Haemophilus influenzae and Streptococcus pneumoniae infections in children with cerebrospinal fluid shunts.

OBJECTIVE: This paper reviews the frequency of central nervous system infections due to Haemophilus influenzae and Streptococcus pneumoniae associated with cerebrospinal fluid (CSF) shunts in pediatric patients. The need for immunizations in this patient population is also evaluated. PATIENTS: All patients with cerebrospinal fluid shunts except those with brain tumors seen in our clinics. METHODS: We reviewed data in three computer databases, kept prospectively recording details of CSF shunt procedures and CSF shunt-related infections. RESULTS: 1,226 patients underwent 3,889 shunt placements between 1957 and 2007. Twelve patients had 14 episodes of Haemophilus or pneumococcal infections. CONCLUSIONS: Children with CSF shunts are at high risk for infection with H. influenzae and S. pneumoniae. Routine immunizations during infancy in addition to the 23-valent polysaccharide pneumococcal vaccine should be highly and actively encouraged by health care providers caring for children with CSF shunts. Additional expanded-coverage vaccines should be utilized if and when they become available.

Histological analysis of DuraGen in a human subject: case report.

OBJECT: DuraGen (Integra Neurosciences, Plainsboro, NJ, USA) is an avascular collagen matrix used for dural closure. Although, numerous animal models have been studied, histological transformation of DuraGen in humans has not been reported. MATERIAL AND METHOD: We analyzed a sample of scarred DuraGen used in a craniectomy patient at time of delayed cranioplasty. CONCLUSION: Histological analysis revealed evidence for both fibroblast infiltration and neovascularization of the DuraGen.

Modulation of macrophage and microglial responses to axonal injury in the peripheral and central nervous systems.

OBJECTIVE: After axonal injury, macrophages rapidly infiltrate and become activated in the mammalian peripheral nervous system (PNS) but not the central nervous system (CNS). We used the dorsal root pathway to study factors that modulate the response of macrophages to degenerating axons in both the PNS and the CNS. METHODS: Lewis rats underwent transection of dorsal roots (Group 1), stab within the spinal cord (Group II), crush at the dorsal root entry zone (Group III), transection of dorsal roots combined with a CNS lesion (Group IV), or systemic administration of a known activator of macrophages, lipopolysaccharide, alone (Group V) or combined with transection of dorsal roots (Group VI). ED-1 antibody stained for macrophages and activated microglia at 7, 14, and 42 days postinjury. RESULTS: At early time points, Group I demonstrated ED-1 cells in the PNS but not the CNS portion of the degenerating dorsal roots. Group II revealed ED-1 cells near the stab lesion. Group III demonstrated ED-1 cells adjacent to the dorsal root entry zone crush site. Group IV revealed ED-1 cells along both the PNS and the CNS portions of the degenerating dorsal roots when the CNS lesion was placed near the transected roots. Group V demonstrated few ED-1 cells in the PNS and the CNS, whereas Group VI revealed a marked ED-1 cellular response along both the PNS and the CNS portions of the transected dorsal roots. CONCLUSION: Local CNS trauma and systemic administration of lipopolysaccharide can "prime" macrophages/microglia, resulting in an enhanced response to degenerating axons in the CNS. Such priming might prove useful in promoting axonal regeneration.

Ultrasound accelerates functional recovery after peripheral nerve damage.

OBJECTIVE: Axonal injury in the peripheral nervous system is common, and often it is associated with severe long-term personal and societal costs. The objective of this study is to use an animal model to demonstrate that transcutaneous ultrasound can accelerate recovery from an axonotmetic injury. METHODS: The sciatic nerve of adult male Lewis rats was crushed in the right midthigh to cause complete distal degeneration of axons yet maintain continuity of the nerve. Beginning 3 days after surgery, various transcutaneous ultrasound treatments or sham treatments were applied 3 days per week for 30 days to the crush site of rats that were randomly assigned to two groups. In the preliminary experiments, there were three animals in each ultrasound group and two control animals. In the final experiment, there were 22 animals in the ultrasound group and 20 animals in the control group. Recovery was assessed by use of a toe spread assay to quantify a return to normal foot function in the injured leg. Equipment included a hand-held transducer that emitted continuous-wave ultrasound. The most successful ultrasound protocol had a spatial peak, time-averaged intensity of 0.25 W/cm2 operated at 2.25 MHz for 1 minute per application. RESULTS: Rats subjected to the most successful ultrasound protocol showed a statistically significant acceleration of foot function recovery starting 14 days after injury versus 18 days for the control group. Full recovery by the ultrasound group occurred before full recovery by the control group. CONCLUSION: Transcutaneous ultrasound applied to an animal model of axonotmetic injury accelerated recovery. Future studies should focus on identification of the mechanism(s) by which ultrasound creates this effect, as a prelude to optimization of the protocol, demonstration of its safety, and its eventual application to humans.

Surgical management and seizure outcome in patients with tuberous sclerosis.

The authors report the results obtained in 11 patients with tuberous sclerosis (TS) who underwent cortical resection surgery for medically intractable epilepsy. Patients' ages at time of surgery ranged from 3 to 46 years (mean 19.6 years). Preoperative epileptiform electroencephalographic abnormalities were focal spike wave discharges in six patients (55%), multifocal in four patients (36%), and generalized in one patient (9%). In the multifocal and generalized groups, all patients (45%) were evaluated by means of subdural grid and strip electrode recordings, whereas electrophysiological localization in the remaining patients was derived from ictal and interictal scalp recordings. The seizure foci were found to be extratemporal in six patients (55%) and temporal in five patients (45%). Surgical intervention consisted of craniotomy and seizure foci resection guided by electrocorticographic monitoring and functional mapping in five awake (45%) and six asleep (55%) patients. Neuropathological examination of the resected seizure foci revealed cortical tubers in eight patients and diffuse gliosis in three patients. Follow up ranged from 8 to 127 months (mean 35 months). Six patients (55%) were seizure free, half of whom were not receiving antiepileptic drugs (AEDs); three patients (27%) had a greater than 70% reduction in seizure frequency, although they required AEDs; one patient (9%) had a 50% temporary reduction in seizure frequency during the initial 6-month postoperative period; and one patient (9%) was lost to follow-up study. From this small but adequately followed patient population with TS, the authors conclude that cortical resection of seizure foci tailored to electrocorticographic findings and functional mapping is encouraging for this difficult to manage patient population with medically intractable epilepsy.

Recurrent intracranial Masson's vegetant intravascular hemangioendothelioma. Case report and review of the literature.

In the central nervous system, recurrence of intracranial Masson's vegetant intravascular hemangioendothelioma (MVIH) is rare. To the authors' knowledge, only three recurrent intracranial cases have been reported. The authors report the case of a 75-year-old woman with a recurrent left-sided cerebellopontine angle and middle cranial fossa MVIH. When the patient was 62 years of age, she underwent preoperative embolization and subtotal resection of the intracranial lesion followed by postoperative radiotherapy. She was well and free from disease until 9 years postoperatively when she became symptomatic. At 71 years of age, the patient again underwent preoperative embolization and near-gross-total resection of the lesion. Follow-up imaging performed 15 months later revealed tumor recurrence, and she underwent stereotactic gamma knife radiosurgery. At a 2.75-year follow-up review, the patient's imaging studies revealed stable residual tumor. This case report is unique in that it documents the clinical and pathological features, surgical and postoperative treatment, and long-term follow-up review of a patient with recurrent intracranial MVIH and suggests that this unusual vascular lesion is a slow-growing benign tumor rather than a reactive process. Because the pathological composition of the lesion may resemble an angiosarcoma, understanding this benign vascular neoplasm is crucial so that an erroneous diagnosis of malignancy is not made and unnecessary adjuvant therapy is not given.

Cerebral autoregulation following minor head injury.

The purpose of this study was to determine whether patients with minor head injury experience impairments in cerebral autoregulation. Twenty-nine patients with minor head injuries defined by Glasgow Coma Scale (GCS) scores of 13 to 15 underwent testing of dynamic cerebral autoregulation within 48 hours of their injury using continuous transcranial Doppler velocity recordings and blood pressure recordings. Twenty-nine age-matched normal volunteers underwent autoregulation testing in the same manner to establish comparison values. The function of the autoregulatory response was assessed by the cerebral blood flow velocity response to induced rapid brief changes in arterial blood pressure and measured as the autoregulation index (ARI). Eight (28%) of the 29 patients with minor head injury demonstrated poorly functioning or absent cerebral autoregulation versus none of the controls, and this difference was highly significant (p = 0.008). A significant correlation between lower blood pressure and worse autoregulation was found by regression analysis in head-injured patients (r = 0.6, p < 0.001); however, lower blood pressure did not account for the autoregulatory impairment in all patients. Within this group of head-injured patients there was no correlation between ARI and initial GCS or 1-month Glasgow Outcome Scale scores. This study indicates that a significant number of patients with minor head injury may have impaired cerebral autoregulation and may be at increased risk for secondary ischemic neuronal damage.

Use of structural allografts in spinal osteomyelitis: a review of 47 cases.

OBJECT: The use of structural allografts in spinal osteomyelitis remains controversial because of the perceived risk of persistent infection related to a devitalized graft and spinal hardware. The authors have identified 47 patients over the last 3.5 years who underwent a surgical decompression and stabilization procedure in which fresh-frozen allografts were used after aggressive removal of infected and devitalized tissue. The patients subsequently underwent 6 weeks of postoperative antibiotic therapy (12 months for those with tuberculosis [TB]). METHODS: Follow-up data included results of serial clinical examinations, radiography, laboratory analysis (erythrocyte sedimentation rate and white blood cell count), and clinical outcome questionnaires. Of the original 47 patients (14 women and 33 men, aged 14-83 years), 39 were available for follow up. The average follow-up period at the time this article was submitted was 17 +/- 9 months (median 14 months, range 6-45 months). In the majority of cases (57%), a Staphylococcus species was the infectious organism. Predisposing risk factors included intravenous drug abuse (IVDA), previous surgery, diabetes, TB, and concurrent infections. During the follow-up period only two patients suffered recurrent infection at a contiguous level; both had a history of IVDA and one also had a chronic excoriating skin condition. No other recurrent infections have been identified, and no patient has required reoperation for persistent infection or allograft/hardware failure. CONCLUSIONS: It is the authors' opinion that the use of structural allografts in combination with aggressive tissue debridement and adjuvant antibiotic therapy provide a safe and effective therapy in cases of spinal osteomyelitis requiring surgery.

Meningeal meningiomatosis in a child: case report.

We report a child with multifocal meningeal lesions demonstrating mixed meningiomatous histologic features. This lesion appears to have evolved over seven years, starting with a brief episode of garbled speech, nausea, and headache at 4.5 years of age. The child was then asymptomatic until 9 when she presented with bilateral leg weakness, in addition to her prior presenting symptoms and communicating hydrocephalus. Meningeal biopsies of two lesions were performed 18 months later. Immunohistochemistry and electron microscopy were needed to substantiate the histologic diagnosis. Radiation therapy to the craniospinal axis and corticosteroids were of some benefit, but more aggressive therapeutic modalities became necessary. The nosology of this lesion is discussed.

Intrathecal baclofen for the treatment of intractable spasticity of spine or brain etiology.

Objective. To determine the long-term relief of spasticity and complication rates in patients who underwent placement of a programmable intrathecal baclofen pump for treatment of medically intractable spasticity of spine or brain etiology. Methods. Sixty-two consecutive adult patients who underwent placement of a programmable pump were retrospectively reviewed. Results. Spasticity was clinically and statistically significantly decreased in all patients. Catheter-related kinks, breaks, dislodgments, and disconnections were the most common complications followed by drug-related effects, infections, and wound complications. Conclusions. Intrathecal baclofen is a very effective strategy for the relief of medically intractable spasticity of spine or brain etiology. Even though 36% of patients have required revisions, no patient has experienced any long-term morbidity. Patients and their primary care givers have been pleased with the long-term effects of this therapy upon quality of life.

Spontaneous cerebellar hemorrhage due to a juvenile pilocytic astrocytoma: case report and review of the literature.

A 13-year-old boy presented to the emergency room with headaches and ataxia. Imaging studies revealed a cerebellar hemorrhage within a posterior fossa tumor. The patient underwent complete resection of this lesion and made a full recovery. Microscopic examination of this lesion revealed a juvenile pilocytic astrocytoma.

Differential macrophage responses in the peripheral and central nervous system during wallerian degeneration of axons.

We characterized quantitatively the macrophage response following axonal injury in both the peripheral (PNS) and central nervous system (CNS) of adult mammals. A monoclonal antibody (ED-1) which stains monocytes, macrophages, and activated microglia was employed. In one model, Wallerian degeneration of the sciatic nerve was studied. An increase in the number of macrophages was seen as early as 1 day following nerve transection. Macrophage number increased synchronously along the length of degenerating nerve over a 21-day period. In a second model, transection of a spinal dorsal sensory root allowed us to compare and contrast the macrophage response along the PNS and CNS portions of a single axonal pathway. An increased number of macrophages restricted to the PNS portion of this pathway was seen by 3 days and continued to increase over a 14-day period. Myelin breakdown occurred in association with an increase in the number of macrophages by 3 days in the PNS but not the CNS portion of the degenerating dorsal root axon pathway. Low-affinity nerve growth factor receptor immunohistochemical staining increased by Day 1 in the PNS but not the CNS portion of this pathway, occurring prior to the invasion of macrophages. In both models, the morphology of infiltrating macrophages changed over time from small slender ramified cells to large elongated multivacuolated cells. In conclusion, our results demonstrate that the macrophage response during Wallerian degeneration of axons in adult mammals is much more rapid and robust in the PNS, where axonal regeneration occurs, than in the CNS, where axonal regeneration is far more limited.

Complement depletion reduces macrophage infiltration and activation during Wallerian degeneration and axonal regeneration.

After peripheral nerve injury, macrophages infiltrate the degenerating nerve and participate in the removal of myelin and axonal debris, in Schwann cell proliferation, and in axonal regeneration. In vitro studies have demonstrated the role serum complement plays in both macrophage invasion and activation during Wallerian degeneration of peripheral nerve. To determine its role in vivo, we depleted serum complement for 1 week in adult Lewis rats, using intravenously administered cobra venom factor. At 1 d after complement depletion the right sciatic nerve was crushed, and the animals were sacrificed 4 and 7 d later. Macrophage identification with ED-1 and CD11a monoclonal antibodies revealed a significant reduction in their recruitment into distal degenerating nerve in complement-depleted animals. Complement depletion also decreased macrophage activation, as indicated by their failure to become large and multivacuolated and their reduced capacity to clear myelin, which was evident at both light and electron microscopic levels. Axonal regeneration was delayed in complement-depleted animals. These findings support a role for serum complement in both the recruitment and activation of macrophages during peripheral nerve degeneration as well as a role for macrophages in promoting axonal regeneration.

Percutaneous placement of ventriculoatrial shunts in the pediatric population.

The percutaneous placement of ventriculoatrial (VA) shunts has been previously described, usually in adults. We report a series of 7 pediatric cases ranging from 6 to 17 years. Five patients were female and 2 were male. All patients had prior ventriculoperitoneal (VP) shunts for hydrocephalus, of which 1 had been subsequently converted to a ventriculopleural shunt. Indications for conversion to a VA shunt were intra-abdominal infection in 6 cases and chronic pleuritic chest pain in 1 patient. The venous entry was the subclavian vein in all cases. All patients have remained asymptomatic since the operation. There were no complications associated with the procedures, with follow-up ranging from 2 to 12 months. This technique is a viable alternative to the open cervical approach for venous entry to the right atrium in the pediatric population.

Semipermeable polymer tubes provide a microenvironment for in vivo analysis of dorsal root regeneration.

The regeneration of lesioned axons is critically influenced by the local microenvironment. In this study, semipermeable polymer tubes were used to provide a defined microenvironment in vivo to analyze the regeneration of dorsal root axons under various conditions in the adult rat. Cut dorsal root fibers grew across a 2.7 mm gap within enclosed polymer tubes by 4 weeks. The pattern of axonal outgrowth was dramatically influenced by mechanical factors such as the inner surface topography of the polymer tube. Tubes containing various molecular and cellular substrates were also used to study their effect on dorsal root regeneration.

Dorsal laminectomy in the adult mouse: a model for nervous system research.

Animal strains with specific genetic mutations can serve as powerful tools to study normal and pathologic cellular and molecular processes. The mammalian species with the largest number of known genetic mutations is the mouse. In spinal cord research, mice have not been used as extensively as other species because of the difficulty in accessing and manipulating their spinal cord. We describe the technique of exposing and manipulating the spinal cord of normal mice and of mice with the severe combined immunodeficiency (scid) mutation. Surgical outcome and complications are discussed. We conclude that dorsal laminectomy with subsequent access and manipulation of the spinal cord and its roots can be accomplished consistently with practice.

Spontaneous resolution of a cervicothoracic syrinx in a child. Case report and review of the literature.

A child with near complete spontaneous resolution of a cervicothoracic syrinx and improvement in a Chiari type I malformation without surgical intervention is presented. The child was followed clinically with serial magnetic resonance (MR) imaging and has remained neurologically stable over an 11-year period. To our knowledge, only 3 pediatric cases of spontaneous resolution of a spinal cord syrinx as documented by MR imaging without surgical intervention have been reported. This case contributes to the literature on the natural history of syringes.

Bacterial meningitis associated with lumbar drains: a retrospective cohort study.

OBJECTIVES: The infective potential of lumbar drainage is an important topic deserving particular study. The aetiology, incidence, and clinical findings associated with bacterial meningitis are described in patients having continuous lumbar CSF drainage to treat communicating hydrocephalus after subarachnoid haemorrhage or CSF leaks after traumatic dural rents. METHODS: Retrospective review of the records of patients with a positive CSF bacterial culture who underwent lumbar drain placement over a 39 month period. RESULTS: Thirteen cases of bacterial meningitis occurred subsequent to the use of 312 lumbar drain kits (4.2%). All meningitic patients had CSF pleocytosis, but not all had peripheral leukocytosis. Fever, peripheral leukocytosis, and CSF pleocytosis did not help to differentiate the presence of bacterial meningitis from other infections. Eight patients had prior CSF drainage procedures, including ventriculostomy (n=5) or lumbar drain (n=5) placements; two patients received both procedures. Six of 13 patients developed their CSF infection within 24 hours of lumbar drain insertion. Six of 13 patients developed meningitis while receiving antibiotics for other reasons. CONCLUSIONS: External lumbar drainage seems to carry a low risk of infectious meningitis and offers a safe alternative to ventriculostomy or serial lumbar punctures. Antibiotics do not seem to protect completely against developing the infection. The infection happens most often with skin organisms. The meningitis often appears within 24 hours after lumbar drain placement. Daily CSF samples should include bacterial cultures but cell counts may not offer any additional useful information in diagnosing the complication. Lumbar drain insertion and management need not be confined to the intensive care unit.

Management of intrinsic gliomas of the tectal plate in children. A ten-year review.

The natural history, management, and long-term outcome for patients with benign, intrinsic tectal plate gliomas remain controversial in spite of their propensity to cause late-onset hydrocephalus. A 10-year retrospective review has identified 11 consecutive children with tectal plate lesions. Headache, vomiting, a decline in school performance, tremor, and complex partial seizures were common presenting symptoms. All patients presented with signs and symptoms of hydrocephalus. Magnetic resonance (MR) imaging delineated an intra-axial mass lesion of the midbrain primarily localized to the tectal plate which uniformly was hyperintense on T2-weighted imaging and had a more variable appearance on T1-weighted imaging and rare enhancement with gadolinium. No patient underwent surgical resection, chemotherapy, or radiotherapy. Three of 11 patients (27%) showed evidence of progression in size or a new focus of enhancement on MR imaging, which was clinically asymptomatic. In this series, no patient with a tectal plate lesion less than 1.5 cm in maximal diameter and without gadolinium enhancement showed any evidence of clinical or radiological progression. Although intrinsic tectal lesions in children are clinically indolent and the initial management consists of CSF diversion, these lesions may eventually progress and still warrant long-term follow-up with serial MR imaging.