1,720,969 research outputs found
Depletion of calcitonin gene-related peptide in perivascular nerves during acute phase of posthemorrhagic vasospasm in the rabbit.
No full textUnusual neuroradiological appearances of benign meningiomas. Histological correlations
No full textThe authors present two cases of meningiomas with unusual neuroradiological preoperative findings but with histological pictures of benign meningiomas. The first female patient has been submitted during childhood to radiation therapy for tinea capitis. At the age of 50 she was operated on for removal of a right frontal convexity meningioma. After two years, MRI control showed a left parietal parasagittal mass, the characteristics of which were completely different from the previously operated tumor. In fact, the lesion was hypointense in T1-weighted images and hyperintense in T2-weighted images. On CT scan it was hypodense without enhancement. At 54 years of age, the second mass was surgically removed and the histological picture was of meningothelial meningioma with microcystic elements. The following year a third meningioma was removed, but the radiological finding was similar to the first lesion. The follow-up is uneventful after nine years from the first operation. The second patient, a 55-year-old woman, experienced a left partial motor seizure followed by generalization. Enhanced CT scan showed a large right fronto-temporal polycystic tumor with mass effect and irregular margins, suggesting the diagnosis of malignant glioma. On the operation we found an extracerebral tumor, adherent to the dura of the pterion, to the lesser wing and convexity. The histopathological feature was of angioblastic meningioma. Misleading neuroradiological features and histological correlations are discussed
Management of head-injured patients in the emergency department: a practical protocol
No full textBACKGROUND
The management of head-injured patients admitted to emergency departments is not standardized.
METHODS
The authors performed a retrospective analysis of 10,000 head-injured patients admitted to the Emergency Department of our hospital in a 21-month period and, on the basis of a statistical correlation between each clinical parameter (symptoms and signs upon arrival at the hospital or risk factors) and the presence of intracranial lesions, they propose a practical protocol in an attempt to avoid the overuse of radiologic examinations and yet identify patients with possible life-threatening complications.
RESULTS
On the basis of this correlation the patients have been divided into four groups, In the first group (called group alpha) are patients with: no history of loss of consciousness, no vomiting or amnesia, a normal neurologic examination, and minimal if any subgaleal swelling. They can be released into the care of relatives who are given a special instruction sheet (X rays unnecessary). No patient in group alpha had complications of any kind. The second group (group beta) is made up of patients with at least one of the following features: transient loss of consciousness, posttraumatic amnesia, a single episode of vomiting or significant subgaleal swelling. They undergo a computed tomography (CT) scan and if this is normal, only a short period of observation is needed. If CT scan is not available, the skull is X rayed and, if this X ray is negative, the patient is sent home with the warning sheet after an observation period. If a fracture is found, CT scan should be performed promptly. No patient in group beta with normal skull X rays developed intracranial lesions. The third group (group gamma) contains patients with at least one of the following symptoms: impaired consciousness, repeated episodes of vomiting, neurologic deficits, otorrhagia, otorrhea, rhinorrea, signs of basal skull fracture, seizures, penetrating or perforating wounds, lack of cooperation for varying reasons, patients who have undergone previous intracranial operations or been affected by coagulopathy or submitted to anticoagulant therapy, and finally, epileptic or alcoholic patients. They receive a CT scan immediately and, if necessary, again prior to discharge. Six patients in group gamma with GCS = 15 upon admission were operated on for intracranial hematoma. The fourth group (group delta) is composed of comatose patients. Immediately following resuscitation maneuvers and prior to any surgical intervention, they undergo a CT scan. A linear association between the severity groups and the presence of intracranial lesions has been demonstrated.
CONCLUSIONS
The present protocol stresses the importance of the patient's clinical and anamnestic evaluation upon arrival in the Emergency Department, especially in minor head injuries
Cranial nerves palsy in the surgery of cerebello-pontine angle meningiomas
No full textA surgical series of 15 patients with cerebellopontine angle meningiomas between 1990-1997 has been reviewed. Preoperative cranial nerve palsy was present in 10 cases. A retrosigmoid suboccipital approach was performed in 14 cases, subtemporal transtentorial in one case. Total removal was achieved in 13 cases, subtotal in 2. There was no surgical mortality. Two patients suffered new cranial nerve palsy (IVth and VIth nerve) as a result of the operation (improved at follow-up). Worsening of preoperative facial nerve palsy occurred in 3 cases, improvement of pre-operative palsy of cranial nerves (Vth, VIIth, XIth-Xth) occurred in 5 cases. In our experience it was more difficult to recognize and preserve the fourth and sixth nerve than other cranial nerves when the attachment and the extension of the tumor was in the cranial and caudal direction and toward the lateral clivus
Intracranial meningiomas in patients over 70 years old. Follow-up in operated and unoperated cases.
No full textAbstract
Forty-six cases of intracranial meningioma in patients above 70 years of age form the basis of this study; 34 underwent surgery while 12 did not. The decision to operate was based on the general condition of the patient, evaluated according to the Karnofsky index, neurological conditions, the site and dimensions of the tumor, and the presence of peritumoral edema. The post-surgical mortality rate was 11.5% at 30 days, and 20% at 3 months. Long-term follow-up in both patient groups ranged from 1 to 5 years, and quality of life was evaluated by the Karnofsky index. Five operated patients died during follow-up (only 1 from intracranial pathology); the 22 survivors showed further improvement in their grading level compared to scores immediately following surgery. Among the unoperated patients, 6 died within two years of diagnosis, all from causes related to intracranial pathology; among the survivors, the Karnofsky index was unchanged in 2, and diminished in the other 4 cases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
