James A. Taren

Spinal Cord Compression by Catheter Granulomas in High-dose Intrathecal Morphine Therapy: Case Report

OBJECTIVE AND IMPORTANCE: The use of chronic intrathecal morphine for the treatment of intractable, nonmalignant pain is becoming more prevalent. A rare but devastating complication of this therapy is the development of spinal cord compression secondary to the formation of intrathecal granulomas. CLINICAL PRESENTATION: We report three cases of intrathecal granuloma formation in the thoracic subarachnoid space, associated with intrathecal morphine pumps. These three patients were receiving high doses of morphine to control their pain (25 mg/d, 28 mg/d, and 45 mg/d, respectively) when they presented with signs and symptoms of thoracic spinal cord compression. Myelography and postmyelographic computed tomography of the spine revealed masses causing spinal cord compression. INTERVENTION: Two patients underwent thoracic laminectomies for resection of these masses, and the other patient had the intrathecal catheter removed. A pathological examination revealed sterile granulomas in the resected masses. CONCLUSION: Intrathecal granulomas are likely to occur with increasing frequency as the use of chronic intrathecal morphine delivery increases in patients with nonmalignant pain. The cause of intrathecal granulomas is unknown, although it is likely that morphine plays a major role in their formation. We think that those patients receiving high doses of morphine are at greater risk for developing this complication.

Radio-Frequency Thrombosis of Vascular Malformations with a Transvascular Magnetic Catheter

A tiny magnetic electrode catheter introduced into the human carotid artery has been mechanically and magnetically propelled, with fluoroscopic control, to cranial arteriovenous malformations. Radio-frequency heating of the catheter tip in successive positions occludes abnormal blood vessels.

Late Local and Remote Structural Changes after Capsulotomy for Obsessive Compulsive Disorder

Stereotactic subcaudate capsulotomy (SC) is used to treat medically intractable obsessive compulsive disorders (OCD). Although clinical improvement has been observed, post-SC structural correlates are lacking in this biological disorder. Our study provides imaging evidence for local and distant alterations in structures which may have an important role in the manifestations of OCD. Five OCD patients treated with SC received MR imaging for pre-SC planning, early (1-7 days) post-SC assessment, and late (5-12 months) follow-up. The volumes of the anterior limb of the internal capsules, caudate heads, third ventricle, mamillary bodies, thalami, and hippocampal formations were digitally computed. Volumes from each of the serial imaging studies were compared. At 5-12 months post-SC, all patients showed reduction in volume of the anterior limbs of the internal capsules, caudate heads, thalami, and increased volume of the third ventricle (reflecting thalamic/caudate atrophy). 2-5 patients showed reduction in hippocampal formation volume. The post-SC reduction in volume of these structures, some far distant to the stereotactic lesion, suggests that the interrelationships of the anterior limb of the internal capsule, the caudate/thalamic nuclei, and possibly the pallidal and limbic systems are necessary for the manifestations of OCD and their variants.

Management of anteriorly located C1-C2 neurofibromata

The authors discuss their recent experience with anteriorly located C1-C2 neurofibromata in five patients with cervical myelopathy and magnetic resonance scans consistent with intradural extramedullary masses in this region. Surgery was performed using a posterolateral approach with microscopic intradural exploration. Gross total intradural tumor removal was achieved in all cases. Improvement in cervical myelopathy occurred in all patients. This report concludes that C1-C2 neurofibromata located anterior to the spinal cord can be totally and safely removed using a posterolateral approach. Improvement in neurologic dysfunction accompanies posterior decompression and gross total intradural tumor removal.

ANATOMICAL PATHWAYS RELATED TO THE CLINICAL FINDINGS IN ANEURYSMS OF THE ANTERIOR COMMUNICATING ARTERY.

Aneurysms of the anterior communicating artery are formidable lesions even when successfully treated surgically for they may produce long-standing ill effects that are out of proportion to the size of the lesion. Indeed, some of our operations which we have judged to be excellent from a technical standpoint have proved to be most disappointing as these patients may develop persistent mental and behavioural changes that prevent them from functioning normally in society. Figure 1 illustrates this point. These are preand postoperative angiograms to document the presence of an aneurysm of the anterior communicating artery and show the obliteration of it by silver clips while preserving both anterior cerebral arteries. This patient was a successful middle-aged tool and die maker before a single episode of subarachnoid

3D Laser Scanning for Image Guided Stereotactic Neurosurgery

While this work is in its very early stages, the 3D laser scanner shows significant promise as a surgical localization device with advantages over other sensing methods. Accurate 3D surface extraction and matching, a central problem in computer vision, is the key to frameless stereotaxic neurosurgery using this technique.

Visual Outcome in Cystic Craniopharyngiomas Treated with Intracavitary Phosphorus-32

Seven patients with cystic craniopharyngiomas were treated with stereotactic instillation of radioactive phosphorus-32 (32P). Five patients had been previously treated with various combinations of surgery and external beam irradiation, whereas two had the 32P instillation at a primary therapy. Visual acuity improved in 13 eyes and remained stable in 1. Visual fields normalized in three patients, improved in two, and remained stable in two. Two patients received single treatments with 32P, whereas five required multiple instillations for recurrent cyst expansion.

Four-decade maintenance of analgesia with percutaneous cordotomy.

The management of severe, medically intractable pain is a significant challenge for neurosurgeons and pain management physicians. An existing technique that can effectively alleviate contralateral chronic pain is cordotomy, interruption of the lateral spinothalamic tract of the spinal cord. Since 1912, cordotomy has evolved from a relatively morbid open surgical procedure to a percutaneous radiofrequency procedure with low morbidity. However, since cordotomy is utilized primarily in cancer pain patients, long-term patient follow-up is rare, and the potential duration of analgesia following cordotomy is not known. Here we describe a case with a 41-year follow-up of percutaneous cordotomy for noncancer pain that resulted in over 35 years of complete analgesia, the longest recorded in the literature to date. This case demonstrates that percutaneous cordotomy can provide long-lasting, complete analgesia in some patients and merits continuation as a part of the neurosurgical arsenal of pain therapies.

Treatment of Cystic Astrocytomas with Intracavitary Phosphorus 32

Cyst formation by astrocytomas can cause progressive neurological deficit and can necessitate multiple surgical procedures. Before the advent of computed tomography (CT) preoperative diagnosis of cystic astrocytomas was difficult and stereotactic management of these lesions was limited. CT-guided stereotaxy provides a safe approach to all cystic astrocytomas including brain stem lesions. Based upon the experience of intracavitary radiation of craniopharyngioma cysts, the authors treated nine patients presenting with cystic astrocytomas utilizing colloidal chromium phosphorus 32 (32P). Control of cyst formation was achieved in eight patients. Our preliminary data suggest that intracavitary 32P may provide a significant adjunctive therapy in the management of cystic astrocytomas.

Physiologic Corroboration in Stereotaxic High Cervical Cordotomy

The recent conversion of cervical cordotomy from an open operation on an anesthetized patient to a closed stereotaxic procedure done on an awake patient has extended the benefits of this procedure to