[Cervical spine osteochondroma presenting with torticollis and hemiparesis].

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.

[Retro-odontoid pseudotumor in diffuse idiopathic skeletal hyperostosis].

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.

[Bowstringing as a complication of deep brain stimulation].

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.

[Primary cranial vault lymphoma].

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.

[Tumours of the nerve root sheath in the spine].

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.