Clinical Experience with Double Cylindrical Cages for Anterior Cervical Interbody Fusion

OBJECTIVE: We performed the surgery using titanium double cylindrical cage for anterior cervical discectomy and interbody fusion in various degenerative cervical diseases. We compared the clinical results and radiologic results in cervical anterior disectomy. Method: From October 2007 to October 2008, 19 patients diagnosed with degenerative disease underwent anterior cervical disectomy and interbody fusion. The postsurgical clinical results were analyzed retrospectively by classifying them into four levels based on Odom's criteria(excellent, good, fair, and poor) after a more than 6-month follow-up period. RESULTS: In all cases, a single segment was involved, and surgery was performed for 19 segments. The C5-C6 inter-vertebral disc was the most commonly affected(9 cases). The clinical outcome was excellent, good, and fair in 5(26.3 %), 10(52.6%), and 4(21.0%) cases, respectively. An excellent or good outcome was considered as a successful result, showing an approximately 78.9% cure rate. No patient had aggravated symptoms compared with their preoperative status. CONCLUSION: Relatively satisfactory clinical and radiographic results were obtained with double cylindrical cages. The surgical method is relatively simple, allows good synostosis, and prevents many complications associated with autografting. It is also less traumatic to the spinal cord during cage insertion. Therefore, double cylindrical cages are generally more recommended for treating cervical spondylosis accompanied with flat cages.

Pontine Hemorrhages and Prognosis

Pontine hematomas are very rare lesions that in the past found at postmortem examination rather than diagnosed from the clinical presentations. Computed tomography has particularly stimulated further neurosurgical interest in this relatively rare condition, making surgical evacuation possible in some cases. Four patients suffering from pontine hemorrhages, revealed by computed tomography, are discussed. The classification regard to the site, clinical features and outcomes of this lesion are discussed in an attempt to establish general criteria for adequate management. With regard to the site, three types of hemorrhage are to be considered the tegmentotectal(type I), the tegmentolateral(type II) and the tegmentobasilar(type III), 2 patients(type I II, treated conservatively) had a fair outcome, and 2 patients(one of type III, treated conservatively, and one of type I, by surgical evacuation) had a death. Surgical management for the pontine hemorrhages should be reserved for the type I(tegmontotectal) and type II(tegmentolateral), whenever the neurological conditions deteriorate progressively.

Induced Hypertension Therapy for Postoperative Cerebral Ischemia in Aneurysm Surgery

The purpose of this study is to clarify the effectiveness and the indications of the dopamine induced hypertension therapy(IHT) in the treatment of symptomatic cerebral ischemia secondary to aneurysm surgery. Eight patients suffering from ischemic complication of postoperative vasospasm were treated with dopamine induced hypertension therapy and intravascular volume expansion. All of patients underwent CT scan in order to ascertain if their neurological deteriorations were due to vasospasm. The criteria of the indication of IHT are as follows : 1) ischemic symptoms were progressively advanced, 2) there is no hematoma or infarction on CT scan, 3) there is no responses to ischemic symptoms with hyperventilation, intravascular volume expansion, 4) there is no hypovolemia. The blood pressure was raised to 30% above the mean arterial pressure that required for reversal of the ischemic deficit with dopamine induced hypertension and increasing the intravascular volume. In seven of eight patient, a marked improvement in ischemic symptoms occurred after raising blood pressure, and blood volume. In 4 cases, the level of consciousness and neurological deficits were improved within 12 hours after IHT started. IHT is expected to restore the brain tissue from ischemia by increasing blood flow through the arteries of vasospasm and collateral circulation.

Auditory Brainstem Evoked Potential Responses in Focal Brain Lesions

Brainstem auditory response abnormalities directly reflect disturbance of neural function rather than the underlying anatomic cause of that disturbance. The test has advantage in detecting lesions that alter electrophysiology but do not produce detectable alterations of radiodensity, displace surrounding structures or change vascular supply and permeability. A sequence of seven low-amplitude potentials that occur in the initial 10 msec following click signals can be recorded from scalp electrodes in 44 patient with focal brain lesions using computer averaging techniques. The potentials, termed auditory brainstem responses, are thought to be the far-field reflection of electrical events originating in the auditory pathway during its course through the brainstem. We have studied auditory brainstem evoked potential responses in a variety of focal brain lesions and found them to be of assistance in evaluating the localization of pontomedullary, pons, midbrain, thalamus, subcortical and functional recovery. 1) Distortion of early components (type I) was occured in the brainstem lesions. 2) Distortion of late components (type II) was developed in the diencephalon or subcortical lesions. 3) Distortion of all components (type III) was developed in the brainstem and diffuse brain contusions. 4) Serial recordings provided information about the evolution of brain stem lesions and good functional recovery marker.

Induced Hypertension Therapy for Postoperative Cerebral Ischemia in Aneurysm Surgery

The purpose of this study is to clarify the effectiveness and the indications of the dopamine induced hypertension therapy(IHT) in the treatment of symptomatic cerebral ischemia secondary to aneurysm surgery. Eight patients suffering from ischemic complication of postoperative vasospasm were treated with dopamine induced hypertension therapy and intravascular volume expansion. All of patients underwent CT scan in order to ascertain if their neurological deteriorations were due to vasospasm. The criteria of the indication of IHT are as follows : 1) ischemic symptoms were progressively advanced, 2) there is no hematoma or infarction on CT scan, 3) there is no responses to ischemic symptoms with hyperventilation, intravascular volume expansion, 4) there is no hypovolemia. The blood pressure was raised to 30% above the mean arterial pressure that required for reversal of the ischemic deficit with dopamine induced hypertension and increasing the intravascular volume. In seven of eight patient, a marked improvement in ischemic symptoms occurred after raising blood pressure, and blood volume. In 4 cases, the level of consciousness and neurological deficits were improved within 12 hours after IHT started. IHT is expected to restore the brain tissue from ischemia by increasing blood flow through the arteries of vasospasm and collateral circulation.

Auditory Brainstem Evoked Potential Responses in Focal Brain Lesions

Brainstem auditory response abnormalities directly reflect disturbance of neural function rather than the underlying anatomic cause of that disturbance. The test has advantage in detecting lesions that alter electrophysiology but do not produce detectable alterations of radiodensity, displace surrounding structures or change vascular supply and permeability. A sequence of seven low-amplitude potentials that occur in the initial 10 msec following click signals can be recorded from scalp electrodes in 44 patient with focal brain lesions using computer averaging techniques. The potentials, termed auditory brainstem responses, are thought to be the far-field reflection of electrical events originating in the auditory pathway during its course through the brainstem. We have studied auditory brainstem evoked potential responses in a variety of focal brain lesions and found them to be of assistance in evaluating the localization of pontomedullary, pons, midbrain, thalamus, subcortical and functional recovery. 1) Distortion of early components (type I) was occured in the brainstem lesions. 2) Distortion of late components (type II) was developed in the diencephalon or subcortical lesions. 3) Distortion of all components (type III) was developed in the brainstem and diffuse brain contusions. 4) Serial recordings provided information about the evolution of brain stem lesions and good functional recovery marker.

Effect of Phentolamine on the Lung and Hypothalamic Lesions in the Experimental Neurogenic Ulmonary Edema in Cats

This experiment was performed to define the paricipation of a discrete hypothalamic neural structure in the genesis of pulmonary edema and the effect of alpha adrenergic blockade. Fifty adult cats weighing 2.5 to 4.0 Kg, were used in this study. The components of the pathophysiological systemic changes, lung weight, and histopathological changes of lung and hypothalamus were studied in groups of animals when intracranial pressure(ICP) was raised to 200 mmH2O of 300 mmH2O for 2 hours by intraventricular infusion with normal saline. The animals were divided into 5 groups : The normal control group was comprised in 10 normal cats. Control and phentolamine treated animal groups which had an elevated ICP of up 200 mmH2O consisted of 10 cats each. Control and phentolamine treated animal groups which had an elevated ICP of up to 300 mmH2O consisted of 10 cats each. The results obtained were as follows : 1) In the animal groups of elevated ICP to 200 mmH2O or 300 mmH2O, there were hemodynamic systemic changes which were neurogenically mediated and caused an immediate elevation in blood pressure of 30 mmHg to 60 mmHg. The hemodynamic data of the animals that had an elevated ICP of up to 300 mmH2O were significantly more deviated from normal control values than the 200 mmH2O ICP groups. The hemodynamic responses of the phentolamine treated animal with elevated ICP of up to 200 and 300 mmH2O were less deviated from normal control values. 2) The lung weights of the animals with an elevated ICP of up to 200 and 300 mmH2O were significantly heavier than the normal control value(p<0.05) and the lung weights of the animals with an elevated ICP of 300 mmH2O were significantly heavier than those with an ICP of 200 mmH2O(p<0.01). The lung weights of the phentolamine treated animal groups were significantly lighter than the control group but showed little increase in the lung weight when compared to the normal value. 3) By controlling the elevated ICP above 200 mmH2O in the experimental animals we have confirmed gross and microscopic appearances of hemorrhagic pulmonary edema. Histopathological changes of the phentolamine treated animals were significantly less sever than in the control groups. 4) By elevating ICP above 200 mmH2O in the experimental animals, we have confirmed discrete bilateral hemorrhagic spots of the anterior hypothalamus, preoptic region induced by increased intracranial pressure. Histopathological changes of the phentolamine treated animals with the elevated ICP were significantly less severe than of the control groups. 5) This experimental model may define the specific particification of the hypothalamus in the pathophysiological pathogenesis of neurogenic pulmonary edema. These results suggest that the lungs are directly affected by the intense sympathetic discharge evoked by release phenomenon from the sympathoinhibitory influence of the hypothalamus, and pulmonary edema was effectively eliminated by alpha adrenergic blockade.

Internal Wiring Fixation of Atlantoaxial Dislocation Caused by Odontoid Fracture in a Child

Although most patients with cervical fractures have damaged the lower cervical spine, there remain a significant number whose injury involve the atlanto-axial level. Since the diagnosis of fracture of he odontoid process was initially missed frequently, it is worth emphasizing the importance of adequate radiological studies for this potentially lethal lesion in head injury patient. The treatment for fractures of the odontoid process has consisted of reduction followed by immobilization using skeletal traction, a plaster case or halo device, or internal fixation by surgical intervention. The advantages of early surgical treatment to minimize external immobilization or prolonged bed confinement are generally accepted but the surgical techniques have varied widely. The authors have managed a case of traumatic atlanto-axial dislocation in a child combined with severe brain injury by internal fixation using wire only after reduction of the dislocation was accomplished by skeletal traction. The available literature regarding this injury is reviewed.

A Case of Metastatic Intracranial Melanoma

Malignant melanoma is known to metastasize to all organs of human body and accounted for the third most frequent primary neoplasm in the intracranial metastases. In a series of melanomas, cerebral symptoms have developed clinically only in 6% although the metastatic cerebral lesions were found by autopsy as high as 39%. The authors have experienced a case of metastatic melanoma on the Rt. Frontoparietal lobe with Jacksonian epilepsy as its presenting symptom.

A Case of Malignant Meningioma with Multiple Extracranial Metastasis

Meningioma is generally regarded as benign and extracranial metastasis of intracranial meningioma is rare. About 60 cases of distant metastasis of meningioma have now been reported. Angioblastic meningioma, although a rare type, shows rapid growth and sarcomatous change frequently, and has higher incidence of metastasis than other types of meningioma. The authors report a case of malignant angioblastic meningioma arisen in left olfactory groove with multiple metastasis to skeletal system. The available literature regarding these tumors is reviewed.