Volumetry of simulated bone grafts in the edentulous maxilla by computed tomography: an experimental study.

OBJECTIVE: To determine the precision of CT for calculating the volume of bone grafts to the maxilla. METHODS: Plaster of Paris was used to simulate bone as onlay and inlay grafts to the maxillary alveolus and sinus in a dry skull. Two mm thick axial CT scans were obtained. The area of the graft on each slice was measured and volumes calculated according to the formula V(graft)=Sigma of areas x the thickness of each section. Scans were repeated with the skull at approximately +5 degrees and -5 degrees to the horizontal plane and the calculations repeated. The real volume was calculated by the displaced water technique. Precision was estimated as reliability coefficient. RESULTS: The reliability coefficients for the right and left inlay and the onlay grafts were 0.97, 0.6 and 0.96 respectively. CONCLUSION: Calculations of the volume of both inlay and onlay grafts to the maxilla from axial CT is precise.

A clinical study of changes in the volume of bone grafts in the atrophic maxilla.

OBJECTIVES: To evaluate the volumetric changes in bone grafts to the severely atrophic edentulous maxilla over 6 months. METHODS: Ten edentulous patients received autogenous bone as buccal onlay grafts to the maxilla and bilaterally particulate bone grafts to the maxillary sinus. Two mm contiguous axial CT scans were obtained 1 to 2 weeks and 6 to 7 months postoperatively. The area of each graft was measured and the volume calculated according to the formula V(graft)=Sigma of areas x the thickness of each section. RESULTS: The volume of the inlay and onlay grafts was reduced by an average of 49.5 and 47% respectively of the initial volume. The coefficient of variation was greater in the onlay group (0.79) compared with the inlay group (0.38). CONCLUSIONS: The volumetric changes in buccal onlay and sinus inlay grafts after 6 months of healing seem similar although there was a wide range in both groups.

Immunologic basis for adverse reactions to radiographic contrast media.

The lymphocyte transformation test (LTT) was used to elucidate whether certain side effects induced by radiographic contrast media have an immunologic etiology. Groups studied were: 8 patients who had previously experienced adverse reactions in association with urography, 6 patients who underwent urography without notable side reactions, 17 occupationally exposed nurses, and 9 unexposed controls. The lymphocytes from 2 hypersensitive patients and from 11 nurses exhibited a positive proliferative response to amidotrizoate. Five nurses who had shown a positive response, had a previous history of hypersensitivity reactions when handling contrast media, whereas the remaining 6 were free of symptoms. Amidotrizoate-specific memory cells were absent in patients who underwent urography without signs of hypersensitivity and in 7/9 of unexposed control subjects. Lymphocytes from patients sensitive to amidotrizoate cross-reacted to structurally related ionic contrast media while non-ionic contrast agents did not induce proliferation of the lymphocytes. Thus, ionic radiographic contrast agents have antigenic properties in man. Irradiated mixtures of radiographic contrast media and serum proteins were, in general, not effective in inducing an LTT response.

Bacteremic pneumococcal pneumonia in Sweden: clinical course and outcome and comparison with non-bacteremic pneumococcal and mycoplasmal pneumonias.

279 patients with 285 episodes of bacteremic pneumococcal pneumonia (Pnb), treated at the 2 departments for infectious diseases in Stockholm, Sweden, were reviewed retrospectively. Almost half of all episodes were caused by serotypes 3, 9 and 4 (in that order). The overall mortality rate was 7% and as low as 5% if patients with extrapulmonary complications were excluded. As in other studies male sex, alcoholism and absence of leukocytosis on admission to hospital were all associated with a higher mortality rate. However, the prognosis for old patients was much better than in most other studies. This was true also when the infecting strain was of serotype 3. For 89 consecutive patients out of the 279 ones with Pnb the clinical, laboratory and chest X-ray data were compared with those of 44 patients with non-bacteremic pneumococcal pneumonia (Pn) and 27 patients with Mycoplasma pneumoniae pneumonia (MP). Within the pneumococcal group almost all non-bacteremic patients had respiratory tract symptoms compared to less than half of the patients with bacteremic disease. High age, alcoholism, chills, pleuritic chest pain, a leukocyte count of greater than 15 x 10(9)l and an elevated CRP were factors significantly more common among those with pneumococcal pneumonia than among the MP patients. On chest X-ray an alveolar pattern was seen in all but 2 of the totally 133 patients with a pneumococcal pneumonia, but also in half the patients with MP.

The epileptogenicity of neurolept anaesthesia in patients during and after neuroradiological examinations with metrizamide.

Previous experimental studies caution against the use of neurolept anaesthesia during subarachnoid injection of metrizamide for neuroradiodiagnostic procedures because of severe epileptogenic complications. To examine whether these recommendations are relevant in the clinical situation or not, 104 patients were studied. They underwent neuroradiological investigations with metrizamide subarachnoidally and were anaesthetized with neurolept anaesthesia either during the investigation (59 patients, Group I) or within 48 h afterwards (45 patients, Group II) when a neurosurgical operation was performed. In 10 patients of Group I, EEG was recorded during the investigation. All patients were observed for occurrence of clinical epileptic manifestations during and after the anaesthesia. Apart from one patient who had a short episode of suspected epileptogenic EEG-activity shortly after the injection of metrizamide, none of the other patients showed EEG-abnormalities of epileptogenic type and none of them had any clinical signs of epileptic manifestations. On the basis of the results of this clinical study it is concluded that neurolept anaesthesia does not increase the risk of epileptic complications during neuroradiological investigations with metrizamide.

Stereotaxic reconstruction of the aqueduct of Sylvius.

A stereotaxic technique has been developed to cannulate the cerebral aqueduct in patients with hydrocephalus resulting from occlusion of the aqueduct of Sylvius. Precise placement of a 15- to 20-mm long radiopaque prosthesis between the third and fourth ventricles can reestablish the normal cerebrospinal fluid (CSF) pathway. Since 1974, seven patients have undergone aqueductal reconstruction. The surgical goal in this series was to manage the hydrocephalus by creating and maintaining a patent aqueductal channel. The follow-up period ranged from 1.5 to 6.5 years. In four cases, aqueductal reconstruction alone resulted in control of the hydrocephalus, although two patients underwent revisions of their prosthesis. Three patients ultimately required shunts, despite initial symptomatic improvement after reconstruction. In these seven cases (13 stereotaxic procedures), no mortality and no significant operative morbidity were encountered. Although the technique is relatively simple to perform, technical difficulties remain. At present, no clinical or radiographic test adequately discerns the ideal candidate for stereotaxic aqueductal reconstruction. Four patients required stereotaxic revision because of malposition or malfunction of the prosthesis. This approach should be reserved for patients with a short aqueductal occlusion, and normal distal CSF pathways and dynamics. The rationale, technique, problems, and results of stereotaxic reconstruction are presented.

Atlantoaxial instability in Marfan's syndrome. Diagnosis and treatment. A case report.

A case of Marfan's syndrome is described in which progressive neurological signs and symptoms were produced by flexion of the head. Radiological examinations revealed hypermotility between the atlas and axis, as well as compression of the medulla oblongata by the odontoid process on flexion, since low positioned cerebellar tonsils prevented dorsal shift of the oblongata. The signs and symptoms disappeared after occipitocervical internal transfixation.

Atlantoaxial arthrography. A postmortem study.

The atlantoaxial joints of nine cadavers were examined with Amipaque. A lateral percutaneous approach was elaborated. Interarticular communications and pertinent anatomical features were analyzed.

Pneumoencephalographic changes with intrasellar cisternal herniation (primary empty sella).

In a selected material of 47 cases of primary intrasellar cisternal herniation, analysis of pneumoencephalographic changes demonstrated the long axis of the anterior part of the third ventricle to point towards the center of the herniation. Transmitted CSF pulsations from the third ventricle probably determine the formation and location of intrasellar herniations. The distribution of air in the subarachnoid space indicated a disturbed CSF circulation in the majority of patients. Visual field defects were unrelated to the slight deformity of the optic nerves observed but rather to a high position of the third ventricle.

Diagnosis of intrasellar cisternal herniation (empty sella) by computer assisted tomography.

Twenty-six cases of empty sella were studied using computer assisted tomography (CAT). Emphasis was placed on the technical factors controlling the pictures. The diagnosis seems to be feasible in a large number of cases provided movement artifacts are reduced and the angulation, thickness, and level of the cut are carefully chosen.

Cisternography with metrizamide of the posterior fossa following lateral C1-C2 puncture.

A report is given of a series of 23 consecutive cisternographies with metrizamide (Amipaque) of the posterior fossa using the lateral puncture at the C1-C2 level. Two to 4 ml metrizamide 300 mg I/ml were injected. The good clinical tolerance with regard to short as well as long-term effects of the contrast medium may be attributed to the low dose used and rendered possible by the selective distribution. No clinical epileptogenic seizures were observed.

Cisternography with the non-ionic water-soluble contrast medium metrizamide. A preliminary report.

In 11 patients the basal cisterns in the posterior cranial fossa were examined with the new water-soluble compound metrizamide. Promising results were obtained when the medium was administered suboccipitally or through the foramen ovale but less favourable after lumbar administration. The clinical tolerance of the compound with regard to short term effects was good.

Metrizamide-phenothiazine interaction. Report of a case with seizures following myelography.

One single clinical complication of grand mal seizures in conjunction with the subarachnoid administration of the new non-ionic contrast medium metrizamide is reported in a patient who had been taking chlorpromazine. An interaction between the contrast medium and phenothiazine derivatives is considered probable.

Anatomy of the cranial nerves in the basal cisterns. A radiologic post-mortem investigation.

A post-mortem radiologic investigation of the basal cisterns has been made with special regard to the cranial nerves. The cisterns were removed in one piece together with the adjacent brain structures and the skull base. The anatomy of the cranial nerves as seen at cisternography and the frequency of their identification have been analysed. The application in clinical cisternography of the information obtained is discussed.