Azadeh Farin

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.

Biological restoration of central nervous system architecture and function: Part 3 – Stem cell- and cell-based applications and realities in the biological management of central nervous system disorders: traumatic, vascular, and epilepsy disorders

STEM CELL THERAPY has emerged as a promising novel therapeutic endeavor for traumatic brain injury, spinal cord injury, stroke, and epilepsy in experimental studies. A few preliminary clinical trials have further supported its safety and early efficacy after transplantation into humans. Although not yet clinically available for central nervous system disorders, stem cell technology is expected to evolve into one of the most powerful tools in the biological management of complex central nervous system disorders, many of which currently have limited treatment modalities. The identification of stem cells, discovery of neurogenesis, and application of stem cells to treat central nervous system disorders represent a dramatic evolution and expansion of the neurosurgeons capabilities into the neurorestoration and neuroregeneration realms. In Part 3 of a 5-part series on stem cells, we discuss the theory, experimental evidence, and clinical data pertaining to the use of stem cells for the treatment of traumatic, vascular, and epileptic disorders.

Endoscopic third ventriculostomy

Among patients with idopathic aqueductal stenosis or impedance of cerebrospinal fluid (CSF) flow in the posterior fossa due to tumour, endoscopic fenestration of the floor of the third ventricle creates an alternative route for CSF flow to the subarachnoid space via the prepeduncular cistern. By reestablishing CSF flow, this procedure dissipates any pressure gradient on midline structures. This may obviate the need for traditional CSF shunt diversion techniques in such settings. Currently, endoscopic third ventriculostomy is indicated in approximately 25% of patients with hydrocephalus and can be performed instead of shunt placement. Appropriate patients are those with aqueductal stenosis (10%), obstructive tumours (10%), and obstructive cysts (5%). Additional recent data suggest the favorability of third ventriculostomy over shunt implantation in additional patient cohorts. Operative technique is discussed.

Optimal reconstruction technique after C-2 corpectomy and spondylectomy: a biomechanical analysis

OBJECT Primary spine tumors frequently involve the C-2 vertebra. Complete resection of the lesion may require total removal of the C-2 vertebral body, pedicles, and dens process. Authors of this biomechanical study are the first to evaluate a comprehensive set of reconstruction methods after C-2 resection to determine the optimal configuration depending on the degree of excision required. METHODS Eight human heads (from the skull to C-6) from 4 males and 4 females with a mean age of 68 +/- 18 years at death were cleaned of tissue, while leaving ligaments and discs intact. Nondestructive flexion and extension (FE), lateral bending (LB), and axial rotation (AR) tests were conducted using a nonconstraining, pure moment loading apparatus, and relative motion across the fusion site (C1-3) was measured using a 3D motion tracking system. Specimens were tested up to 1.5 Nm at 0.25-Nm intervals for 45 seconds each. The spines were instrumented using 3.5-mm titanium rods with a midline occipitocervical plate (4.0 x 12-mm screws) and lateral mass screws (excluding C-2) at the C-1 (3.0 x 40 mm) and C3-5 levels (3.0 x 16 mm). Testing was repeated for the following configurations: Configuration 1 (CF1), instrumentation only from occiput to C-5; CF2, C-2 corpectomy leaving the dens; CF3, titanium mesh cage (16-mm diameter) from C-3 to C-1 ring and dens; CF4, removal of cage, C-1 ring, and dens; CF5, titanium mesh cage from C-3 to clivus (16-mm diameter); CF6, removal of C-2 posterior elements leaving the C3-clivus cage (spondylectomy); CF7, titanium mesh cage from C-3 to clivus (16-mm diameter) with 2 titanium mesh cages from C-3 to C-1 lateral masses (12-mm diameter); and CF8, removal of all 3 cages. A crosslink was added connecting the posterior rods for CF1, CF6, and CF8. Range-of-motion (ROM) differences between all groups were compared via repeated-measures ANOVA with paired comparisons using the Student t-test with a Tukey post hoc adjustment. A p < 0.05 indicated significance. RESULTS The addition of a central cage significantly increased FE rigidity compared with posterior instrumentation alone but had less of an effect in AR and LB. The addition of lateral cages did not significantly improve rigidity in any bending direction (CF6 vs CF7, p > 0.05). With posterior instrumentation alone (CF1 and CF2), C-2 corpectomy reduced bending rigidity in only the FE direction (p < 0.05). The removal of C-2 posterior elements in the presence of a C3-clivus cage did not affect the ROM in any bending mode (CF5 vs CF6, p > 0.05). A crosslink addition in CF1, CF6, and CF8 did not significantly affect primary or off-axis ROM (p > 0.05). CONCLUSIONS Study results indicated that posterior instrumentation alone with 3.5-mm rods is insufficient for stability restoration after a C-2 corpectomy. Either C3-1 or C3-clivus cages can correct instability introduced by C-2 removal in the presence of posterior instrumentation. The addition of lateral cages to a C3-clivus fusion construct may be unnecessary since it does not significantly improve rigidity in any direction.

Cervical spine dural arteriovenous fistula with coexisting spinal radiculopial artery aneurysm presenting as subarachnoid hemorrhage: case report.

BACKGROUND AND IMPORTANCE We present a patient with a cervical spine dural arteriovenous fistula associated with a radiculopial artery aneurysm at the same vertebral level presenting with subarachnoid hemorrhage. CLINICAL PRESENTATION A 45-year-old Native American man presented with sudden-onset severe headache, lethargy, and right hemiparesis. Computed tomography (CT) of the head showed subarachnoid hemorrhage and hydrocephalus. A subsequent CT of the neck showed an anterior spinal subdural hematoma from C2 to C4 causing mild cord compression. Carotid and vertebral angiography failed to demonstrate an intracranial aneurysm, but showed a spinal dural arteriovenous fistula originating from the right vertebral artery at the C5 neuroforamen. The severity of the patients symptoms, atypical for rupture of a dural arteriovenous fistula, prompted more thorough angiographic evaluation. Thus, injection of the right thyrocervical trunk was performed, demonstrating a 4-mm spinal radiculopial artery aneurysm. Following ventriculostomy, a hemilaminectomy from C4 to C7 was performed with disconnection of the fistula from its drainage system. Subsequent resection of the aneurysm, which was determined to be the cause of the hemorrhage, was accomplished. The patient improved neurologically and was discharged to rehabilitation. CONCLUSION Spinal cord aneurysms from a separate vascular distribution may coexist with spinal dural arteriovenous fistulas. In the setting of spinal hemorrhage, especially in situations with an atypical clinical presentation, comprehensive imaging is indicated to rule out such lesions.

The biological restoration of central nervous system architecture and function: Part 1 - foundations and historical landmarks in contemporary stem cell biology

SINCE THEIR DISCOVERY, stem cells have fascinated scientists with their ultimate potential: the ability to cure disease, repair altered physiology, and reverse neurological deficit. Stem cell science unquestionably promises to eliminate many of the tragic limitations contemporary medicine must acknowledge, and cloning may provide young cells for an aging population. Although it is widely believed that stem cells will transform the way medicine is practiced, therapeutic interventions using stem cell technology are still in their infancy. The 3 most common stem cell sources studied today are umbilical cord blood, bone marrow, and human embryos. Although cord blood is currently used to treat dozens of disorders and bone marrow stem cells have been used clinically since the 1960s, human embryonic stem cells have yet to be successfully applied to any disease. Undeniably, stem cell therapy has the potential to be one of the most powerful therapeutic options available. In this introductory article of a 5-part series on stem cells, we narrate the evolution of modern stem cell science, delineating major landmarks that will prove responsible for taking stem cell technology from the laboratory into revolutionary clinical applications: from the first milestone of identifying the mouse hematopoietic stem cell to the latest feats of producing pluripotent stem cells without embryos at all. In Part 2, we present the evidence demonstrating the certainty of adult mammalian neurogenesis; in Parts 3 and 4, we describe neurosurgical applications of stem cell technology; and in Part 5, we discuss the philosophical and ethical issues surrounding stem cell therapy, as well as future areas of exploration.

Thymoma metastatic to the extradural spine

BACKGROUND Spinal epidural metastases are the most common spinal tumor, occurring in 10% of cancer patients. Malignant thymoma is a mediastinal tumor, with extrathoracic metastases occurring in 15% of patients to liver, kidney, and bone. Spinal metastasis is exceptionally rare. We present a case of thymoma with extradural metastasis and discuss the relevant literature. CASE REPORT We describe a 45-year old man presenting with back pain and hypoesthesia twelve years after a diagnosis of thymoma. A review of the literature reveals few cases of thymoma metastatic to the extradural spine. We describe a novel surgical approach allowing ventral spinal cord decompression through a posterior incision. CONCLUSION Spinal epidural metastases should be suspected in all cancer patients with back pain. Early detection of epidural metastases may enable improved pain control and preservation of spinal stability, ambulation and sphincter control.

The biological restoration of central nervous system architecture and function: part 2-emergence of the realization of adult neurogenesis.

BEFORE THE 1960s, adult mammalian neurogenesis was conceptually unimaginable. Despite 45 years of observations supporting this revolutionary phenomenon, many scientists rejected this notion until irrefutable evidence provided at the end of the 20th century established that lifelong neuronal generation occurs in the adult mammalian brain. Today, in place of being viewed as a nonregenerative dormant organ, a defining characteristic of the brain is its plasticity, or capacity to undergo environment- and activity-related cytophysiological remodeling. In this second article in a 5-part series on stem cells, we trace the milestones that gave birth to a new era in neuroscience: the realization of adult mammalian neurogenesis.

Microvascular decompression for intractable singultus: technical case report.

OBJECTIVE Intractable singultus is a rare but significantly disruptive clinical phenomenon that often accompanies other diseases but can present in isolation due entirely to intracranial pathology. We report a case of intractable singultus that improved after microvascular decompression and present a comprehensive review of singultus by discussing its similarity to other cases of microvascular decompression, its history and etiology, and its evolutionary basis. CLINICAL PRESENTATION The patient exhibited intractable singultus for 15 years, resistant to multiple medical regimens. INTERVENTION Microvascular decompression to relieve pressure on the tenth cranial nerve and medulla oblongata resulted in near total resolution of the singultus. CONCLUSION Neurovascular compression should be considered a potentially reversible cause of intractable singultus, a significantly disabling clinical phenomenon.

Intradural cranial congenital dermal sinuses: diagnosis and management

ObjectiveThe congenital dermal sinus (CDS) is a benign tumor-like entity that has unique anatomical and clinical features. We retrospectively examined our data to determine factors associated with adverse outcomes for cranial-based dermal sinuses.MethodsWe retrospectively examined our data obtained from patients presenting between 1975 and 2002. Sixty-seven patients with a CDS were found. Of these, 20 cases of a cranial CDS were identified, 15 of which had evidence of an intradural component.ResultsSurgical treatment of congenital dermal sinuses was accompanied with, in general, excellent results. Poor outcomes were most strongly associated with delays in diagnosis. The most common complications were infection at the surgical site (five patients) and hydrocephalus necessitating ventriculoperitoneal shunt placement (two patients). Permanent neurological deficits were rare.ConclusionCranial CDSs are unusual lesions found in children. A majority of these lesions may penetrate the dura and lead to significant complications if not promptly identified and treated in an appropriate and timely fashion.