Traumatic atlanto-occipital dislocation in children.

Traumatic atlanto-occipital dislocation is seen in approximately 25% of fatal pediatric trauma. This was previously considered to be a rare and fatal entity, however with improvements in resuscitation in the field, many patients who previously might have died are now evaluated in the hospital. Treatment of atlanto-occipital instability is internal fixation. Many authors have advocated supplemental external immobilization with a halo vest. However, there are several circumstances where the application of a halo vest is undesirable. Thus a method of internal fixation and fusion that is rigid enough not to require supplemental external orthosis is necessary. We present 2 cases of atlanto-occipital dislocation which were treated with Locksley intersegmental tie bar occipital cervical fusion. Both patients achieved solid fusion without supplemental halo bracing, and made complete neurologic recoveries. Traumatic atlanto-occipital dislocation is a potentially survivable injury that requires aggressive resuscitation in the field, a high index of suspicion and early definitive surgical stabilization.

Delayed appearance of a traumatic intracranial aneurysm. Case report and review of the literature.

Giant traumatic intracranial aneurysms are rare, and thus their incidence and clinical behavior are poorly understood. In most cases, traumatic aneurysms develop and become symptomatic within months following injury. The authors present the case of a 46-year-old war veteran, in whom a giant internal carotid artery aneurysm developed as a result of a penetrating cranial shrapnel injury sustained 25 years earlier during the Vietnam war. The aneurysm had not been evident on previous imaging studies. At surgery, a piece of shrapnel was found embedded in the dome of the aneurysm. The presentation, diagnosis, management, and treatment options related to this lesion are discussed.

Pump-regulated lumbar subarachnoid drainage.

OBJECTIVE: The diversion of cerebrospinal fluid (CSF) has been widely used in the prevention and treatment of CSF fistulae. A common method is the use of a lumbar drainage system. Although it is effective, several serious complications can develop, which can be avoided by regulating the flow of CSF with a standard intravenous infusion pump. TECHNIQUE: We present a simple, inexpensive, and accurate method of flow-controlled lumbar subarachnoid drainage that minimizes patient discomfort and the unpredictability of a gravity-dependent system. This system uses a standard lumbar drain connected to an intravenous infusion pump to provide drainage of CSF in a constant and predictable manner. RESULTS: A total of 42 patients from two institutions were treated with this method. CSF fistulae occurred secondary to trauma in 9 patients, after spinal surgery in 11 patients, after transsphenoidal surgery in 10 patients, and after cranial base surgery in 12 patients. Resolution of the fistula was attained in 36 of 42 patients. There were no deaths, no cases of deep venous thrombosis, and no incidence of meningitis. One patient developed tension pneumocephalus, and two patients developed headache with nausea and vomiting. All patients were ambulatory, and only three patients required narcotic analgesia for headaches. CONCLUSION: Pump-regulated lumbar subarachnoid drainage is safe and effective in the treatment of CSF fistulae, as reported elsewhere in the literature. The advantage of this method is that the drainage of CSF can be carefully controlled and titrated in a predictable fashion. Because the system is independent of gravity to produce drainage of CSF, patients are not confined to bed and serious complications of overdrainage can be avoided.

Fusion and instrumentation at C1-3 via the high anterior cervical approach.

OBJECT: The high anterior cervical, retropharyngeal approach to the anterior foramen magnum and upper cervical spine is a favorable alternative to the transoral and posterolateral approaches, which both cause instability of the craniovertebral junction. Previously, such instability was corrected via an occipitocervical fusion during a separate surgical procedure. METHODS: Seven patients requiring C-2 corpectomy (foramen magnum meningioma [two patients], critical stenosis secondary to rheumatoid arthritis [two patients], C-2 fracture [two patients], and stenosis secondary to Rickets [one patient]) are presented. All patients underwent C1-3 fusion followed by instrumentation with a Caspar plate. A solid fusion was achieved in six patients. One patient experienced erosion of the anterior arch of C-1 requiring posterior stabilization. CONCLUSIONS: Fusion and instrumentation at C1-3 can be performed safely and with minimal increase in surgical time. In selected patients, this may eliminate the need for an additional posterior procedure and maintain occipital-C1 mobility.

Brain wounds and their treatment in VII Corps during Operation Desert Storm, February 20 to April 15, 1991.

OBJECTIVE: To evaluate field neurosurgery supporting VII Corps during combat in Operation Desert Storm. RESULTS: (1) Only 1 of 22 patients who had a head wound died. (2) The one computed tomography unit in a forward hospital worked well, aiding diagnosis and surgical management. The occurrence of hematoma at a distance from the missile track has been worrisome to past field neurosurgeons, but none of 9 patients who had predebridement scans had a distant clot. (3) The number of brain wounds was fewer than expected for Americans, and the wounds were basilar in location. Iraqis, by contrast, had wounds that were randomly distributed about the head. CONCLUSIONS: (1) Although computed tomography is a useful diagnostic adjunct, its availability should not be a sine qua non for forward neurosurgery. (2) The current Kevlar helmet design appears successful.

Carpal tunnel syndrome. A guide to prompt intervention.

Carpal tunnel syndrome is the most common entrapment neuropathy in the United States. The diagnosis should be considered for any patient with hand or wrist pain, weakness, or numbness. Changes in sensory conduction velocities across the wrist appear to be the most sensitive electrophysiologic indicators of the condition. Treatment of mild cases involves avoiding the precipitating activity, wrist splinting, and local steroid injections; surgical decompression is often required for moderate and severe cases. Overall, prognosis relates directly to the severity of the median nerve injury at diagnosis, the clinical cause, and the mode of treatment.

Delayed hearing loss after neurovascular decompression.

We report two unusual cases of delayed hearing loss after neurovascular decompression of structures within the cerebellopontine angle. In the first case, the patient noted a unilateral hearing loss 3 weeks after undergoing vascular decompression of the trigeminal nerve for tic douloureux. This gradually improved over an 18-month period. In the second case, the patient awoke on the 4th day after vascular decompression of the facial nerve for hemifacial spasm with a bilateral hearing loss that has remained unchanged after the onset. These are examples of delayed acoustic dysfunction occurring with a shift in surgically freed vessels and may have been induced by newly directed neurovascular compression or distortion.

The rCBF response to Diamox in normal subjects and cerebrovascular disease patients.

Age-related norms for the regional cerebral blood flow (rCBF) response to Diamox (acetazolamide) were based on studies of 55 normal subjects at rest and on studies of 33 of these 55 normal subjects following an intravenous injection of Diamox (22 mg/kg). After the Diamox injection, rCBF increased at all locations measured in all subjects. On average, rCBF increased 1.7 times. The following were found for rCBF in both resting and Diamox-treated subjects: 1) rCBF decreased significantly with increasing age; 2) slope and intercept for the regression of rCBF on age were largest for frontal detectors, intermediate for parietal detectors, and smallest for occipital detectors; 3) rCBF hyperfrontality was most noticeable in younger subjects; 4) in subjects of any age, 95% confidence intervals for rCBF were relatively large (expected value +/- 30%) and lower 95% confidence intervals for Diamox rCBF tended to overlap the upper 95% confidence intervals for resting rCBF; and 5) side-to-side percentage difference in rCBF did not have a significant regression on age and tended to be less than 10% to 20%. Diamox did not have an important effect on blood pressure, pulse rate, or respiratory rate. The normative data for the rCBF response to Diamox was used in evaluating 20 patients with cerebrovascular disease. Forty percent of these patients, all of whom exhibited angiographic evidence of potentially hemodynamically significant lesions, had normal rCBF at rest and after Diamox injection. Twenty percent had normal resting flows with abnormal Diamox-activated flows. Asymmetry in rCBF was the most sensitive indicator of a potential abnormality in cerebral perfusion. Thirty percent of the abnormal studies showed only significant asymmetry. It is suggested that rCBF studies at rest and after Diamox treatment, with age-related norms, may be useful in the management of patients with cerebrovascular disease.

Ossification of the posterior longitudinal ligament in Caucasians: diagnosis and surgical intervention.

Six cases of ossification of the posterior longitudinal ligament (OPLL) in Caucasians have been diagnosed during a 2-year period at Walter Reed Army Medical Center. Five cases were in men and one was in a woman. Three cases presented as myelopathy and three as radiculopathy. Diagnosis was best confirmed with computer-assisted tomography. All six cases were treated surgically via an anterior approach, microsurgical resection of the OPLL, and autograft fusion. Patients with radiculopathy had immediate pain relief after operation. Those with myelopathy required vertebrectomy and regained strength after operation. All patients improved with operation. OPLL is not a rare condition in Caucasians. With diagnosis and proper surgical intervention, prognosis for improvement is good.

Heparin-associated thrombocytopenia in the neurosurgical patient.

Although thrombocytopenia occurs in approximately 10% of medical patients who receive heparin, this complication has not been described in neurosurgical patients. We report the clinical course of two patients who in the immediate postoperative period developed heparin-associated thrombocytopenia that resulted in significant morbidity. In these two cases, the origin of the heparin was in "flush" solutions used to maintain the patency of indwelling vascular catheters and was infused at a dose of 250 to 500 units/day. The minimal daily dose previously reported to result in thrombocytopenia is 9000 units/day administered in divided doses subcutaneously. The case reports indicate that heparin in "flush" solutions should be considered as a cause for unexpected thrombocytopenia and that platelet counts should be monitored in patients receiving heparin in any amount.

Morphological studies of human arteriovenous malformations. Effects of isobutyl 2-cyanoacrylate embolization.

Ten patients with symptomatic arteriovenous malformations (AVM's) underwent embolization with isobutyl 2-cyanoacrylate (Bucrylate) delivered via a mini-balloon catheter according to the protocol of George and Pevsner. These patients underwent surgical removal of their embolized AVM, and surgical specimens were evaluated by light and scanning electron microscopy. Ten other patients with AVM's underwent surgical resection without prior embolization, and these surgical specimens were evaluated in a similar manner. Results from this study indicate that Bucrylate incites an inflammatory response characterized by foreign-body giant cells. This reaction was present as early as 3 weeks after embolization and persisted in specimens resected almost 1 year after the last embolization. No such reaction was observed in unembolized AVM's. Both light and scanning electron microscopy demonstrated a lattice structure of the Bucrylate embolus within the AVM vessels. These studies also demonstrated micro-channels within the Bucrylate embolus and the presence of what appears to be normal red blood cells within the latticework of the embolus. Vascular endothelium not in direct contact with the Bucrylate embolus retains a normal morphology as revealed by scanning electron microscopy.

Transthoracic anterolateral decompression for thoracic spinal lesions.

Since 1978, the authors have treated 11 patients with lesions of the ventral thoracic spine via a transpleural anterolateral approach. Each of the patients presented with pain and paraparesis, 8 had sensory dysfunction, and 6 had demonstrated sphincteric disturbances. All 11 had radiographic confirmation of anterior cord compromise, and each underwent an anterior decompression, with 8 requiring graft stabilization. There were no surgical mortalities, and the postoperative complications were limited. In follow-up, 10 of the 11 patients had complete resolution of their preoperative pain and were able to ambulate independently. Remission of sensory disturbances was noted in 6 patients, and 5 regained sphincteric control. The authors have found that this approach is both safe and effective, with several advantages over conventional laminectomy and posterolateral techniques.

Craniocervical abnormalities. A comprehensive surgical approach.

Guidelines are proposed for surgical management of symptomatic abnormalities of the craniocervical junction. Experience with 17 recent cases is described. Gas or metrizamide (Amipaque) myelograms with pluridirectional tomograms revealed the etiology and mechanisms of compression of the cervicomedullary junction, as well as its reducibility. Stabilization was the goal in treatment of reducible lesions. Decompression of the cervicomedullary junction was paramount in irreducible cases. Ventral compression was treated in nine patients by transoral transpalatine resection of the odontoid-clivus complex, and all nine improved. A posterior decompression was carried out when bone impingement was present from the dorsal aspect. Fusion was performed in cases in which stability was not achieved by either procedure.

The Doppler ultrasonic flowmeter as an adjunct to operative management of cerebral arteriovenous malformations.

The Doppler ultrasonic flowmeter has been used to assist in the removal of five intracranial arteriovenous malformations. The instrument is generally available in most institutions, and is simple and easy to use. It provides a means for locating and confirming the boundaries of a malformation, distinguishing feeding arteries from arterialized draining veins, determining whether the artery is going to the malformation or normal brain, and evaluating the completeness of obliteration.

Cerebral cystic hemangioblastoma.

A 26-year-old man having a large left frontal lobe cystic mass due to a 1.5 cm capillary hemangioblastoma acting as a mural nodule is presented. The cerebral topographical location of hemangioblastoma is rare and the reported cases are summarized and analyzed. The distinction between hemangioblastoma and angioblastic meningioma is emphasized by the occurrence of a cystic capillary hemangioblastoma in the cerebrum.

Normal pressure hydrocephalus due to membranous obstruction of the sylvian aqueduct.

In a patient presenting with the clinical features of normal pressure hydrocephalus, a membranous obstruction of the aqueduct of Sylvius was demonstrated by combined air encephalography and contrast ventriculography. Ventriculoatrial shunting resulted in clinical improvement without significant change in ventricular size.

Extrapyramidal disorder with pineal germinoma. Case report.

Space-occupying lesions of the basal ganglia are a rare cause of extrapyramidal dysfunction in children. Metastatic pineal germinoma in both basal ganglia produced dystonia in a 12-year-old boy. The literature is reviewed. Extrapyramidal manifestations in the child are compared with previously reported cases of basal ganglia neoplasms.