Search results for "Medulla Oblongata"
showing 10 items of 25 documents
Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven: I. Xenoplastischer Austausch von…
2010
By transplantation of parts of the neural plate (latter medulla oblongata) from Xenopus laevis (Daud.) to Hymenochirus boettgeri (Torn.) larval chimaeras were obtained, which showed donorlike rhythmical movements of the mouth and pharyngeal region, movements which the host species lacks. Nevertheless, some of these tadpoles were still able to catch small prey in a reaction which is typical for the host and lacking in the donor.
Complications in Craniovertebral Junction Instrumentation: Hardware Removal Can Be Associated with Long-Lasting Stability. Personal Experience
2017
Background The causes of craniovertebral junction (CVJ) instabilities include trauma, rheumatological diseases, tumors, infections, congenital malformations, and degenerative disease processes; these complex pathologies often require CVJ instrumentation. Hardware complications were analyzed in a personal series of 48 treated patients. In light of the analysis of very unusual radiological and clinical findings, the authors tried to better investigate the related mechanisms and to reach possible useful conclusions. Methods In a series of 48 patients who underwent CVJ instrumentation and fusion procedures in our Institution, we describe three cases of hardware failure, due to: (1) infection; (…
Medullary infarcts may cause ipsilateral masseter reflex abnormalities.
2007
There is a suprasegmental influence on the masseter reflex (MassR) in animals, which is mediated via the fifth nerve spinal nucleus (5SpN). Corresponding data in humans are lacking. Out of 268 prospectively recruited patients with clinical signs of acute brainstem infarctions, we identified 38 with magnetic resonance imaging (MRI)-documented unilateral infarcts caudal to the levels of the fifth nerve motor and main sensory nuclei. All had biplanar T2- and echo planar diffusion-weighted MRI and MassR testing. Five patients (13%) had ipsilateral MassR abnormalities. In all, the infarcts involved the region of the 5SpN. Patients with medullary infarcts involving the region of the 5SpN may thus…
Influence of rubrospinal tract and the adjacent mesencephalic reticular formation on the activity of medullary respiratory neurons and the phrenic ne…
1988
Suprapontine brain sites acting on the central respiratory system have been demonstrated to give rise to inspiratory as well as expiratory facilitatory effects. In the present study the inspiratory inhibitory effect which has been reported in the cat to be elicited consistently by electrical stimulation of the rubrospinal tract and the adjacent mesencephalic reticular formation was examined in the urethane-anaesthetized rabbit. Stimulation of these sites with single electrical shocks of moderate intensity induced a short latency (onset after 3.0 ms) transient (duration: 29 ms) inhibition of the phrenic nerve activity (PHR). Short volleys of stimuli applied in mid- to late-inspiration led to…
Ipsilateral facial weakness in upper medullary infarction-supranuclear or infranuclear origin?
1999
We describe two patients with upper medullary infarctions showing ipsilateral facial weakness and relative sparing of the upper facial muscles. Electrophysiological follow-up using transcranial magnetic stimulation of the motor cortex in combination with stimulation of the peripheral facial nerve disclosed a supranuclear (corticofacial) tract lesion in one patient and a partial nuclear/infranuclear intra-axial facial nerve lesion in another.
Temporal retrogasserian resection of trigeminal root versus controlled elective percutaneous electrocoagulation of the ganglion of gasser in the trea…
1972
In his experience with 531 surgical procedures for the relief of trigeminal neuralgia between 1955 to 1970, the author developed a strong preference for the percutaneous electro-coagulation of the gasserian ganglion. Although the method was repeatedly modified in the early years, a standardized technique of controlled, selective and fractional coagulation in the semiawake state of neurolept-anaesthesia was used since 1963 in 183 of his 311 patients, treated in this manner. The advantages of the method, particularly in comparison to open intracranial root sections, are: Minimal operative risk, control of operative effect during the operation, small sensibility deficit, low rate of complicati…
Landmarks for vertebral artery repositioning in bulbar compression syndrome: anatomic and microsurgical nuances
2004
Abstract OBJECTIVE: The purpose of this study was to better elucidate the anatomic relationship between the vertebral artery (VA) along with its perforating vessels and the brainstem to develop anatomic guidelines that would be helpful when decompressing medulla oblongata compressed by the VA. METHODS: Microanatomy dissection was performed in six formalin-fixed cadaveric heads. The VA, posteroinferior cerebellar artery (PICA), anteroinferior cerebellar artery (AICA), and lower brainstem perforators were examined under magnification using a surgical microscope. The outer diameters of the VA, PICA, and AICA were measured. The distance between the VA, lying within the lateral cerebellomedullar…
Spatial distribution of various types of bulbar respiratory neurons in the rabbit
1977
In anesthetized rabbits, the burst activity of 277 single respiratory neurons was recorded extracellularly. The neurons were classified according to their spike incidence distribution within the respiratory cycle and to their response to lung distension or collapse (alpha or beta type). About one third of the neurons found in all animals were located at the level of the caudal end of the promontorium gliosum, widely scattered over the bulbar cross-section. More rostrally the units were located within a dorsal area neighbouring the tractus solitarius, more caudally within a ventral field surrounding the nucleus ambiguus. Most of the inspiratory neurons (the most frequently encountered type) …
AN ULTRASTRUCTURAL STUDY OF THE RETINA IN HUMAN LATE INFANTILE NEUROAXONAL DYSTROPHY
1993
A case involving a girl who died at 11 years of age and who had developed normally until the age of 18 months, at which time further psychomotor maturation stopped and then regressed, is reported. The patient appeared hypotonic and showed loss of deep tendon reflexes, as well as bulbar signs and increasing immobility. Visual impairment resulted in blindness at the age of 7 years. Her disease was diagnosed as late infantile neuroaxonal dystrophy (LINAD) after examination of sural nerve biopsy samples and after autopsy. Under electron microscopy, retinal axons were filled with tubulocisternal profiles and occasional large lamellar clefts close to or distant from synaptic complexes. These lesi…
Inspiratory inhibition and rebound activation elicited by intermittent electrical bulbar stimulation in various states of pulmonary afferent vagal ex…
1975
In anesthetized rabbits spirogram and diaphragmatic activity were examined during electrical stimulation of regions of the medulla oblongata. The volleys were triggered by the animal's own respiration. 1. One volley of 120 msec duration at 100 pulses p.s., applied during inspiratory, caused an immediate and transient inhibition of the diaphragmatic activity. After the end of the volley and inspiratory rebound appeared: the tidal volume was increased and the inspiration was prolonged by some 150 msec. The respiratory rate decreased. 2. Continuous low or high frequency electrical stimulation of pulmonary stretch afferents caused an inspiratory or an expiratory effect respectively. In both con…