Harold L. Rekate

Elevated intracranial venous pressure as a universal mechanism in pseudotumor cerebri of varying etiologies

Article abstract-Pseudotumor cerebri (PTC), or idiopathic intracranial hypertension, is a syndrome associated with multiple clinical conditions. We hypothesize that most if not all etiologies result in an increase in intracranial venous pressure as a final common pathway. We studied 10 patients with PTC. Five had dural venous outflow obstruction as demonstrated by venography, and the five remaining patients had normal venous anatomy. Pressure measurements, made during venography in eight patients, all showed elevated pressures. Pressure measurements in the superior sagittal sinus ranged from 13 to 24 mm Hg (mean, 16.6 mm Hg). Patients with obstruction tended to have a high pressure gradient across the stenotic segment. Five patients with normal dural venous anatomy had elevated right atrial pressures (range, 6 to 22 mm Hg; mean, 11.8 mm Hg), which were transmitted up to the intracranial venous sinuses. Endovascular techniques, including angioplasty and infusion of thrombolytic agents in some cases, improved outlet obstruction from a hemodynamic perspective but were ineffective in consistently and reliably alleviating the clinical manifestations of PTC.Patients in both groups tended to respond well to conventional CSF diversion procedures. Our study suggests that elevated intracranial venous pressure may be a universal mechanism in PTC of different etiologies.This elevated venous pressure leads to elevation in CSF and intracranial pressure by resisting CSF absorption. Although the mechanism leading to venous hypertension in the presence of outflow obstruction is obvious, the etiology of increased intracranial and central systemic venous pressure in PTC remains obscure. NEUROLOGY 1996;46: 198-202

The infant whiplash-shake injury syndrome: a clinical and pathological study.

The cases of 13 infants (median age, 3 months) who sustained nonaccidental trauma were reviewed. All presented with profound neurological impairment, seizures, retinal hemorrhages, and intracranial subarachnoid and/or subdural hemorrhages. Of 8 infants who died, autopsy was performed on 6. No patient had a skull fracture, and only one had an extracalvarial contusion. Five of the 6 patients on whom autopsy was performed had injuries at the cervicomedullary junction consisting of sub- or epidural hematomas of the cervical spinal cord with proximal spinal cord contusions. The authors conclude that direct cranial trauma is not an essential element of the injury mechanism in young patients who sustain severe whiplash-shake injuries. In addition to the classic injuries reported to occur with the shaken-baby syndrome, hemorrhages and contusions of the high cervical spinal cord may contribute to morbidity and mortality.

Spinal cord ependymoma: Radical surgical resection and outcome

OBJECTIVE Several authors have noted increased neurological deficits and worsening dysesthesia in the postoperative period in patients with spinal cord ependymoma. We describe the neurological progression and pain evolution of these patients over the 1-year period after surgery. In addition, our favored method of en bloc tumor resection is illustrated, and the rate of complications, recurrence, and survival in this group of patients is addressed. METHODS We operated on 26 patients (12 male and 14 female) with low-grade spinal cord ependymomas between 1975 and 2001. The median age at diagnosis was 42 years. Tumors extended into the cervical cord in 13 patients, the thoracic cord in 7 patients, and the conus medullaris in 6 patients. Eleven patients had previous surgery and/or radiation therapy. RESULTS We achieved a gross total resection in 88% of patients, whereas 8% had a subtotal resection and 4% had a biopsy. Only 1 patient developed a recurrence over a mean follow-up period of 31 months. CONCLUSION We conclude that radical surgical resection of spinal cord ependymomas can be safely achieved in the majority of patients. A trend toward neurological improvement from a postoperative deficit can be expected between 1 and 3 months after surgery and continues up to 1 year. Postoperative dysesthesias begin to improve within 1 month of surgery and are significantly better by 1 year after surgery. The best predictor of outcome is the preoperative neurological status.

Traumatic atlantooccipital dislocation with survival.

Survival after traumatic atlantooccipital dislocation is rare. Only long-term survivors have been reported in the literature; however, improved prehospital care is likely responsible for the increase in the number of these patients seen at neurotrauma centers over the last decade. Associated severe and persistent neurological deficits are common in the few survivors. We report the case of a 10-year-old boy with traumatic atlantooccipital dislocation and a severe neurological injury. Low-field magnetic resonance imaging provided the additional diagnosis of an associated cervicomedullary epidural hematoma. The patient underwent emergency operative evacuation of the hematoma and an occipital-cervical fusion with internal fixation. He had a remarkable recovery in neurological function and achieved stable bony fusion 3 months postoperatively. With early recognition of this entity, improved neuroradiological imaging techniques, and aggressive treatment, patients may survive with significant neurological recovery.

Application of neuroendoscopy to intraventricular lesions.

We present an overview of the history, development, technological advancements, current application, and future trends of cranial endoscopy. Neuroendoscopy provides a safe and effective management modality for the treatment of a variety of intracranial disorders, either tumoral or non-tumoral, congenital, developmental, and degenerative, and its knowledge, indications, and limits are fundamental for the armamentarium of the modern neurosurgeon.

Transcallosal Resection of Hypothalamic Hamartoma for Intractable Epilepsy

Summary:  Purpose: To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study.

Pediatric spinal cord injury without radiographic abnormalities: report of 26 cases and review of the literature.

Spinal cord injury without radiographic abnormality (SCIWORA) occurs primarily in the pediatric population but is less common than other forms of spinal injury among children. Between 1972 and 1990, 159 pediatric patients were admitted to the Barrow Neurological Institute with acute traumatic spinal cord or vertebral column injuries. Of these, 26 children (16%) sustained SCIWORA. The mechanism of injury, its severity, and the prognosis for recovery were related to the patients age. In young children, SCIWORA accounted for 32% of all spinal injuries and tended to be severe; 70% were complete injuries. In older children, SCIWORA accounted for only 12% of the spinal injuries, was rarely associated with a complete injury, and had an excellent prognosis for complete recovery of neurologic function. As with other types of spinal cord injuries, the severity of neurological injury was the most important predictor of outcome. Patients with complete neurological deficits from SCIWORA had a poor prognosis for recovery of neurological function.

Traumatic Occipitoatlantal Dislocations

Fourteen occipitoatlantal dislocations were treated during an 11-year period. All patients presented with neurological deficits and definite evidence of spinal instability. Plain radiographs provided the diagnosis conclusively in 11 patients. Three patients required computed tomography (CT) or magnetic resonance (MR) imaging for diagnosis. Rotational subluxations were radiographically occult and associated with less severe neurological injuries compared to distracted or translated subluxations. Ten patients died acutely. One patient, who had complete C1 level quadriplegia, died after 3 months. Three patients with incomplete spinal cord syndromes had long-term survival and functional neurological recoveries. Extensive ligamentous injury predisposed patients to recurrent subluxations. In several patients, traction or a cervical collar caused distraction and neurological injury. Halo immobilization and urgent fusion are necessary for patients with salvageable neurological function. Nonoperative measures are inadequate for immediate or long-term spinal stability.

Pediatric intracranial aneurysms: simple and complex cases.

Between 1984 and 1990, 20 aneurysms in 16 patients (9 males and 7 females), 18 years or younger (mean age, 8 years; range, 7 months to 18 years), were treated at our institution. Seven patients had a solitary saccular aneurysm located at an arterial bifurcation which manifested as a subarachnoid hemorrhage. Six of these patients were treated with clip obliteration. Postoperative results were excellent or good in 5 and fair in 1. Nine patients had complex or multiple aneurysms of variable origins (3 giant, 2 infectious, 2 traumatic and 2 associated with an arteriovenous malformation) and presentation. Surgical treatment of these children required the use of hypothermic arrest, trapping, bypass and anastomotic procedures. Outcome was excellent or good in 7 and fair in 2. An analysis of these patients with regard to pathogenesis and management is presented.

The importance of the cortical subarachnoid space in understanding hydrocephalus

OBJECT In this paper the authors define the role of the cortical subarachnoid space (CSAS) in poorly understood forms of hydrocephalus to cerebrospinal fluid (CSF) dynamics to improve understanding of the importance of the CSAS and its role in selecting patients for endoscopic third ventriculostomy (ETV). The secondary purpose of this work was to define testable hypotheses to explain enigmatic disorders of CSF dynamics and to suggest how these concepts could be tested. METHODS The magnitude of the contribution of the CSAS is explored using the solid geometry of concentric spheres. With this starting point, clinical conditions in which CSF dynamics are not easily understood are explored regarding the potential role of the CSAS. Overall, problems of CSF dynamics are easily understood. Insights may be gained when the results of a pathological process or its treatment vary from what has been expected. RESULTS Acute changes in ventricular volume at the time that hydrocephalus develops, the failure of shunts, and the changes in ventricular volume with shunt repair may occur very rapidly. Changes in the volume of water in the brain, especially in the brain substance itself, are unlikely to occur at this rapid rate and may be interpreted as a simple redistribution of the CSF between the ventricle and CSAS with no initial change in the actual volume of brain parenchyma. Problems such as pseudotumor cerebri, shunt failure with nonresponsive ventricles, and negative-pressure hydrocephalus can be explained by assessing the ability of ventricular CSF to flow to the CSAS and the ability of this fluid to exit this compartment. Ventricular enlargement at the time of shunt failure implies a failure of flow between the ventricles and CSAS, implying that all patients who show this phenomenon are potential candidates for ETV. CONCLUSIONS The important role of the CSAS in the pathophysiology of various forms of hydrocephalus has been largely ignored. Attention to the dynamics of the CSF in this compartment will improve understanding of enigmatic conditions of hydrocephalus and improve selection criteria for treatment paradigms such as ETV. These concepts lead to clearly defined problems that may be solved by the creation of a central database to address these issues.