scholarly journals Vascular Microanatomy of the Pontomedullary Junction, Posterior Inferior Cerebellar Arteries, and the Lateral Spinal Arteries

2008 ◽  
Vol 14 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Ph. Mercier ◽  
G. Brassier ◽  
H-D Fournier ◽  
J. Picquet ◽  
X. Papon ◽  
...  
Keyword(s):  
Brain Stem ◽  
Lateral Surface ◽  
Cerebellar Hemisphere ◽  
Common Trunk ◽  
Posterior Surface ◽  
The Common ◽  
The Brain ◽  
Pontomedullary Junction ◽  
Perforating Arteries ◽  
Lateral Spinal Artery

This study of 25 brains at the pontomedullary junction defined the different possible origins of the perforating arteries and lateral spinal arteries in relation to the posterior inferior cerebellar arteries (PICAs). - If the PICA emerges from the common trunk of the AICA-PICA coming from the basilar artery, it never gives perforating arteries or a lateral spinal artery on the lateral surface of the brain stem but supplies blood to a part of the ipsilateral cerebellar hemisphere. - If the PICA arises extradurally at C1, it never gives perforating arteries for the lateral surface of the brain stem, but it gives pial branches for the posterior surface of the medulla oblongata and is always the origin of the lateral spinal artery. - If the PICA emerges in the intradural vertebral artery, it is the source of the perforating arteries for the lateral surface of the brain stem and of the blood supply of the ipsilateral cerebellum.

Genesis of rhythmic respiratory activity in pons independent of medulla

1985 ◽  
Vol 59 (3) ◽  
pp. 684-690 ◽  
Author(s):  
W. M. St John ◽  
T. A. Bledsoe
Keyword(s):  
Brain Stem ◽  
Phrenic Nerve ◽  
Respiratory Activity ◽  
Respiratory Rhythm ◽  
Related Activity ◽  
Pharmacological Agents ◽  
Pneumotaxic Center ◽  
Trigeminal Nerves ◽  
The Brain ◽  
Pontomedullary Junction

We hypothesized that rhythmic respiratory-related activity could be generated in pons independent of medullary mechanisms. In decerebrate, cerebellectomized, vagotomized, paralyzed, and ventilated cats, we recorded efferent activities of the phrenic nerve and mylohyoid branch of the trigeminal nerve. Following transections of the brain stem at the pontomedullary junction, the phrenic and trigeminal nerves discharged with independent rhythms. Spontaneous trigeminal discharges eventually ceased but were reestablished after strychnine, doxapram, and/or protriptyline were administered. In some animals having no spontaneous trigeminal discharges after transection, these discharges appeared, with a rhythm different from the phrenic, following administration of these agents. In other cats having no transections between pons and medulla, these pharmacological agents induced trigeminal and phrenic discharges after kainic acid had been injected into the entire dorsal and ventral medullary respiratory nuclei. Phrenic and trigeminal discharges were linked, indicating survival of bulbospinal neurons or presence of pontospinal units. We conclude that rhythms, similar to respiratory rhythm, can occur by mechanisms in isolated pons. Such mechanisms are hypothesized to be within the pneumotaxic center and may underlie the neurogenesis of eupnea.

scholarly journals Microsurgical treatment of distal aneurysms of the posterior inferior cerebellar artery

2019 ◽  
Vol 21 (4) ◽  
pp. 12-23
Author(s):  
V. G. Dashyan ◽  
I. V. Senko
Keyword(s):  
Informed Consent ◽  
Brain Stem ◽  
Postoperative Period ◽  
Conflict Of Interest ◽  
Posterior Inferior Cerebellar Artery ◽  
Cerebellar Artery ◽  
Pica Aneurysms ◽  
The Brain ◽  
Perforating Arteries ◽  
Suboccipital Approach

The study objective is to analyze characteristics of distal aneurysms of the posterior inferior cerebellar artery (PICA) using the results of surgical treatment of 11 patients with this disorder.Materials and methods. Eleven patients with distal PICA aneurysms (7 men and 4 women aged between 32 and 57 years (mean age 44 years)) were operated in N.V. Sklifosovsky Research Institute for Emergency Medicine. Aneurysms were visualized using cerebral angiography in 2 patients and using computed angiography in 9 patients. The aneurysms were classified using the classification system developed by J.R. Lister and A.L. Rhoton. Aneurysms located in the tonsillomedullary segment were most common. Saccular aneurysms were found in 7 (64 %) patients, whereas fusiform aneurysms were observed in 4 (36 %) patients. Two saccular aneurysms had a large neck. The size of aneurysms varied between 2 and 9 mm. The majority of patients (70 %) had aneurysms less than 7 mm.Results. Five patients were operated via median suboccipital approach, while the remaining 6 patients were operated via lateral suboccipital approach. We performed either reconstructive (n = 9) or deconstructive (n = 2) aneurysm clipping depending on the possibility of preserving the PICA lumen and presence of damage to the perforating arteries of the brain stem. Nine patients (82 %) had Glasgow Outcome Score of 5; two patients (18 %) died (one of them was admitted in sopor with occlusive hydrocephalus; another one had grade III–IV obesity and developed purulent septic respiratory complications and secondary purulent meningitis). Two patients (18 %) developed dysarthria and dysphagia in the postoperative period, but these symptoms disappeared by the moment of discharge.Conclusion. Distal PICA aneurysms are quite rare and require tailored approach to treatment. A surgeon should bear in mind specific anatomical characteristics of aneurysms, control arterial patency when isolating the aneurysm from the bloodstream, and use revascularizing methods whenever possible. In addition to that, a surgeon should be extremely careful during manipulations with perforating arteries of the brain stem and distal cranial nerves, because their damage result in a more difficult postoperative period.Conflict of interest. The authors declare no conflict of interest.Informed consent. All patients gave written informed consent to participate in the study and to the publication of their data. 

Brain stem augmentation of cardiovascular activity

1960 ◽  
Vol 198 (2) ◽  
pp. 421-423 ◽  
Author(s):  
Richard L. Glasser
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Brain Stem ◽  
Cardiovascular Activity ◽  
Rostral Portion ◽  
The Brain ◽  
Pontomedullary Junction

Midpontile ischemic decerebration in vagotomized mesencephalic cats produced marked tachycardia and hypertension. Subsequent transection of the brain stem at or above the midpontile level did not affect the cardiovascular hyperactivity. Transection at the pontomedullary junction abolished the brain stem augmentation of heart rate and blood pressure. The results suggest the existence of a cardiovascular augmenter area in the caudal half of the pons and a cardiovascular depressor area in a more rostral portion of the brain stem.

Adenosine stimulates breathing in fetal sheep with brain stem section

1992 ◽  
Vol 72 (1) ◽  
pp. 94-99 ◽  
Author(s):  
B. J. Koos ◽  
A. Chao ◽  
W. Doany
Keyword(s):  
Brain Stem ◽  
Blood Gases ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Arterial Infusion ◽  
Fetal Sheep ◽  
Stem Section ◽  
Peripheral Arterial ◽  
Arterial Po2 ◽  
The Brain ◽  
Pontomedullary Junction

Breathing responses to adenosine were determined in 12 chronically catheterized fetal sheep (greater than 0.8 term) in which hypoxic inhibition of breathing had been eliminated by brain stem section. The caudal extent of transection varied from the rostral midbrain to the pontomedullary junction. Isocapnic hypoxia [delta arterial PO2 (PaO2) of -12 Torr] doubled the incidence and depth of breathing activity and increased the incidence of eye movements. Intra-arterial infusion of adenosine (0.30 +/- 0.03 mg.min-1.kg fetal wt-1) increased the incidence and amplitude of breathing without affecting blood gases. Adenosine did not significantly alter the incidence of eye activity. Intra-arterial injection of oligomycin (120 +/- 26 micrograms/kg fetal wt), an inhibitor of mitochondrial oxidative phosphorylation, also stimulated breathing activity. In four fetuses with brain stem section, peripheral arterial chemodenervation blunted the stimulatory effects of hypoxia on breathing activity and abolished altogether the excitatory effects of adenosine. It is concluded that 1) hypoxia and adenosine likely inhibit breathing in normal fetuses by affecting similar areas of the brain stem and 2) in fetuses with brain section, hypoxic hyperpnea depends on peripheral and central mechanisms, whereas adenosine stimulates breathing via the peripheral arterial chemoreceptors.

Arteriovenous malformations of the posterior fossa

1986 ◽  
Vol 64 (6) ◽  
pp. 849-856 ◽  
Author(s):  
Hunt Batjer ◽  
Duke Samson
Keyword(s):  
Brain Stem ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Disease Process ◽  
Health Science ◽  
Cerebellar Hemisphere ◽  
Science Center ◽  
Content Type ◽  
History Of ◽  
The Brain

✓ Infratentorial arteriovenous malformations (AVM's) represent only 5% to 1% of all AVM's in major series. Since 1977, 32 patients with intracranial intradural malformations of the brain stem or cerebellum have been evaluated at the University of Texas Health Science Center, 30 of whom underwent surgical treatment. Twenty-three patients presented with intracranial hemorrhage, which was recurrent in 11 cases, and nine patients were evaluated for progressive brain-stem or cerebellar deficits. A history of progressive deficits was unusual in the group that presented with hemorrhage, and a prior or subsequent hemorrhage was rare in the patients initially evaluted for progressive deficits. Seventeen of these AVM's were located in the vermis, seven within the cerebellar hemisphere, two in the tonsil, two in the cerebellopontine angle, and four within the brain stem. Operative intervention was directed at primary resection in 15 cases, staged resection in seven, embolization and resection in five, and evacuation of hematoma in three. Operative mortality in this surgical series was 7%, with significant morbidity in 13%. Use of modern microsurgical techniques in removal of posterior fossa AVM's may offer results better than the natural history of the disease process, especially in patients who present with hemorrhage.

Identification of medullary loci critical for neurogenesis of gasping

1984 ◽  
Vol 56 (4) ◽  
pp. 1008-1019 ◽  
Author(s):  
W. M. St John ◽  
T. A. Bledsoe ◽  
H. W. Sokol
Keyword(s):  
Electrical Stimulation ◽  
Radio Frequency ◽  
Brain Stem ◽  
Central Pattern Generator ◽  
Kainic Acid ◽  
Pattern Generator ◽  
Critical Area ◽  
Recurrent Laryngeal Nerves ◽  
The Brain ◽  
Pontomedullary Junction

We hypothesized that a discrete medullary locus, critical for gasping neurogenesis, could be identified. In decerebrate, cerebellectomized, vagotomized, paralyzed, and ventilated cats, activities of phrenic, hypoglossal, and recurrent laryngeal nerves were monitored. Gasping was induced by freezing the brain stem, via a fork thermode, at the pontomedullary junction. By reversible cooling of the medulla, chemical lesions with kainic acid, and radio-frequency lesions, a critical area for gasping neurogenesis was localized bilaterally 2–3 mm rostral to obex, 2.0–2.5 mm lateral to midline, and 3–4 mm ventral to medullary surface. Electrical stimulation in this area elicited premature gasps, whereas unilateral lesions or lidocaine injections eliminated gasping activities in all nerves. These procedures did not cause similar changes during eupnea. In apneusis, however, lidocaine injections markedly altered the pattern or caused apnea. We conclude that discharge of neurons in a discrete portion of the lateral tegmental field of medulla is required for gasping neurogenesis. Our results are consistent with these neurons comprising the central pattern generator for gasping.

Computed Tomography and Magnetic Resonance Imaging in Traumatic Locked-In Syndrome

Neurosurgery ◽  
1988 ◽  
Vol 22 (3) ◽  
pp. 591-593 ◽  
Author(s):  
Edward J. Zampella ◽  
Ernest R. Duvall ◽  
Keith H. Langford
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Brain Stem ◽  
Resonance Imaging ◽  
Computed Tomographic ◽  
Brain Stem Lesion ◽  
Magnetic Resonance Scan ◽  
The Brain ◽  
Pontomedullary Junction

Abstract The first reported case of traumatic locked-in syndrome with computed tomographic and magnetic resonance scan confirmation of the brain stem lesion is presented. The lesion responsible for the patient's condition consisted of a hemorrhage in the ventral pontomedullary junction. The pathophysiology of the production of such lesions is discussed. (Neurosurgery 22:591-593, 1988)

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

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