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Biomedical subjects

E R Laws

Publications and source records attributed to E R Laws.

At least 235 records · Page 13Linked to original sources
PubMed1982

The neurosurgical management of optic glioma. Results in 104 patients.

A series of 104 patients with surgically verified optic nerve gliomas is presented. Anterior lesions primarily affecting the optic nerve were present in 42 patients, who have a long-term survival rate of 85.5%. Posterior lesions primarily affecting the optic chiasm were present in 62 patients, most of whom underwent radiation therapy postoperatively, and they have a long-term survival rate of 50%. Unequivocal signs of neurofibromatosis were present in 14%. On the basis of these findings and a review of the literature, recommendations are made for the surgical management of these tumors.

Adolescent↗
PubMed1982

Thrombosed arteriovenous malformations of the brain. An important entity in the differential diagnosis of intractable focal seizure disorders.

Thrombosed arteriovenous malformations (AVM's) in patients with no previous history of hemorrhage are uncommon but benign lesions that present with clinical and radiographic findings which are often indistinguishable from those of other mass lesions, particularly low-grade gliomas. The authors report seven cases of thrombosed AVM's presenting as intractable seizure disorders in which the radiographic studies had suggested a low-grade glioma. All seven patients are now seizure-free 2 to 40 months postoperatively. The importance of surgical exploration in the management of such patients is emphasized. A review of 32 cases reported in the literature is presented. The reasons why angiography may fail to demonstrate an AVM, and the possible etiologies for the spontaneous thrombosis of an AVM are discussed.

Adolescent↗
PubMed1981

Posterior fossa approach for removal of acoustic neurinomas.

Herein we review our experience with surgical removal of acoustic neurinomas in 74 patients from January 1978 through December 1980. The surgical approach was through the posterior fossa. Total removal was accomplished in 73 of 74 patients, and there were no surgical or postoperative deaths. The facial nerve was preserved in 54 patients, and hearing was preserved in five (21% of patients with small tumors). We believe that this approach to acoustic neurinomas has the advantages of being universally applicable, having a low complication rate, and possessing the potential of saving both facial and cochlear function.

Adolescent↗
PubMed1981

The cytotoxic effect of ethylnitrosourea on the developing rat cerebellum. Morphologic observations.

A single i.p. injection of 240 mg/kg of ethylnitrosourea (ENU) into rats in the perinatal period resulted in lethal damage to the proliferating external granular cells of the developing cerebellar cortex. Lethally damaged cells of the external granular layer were also observed in fetal rats at 20 days of gestation after transplacental administration of the same dose of ENU. The percentage of susceptible cells affected remained constant throughout the period investigated. Light microscopy showed large numbers of randomly distributed pyknotic nuclei and complete inhibition of mitotic activity 6 h after ENU administration. Electron-microscopic examination showed that damaged granular cells had clumping of chromatin along the nuclear membrane. Cell organelles were morphologically distorted and unidentifiable; lysosomal bodies accumulated in the cytoplasm. Nonproliferating Purkinje cells were not lethally affected; however, dilatation of the Golgi apparatus and an increase in the number of lysosomes were commonly observed cytoplasmic changes.

Animals↗
PubMed1981

Primary amenorrhea and pituitary adenomas.

From 1972 to 1980, 210 patients underwent transsphenoidal operation for removal of a prolactin-secreting tumor. Eight of the patients had primary amenorrhea. All eight patients had had a normal thelarche and pubarche without menarche, and all eight had hyperprolactinemia and abnormal findings on sella turcica tomography. After operation, only one patient did not have persistent hyperprolactinemia, and this patient was the only one who began spontaneous menses. The data indicate that although prolactin hypersecretion interferes with menstrual function, it does not alter other pubertal development and that, if the source of the excessive prolactin can be removed, the removal alone may initiate spontaneous menses. In this report, however, patients with prolactin-secreting adenomas and primary amenorrhea had a high incidence of persistent hyperprolactinemia after operation (seven of eight patients).

Adenoma↗
PubMed1981

Microvascular decompression of the facial nerve for hemifacial spasm: clinical and electrophysiologic observations.

Eight patients with idiopathic hemifacial spasm were studied before and after decompression of the facial nerve. Seven patients had an excellent clinical response to surgery, with total resolution of the spasm. One patient had a complete facial palsy and sensorineural deafness on the involved side after surgery, with recurrence of the spasm 6 months later. In all patients, synkinetic activity was present on the involved side before surgery and disappeared after surgery. These findings suggest that the disorder involves the extra-axial portion of the facial nerve. The findings do not require an etiologic role of vascular compression because the response to surgery could be related either to mild trauma of the nerve during the surgical procedure or to subsequent fibrosis.

Adult↗
PubMed1981

Multiple primary brain tumors of different cell types.

Eighteen cases of multiple primary brain tumors of different histological types were found in a review of Mayo Clinic records from 1950 to 1978. The predisposing factors, clinical presentation, location, and type of tumor are discussed. The clinical significance and etiology of these multiple tumors are considered.

Adult↗
PubMed1981

Pathogenesis and prophylaxis of postlaminectomy deformity of the spine after multiple level laminectomy: difference between children and adults.

The pathogenesis of postlaminectomy spinal deformity and instability in children was evaluated by reviewing appropriate roentgenographic findings. First, we reviewed spine roentgenograms of patients below 40 years of age who underwent spinal fusion for deformity and instability of the spine developing after a multiple level laminectomy. Two types of deformity were recognized on the roentgenograms: increased mobility between the vertebral bodies and wedging deformity of the ventral aspect of the vertebral bodies. Second, we did a follow-up study of another group of patients who had undergone laminectomy. We found the same two types of deformity in children, but not in adult patients. The incidence of deformity was higher after laminectomies of the cervical or cervicothoracic region than after lumbar laminectomies. Our data suggest that postlaminectomy spinal deformity can develop in children without irradiation or facet injury. The deformity is due to a wedging change in the cartilaginous portion of the vertebral body and to the viscoelasticity of ligaments in children. When treatment of this complication becomes necessary, anterior fusion may be effective in arresting progression. Prophylactic measures against the development of deformity are discussed. Our hypothesis concerning the mechanism of development of this complication supports the rationale of osteoplastic laminar resection and reconstruction instead of laminectomy, particularly in the management of children.

Adolescent↗
PubMed1981

Diagnosis of acoustic neurinoma.

Seventy-six patients underwent the primary removal of an acoustic neurinoma at the Mayo Clinic from 1978 through 1980. Hearing loss was present in 97% of the patients, and tinnitus and dysequilibrium occurred in 70% of the patients. The most common signs were a decreased corneal reflex, nystagmus, and facial hypesthesia. In these patients, pure tone and speech audiometry are used to define the hearing loss. When hearing is still present, the speech discrimination is often disproportionately low. Acoustic reflex testing and brain stem evoked response are used to determine whether the hearing loss is cochlear or retrocochlear. When these tests could be performed in this series of patients, they were accurate in 85 to 95%. The vestibular response to caloric testing is expected to be decreased or absent in about 90% of patients, and this was so in 86% of our patients. Radiographic studies are the most important tests currently used for the diagnosis of acoustic neurinoma. Tomography of the internal auditory canal shows abnormalities in 80% of patients. Computed tomography with contrast enhancement demonstrates abnormalities in 90% of patients. The computed tomographic (CT) scan may reveal the location, the size, and often the consistency of the tumor. In cases still questionable after CT scanning, positive contrast rhombencephalography is used for clarification. In this series, no single symptom, sign, abnormal audiometric test result, or abnormal radiographic finding was present in all patients; therefore, the most important factor in diagnosis is an alert physician.

Adolescent↗
PubMed1981

Pineal tumors in children and adolescents. Treatment by CSF shunting and radiotherapy.

Tumors of the pineal region account for 3% to 8% of pediatric intracranial tumors. The treatment of such tumors has been in a state of flux between conservative therapy (cerebrospinal fluid shunting and radiotherapy) and direct surgical removal. A brief history and review of the literature with analysis of both approaches is given, and the Mayo Clinic's experience with conservative treatment of tumors in the pineal region in patients 20 years old and younger (27 cases) is studied and analyzed. The series comprises 21 boys and six girls, with an age range of 1 to 20 years (mean 13.7 years). Follow-up examinations are complete and range from 1 to 24 years, with a mean follow-up period of 7.8 years. The median survival time for these patients treated with shunt and radiotherapy is 17.7 years. There was no mortality from treatment and complications were rare. The details of the clinical presentation, diagnostic findings, pathology, therapy, recurrence, and survival are presented. All patients under 6 years of age (six cases) had recurrences, 50% in other areas in the brain and 50% in the spinal cord, perhaps pointing to the need for whole-brain and spinal-axis irradiation in patients in this age group. The results of this study of the conservative approach form a standard against which results of any other type of therapy may be compared.

Adolescent↗
PubMed1980

Nasal gliomas.

Nasal glioma is a developmental abnormality of neurogenic origin with o malignant potential. An intranasal mass requires careful rhinologic and occassionally ophthalmologic, neurologic, and roentgenologic examinations. With a bony defect, pneumoencephalography, angiography, or computerized tomography may be helpful. In such cases, a neurosurgeon should be available at the time of biopsy. Biopsy is necessary for establishing a histopathologic diagnosis. Aspiration of the tumor with a needle or incisional biopsy may yield inconclusive findings and may be associated with CSF rhinorrhea and meningitis, especially if there is an intracranial connection. With adequate initial removal, excisional biopsy usually offers complete cure. A frontal craniotomy approach is preferred for those patients who have nasal glioma with an intracranial connection, CSF rhinorrhea, or recurrent episodes of meningitis. With no evidence of an intracranial connection, a conservative extracranial approach is recommended.

Adolescent↗