[Retro-odontoid pseudotumor in diffuse idiopathic skeletal hyperostosis]. / Pseudotumor retroodontoideo en un paciente con hiperostosis esquelética idiopática difusa.

Retro-odontoid pseudotumors are lesions caused by inflammatory granulation or reactive soft tissue hypertrophy from chronic atlantoaxial subluxation. However, one-third of the cases reported in the medical literature did not show atlantoaxial instability clearly. The authors present the case of a 76-year-old man previously diagnosed with diffuse idiopathic skeletal hyperostosis who presented with severe progressive myelopathy. A magnetic resonance imaging of his cervical spine revealed a retro-odontoid predural mass, which caused a severe compression of the cervical spinal cord. The patient underwent a posterior laminectomy of the atlas and an occipitocervical fusion. After surgery, the pseudotumor was considerably smaller and the neurological symptoms improved.

[Cervical spine osteochondroma presenting with torticollis and hemiparesis]. / Osteocondroma de la columna cervical provocando tortícolis y hemiparesia.

Osteochondromas are slow-growing benign bone tumors that are located frequently in the long bones. Approximately 1-4% of them occur in the spine. Solitary spinal osteochondromas may produce a wide variety of symptoms depending on their location and relationship to associated structures. We report a case of a 74-year old woman who was admitted to our hospital with complaints of progressive left hemibody weakness and cervicalgia. Neurological examination disclosed mild left-sided hemiparesis and left torticollis. Computed tomography and magnetic resonance imaging of the cervical spine revealed an expansive lesion affecting the left C3-C4 facet joint. The patient underwent a posterior C3 and C4 hemilaminectomy, complete excision of the lesion and instrumented posterior cervical fixation. Histological examination confirmed the diagnosis of osteochondroma. After surgery her symptoms improved progressively with no neurological sequels.

[Bowstringing as a complication of deep brain stimulation]. / Bowstringing como complicación de estimulación cerebral profunda.

Deep brain stimulation (DBS) is an established surgical therapy for intractable movement disorders, such as Parkinson's disease, essential tremor and dystonia. As the number of treated patients has increased rapidly, new sets of problems about complications of DBS have arisen. Bowstringing is defined as abnormal tethering of leads between the pulse generators and stimulating electrode, associated with pain and contracture of the neck over the extension cable. We report the case of a 56-year-old woman with a history of advanced Parkinson's disease who had been treated by implantation of a bilateral, subthalamic nucleus, deep brain stimulator. A car accident caused the rupture of the right electrode, which was replaced. Six months after the replacement the patient presented disabling pain and tension in the neck where deep brain extension cables were located. A cervical incision was performed to excise scar tissue. Bowstringing is a rare complication of DBS and although patients sometimes report discomfort and tension in the cervical region, surgical procedures are not normally required.

[Primary cranial vault lymphoma]. / Linfoma primario de la calota craneal.

INTRODUCTION: Primary bone lymphomas account for 3-7% of all malignant bone tumours and less than 2% of lymphomas in adults. Having the cranial vault as their primary location is very infrequent. CASE REPORT: A 59-year-old female who presented a painful tumour on the cranial vault which, following radical surgical removal, was found to be an ALK-negative primary large-cell lymphoma. CONCLUSIONS: After reviewing the literature we believe that this is the first case of cranial vault lymphoma in which the translocation of the ALK protein-producing gene has been studied.

[Tumours of the nerve root sheath in the spine]. / Tumores de la vaina de las raíces nerviosas espinales.

INTRODUCTION: Spinal schwannomas account for about 30% of intradural spinal cord tumors in adults. More are solitary tumors, which can occur throughout the spinal canal. The multiple form of neurofibromas is known as von Recklinghausen disease. AIM. To analyze clinical and radiologic characteristics, treatment and evolution of patients with spinal nerve sheath tumor. PATIENTS AND METHODS: This was a retrospective study in a series of patients treated surgically of spinal schwannomas during 25 years. The following variables were evaluated: gender, age, symptomatology, radiological findings, localization, surgical findings and results. RESULTS: We treated 35 male and 33 female with a mean age of 55 years (range: 12-76 years).The most common pre-surgical symptom was local or radicular pain in 55 patients (80.8%). In 49 cases (66.2%), the tumor was sited in the lumbosacral, in 15 cases (20.2%) in the dorsal tract, and in 10 cases (13.6%) in the cervical tract. Total removal was achieved in 70 cases (94.5%) and subtotal resection in 4 (5.5%). 66 tumors (89.1%) were schwannomas and the other 8 cases (10.9%) neurofibromas. CONCLUSIONS: Tumors of the spinal root sheaths can occur at any level of the spinal canal. Most patients present with local and/or radicular pain and in most cases total resection its possible with good functional recovery.