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Michael L. Levy, Brian H. Wieder, John Schneider and Martin H. Weiss

✓ A paucity of formally described information is available in the scientific literature regarding spinal subdural empyema. Patients presenting with neurological deterioration associated with subdural empyema are rarely identified, and treatment is often based upon anecdotal cases. The authors contribute three cases of primary cervical spinal subdural empyema and review the seven found in the literature. All patients had clinical evidence of neurological compromise, cervical tenderness, cervical pain, and leukocytosis upon admission. Cervical involvement ranged from C-2 to C-7. All patients underwent laminectomy with durotomy and drainage. The authors recommend prompt surgical decompressive laminectomy, copious irrigation, and drainage, followed with appropriate adjunctive antibiotic therapy for treatment of these patients.

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John H. Chi and Michael W. McDermott

Tuberculum sellae meningiomas are a classic tumor of the anterior fossa that present in patients with gradual visual deterioration secondary to optic apparatus compression. If untreated, complete blindness can occur. Treatment involves tumor removal and decompression of the optic chiasm via several operative approaches. Gross-total resection (Simpson Grade I or II) is the goal of treatment and can usually be accomplished safely. Special excision-related considerations include appreciation of arachnoid planes separating the tumor from neural tissue, adequate drilling of osseous elements for optimal exposure, and intraoperative preservation of the vascular supply to the optic apparatus. The authors reviewed their experience at the University of California, San Francisco, in cases of tuberculum sellae meningiomas treated between 1992 and 2002. In most patients, improvement of vision can be achieved with minimal postoperative complications and morbidity.

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Yoon-Hee Cha, John H. Chi and Nicholas M. Barbaro

✓ Spinal subdural hematomas (SDHs) are a rare cause of cord compression and typically occur in the setting of spinal instrumentation or coagulopathy. The authors report the first case of a spontaneous spinal SDH occurring in conjunction with low-molecular-weight heparin use in a patient with a history of spinal radiotherapy.

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James M. Drake

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John H. Chi, Heather J. Fullerton and Nalin Gupta

Object

Congenital hydrocephalus has an estimated population incidence of 0.2 to 0.8/1000 live births. With improvements in techniques for cerebrospinal fluid shunting, treatment of hydrocephalus has become safe and routine, yet data describing mortality from congenital hydrocephalus or demonstrating improvements in mortality with the advent of modern treatment are scarce. The authors' analysis sought to rectify this situation.

Methods

The authors performed an electronic search of National Center for Health Statistics death certificate databases to identify deaths from 1979 to 1998 attributed to congenital hydrocephalus, spina bifida with hydrocephalus, and acquired hydrocephalus (both obstructive and communicating) in all children in the US aged 1 day to 20 years. Mortality rates were defined as deaths per 100,000 person-years and were analyzed for differences on the basis of age, race, sex, and year.

The authors identified 10,406 deaths attributed to childhood hydrocephalus within the 20-year study period. The overall mortality rate was 0.71 per 100,00 person-years. Mortality rates were highest in infants, with 3979 deaths; they were similar between girls and boys. Compared with white infants, black infants had higher relative risk (RR) for death caused by congenital hydrocephalus (RR 1.46, p value < 0.0001) and acquired hydrocephalus (RR 2.58, p value < 0.0001) but not for that caused by hydrocephalus with spina bifida (RR 0.65, p value < 0.0001). From 1979 to 1998, the mortality rate due to congenital hydrocephalus declined 66.3%, from spina bifida with hydrocephalus it declined by 30.4%, and from acquired hydrocephalus it declined by 67.5%.

Conclusions

Mortality rates from childhood hydrocephalus have declined in US children over the previous 20 years. Black race is associated with higher mortality rates in infants for both congenital and acquired hydrocephalus, whereas sex has no effect.

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Pregnancy-related vertebral hemangioma

Case report, review of the literature, and management algorithm

John H. Chi, Geoffrey T. Manley and Dean Chou

Pregnancy is a recognized risk factor for quiescent vertebral hemangiomas becoming symptomatic; this usually occurs during the 3rd month of gestation. The natural history of these lesions is poorly understood, and treatment practices must consider the overall safety of the mother and fetus. The authors report a case of cervical vertebral hemangioma presenting during the 24th week of pregnancy and review the current literature.

A 26-year-old woman in her 24th week of pregnancy presented with upper-back pain and progressive spastic paresis in the legs. Neuroimaging studies revealed a diffuse C-7 vertebral body lesion with extradural extension and compression of the spinal cord consistent with a vertebral hemangioma. Successful decompression was accomplished, and the fetus experienced no adverse effects from the surgery.

In a review of the literature, 23 cases of pregnancy-related vertebral hemangioma dating back to 1927 were identified. Prepartum surgical decompression was performed in eight patients, postpartum surgery was performed in 12, and surgery was not performed in four. Overall, patients experienced excellent neurological recovery, regardless of the severity and duration of spastic paresis.

Observation should be considered for symptomatic patients at greater than 32 weeks gestation. Surgery should be considered for patients with severe neurological deficits at less than 32 weeks of gestation.

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John H. Chi, Amith Panner, Kristine Cachola, Courtney A. Crane, Joseph Murray, Russell O. Pieper, C. David James and Andrew T. Parsa

Object

Despite recent advances in cancer immunotherapy, cellular mechanisms controlling expression of tumor-associated antigens are poorly understood. Mutations in cancer cells, such as loss of PTEN, may increase expression of tumor-associated antigens. The authors investigated the relationship between PTEN status and the expression of a glioma-associated antigen, adenosine diphosphate–ribosylation factor 4–like (ARF4L) protein.

Methods

Human glioma cell lines with confirmed PTEN status were examined by Northern blot analysis and quantitative polymerase chain reaction. Western blot analysis was used to measure ARF4L protein levels across multiple cell lines.

Results

The loss of PTEN was shown to lead to increased levels of ARF4L protein but no change in transcript levels. Cell lines with serial mutations, including activation of Ras and Akt pathways, also demonstrated increased levels of ARF4L protein, which decreased after treatment with rapamycin. The ARF4L transcript preferentially localized to the polysomal compartment after PTEN loss in glioma or activation of Akt in human astrocytes.

Conclusions

Expression of ARF4L is controlled by the activated Akt/mTOR pathway, which is a downstream effect of the loss of PTEN function. Mutations leading to oncogenesis may impact the regulation and expression of tumor specific antigens. Screening of mutation status in glioma may be helpful in selecting patients for immunotherapy trials in the future.

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John H. Chi, Sanjay S. Dhall, Adam S. Kanter and Praveen V. Mummaneni

Object

Thoracic disc herniations can be surgically treated with a number of different techniques and approaches. However, surgical outcomes comparing the various techniques are rarely reported in the literature. The authors describe a minimally invasive technique to approach thoracic disc herniations via a transpedicular route with the use of tubular retractors and microscope visualization. This technique provides a safe method to identify the thoracic disc space and perform a decompression with minimal paraspinal soft tissue disruption. The authors compare the results of this approach with clinical results after open transpedicular discectomy.

Methods

The authors performed a retrospective cohort study comparing results in 11 patients with symptomatic thoracic disc herniations treated with either open posterolateral (4 patients) or mini-open transpedicular discectomy (7 patients). Hospital stay, blood loss, modified Prolo score, and Frankel score were used as outcome variables.

Results

Patients who underwent mini-open transpedicular discectomy had less blood loss and showed greater improvement in modified Prolo scores (p = 0.024 and p = 0.05, respectively) than those who underwent open transpedicular discectomy at the time of early follow-up within 1 year of surgery. However, at an average of 18 months of follow-up, the Prolo score difference between the 2 surgical groups was not statistically significant. There were no major or minor surgical complications in the patients who received the minimally invasive technique.

Conclusions

The mini-open transpedicular discectomy for thoracic disc herniations results in better modified Prolo scores at early postoperative intervals and less blood loss during surgery than open posterolateral discectomy. The authors' technique is described in detail and an intraoperative video is provided.

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Matthew C. Tate, Anurahda Banerjee, Scott R. Vandenberg, Tarik Tihan, John H. Chi, Christopher P. Ames and Andrew T. Parsa

This 18-year-old woman presented with headache and diplopia over several months and was found to have an enhancing pineal tumor with resultant obstructive hydrocephalus. Following standard preoperative diagnostic tests, including spinal axis imaging, the patient was taken to the operating room for an endoscopic third ventriculostomy to relieve hydrocephalus and then subsequently underwent a craniotomy for gross-total resection of the pineal mass. The patient was discharged after an uneventful hospital course and received standard adjuvant cranial-spinal radiation and chemotherapy as an outpatient. Follow-up imaging 1 year after surgery demonstrated a metabolically active, lytic lesion in the C-3 vertebral body and new lung lesions suggesting a metastatic pineoblastoma. The patient underwent a C-3 anterior corpectomy and reconstruction without complication as aggressive therapy for presumed metastatic disease. Final pathological results from the vertebral lesion were consistent with radiation-induced reactive changes, not metastatic pineoblastoma as originally suspected. The patient recovered well and remains symptom free. To the authors' knowledge this is the first reported case of reactive changes mimicking metastasis in a single vertebral body following standard therapy for resected primary pineoblastoma.

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Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010