chemometric methods

Two methods, absorption correction and multivariate spectrophotometric methods were developed for simultaneous estimation of Celecoxib (CEL) and Diacerein (DIA) in combined dosage form. Absorption correction method involves direct estimation of DIA at wavelength 341 nm in which CEL has zero absorbance and shows no interference. For estimation of CEL, corrected absorbance was calculated at 253 nm due to the interference of DIA at this wavelength. Linearity was observed in the range of 6-22 μg mL(-1) for CEL and 3-11 μg mL(-1) for DIA. The method was validated as per ICH guidelines. Chemometric methods including classical least square (CLS), inverse least square (ILS), principal component regression (PCR) and partial least square (PLS) were studied for simultaneous determination of CEL and DIA in capsule using spectrophotometry. A set of 25 standard mixtures containing both drugs were prepared in range of 5-25 μg mL(-1) for CEL and 3-15 μg mL(-1) for DIA. Analytical figure of merit (FOM), such as sensitivity, selectivity, analytical sensitivity, limit of detection and limit of quantitation were determined for chemometric methods. The proposed methods were applied for determination of two components from combined dosage form.

Assessment of the impact of comorbidities on perioperative complications in pediatric neurosurgery

OBJECT

Recent attempts to control health care costs focus on reducing or eliminating payments for complications, hospital-acquired conditions, and provider preventable conditions, with payment restrictions applied uniformly. A patient's preexisting comorbidities likely influence the perioperative complication incidence. This relationship has not previously been examined in pediatric neurosurgery.

METHODS

The authors conducted a retrospective assessment of prospectively collected relevant patient comorbidities and morbidity and mortality events at a large pediatric neurosurgical unit over a 5-year period. The authors examined the impact of specific comorbidities and the cumulative effect of multiple comorbidities on complication incidence.

RESULTS

A total of 1990 patients underwent 3195 procedures at the authors' institution during the 5-year study period. Overall, 396 complications were analyzed; 298 patients (15.0%) experienced at least one complication. One or more comorbidities were present in 45.9% of patients. Renal comorbidities were clearly associated with the increased incidence of complications (p = 0.02), and they were specifically associated with infection (p = 0.006). Neurological comorbidities had a borderline association with complications (p = 0.05), and they were specifically associated with death (p = 0.037). A patient's having more comorbidities did not correlate with an increased risk of a perioperative complication (p = 0.8275).

CONCLUSIONS

The complication incidence in pediatric neurosurgery is variable and may be influenced by the type of neurosurgical procedure and patient-related factors. While patient-related factors beyond the control of the provider can significantly impact complications and hospital-acquired conditions in pediatric neurosurgery, an increasing number of comorbidities do not correlate with an increased risk of complications per patient.

Double-barrel bypass for cerebral ischemia: technique, rationale, and preliminary experience with 10 consecutive cases

BACKGROUND

In selected patients, extracranial-intracranial bypass remains an important treatment for the prevention of stroke. Traditionally, superficial temporal artery-middle cerebral artery (STA-MCA) bypass uses 1 STA branch. We have adopted a "double-barrel" technique in which both branches are joined with MCA recipients in distinct vascular territories.

OBJECTIVE

To assess the feasibility of routinely using both branches of the STA for cerebral revascularization.

METHODS

Ten consecutive patients underwent double-barrel bypass. Patients were selected if they demonstrated symptomatic MCA hypoperfusion resistant to medical therapy or had symptomatic moyamoya disease. Flow-directed bypass was performed to augment flow to the territories most at risk in each case, based on preoperative and intraoperative data. Computed tomography perfusion was routinely performed to evaluate baseline deficits and postoperative augmentation. Clinical data were analyzed to assess patient demographics and outcomes.

RESULTS

The double-barrel bypass was no more difficult technically than the traditional approach, with the second branch harvested through a small satellite incision. By isolating temporary occlusion to each territory, there was no additional ischemia to each brain region. No intraoperative complications or wound-healing issues occurred. Postoperative computed tomography perfusion studies all showed improvement, and delayed vascular imaging demonstrated universal graft patency. Nine of 10 patients have been asymptomatic since surgery, whereas 1 patient demonstrated symptoms in a separate vascular distribution.

CONCLUSION

Double-barrel STA-MCA bypass is both feasible and potentially advantageous. In our series, both bypass branches remained patent, augmenting flow to the territories most at need.

Osteosarcoma of the cranial vault and skull base in pediatric patients

Cranial osteosarcoma is very rare in children, rendering the development of optimal treatment algorithms challenging. The authors present 3 cases of pediatric cranial osteosarcoma: a primary calvarial tumor, a cranial metastasis, and a primary osteosarcoma of the cranial base. A review of the literature demonstrates significant variation in the management of cranial osteosarcomas and the outcome for patients with these tumors. This series and literature review is presented to improve the understanding of pediatric cranial osteosarcoma and to reinforce the importance of maximal resection in optimizing outcome.

Rh-BMP-2 for L5-S1 arthrodesis in long fusions to the pelvis for neuromuscular spinal deformity in the pediatric age group: analysis of 11 patients

PURPOSE

Neuromuscular scoliosis is a challenging pathology to treat with high incidence of complications and failure of surgical fusion. Surgical correction can entail long fusion constructs extending to the pelvis. We report our experience in the use of bone morphogenetic protein (BMP) to augment L5-S1 arthrodesis in long segment fusions in pediatric patients with neuromuscular scoliosis.

METHODS

Retrospective review of 11 pediatric patients with neuromuscular spinal deformity (mean, age 13.7 years; range, 10-20 years) who underwent long (mean, 15 levels; range, 10-18 levels) spinal instrumentation and fusion to the pelvis at a single institution from 2007 to 2012 with an average follow-up of 34 months (range, 11-62 months).

RESULTS

Of the 11 patients, one had pseudoarthrosis at L5-S1. The average coronal Cobb angle measured 59° before surgery and 42° immediately after surgery. The average preoperative thoracic kyphosis and lumbar sagittal lordosis measured 34 and 59°, respectively. Immediately after surgery, the thoracic and lumbar angles measured 28 and 39°, respectively. At last follow-up, the average coronal Cobb angle was maintained at 43° and the thoracic and lumbar sagittal angles were 28 and 44°, respectively. An average of 14.2 mg of recombinant human bone morphogenetic protein-2 (rh-BMP-2) was used for each case.

CONCLUSIONS

L5-S1 arthrodesis may be effectively achieved in long fusions for pediatric neuromuscular spinal deformity with posterolateral fusion supplemented with rh-BMP-2. This surgical strategy may be associated with lower complication rates, decreased blood loss, and shorter operative times than circumferential fusion, which is particularly important in this complex fragile patient population.

Iliac screw placement in neuromuscular scoliosis using anatomical landmarks and uniplanar anteroposterior fluoroscopic imaging with postoperative CT confirmation

OBJECT

Neuromuscular scoliosis is a challenging pathology to treat. Surgical correction can involve long fusion constructs extending to the pelvis. The deformity inherent in these patients makes it difficult to obtain adequate lateral intraoperative radiographs for traditional image-guided placement of iliac screws.

METHODS

A clinical and radiographic assessment of 14 patients with neuromuscular spinal deformity was conducted. From 2007 to 2013, 12 of these patients (mean age 14.25 years, range 10-20 years) underwent long spinal instrumentation (mean 15 levels, range 10-18 levels) and fusion to the pelvis, and 2 underwent placement of a growing rod construct with iliac screw placement at a single institution. The average length of follow-up was 33.7 months (range 6-64 months). Iliac screws were placed after identifying the posterior superior iliac spine and using only anteroposterior fluoroscopy (view of the inlet of the pelvis), rather than the technique of direct palpation of the sciatic notch. The accuracy of iliac screw placement was assessed with routine postoperative CT.

RESULTS

A total of 12 patients had 24 screws placed as part of a long-segment fusion to the pelvis, and 2 patients had two iliac screws placed as part of a growing rod construct for neuromuscular scoliosis. There were no iliac screw misplacements, and no complications directly related to the technique of iliac screw placement. For cases of definitive fusion (n = 12), the average coronal Cobb angle of patients with neuromuscular spinal deformity measured 62° before surgery and 44.3° immediately after surgery. The average preoperative thoracic kyphosis and lumbar sagittal lordosis measured 37.3° and 60.7°, respectively. Immediately after surgery, the thoracic and lumbar angles measured 30° and 41.1°, respectively. At last follow-up, the average coronal Cobb angle was maintained at 45.1°, and the thoracic and lumbar sagittal angles were maintained at 32.8° and 45.3°, respectively.

CONCLUSIONS

A less invasive technique for iliac screw placement can be performed safely with a low likelihood of screw misplacement. This technique offers the biomechanical advantages of iliac fixation without the soft tissue exposure typically needed for safe screw insertion. The technique relies on identification of the posterior superior iliac spine and high quality anteroposterior fluoroscopic imaging for a view of the pelvic inlet.

Bilateral pallidal deep brain stimulation for X-linked dystonia-parkinsonism

BACKGROUND

X-linked dystonia-parkinsonism (XDP) is a progressively debilitating movement disorder that begins with focal dystonia and eventually generalizes. It exclusively affects Filipino inhabitants of the island of Panay. We report a case of XDP successfully treated by deep brain stimulation (DBS) and review the literature.

METHODS

A 36-year-old man with XDP failed medical management and underwent bilateral globus pallidus internus DBS. A search of the PubMed database was performed to identify all articles discussing DBS and XDP. "Stimulation," "DYT3," "Lubag," "torsion dystonia," and "dystonia-parkinsonism" were used as MeSH headings.

RESULTS

The patient's postoperative course was notable for delayed emergence from anesthesia. When stimulation was started, he had immediate improvement in his symptoms, and at 6-month follow-up, he is able to ambulate with the assistance of a walker. Review of the literature revealed 5 previously reported cases of XDP treated with DBS.

CONCLUSIONS

The published experience with globus pallidus internus DBS for XDP has been very positive to date. Although long-term follow-up data are needed, early results provide optimism for patients with this debilitating disorder.

Disseminated intracranial juvenile xanthogranulomatosis in a neonate without cutaneous lesions

Juvenile xanthogranuloma (JXG) is a rare disease that is part of a spectrum of histiocytic dendritic cell disorders. The authors report an unusual case of a 6-week-old male who presented with seizures. Neuroimaging revealed disseminated intracranial disease involving the optic apparatus, basal ganglia, lateral ventricles, and brainstem. The patient did not have any cutaneous lesions or evidence of extracranial disease. The patient underwent open biopsy of a large right midbrain lesion; pathology was consistent with JXG. He underwent postoperative chemotherapy and is doing well 7 months after surgery with regression of the intracranial lesions. To the best of the authors' knowledge, this is the first report of a neonate with disseminated intracranial JXG without cutaneous stigmata.

Congenital hypoplasia or aplasia of the lumbosacral pedicle as an unusual cause of spondylolisthesis in the pediatric age group

The authors describe rare cases of congenital hypoplasia of the L-5 pedicles and the congenital absence of the left S-1 pedicle in 2 young girls, respectively, including the presentation, diagnosis, and treatment. Moreover, they review the literature on this clinical entity. The patients presented with intractable chronic low-back pain. Plain radiographs and 2D CT scanning revealed the presence of the aforementioned anomalies. Degenerative changes to adjacent level and contralateral facet joints were thought to be the result of overload and instability and seemed to have led to spondylolisthesis, micromotion at L-5 and S-1, and subsequent low-back pain. The pediatric patients were treated with posterior instrumented fusion with good functional outcomes at a minimum 3-month follow-up. To the best of the authors' knowledge, these are the first reports of intractable low-back pain and spondylolisthesis accompanied by hypoplastic-aplastic pedicles at the lumbosacral junction in children.

Successful percutaneous coronary intervention in a patient with combined deficiency of FV and FVIII due to novel compound heterozygous mutations in LMAN1

Percutaneous coronary intervention (PCI) in patients with congenital coagulation factor deficiencies presents a unique challenge. They are not only at increased risk of perioperative bleeding but can also suffer thrombosis of the stent as preventive anticoagulation and antiplatelet therapy is difficult. Several cases of successful PCI have been described in patients with haemophilia A and B, but there are no reports in patients with combined coagulation factor deficiencies. We used PCI to treat the coronary artery disease in a patient with the combined deficiency of factor V and factor VIII (F5F8D) and analysed the molecular basis of the disorder for this patient. A 68-year-old patient was admitted for urgent PCI with bare metal stent placement after the diagnosis of the F5F8D. Peripheral blood DNA was extracted for the sequence analysis of LMAN1 and MCFD2 genes. Mutations in LMAN1 was confirmed by molecular cloning of the PCR product and resequencing of the resulting clones. The patient underwent successful PCI with good long-term outcome. Our patient tolerated anticoagulation therapy well, with unfractionated heparin, and double antiplatelet therapy while he was initially supported with fresh frozen plasma and recombinant FVIII. Molecular analysis revealed that the patient carries unusual compound heterozygous frameshift mutations on the same microsatellite repeat region in exon 8 of LMAN1, one of which is a novel mutation (c.912delA). Our results suggest that patients with F5F8D can safely undergo PCI for coronary artery disease, with the treatment individualized to the specific patient.

Isolated cervical spinal canal stenosis at C-1 in the pediatric population and in Williams syndrome

OBJECT

Isolated cervical canal stenosis at the level of the atlas (C-1) is a rare cause of cervical myelopathy in the pediatric population. It has been associated with several genetic disorders including spondyloepiphysial dysplasia congenita, Down syndrome, and Klippel-Feil syndrome. The purpose of this study is to highlight the authors' experience with 4 additional pediatric cases, review the literature, and report a new association of this disease with Williams syndrome.

METHODS

The medical records and radiological imaging studies of 4 patients treated at Texas Children's Hospital for symptomatic hypoplasia of the atlas were retrospectively reviewed. Pertinent patient demographic data, clinical presentation, imaging findings, and outcomes after surgery were recorded. A thorough literature review was performed, allowing the authors to compare and contrast their 4 cases to surgical cases already published in the literature.

RESULTS

There were 11 boys and 1 girl in the aggregate series. The average age of the patients was 7 years (range 13 months-14 years), and the duration of symptoms prior to presentation was 6 months (range 0-36 months). The mean sagittal diameter of the spinal canal at the level of the atlas measured from the posterior aspect of the dens to the anterior aspect of the arch of C-1 was 11.9 mm (range 8.3-16 mm) in the aggregate series. In 2 new pediatric patients with hypoplasia of the atlas the disease was associated with Williams syndrome, which has not been previously described. Patients in the aggregate series were followed for an average of 18 months (range 3-50 months). Laminectomy of C-1 provided neurological improvement in all patients who presented.

CONCLUSIONS

Isolated cervical spinal canal stenosis at the level of the atlas is a rare cause of cervical myelopathy. The authors hope that this report will prompt clinicians to consider it when searching for the origin of signs and symptoms of cervical myelopathy, especially in children.

Open craniotomy for brain abscess: A forgotten experience?

Background:

Brain abscess carries a high morbidity and mortality despite medical advances. In this paper, we present a single institution's experience with the surgical treatment of brain abscess.

Methods:

We retrospectively analyzed 33 cases of intracranial abscess who underwent surgical treatment between January 2001 and December 2009. Patients were treated with aspiration through a single burr hole, open aspiration with ultrasound guidance, or complete abscess resection. The medical records were analyzed for demographics, clinical presentation, predisposing factors, imaging, microbiological investigations, treatment, and outcomes.

Results:

There were 26 male and 7 female patients, aged between 12 and 78 years. The most common predisposing factor was head trauma. Surgical excision of the abscess was performed in 22 patients, open aspiration in 9 patients, and burr-hole aspiration in 2 patients. Repeat surgical procedure was required in six patients. Mortality in this series was 21%. A favorable outcome (Glasgow outcome scale 4 and 5) was achieved in 54%. There was no significant correlation between outcome and age, predisposing factor, treatment modality, or culture results.

Conclusions:

In this series, most patients were treated with an open technique, either by surgical excision or open aspiration of brain abscess. An open technique may reduce the need for additional imaging, surgical treatment, and length of antibiotic therapy. In resource-limited settings, excision of brain abscess may play a more important role in patient management while maintaining favorable outcomes.

Capillary versus venous haemoglobin determination in the assessment of healthy blood donors

BACKGROUND AND OBJECTIVES

To determine the accuracy of fingerstick haemoglobin assessment in blood donors, the performance of a portable haemoglobinometer (HemoCue Hb 201+) was prospectively compared with that of an automated haematology analyzer (Cell-Dyn 4000). Haemoglobin values obtained by the latter were used as the 'true' result.

MATERIAL AND METHODS

Capillary fingerstick samples were assayed by HemoCue in 150 donors. Fingerstick samples from two sites, one on each hand, were obtained from a subset of 50 subjects. Concurrent venous samples were tested using both HemoCue and Cell-Dyn devices.

RESULTS

Capillary haemoglobin values (HemoCue) were significantly greater than venous haemoglobin values (HemoCue), which in turn were significantly greater than venous haemoglobin values by Cell-Dyn (mean ± SD: 14.05 ± 1.51, 13.89 ± 1.31, 13.62 ± 1.23, respectively; P < 0.01 for all comparisons among groups). Nine donors (6%) passed haemoglobin screening criteria (≥ 12.5 g/dl) by capillary HemoCue, but were deferred by Cell-Dyn values (false-pass). Five donors (3%) were deferred by capillary sampling, but passed by Cell-Dyn (false-fail). Substantial variability in repeated fingerstick HemoCue results was seen (mean haemoglobin 13.72 vs. 13.70 g/dl, absolute mean difference between paired samples 0.76 g/dl). Hand dominance was not a factor.

CONCLUSIONS

Capillary samples assessed via a portable device yielded higher haemoglobin values than venous samples assessed on an automated analyzer. False-pass and false-fail rates were low and acceptable in the donor screening setting, with 'true' values not differing by a clinically significant degree from threshold values used to assess acceptability for blood donation.

Computed tomography morphometric analysis for lateral mass screw placement in the pediatric subaxial cervical spine

Object

Lateral mass screws are routinely placed throughout the subaxial cervical spine in adults, but there are few clinical or radiographic studies regarding lateral mass fixation in children. The morphology of pediatric cervical lateral masses may be associated with greater difficulty in obtaining adequate purchase. The authors examined the lateral masses of the subaxial cervical spine in pediatric patients to define morphometric differences compared with adults, establish guidelines for lateral mass instrumentation in children, and define potential limitations of this technique in the pediatric age group.

Methods

Morphometric analysis was performed on CT of the lateral masses of C3–7 in 56 boys and 14 girls. Measurements were obtained in the axial, coronal, and sagittal planes.

Results

For most levels and measurements, results in boys and girls did not differ significantly; the few values that were significantly different are not likely to be clinically significant. On the other hand, younger (< 8 years of age) and older children (≥ 8 years of age) differed significantly at every level and measurement except for facet angularity. Sagittal diagonal, a measurement that closely estimates screw length, was found to increase at each successive caudal level from C-3 to C-7, similar to the adult population. A screw acceptance analysis found that all patients ≥ 4 years of age could accept at least a 3.5 × 10 mm lateral mass screw.

Conclusions

Lateral mass screw fixation is feasible in the pediatric cervical spine, particularly in children age 4 years old or older. Lateral mass screw fixation is feasible even at the C-7 level, where pedicle screw placement has been advised in lieu of lateral mass screws because of the small size and steep trajectory of the C-7 lateral mass. Nonetheless, all pediatric patients should undergo high-resolution, thin-slice CT preoperatively to assess suitability for lateral mass screw fixation.

Disseminated germinoma in the brain and cervical spinal cord 10 years after radiographic resolution of pineal germinoma

Intracranial germinoma, a radiosensitive tumor, is seldom recurrent following initial treatment. When it does recur, it is usually soon after initial treatment and secondary to inadequate radiation field coverage of the tumor. Rarely, there have been case reports of late recurrence many years after initial therapy. Patients with recurrent germinoma in the spine have a less favorable prognosis in terms of treatment response compared to the initial lesion. Thus, careful consideration of the initial lesion, its treatment, and serial imaging of the neural axis with close follow-up is important. We report a patient with a rare delayed recurrence in the brain and cervical spinal cord despite close follow-up with clinical examination and serial imaging.