Type 1 Stickler syndrome: a histological and ultrastructural study of an untreated globe.

AIMS: To present a histological and ultrastructural study of an untreated globe in a patient with genetically confirmed type 1 Stickler syndrome. METHODS: Histological and electron microscopic examinations were performed on the enucleated globe from the proband of a pedigree with type 1 Stickler syndrome. Linkage analysis was carried out using polymorphic markers flanking the COL2A1 gene and the mutation was identified by direct sequencing. RESULTS: The significant retinal abnormality was incarceration of vitreous collagen within glial strands on the inner surface of an atrophic and gliotic detached retina. The incarcerated collagenous layers contained glial cells and extended from the retina to form strands, some of which contributed to a retrolental membrane. Mutation screening detected a C to T mutation in exon 47 that inserted a premature termination codon into the reading frame of the mRNA. Sequence analysis of three of the four affected children confirmed that they were also heterozygous for the base change. The youngest child's DNA was not analysed. CONCLUSIONS: The study represents the first evidence of abnormal interactions between pathological vitreous collagen and the inner retina in a patient with type 1 Stickler syndrome with a confirmed mutation in the COL2A1 gene.

Successful management of venous air embolism with inotropic support.

PURPOSE: Since venous air embolism may occur during many different types of surgery, management of this clinical emergency can be required in patients who do not have a previously established central venous access for aspiration of air. Recent reviews suggest that management of right heart syndromes in patients with embolism is critical in improving outcome. CLINICAL FEATURES: Abrupt decreases in oxygen saturation (from 98% to 40%) and end-tidal carbon dioxide tension (from 24 to 6 mm Hg), compatible with venous air embolism were observed in a 73-yr-old woman during craniotomy for meningioma in the supine position. Since no access for aspiration of air was readily available, therapy was directed at inotropic support of the right heart using a bolus of ephedrine. Cardiorespiratory variables rapidly returned to normal, and the patient recovered from anesthesia and surgery without sequelae. CONCLUSIONS: Venous air embolism places an acute load on the right ventricle and may provoke right heart failure, even in the absence of total cardiovascular collapse. Treatment that supports right heart function may allow sufficient time for redistribution of embolized air and produce a good outcome when access for central aspiration of air is not available.

Prospective study of postoperative magnetic resonance imaging in patients with malignant gliomas.

PURPOSE: We studied the natural history of postoperative enhancement on magnetic resonance (MR) scans in patients with malignant glioma to determine the following: (1) when a postoperative MR scan most accurately shows residual enhancing tumor; and (2) whether repeated doses of the contrast agent gadopentetate dimeglumine (Gd-DTPA) were well tolerated. PATIENTS AND METHODS: Seventeen patients with malignant glioma underwent tumor resection; four (24%) had nonenhancing tumors preoperatively. Serial MR scans were performed on postoperative days 1, 3, 5, 7, 14, and 21 and were analyzed qualitatively and quantitatively. The evolution of enhancement and subacute hemorrhage were described and measured. A uniform schedule of postoperative dexamethasone administration was used in all but four patients (24%) (each required higher doses to maintain neurologic function). RESULTS: Nontumoral, marginal (i.e., postsurgical) enhancement, potentially mimicking residual tumor, developed in eight patients (53%), including tumors that were nonenhancing preoperatively, and was maximal from days 5 to 14. Tumor enhancement was optimally visualized on postoperative days 3 to 5. Nine of 10 patients (90%) with gross residual enhancing tumor showed an increase of enhancing tumor size during the study. Methemoglobin was detected at some time in all patients (100%) and was usually minor, but in six (35%) it interfered with residual tumor assessment. The 97 doses of Gd-DTPA, administered in 17 patients, were well tolerated. CONCLUSION: When accurate assessment of residual enhancing tumor is needed in patients with malignant glioma, an MR scan performed on postoperative days 3 to 5 should minimize the confounding effects of postsurgical enhancement and methemoglobin. The repeated administration of Gd-DTPA over several weeks is well tolerated.

Parapharyngeal branchial cleft cyst presenting with cranial nerve palsies.

The authors report a case of branchial cleft cyst for which the location and presentation of the lesion were unusual. This abnormality should be considered in the differential diagnosis of cystic lesions of the parapharyngeal space. The presence of multiple cranial nerve palsies in association with a mass in this region does not necessarily indicate a neoplastic lesion.

Atlantoaxial dislocation as the presenting symptom of ankylosing spondylitis.

A 27-year-old woman presented with nontraumatic atlantoaxial dislocation that required a C1-C2 fusion. A comprehensive investigation initially failed to reveal any evidence of infectious or rheumatologic disease and she remained well for 3 1/2 years, at which time a diagnosis of ankylosing spondylitis was established. There are no other similar cases reported in the medical literature. When dealing with a patient who has experienced a spontaneous atlantoaxial dislocation, a thorough assessment looking for an underlying infectious or inflammatory etiology is mandatory. Furthermore, the authors recommend that any patient who has negative investigations be followed long-term; an underlying covert inflammatory cause may only become evident after significant delay.

Adenoid cystic carcinoma: an unusual sellar mass.

Adenoid cystic carcinoma represents approximately 20% of tumours of the minor salivary glands. It can originate in the sphenoidal sinus and invade the sella turcica. The authors describe a patient in whom a tumour of this type was shown by computed tomography.

Calcified herniations of the thoracic disk: role of magnetic resonance imaging and computed tomography in surgical planning.

Herniations of thoracic disks are uncommon, and their surgical management can be challenging. Magnetic resonance imaging (MRI) is rapidly becoming the method of choice for assessing degenerative disease in thoracic disks. However, calcification may be difficult to detect with MRI and plain films alone. The authors report a case in which MRI and myelography underestimated the true extent of disk calcification, the detection of which would have altered the initial surgical approach.

Benign osteoblastoma of the spine in childhood.

Osteoblastoma of the spine is a rare but important cause of back pain in children. Ten children with this tumor were treated at the Alberta Children's or Foothills Hospital in Calgary, Alberta, between 1974 and 1986. There were seven boys and three girls; the age at diagnosis ranged from 2 to 16 years (average 11 years). In nine patients the tumor involved the posterior vertebral elements. One of the cervical lesions was in the vertebral body. Three patients had tumor in the extradural space. The commonest symptom was pain in the back and neck. Bone scans were positive in all patients, and computerized tomography scans were abnormal in the eight patients who had this imaging performed. Nine children were treated with laminectomy and removal of the abnormal pedicle and facet. Two patients required two operations each because of incomplete tumor excision at the first operation; in these, subsequent surgery gave complete relief of symptoms and radiographic studies showed no further tumor. In three other patients, tumor removal was incomplete, and one patient received postoperative radiation therapy. Bone grafts were placed in four patients. The diagnosis of benign osteoblastoma was confirmed histologically in nine patients. The outcome was good in all cases, with excellent pain relief. The follow-up period has varied from 8 to 153 months (average 66 months) and there have been no recurrences. Based on this experience, complete excision of spinal osteoblastomas is recommended whenever possible. However, a satisfactory outcome may be achieved following incomplete excision and bone grafting.