Hemangioma of the transverse sinus.
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Brain Neoplasms↗
Biomedical subjects
John C Wellons
Publications and source records attributed to John C Wellons.
The effectiveness of Hering's nerve stimulation in controlling penicillin-induced seizures in the rat is dependent on the amygdala.
OBJECTIVE: This study tests the hypothesis that the ability of Hering's nerve stimulation (HNS) to blunt seizure activity is dependent on the availability of dopamine in the amygdala. METHODS: In 10 rats, Hering's nerve (HN) on the right side was isolated and placed on an electrode and penicillin was locally placed on each rat's left frontoparietal region to induce seizures. After the initiation of seizures, HN was stimulated. After the recurrence of seizure activity, the left basolateral amygdala was injected with 1.0 microl of normal saline, dopamine, haloperidol or 1% lidocaine in sequential tests. HN was stimulated after each injection and the latency and amplitude of the seizure activity were assessed. RESULTS: Focal cortical penicillin induced seizures that resulted in tonic-clonic movement of the limbs and face that lasted 35-45 min. Tonic-clonic movements of the limbs and face of similar latency and amplitude were induced by repeated reapplication of penicillin in untreated rats. HNS decreased seizure activity, but infusion of haloperidol or lidocaine into the basolateral amygdala blocked this antiseizure effect of HNS. In contrast, infusion of saline or dopamine had no effect on the ability of HNS to blunt seizure activity. None of the amygdala injections altered the latency or amplitude of seizure activity. CONCLUSION: These results demonstrate that the ability of HNS to blunt seizure activity in the rat is dependent on an intact dopamine system in the basolateral amygdala. These data will hopefully be useful in furthering our understanding of the circuitry that allows peripheral nerve stimulation to alter seizure activity.
Amygdala↗
Cortical representation of Hering's nerve: a possible anatomical pathway for seizure cessation following electrical stimulation.
OBJECTIVE: We recently found that Hering's nerve stimulation (HNS) effectively blunts seizure activity. This study characterizes the cortical areas that are activated by HNS. METHODS: Hering's nerve (HN) was stimulated in 3 dogs and 6 pigs, and then the brains of the animals were removed. The insular and mesial temporal cortices were removed and evaluated for increased neuronal activity by examining Fos-like activity. RESULTS: In both the dogs and pigs, Fos activity was elevated in the anterior insular and mesial temporal cortices. Increased cortical activity was not noted in adjacent areas such as the frontal cortex. CONCLUSION: This study demonstrates that the mesial temporal and anterior insular cortices are selectively activated by stimulation of HN, thus suggesting cortical loci at which HNS might blunt seizure activity.
Animals↗
Posterior atlantooccipital membrane for duraplasty. Technical note.
The authors describe the use of autogenetic posterior atlantooccipital (PAO) membrane for duraplasty following after posterior cranial fossa surgery. The PAO membrane is routinely exposed for procedures of the posterior cranial fossa and merely needs to be dissected free of the underlying dura mater. Recently this membrane was obtained in several pediatric patients following procedures of the posterior cranial fossa such as duraplasty in case of Chiari I malformation. No postoperative complications were found at 6-month follow-up examination. The advantages of this intervention include less manipulation of muscle and fascia than that involved in other procedures and, therefore, seemingly less postoperative pain and the negation of issues inherent with foreign-body graft sources. The authors believe this structure to be of use as a dural substitute in small dural openings of the posterior cranial fossa.
Arnold-Chiari Malformation↗
Quantitative anatomy of the transverse ligament tubercles.
OBJECT: The medial tubercles of the atlas serve as the attachments of the transverse ligament and provide an important anchoring site for which no discussion of their fine anatomy is published in the literature. In this study the authors examine this anatomy along with its osseous relationships. METHODS: One hundred dry cadaveric atlantal tubercles were assessed for size and relationship to nearby anatomical osseous structures. In addition, eight cadaveric specimens were evaluated for their anatomy in this area. All specimens exhibited atlantal tubercles for the attachment of the transverse portion of the cruciate ligament of the atlas. Right-sided tubercles tended to be of a larger caliber. Overall, right-sided vertical distances between these tubercles and the superior articular facets and inferior articular facets were greater, although distances from each tubercle to the lateral margin of the dental facets anteriorly were found to be constant, as were intertubercular distances. The mean angle formed between both tubercles and the dental facet was 75 degrees. CONCLUSIONS: The data derived in this study should be useful to the clinician for whom the craniocervical junction is a vital anatomical area.
Aged↗
Pediatric high-grade gliomas.
High-grade gliomas, including glioblastoma multiforme, anaplastic astrocytoma, and intrinsic pontine, are very difficult to treat in children. Despite aggressive treatment with multimodal therapy, most children with these diseases do not survive. Data from published series support aggressive surgical resection when clinically feasible. Patients who have had aggressive resections tend to have a longer survival than those who have undergone only biopsies or partial resections. Almost all patients with high-grade gliomas respond to radiation therapy, and it is the current mainstay of adjuvant therapy. Radiation therapy also tends to prolong survival, but it is rarely curative. Although responses to chemotherapy have been demonstrated, there are no compelling data indicating that it prolongs survival for this group of patients. Current and proposed studies are combining radiation therapy and/or chemotherapy with agents that have shown preclinical promise as radiosensitizers, anti-angiogenesis factors, growth factor receptor inhibitors, and free radical inducers. Other biologic therapies, including gene therapy, are also being investigated. Improved survival for these patients will likely require combined therapy that includes novel treatment.
Brain Neoplasms↗
In utero spontaneous cervical thoracic epidural hematoma imitating spinal cord birth injury.
A neonate male born cesarian due to a breech presentation was noted to have no spontaneous movements of the limbs after delivery. Radiographs were not demonstrative of pathology. However, MRI revealed a large intraspinal mass with significant distortion of the cervicothoracic spinal cord. At operation, a brown, fibro-gelatinous, moderately adherent mass was evident extradurally dorsal to the spinal cord. It was noted to extend anterolaterally to the left such that the cord was deviated anteriorly and to the right. There was no indication of the mass being under pressure but the cord was not pulsatile. There was sufficient mass to the anterolateral component of the cord that it appeared rotated to the right within the canal. The right cervical roots exited dorsally, with a markedly lengthened course through the spinal canal before exiting above their respective pedicles. Histology was that of blood clot. The patient clinically demonstrated no neurologic improvement post-operatively. Now, six months after surgery, the patient has still had no significant change in clinical function. To our review, this is the first reported case of a spontaneous spinal epidural hematoma mimicking a birth-related spinal injury.
Diagnosis, Differential↗