Symptomatic intracranial steal.

The phenomenon of shunting of blood in association with various intracranial lesions is well known; however, usually clinical symptoms are attributable to the lesion and not to the redistribution of regional cerebral blood flow (rCBF). We report three patients investigated by angiography and rCBF studies in whom symptoms appeared to be due to a hemodynamic steal within one cerebral hemisphere, between hemispheres, and from the brain into a tumor, respectively.

Spatial and temporal registration of CT and SPECT images: development and validation of a technique for in vivo three-dimensional semiquantitative analysis of bone.

UNLABELLED: The combined use of postoperative 3-dimensional CT and SPECT imaging provides a means of relating anatomy and physiology for the semiquantitative in vivo analysis of bone. This study focuses on the development and validation of a technique that accomplishes this through the registration of SPECT data to a 3-dimensional volume of interest (VOI) interactively defined on CT images. METHODS: Five human cadaver heads served as anthropomorphic models for all experiments. Four cranial defects were created in each specimen with inlay and onlay split-skull bone grafts reconstructed to skull and malar recipient sites. To acquire all images, each specimen was landmarked with 1.6-mm ball bearings and CT scanned. Bone surfaces were coated with 99mTc-doped paint. The locations of the ball bearings were marked with paint doped with 111In. Separate SPECT scans were acquired using the energy windows of 99mTc and 111In. RESULTS: Serial SPECT images aligned with an average root-mean-square (RMS) error of 3.8 mm (i.e., <1 pixel). CT-to-SPECT volume matching aligned with an RMS error of 7.8 mm. Total counts in CT-defined VOIs applied to SPECT data showed a strong linear correlation (r2 = 0.86) with true counts obtained from a dose calibrator. CONCLUSION: The capability of this multimodality registration technique to anatomically localize and quantify radiotracer uptake is sufficiently accurate to warrant further assessment in an in vivo trial.

High-resolution CT scanning of facial trauma.

Computed tomographic (CT) scanning offers a simple, fast, and accurate study of complex maxillofacial trauma especially in the patient with multiple injuries. At the time of CT brain scanning, the facial bones can be scanned with only minimal extra time. High-resolution scanning provides excellent bony detail equal to or better than complex-motion tomography with the advantage of better contrast resolution as well. Application of craniofacial surgical techniques is facilitated by the accurate display of the nature and extent of fracturing. Surgical findings of extent of fracturing correlate better with high-resolution scanning than with plain films and conventional tomography.

Squamous cell carcinoma arising in a suprasellar epidermoid cyst. Case report.

A case is presented in which a squamous cell carcinoma developed in an intracranial epidermoid cyst. The patient was a 54-year-old woman with a 3-year history of depression and amblyopia; no focal findings were noted and she was diagnosed as having psychiatric disorders. On her final admission she showed clinical evidence of a rapidly growing intracranial mass. Computerized tomography (CT) identified a right parasellar and temporal lesion which was then incompletely removed. The literature on primary intracranial squamous cell carcinoma is reviewed, and the role of CT scanning in preoperative diagnosis of this lesion is discussed.

Psychological, topographic EEG, and CT scan correlates of frontal lobe function in schizophrenia.

This study examined frontal lobe function in a group of 20 patients with schizophrenia, on and off medication, compared to 20 normals matched for age, sex, handedness, intelligence, and educational level. Schizophrenic patients generally did not perform as well as normals on the Wisconsin Card Sorting Test (WCST). Patients off medication performed less well on this test than those on medication. Those on medication did not perform as well as those off medication on the design and word fluency tests, which suggested that medications may affect various aspects of frontal lobe function differently. During the WCST, normal subjects demonstrated an increase in beta mean frequency of the electroencephalogram in frontal and centrotemporal regions which was not statistically significant in either schizophrenic group. This shift in beta mean frequency was found to correlate positively with performance on the WCST in normals, but not in patients. Patients with more negative symptoms tended to show a smaller increase in beta mean frequency during the WCST. Performance on the WCST was correlated negatively with ventricle-brain ratio in all subjects, suggesting that frontal lobe function might be related to computed tomographic measures in the normal population as well as in schizophrenic patients. There was no correlation with performance on the WCST and length of illness.

Sophisticated CT in complex maxillofacial trauma.

Conventional radiology and selective complex-motion tomography suffice for the diagnosis of isolated facial fractures. Complex facial fractures, however, require a more directed diagnostic approach, utilizing the imaging potential of computed tomography (CT). In the acutely injured but stable patient, unenhanced axial CT (preview-monitored under clinical orientation) provides the most effective, safe, reasonably rapid diagnostic examination. Direct coronal CT can also be utilized. The brain is studied by contiguous 10 mm slices; the facial skeleton is studied with contiguous 5 mm slices, which permits coronal and sagittal reformations. In suspected cervical spine injury (where direct coronal CT is contraindicated), the axial CT format above will provide essential diagnostic information and allow image reconstruction. The late complications of brain abscess and CSF leak are well imaged by CT; the latter is best assessed (during activity) by preview-controlled CT after intrathecal injection of metrizamide.

Isolated basilar artery occlusion associated with a clivus fracture.

Most vascular injuries to the brain secondary to blunt head trauma involve the internal carotid circulation. A case of isolated basilar occlusion secondary to a clival fracture is described and compared to three other cases in the literature.

Adenoid cystic carcinoma: an unusual neurosurgical entity.

Adenoid cystic carcinoma, or cylindroma, usually presents in the salivary glands or in the upper respiratory passages. We report an unusual case of adenoid cystic carcinoma in a 45-year-old woman who presented with a three-year history of progressive right trigeminal sensory palsy, most pronounced in the second division. There was, in addition, a right trigeminal motor palsy and a partial right 6th nerve palsy. CT scanning showed only a small soft tissue mass spanning an enlarged right foramen ovale. Solid adenoid cystic carcinoma was resected from Meckel's cave via a middle cranial fossa approach. A subsequent biopsy of the right maxillary antral mucosa found tumor tissue. We concluded that the tumor originated in the maxillary antrum and spread posteriorly along the infraorbital nerve to enlarge in the foramen ovale. Radiation to a total of 5,000 cGy was given. At 22 months there was neither radiographic nor clinical evidence of recurrence. At 30 months, the development of unsteady gait signalled the presence of recurrent tumor extending backwards from Meckel's cave into the right cerebello-pontine angle.

Spinal injuries due to hockey.

Although many types of sports and recreational activities have been identified as common causes of acute spinal cord injury, hockey has been a rare cause of acute cord injury in Canada or elsewhere. For example, from 1948 to 1973 there were no patients with cord injuries due to hockey in a series of 55 patients with acute cord injuries due to sports or other recreational activities admitted to two Toronto hospitals. In contrast, between 1974 and 1981, the Acute Spinal Cord Injury Unit, Sunnybrook Medical Centre treated six patients with cervical spinal injury due to hockey, five of whom were seen during a 13 month period from September, 1980 to October, 1981. Five of the six sustained a severe acute cervical spinal cord injury, and one a cervical root injury. The cord injury was complete in two cases, while three had complete motor loss but incomplete sensory loss below the level of the lesion. All were males aged 15 to 26 years. Of the players with cord injury, four struck the boards with the neck flexed, and one struck another player with the neck flexed. The one player without cord injury struck the boards with his neck extended. The commonest bony injury was a burst fracture of C5 or C6. One of the patients with a complete cord injury died three months later of a pulmonary embolus, and the other patients with cord injury showed some recovery of root function, but little or no cord recovery. The reasons for the increase in spinal injuries in hockey are unknown.

Older volunteers: a discussion of the Minnesota Senior Study.

We used findings from the Minnesota Senior Study to examine the theoretical and methodological difficulties of defining, coding, and analyzing data on older volunteers. This study, the first statewide survey of the needs and resources of the elderly in Minnesota in almost 20 years, found that over half (52%) of older Minnesotans do volunteer work for organizations--considerably higher than has been found in national surveys. Problems in definition and methodology, however, have confounded analyses. This paper proposes a new conceptual model for classifying volunteer roles, based on three dimensions: whether the voluntary service is "formal" or "informal"; whether the activity entails a regular or an occasional time commitment; and the nature of the service activity (person-to-community, person-to-object, or person-to-person).

The role of primary bone grafting in complex craniomaxillofacial trauma.

The role of craniofacial surgical techniques and immediate bone grafting in the management of complex craniofacial trauma has been reviewed. Four hundred and one patients with complex facial injuries have been treated. Two hundred and forty-one primary bone and cartilage grafts have been performed in 66 patients. Complex facial injuries should be managed by direct exposure, reduction, and fixation of all fractures utilizing interfragmentary wiring. Very comminuted or absent bone is replaced by immediate bone grafting, producing a stable skeleton without the need for external fixation devices. Associated mandibular fractures are managed with rigid internal fixation utilizing A-O technique. Results of immediate bone grafting have been excellent, and complications are rare. All deformities should be corrected, whenever possible, during the initial operation. This one-stage reconstruction of even the most complex facial injuries will prevent severe postoperative traumatic deformity and disability that may be extremely difficult or impossible to correct secondarily.

Anatomic variants of the cerebello-pontine cisterns and their significance in positive contrast cisternography.

Far lateral extension of the cerebello-pontine cistern is a common variant which is found in greater than 50% of people. When present it may cause the internal auditory canal to be obscured during positive contrast cisternography. A technique of cisternography is described which facilitates the diagnosis of intracanalicular lesions as well as better delineating small lesions in the cerebello-pontine angle.

Positive contrast cisternography: analysis of 1) false negative studies, 2) false positive diagnoses of acoustic neuroma.

In performing and interpreting positive contrast cisternograms, one must be aware that both false negative and false positive studies are possible. The former may be avoided by an appreciation of normal anatomical variants of the cisterns and by adequate projections. The false positive study in which a lesion other than an acoustic neuroma is found, is mainly a problem where there is non-filling of the internal auditory canal without a significant angle mass. The differential diagnosis of such lesions is discussed.

Radiologic studies of facial trauma associated with a regional trauma centre.

The study of severe facial trauma has been altered by the development of computed tomography (CT). As a regional trauma unit we have gained increasing experience with complex fractures of the face. In those patients most severely injured, high resolution CT has become the imaging modality relied upon to offer the safest and most accurate information. Conventional films still have a role, especially in the less severely traumatized patient. We describe our methods and observations, based upon experience at a trauma unit, in the radiologic investigation of facial injuries.

CT of the cranium in head injury.

Computed tomography (CT) allows fast, accurate diagnosis of intracranial bleeding so that the role of cerebral angiography in acute trauma is now quite limited. Management of the patient with multiple injuries including head injury may differ from that of patients with head injury alone. Several different intracranial abnormalities may occur immediately after injury and during the following few days, including intracranial bleeding and edema. CT is of great help in following the clinical course of such patients.

Computed tomography and cerebrospinal fluid leak.

Cerebrospinal fluid (CSF) rhinorrhea is a serious condition which if untreated may lead to meningitis. Detection of the leak site at surgery may be difficult without prior accurate radiological localization of the leak and at times repeat operation has been required. Clinical and radiological localization of the leak is not always easy and many different tests have been tried. Prior to computed tomography (CT), the most common combination of radiological tests were plain films and tomograms of the skull and CSF isotope studies. Although CT scanning may be helpful in assessing a patient with CSF rhinorrhea, it is most effective when combined with intrathecal Metrizamide. The combination of Metrizamide and CT was first reported in 1977 and several case reports and small series of cases have since been reported. The purpose of this article is to review the value of CT especially when used in combination with Metrizamide in the patient with CSF leak and also to discuss the technique of the combined study and to show its value with illustrative cases.

Changes in cerebral blood flow during a migraine attack.

Regional cerebral blood flow studies during a typical prodromal phase of a migraine attack in a young woman showed a global decrease of cerebral blood flow in the carotid artery territory. These studies were repeated during the subsequent headache phase of the same attack and hemispheric blood flow increased considerably. Ergotamine tartrate was then administered intramuscularly which brought definite relief of symptoms but no change in cerebral blood flow. Carotid angiography performed immediately afterwards showed retrograde filling of the proximal portion of the basilar artery, which suggested that the brain stem was the site of hyper-perfusion. These findings illustrate certain features underlying both the pathophysiology of migraine itself and its response to ergotamine preparations.

CT of myeloma involving the skull base.

We report three patients with myeloma involving the skull base. A large extracranial soft-tissue mass, intracranial extension, homogeneous enhancement, smooth margins, and bone remodelling were features common to the three lesions. In two patients the lesions extended into the orbit with one patient presenting with proptosis.