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Biomedical subjects

Peter Nakaji

Publications and source records attributed to Peter Nakaji.

17 recordsLinked to original sources
PubMed2006

Multimodality treatment of trigeminal neuralgia: impact of radiosurgery and high resolution magnetic resonance imaging.

This study was conducted to evaluate the two main surgical modalities, microvascular decompression (MVD) and gamma-knife radiosurgery (GK), the treatment of trigeminal neuralgia (TN) and outline for an algorithm for the selection of these procedures. The authors have identified distinct differences in the two treatment groups and formulated a scale that predicts the outcome and satisfaction of patients who underwent the procedures. This series included 34 TN patients treated in 2000 and 2001 with MVD (19) and GK (15). Patients with TN associated with tumor or multiple sclerosis were excluded. Each patient's age, past medical history, clinical features of pain or pre-operative pain grade, duration of TN, medications, and prior surgical procedures were recorded. Long-term results were assessed by a structured interview by telephone. Clinical outcome was classified as excellent (complete relief without medications and numbness), good (complete relief without medications), fair (> 50% relief or with substantial numbness and weakness), or poor (< 50% relief or treatment failure). Patient self-rated satisfaction score was rated on a scale of 1 (unsatisfied) to 10 (completely satisfied). Statistical analysis was performed by paired t-tests and anova with post-hoc analysis by the Tukey-Kramer method. The median follow-up was 17 months (18 months for MVD and 16 months for GK). The average age of MVD patients was 61 years compared to 74 years for GK patients (p = 0.0005). In both groups there was a female majority (68% for MVD and 60% for GK). The latency between first symptom of TN and treatment procedure was 3.0 years for MVD and 3.9 years for GK (p > 0.05). There was no significant difference in pain grade between the two groups. The average TN complexity grade was significantly different between the two groups (3.0 for MVD and 5.8 for GK) (p < 0.001). Average response to procedure for MVD was 3.4 (good) and 2.4 (fair) for GK (p = 0.017). The satisfaction outcome for MVD was 8.7 compared to 6.4 for GK (p = 0.02). There was a significant correlation (r = -0.818, p < 0.001) between TN complexity grade and response. Additionally, a significant correlation between TN complexity grade and patient satisfaction was found (r = -0.763, p < 0.0001). The data here support the treatment algorithm employed by the senior author (JFA) of this study. The TN complexity grade accurately correlates with the patient's response and satisfaction to the surgical procedure. This complexity grade may be useful for patient counseling when choosing between treatment options.

Adult↗
PubMed2006

Lumbar diskectomy in a human-habituated mountain gorilla (Gorilla beringei beringei).

The authors report a case of a human-habituated mountain gorilla, Alvila, resident at the San Diego Zoo, who was found to have a herniated intervertebral lumbar disc after being attacked by the gorilla troop's silverback male gorilla. Ultimately, the gorilla required surgical intervention for her disease and made a full recovery. To our knowledge, this is the only known case of spine surgery. A 36-year-old female human-habituated mountain gorilla (Gorilla beringei beringei), resident at the San Diego Zoo, was noticed by caregivers to walk with a substantial limp after being attacked by the gorilla troop's silverback male gorilla. Magnetic resonance (MR) imaging of her lumbar spine revealed a large herniated disk at the L1-2 level on the right. This finding appeared to correlate well with the gorilla's symptoms. The gorilla underwent a lumbar diskectomy under loupe. Post-operatively the gorilla did very well. The right leg weakness was immediately improved post-operatively. The gorilla continued to "crutch walk" initially, swinging on the upper extremities and not bearing weight on the lowers. However, by 2 weeks the limp was no longer noticeable to the zoo caregivers. The wound healed well and there was no evidence of wound infection or CSF leak. The gorilla was reunited with her troop and has reintegrated well socially. With 10 months of follow-up, the gorilla continues to do well. This is the only known case of spine surgery in a gorilla. For best surgical results, one needs to consider the similarities and differences between the gorilla and human vertebral anatomy. We believe that careful pre-operative planning contributed to the good early post-operative result. Ultimate assessment of the long-term outcome will require additional follow-up.

Animals↗
PubMed2005

Endogenous stem cell proliferation after central nervous system injury: alternative therapeutic options.

The continuous regeneration of glial cells arising from endogenous stem cell populations in the central nervous system (CNS) occurs throughout life in mammals. In the ongoing research to apply stem cell therapy to neurological diseases, the capacity to harness the multipotential ability of endogenous stem cell populations has become apparent. Such cell populations proliferate in response to a variety of injury states in the CNS, but in the absence of a supportive microenvironment they contribute little to any significant behavioral recovery. In the authors' laboratory and elsewhere, recent research on the regenerative potential of these stem cells in disease states such as spinal cord injury has demonstrated that the cells' proliferative potential may be greatly upregulated in response to appropriate growth signals and exogenously applied trophic factors. Further understanding of the potential of such multipotent cells and the mechanisms responsible for creating a favorable microenvironment for them may lead to additional therapeutic alternatives in the setting of neurological diseases. These therapies would require no exogenous stem cell sources and thus would avoid the ethical and moral considerations regarding their use. In this review the authors provide a brief overview of the enhancement of endogenous stem cell proliferation following neurological insult.

Animals↗
PubMed2005

Middle cerebral artery stenosis: endovascular and surgical options.

Atherosclerotic middle cerebral artery stenosis is a rare but potentially devastating cause of cerebral ischemia and stroke. While medical management remains the mainstay for stroke prevention, surgical and/or endovascular intervention is indicated in selected patients. This article reviews the role of surgery and endovascular techniques in the treatment of middle cerebral artery stenosis based on its natural history, pathophysiology, and prognosis when treated medically.

Journal Article↗
PubMed2005

Sinonasal leiomyosarcoma: review of literature and case report.

OBJECTIVES/HYPOTHESIS: To determine prognosis of primary sinonasal leiomyosarcomas after treatment. STUDY DESIGN: Literature review and case report. METHODS: Review of English literature from MEDLINE and independent sources with the addition of our case. RESULTS: Including our case, 63 cases have been reported. Primary treatment includes resection with or without radiation. Chemotherapy has not been reported to be effective. In our case, however, chemotherapy, consisting of etoposide and high-dose ifosfamide, caused the tumor to shrink significantly. On the basis of a review of all reported cases, the overall survival rate at a mean follow-up of 38.24 month is 66%. The minimal overall survival rates at 5 and 10 years are 20% and 6%, respectively. CONCLUSION: The prognosis for primary sinonasal leiomyosarcomas is poor. However, a 10-year survival has been reported in a few patients. Chemotherapy may be a useful adjunct when managing extensive lesions unamenable to curative resection.

Adult↗
PubMed2005

Prospective evaluation of surgical microscope-integrated intraoperative near-infrared indocyanine green videoangiography during aneurysm surgery.

OBJECT: The authors prospectively compared a new technique of surgical microscope-based indocyanine green (ICG) videoangiography with intraoperative or postoperative digital subtraction (DS) angiography. METHOD: The technique was performed during 187 surgical procedures in which 124 aneurysms in 114 patients were clipped. Using a newly developed setup, the ICG technique has been integrated into an operating microscope (Carl Zeiss Co., Oberkochen, Germany). A microscope-integrated light source containing infrared excitation light illuminates the operating field. The dye is injected intravenously into the patient, and intravascular fluorescence from within the blood vessels is imaged using a video camera attached to the microscope. The patency of parent, branching, and perforating arteries and documentation of clip occlusion of the aneurysm as shown by ICG videoangiography were compared with intraoperative or postoperative findings on DS angiography. The results of ICG videoangiography corresponded with intra- or postoperative DS angiography in 90% of cases. The ICG technique missed mild but hemodynamically irrelevant stenosis that was evident on DS angiography in 7.3% of cases. The ICG technique missed angiographically relevant findings in three cases (one hemodynamically relevant stenosis and two residual aneurysm necks [2.7% of cases]). In two cases the missed findings were clinically and surgically inconsequential; in the third case, a 4-mm residual neck may require a second procedure. Indocyanine green videoangiography provided significant information for the surgeon in 9% of cases, most of which led to clip correction. CONCLUSIONS: Microscope-based ICG videoangiography is simple and provides real-time information about the patency of vessels of all sizes and about the aneurysm sac. This technique may be useful during routine aneurysm surgery as an independent form of angiography or as an adjunct to intra- or postoperative DS angiography.

Adult↗
PubMed2005

Management of arteriovenous malformations: a surgical perspective.

The management strategies for arteriovenous malformations (AVMs) continue to evolve, spurred by advancing technology and improved understanding of the natural history of these lesions. In general, intervention is reserved for Spetzler-Martin Grade I-III lesions or for those with certain high-risk features. Grade IV-V AVMs, in contrast, are usually managed conservatively. Although multimodality therapy incorporating endovascular and/or radiosurgical techniques is increasingly common, microsurgical removal remains the definitive form of treatment.

Arteriovenous Malformations↗
PubMed2005

Cavernous malformation of the trigeminal nerve manifesting with trigeminal neuralgia: case report.

OBJECTIVE AND IMPORTANCE: We describe a patient with a cavernous malformation within the trigeminal nerve at the nerve root entry zone who presented with trigeminal neuralgia. CLINICAL PRESENTATION: A 52-year-old woman sought treatment after experiencing dizziness and lancinating left facial pain for almost a year. Neurological examination revealed diminished sensation in the distribution of the trigeminal nerve on the left. Magnetic resonance imaging demonstrated a minimally enhancing lesion affecting the trigeminal nerve. INTERVENTION: The patient underwent a retrosigmoid craniotomy. At the nerve root entry zone, the trigeminal nerve was edematous with hemosiderin staining. The lesion, which was resected with microsurgical technique, had the appearance of a cavernous malformation on gross and histological examination. The patient's pain improved significantly after resection. CONCLUSION: Cavernous malformations can afflict the trigeminal nerve and cause trigeminal neuralgia. Microsurgical excision can be performed safely and is associated with improvement in symptoms.

Cranial Nerve Neoplasms↗
PubMed2004

Intramedullary spinal cord metastasis of lung adenocarcinoma presenting as Brown-Sequard syndrome.

BACKGROUND: It is extremely rare for cancer to present first as an intramedullary spinal cord metastasis. Furthermore, because it is unlikely for spinal cord neoplasm to present acutely, an acute presentation may signify metastatic disease and should be considered in the initial differential diagnosis. METHODS: The authors present a case of a 59-year-old man presenting with Brown-Sequard syndrome and in whom metastatic lung adenocarcinoma to the spinal cord was subsequently discovered. Review of the literature reveals this case to be one of only a very few where intramedullary tumor was the first manifestation of metastatic disease. RESULTS: The mainstay of treatment for intramedullary spinal metastases remains steroids, radiation, and chemotherapy, though no well-designed study compares these modalities by long-term survival and functional results. This patient underwent local radiation and systemic chemotherapy following surgical resection. CONCLUSIONS: This patient had no preoperative signs suggesting disease in other organs, making the diagnosis of lung adenocarcinoma metastatic to the intramedullary cord surprising, especially given the extremely rare incidence of spinal intramedullary metastatic disease. However, the patient had an acute presentation, uncommon for primary neoplasm, which may be an indication of metastatic disease.

Adenocarcinoma↗
PubMed2004

Syringocephaly.

Syringomyelia is associated with Arnold-Chiari Type I malformations. Syringobulbia describes the phenomenon of syrinx extension into the brain stem. Syringocephaly is the further dissection of the fluid-filled cavity into the cerebral peduncles and cerebrum. In this case report, we describe a patient who presented with bulbar, sensory, motor, and coordination deficits both ipsilateral and contralateral to the lesion. This is most likely attributable to the wandering course the syrinx takes as it dissects through the spinal cord and into the internal capsule. This ill-defined syrinx disrupts various nuclei and fasciculi, both pre- and post-decussation, thus explaining the multiple deficits on each side. We initially treated this patient with a suboccipital craniectomy, C1 laminectomy, and duraplasty, which mildly improved his deficits. During follow-up, the patient was then found to have an exacerbation of his symptoms, at which time we performed a VP shunt revision (the patient had a history of hydrocephalus treated by a functioning VP shunt). Approximately 2 weeks after revision of the VP shunt, the patient had worsening of his symptoms, which we treated with a syringopleural shunt. This proved to be the most effective treatment with the greatest clinical improvement. Several months later, however, the patient died secondary to pulmonary disease exacerbated by VP shunt infection. In this paper, we also review the literature regarding the formation and treatment of syringocephaly, a rare and poorly understood entity.

Cerebellum↗
PubMed2004

Neuro-oncologic applications of endoscopy.

Neurooncology, in all its aspects, provides an ideal venue for the application of endoscopy. The main obstacle to its use has been neuro-surgeons' lack of familiarity with the techniques and their advantages. As the neurooncologic surgeon uses the endoscope more, endoscopy will take its rightful place in the surgeon's armamentarium. The advantages of improved visualization of intraventricular pathology, better management of tumor-related hydrocephalus, less morbid biopsies, and minimally invasive removal of intraventricular tumors are invaluable adjuncts to traditional tumor management. Furthermore, endoscopy is the logical next step for surpassing the limitations of traditional microsurgery. Endoscopy is still in its infancy. Rigorous application of the technology is increasingly allowing us to provide our patients the most maximally effective and minimally invasive surgery possible.

Biopsy↗
PubMed2003

Ependymoma.

INTRODUCTION: The management of a patient with an ependymoma is controversial. Although the necessity for a multi-disciplined approach is accepted, the exact roles for all disciplines are poorly defined. REVIEW: This review article examines the current status of histopathological and cytogenetic diagnosis, surgical, chemotherapeutic and radiotherapeutic treatment and future directions.

Brain Neoplasms↗
PubMed2003

Improvement of aggressive and antisocial behavior after resection of temporal lobe tumors.

Seizures associated with temporal lobe tumors may rarely manifest as episodic aggressive behavior. We describe 2 cases involving pediatric patients who presented with histories of unusually aggressive and antisocial behavior. Magnetic resonance imaging identified right mesial temporal lobe masses in both patients. After craniotomy for tumor removal, both patients were seizure-free and had marked reductions in their aggressive behavior. Tumors in the temporal lobe may be associated with behavioral problems, including aggression and rage attacks, which can be alleviated with surgical intervention. It is important to distinguish this subgroup of pediatric patients from those with alternative diagnoses such as attention-deficit/hyperactivity disorder or oppositional defiant disorder.

Adolescent↗
PubMed2002

Endoscopic assisted posterior decompression for spinal neoplasms.

The authors describe a technique for anterior thoracic decompression via a posterolateral approach for spinal metastatic disease followed by anterior and posterior column stabilization. We discuss the benefits of decompression via a posterolateral approach including minimization of cord retraction, avoidance of thoracotomy, early mobilization and shorter hospital stay. Technical details are reviewed and difficulties of the approach discussed.

Decompression, Surgical↗