[Skull-base plasmacytoma with craniocervical instability]

INTRODUCTION

Cranio-cervical instability is, in some cases, the main surgical concern in posterior skull base tumors. We report on a case in which a solitary plasmacytoma of the skull base presented with cranio-cervical instability. Vertebral artery was injured during surgery. The surgical anatomy is reviewed, with emphasis in vascular complications avoidance.

CASE REPORT

A 66 year-old woman was diagnosed of a cranial base solitary plasmacytoma and treated with radio and chemotherapy with complete remission. After receiving that treatment, she presented with tetraparesis and a cranio-cervical instability was diagnosed. She was operated on, under cranial traction, of posterior occipito-cervical instrumentation with C1 to C2 transarticular Magerl screws. The right vertebral artery was injured during surgery without additional neurological deficit. Two years after the operation she remains independent for daily activities.

CONCLUSIONS

Transarticular screws at the C1 to C2 level of the cervical spine may provide rigid fixation in posterior cranio-cervical instrumentation for osteolytic lesions, but there is a risk of injury to the vertebral artery, specially when some variations in the surgical anatomy exist.

[Spinal cord compression due to a epidural lipoma]

INTRODUCTION

The spinal extradural space is normally occupied by adipose tissue and a venous plexus, so it should be not surprising that lipomas arise and reach sufficient size to compress symptomatically the spinal cord. Nevertheless, the spinal epidural lipomas are rare and benign tumours may present as a progressive spinal cord compression syndrome. Magnetic resonance imaging is useful in demonstrating the full extent and characteristics of these lesions, the severity of cord compression and the location in the canal. Usually, the lesion is amenable to total surgical extirpation and the functional prognosis is good. Histopathologically the tumour consists of a mature adipose cells matrix intermixed with vascular endothelial channels, that is the reason why it is also named angiolipomas.

CASE REPORT

A 47 year-old woman complained of dorsal and bilateral submamarian pain lasting two years and progressive loss of sensibility and weakness in her legs. Following magnetic resonance studies a posterior spinal cord compression by an extradural tumour at T3-T7 levels was observed. She was operated on and we found an extradural yellow tumour easily to dissect and it was completely removed. One year later she is asymptomatic.

CONCLUSIONS

Spinal epidural lipoma is a benign tumour which initially presents itself with local or radicular pain accompanied by progressive spinal cord compression syndrome. The choice treatment is laminectomy and total excision. Probably, this is one of the easiest tumours to remove of the spinal canal and a source of satisfaction because a complete recovery can usually be achieved.

Aspergillus granuloma of the cavernous sinus: magnetic resonance imaging with pathologic correlation

This case illustrates the correlation between Magnetic Resonance Imaging (MRI) and the pathological findings in a case of cavernous sinus (CS) aspergilloma.

[Anatomical landmarks and surgical limits in the suboccipital transmeatal approach to the acoustic neuroma]

INTRODUCTION

To completely remove the intracanalicular portion of the acoustic neuroma through the retrosigmoid approach, we must open the posterior wall of the internal auditory canal (IAC). Therefore, drilling the IAC is one of the key steps we need to take in the transmeatal surgical approach. Nevertheless, there are no clear anatomical landmarks to identify structures such as the semicircular canals, the jugular bulb or air cells. The individual anatomical variations and those caused by the tumour itself make preoperative evaluation essential if we wish to avoid complications such as deafness, cerebrospinal fluid leakage, bleeding and air embolism.

OBJECTIVE

We describe here the personal experience of the senior author (EU) in drilling the posterior wall of the IAC, with special reference to the anatomical landmarks and surgical limits in the suboccipital approach to the intracanalicular portion of the acoustic neuromas.

MATERIAL AND METHODS

This work is based on anatomical data obtained from drilling human temporal bones obtained from cadavers, along with our experience with 20 patients who were operated on for acoustic neuroma using Samii's technique.

RESULTS

We did not operate on any purely intracanalicular neurinomas using this approach. Two tumors were grade II (up to 20mm in diameter), 12 were grade III and 6 were grade IV. We did not drill far enough in any of these cases to be able to see the fundus of the IAC, which was confirmed by postoperative CT. Despite this, the tumor was considered to be completely removed in 17 cases. There was no mortality and we has no major complications as a result of drilling the IAC such as cerebrospinal fluid leakage or air embolism. we cannot guarantee that hearing loss of postoperative deafness, which were the norm except in one case of grade II, were caused by nervous, ischemic or labyrinthine lesions.

CONCLUSION

In our material it was not possible to completely expose the IAC fundus using a retrosigmoid approach without injury to labyrinth. The areas in which the risk of secondary complications is greatest when drilling are the inferior wall and the IAC fundus. The medial extension of the suboccipital craniotomy makes drilling the intrameatal tumor exposure easier. There are no intraoperative landmarks to locate the petrous structures while drilling the IAC except for those provided by the surgeon's own experience.

[Evaluation of the Mullan's technique in the treatment of trigeminal neuralgia]

OBJECTIVE

The aim of the present study is to examine the operative technique and results of the treatment of trigeminal neuralgia (TN) by percutaneous microcompression of the trigeminal ganglion (Mullan's technique) in 20 consecutive patients over 3 years.

PATIENTS AND METHODS

The average age of the patients was 63 years. There were 8 men and 12 women. The operative technique is similar to Mullan and Lichtor's original description with some modifications.

RESULTS

On average it takes 30 minutes to complete the procedure. On 2 occasions the catheter had to be replaced as the balloon burst without clinical repercussions. Detectable changes were noted in systemic blood pressure and cardiac rhythm in 10 cases. On 17 occasions the radiographic appearance of the balloon was pear-shaped and in the remaining cases it was oval or irregular. Follow-up ranged from 6 months to 3 years. All but 1 patient were initially relieved of pain and it was progressively possible to suspend treatment with carbamazepine. The recurrence rate was 25%. Mean time until recurrence was 18 months. There was no relation between pain location and recurrence. Morbidity: some degree of transient cheek discomfort, herpes simplex perioralis, hypesthesia and masseter weakness were the rule. Meningitis in one case.

CONCLUSIONS

Early results indicate that Mullan's technique provides a reliable, safe, cheap and effective, with low morbidity and no mortality.

Delayed glossopharyngeal and vagus nerve paralysis following occipital condyle fracture. Case report

This report describes a case of delayed glossopharyngeal and vagus nerve paralysis following a closed head injury. A depressed fracture of the occipital condyle was diagnosed using high-resolution computerized tomography (CT) scanning and three-dimensional CT images. Magnetic resonance imaging complemented the study. The anatomical features, mechanisms, diagnosis, and treatment of this unusual lesion are discussed.

Macroscopic effects of percutaneous trigeminal ganglion compression (Mullan's technique): an anatomic study

After the use of Mullan's technique, macroscopic changes take place on the gasserian ganglion and the surrounding structures. These changes were studied on 20 trigeminal nerves of 10 fresh adult cadavers. Changes took place on the dura as well as in the neural elements. There was compression on the ganglion and on the trigeminal nerve, and there were changes in the position of the trigeminal root, with shortening of its cisternal segment. When the balloon was inflated to capacity (0.75-1.0 ml), dural stretching in an area of 15 x 10 mm took place. This stretching of the dura extended from the lateral wall of the cavernous sinus to the level of the porus trigemini. Despite these important mechanical effects, we never found a rupture or tear on the dura or the trigeminal nerve fibers. We discuss the relationship between mechanical effects and clinical results.