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At least 145 records · Page 8Linked to original sources
PubMed1985

Gunshot wound to the pons with functional neuroanatomical and electrophysiological correlation.

We describe a patient with a gunshot wound to the brain that traversed the left cerebellar hemisphere and terminated in the left lateral midpons. The clinical findings, operative course, neuroradiographic features, and evoked potential data are correlated with the functional anatomy of the pons. It is possible to demonstrate that a local lesion in the lateral pons causes a hemiparesis, worse in the upper extremity, thus suggesting a somatotopic localization of the pontine corticospinal tract not previously described.

Adult↗
PubMed2001

[Resection of neoplasm in fourth ventricle and at the back of pons through cerebellomedullary fissure approach].

OBJECTIVE: To investigate the advantage of cerebellomedullary fissure approach to resect the space occupying lesion in the fourth ventricle region and at the back of pons and to discuss the microsurgical skills. METHODS: The craniotomy is through the posterior fossa. To maximize the width of exposure, a long skin incision is made from the occipital protuberance down to the C4-5 level, and a free occipital bone flap is turned. The tonsils of cerebellum are reached by opening the tonsillovermian fissure and then moved upward so as to expose the operating field. Neoplasm in the fourth ventricle and at the back of pons was resected. RESULTS: Among the 23 cases, total resection was achieved in 20, and subtotal resection in 3. CONCLUSION: The cerebellomedullary fissure approach can provide a panoramic view between the two lateral recesses and from the obex to the aqueduct without excision of neural tissue. During the operation, the inferior vermis is not incised. The vessels and nervous tissue are extracted at a minimum extent. Such a procedure is much safer.

Adolescent↗
PubMed2002

[Disturbance of jaw-opening due to extension of syringobulbia to the pons--a case report].

We report a patient with syringobulbia extending to the pons, who could not open his mouth widely. He had been involved in the traffic accident at 16 years of age. Since them he had suffered numbness in the left neck and arm. At age 30, he became unable to open the mouth widely with pain in the left jaw joint. He also noted dysphagia and tinnitus. Neurologically, there were vocal cord paresis, dysesthesia of the face, ageusia and cerebellar ataxia all on the left side. Brain MRI revealed syringobulbia which extended to the pons. Spinal MRI revealed syringomyelia through the entire spinal cord. The syrinx of the spinal cord seemed to connect with the brainstem lesion. EMG of the masticatory muscles revealed paradoxical activity in the left masticatory muscles. We concluded that disturbance of jaw-opening in this case was caused by syringobulbia, the lesion of which could involve masticatory central pattern generator in the brainstem.

Adult↗
PubMed1992

[Changes of the 5-HT content in hippocampus, midbrain-pons, spinal cord and concentration of blood glucose after intraperitoneal injection of ACTH in rats].

Effects of ACTH on the content of 5-HT in the hippocampus, midbrain-pons, and spinal cord and the concentration of blood glucose in rats by spectrofluorometric assay and glucose oxidase method were studied. ACTH ip 10 IU.kg-1 or 20 IU.kg-1 significantly increased the content of 5-HT in the hippocampus, midbrain-pons and spinal cord and blood glucose level, both in a dose-dependent manner; para-chloroaphetamine, p-Cpa 4 mg icv markedly reduced the 5-HT in these brain regions and spinal cord and the blood glucose level (P less than 0.01); the level of 5-HT and blood glucose were not significantly altered after icv p-Cpa+ip ACTH; adrenalectomy+ip ACTH markedly increased the 5-HT content in the brain regions and spinal cord, but the blood glucose was decreased (P less than 0.01); and 5-HT was markedly decreased by sc alloxan tetrahydrate+ip ACTH, but blood glucose did not decrease (P greater than 0.05). Thus, ACTH may influence the blood glucose level through central nervous system 5-HT, and the change of 5-HT may be related to the insulin (secretion).

Adrenocorticotropic Hormone↗
PubMed1992

Further data on the development of SRIF-like immunoreactive nerve cell populations in the chick embryo brain stem. I. Medulla and pons.

Further immunocytochemical analysis of the neuroblasts with SRIF-like immunoreactivity (ir) was carried out on the chick embryo medulla and pons. 5 or 100 microns rombencephalon sections were obtained from 60 White Leghorn chick embryos at stages (E = Embryonic days) ranging from E4 1/2 to E18 and incubated with rabbit polyclonal antibodies against synthetic cyclic Somatostatin-14, according to PAP-DAB technique. In the medulla and pons the ir appeared as from E12. From E12 to E13 1/2-E14 the ir distribution gradually changed. From E14 to E18 numbers and spatial arrangement of the positive neuroblast groups did not show substantial changes; in these respects the ir distributional pattern proved to be markedly different from the one observed by the Authors in adult animals. Moreover, from E13 to E15 the positive neuroblast density appeared to be higher than that of positive neurons in adults. These results are consistent with a possible SRIF local regulative role.

Animals↗
PubMed1991

[Identification of effective region of the pons in response to inaperisone which facilitates urine storage].

To identify the effective region of the pons in response to inaperisone which facilitates urine storage, inaperisone (100 mM, 0.2 microliters) was injected into the nucleus locus coeruleus alpha (LCa, the pontine micturition center), the nucleus locus subcoeruleus (LSC, the pontine urine storage center) and the nucleus reticularis pontis oralis (PoO, micturition inhibitory region) of the decerebrate cats. On reflex micturition, inaperisone injection into the LSC decreased voiding volume, and increased residual volume and bladder capacity, significantly. However, there was no difference in the maximum bladder pressure before and after inaperisone injection into the LSC. Inaperisone injection into the LCa or the PoO had no influence on reflex micturition. These results suggest that effective region of the pons in response to inaperisone is the LSC, and that inaperisone facilitates the urine storage neural mechanism in the LSC.

Animals↗
PubMed1991

Reduced midbrain and pons size in children with autism.

Recent reports suggested functional abnormalities of the brain stem in autistic children. Moreover, structural brain abnormalities have also been reported, so we analyzed magnetic resonance imaging (MRI) scan in autistic children. MRI scans for 29 autistic children were compared with 15 control MRI scans. The midbrain and pons were measured. The midbrain and pons size were found to be significantly smaller in the autistic group. This suggests that the structure of the brain stem is anatomically altered in autistic children.

Autistic Disorder↗
PubMed1990

[Pure sensory hemisyndromes caused by infarctions in the pons].

This study reports 3 cases of pure hemisensory syndrome due to lacunar infarction at the pons, demonstrated by magnetic resonance. In all patients somatosensory evoked potentials were abnormal. In two out of the 3 cases these potentials remained abnormal even after clinical exploration normalized. Due to the distribution of the sensitive pathways it may be assumed that the hemisensory syndrome would be caused by lesions located from the cortex to the pons. By means of clinico-pathological correlations the hemisensory syndrome was attributed to lesions exclusively located at the cerebral cortex or at the thalamus. However, in 1984 the first case of hemisensory syndrome due to pontine infarction was demonstrated by computerized tomography. After this report a series of approximately 10 patients have been published in the english and french literature. None of them had data on somatosensory potentials. In our experience the study of somatosensory evoked potentials has a high sensitivity. It appears that the distribution of the sensitive defect is independent of the location of the structural lesion.

Aged↗
PubMed1989

[Pressure waves induced by electrical stimulation of upper pons and lower midbrain in dogs with experimental subarachnoid hemorrhage].

Neurogenic mechanisms of pressure waves were investigated by means of electrical stimulation of the upper pons and the lower midbrain of 32 dogs in which subarachnoid hemorrhage had experimentally been made. The dogs were slightly anesthetized, immobilized and artificially respired. After subarachnoid infusion of red blood cells, continuous recordings of systemic blood pressure (SBP), intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were made simultaneously. At the stage of increased ICP, pressure waves were induced by electrical stimulation of the upper pons and the lower midbrain from 6 to 12 mm rostral to external auditory meatus. Stimulation parameters, i.e., intensity, duration and frequency, were kept constant at 0.1 mA, 1 msec and 40-50 Hz, respectively, throughout experiments. The induced pressure waves were classified into three types: fast, slow and plateau waves. Fast waves had a duration of 10-30 sec, being associated with a marked increase in SBP. They were induced by stimulation of 41 points in various portions of the pontine and mesencephalic tegmentum. Slow waves had a duration of 30 sec to 3 min, being associated with no change or a decrease in SBP. They were induced by stimulation of 12 points in the rostral pontine reticular formation and the mesencephalic reticular formation. Plateau waves had a duration of 3 min or more, being associated with no change or a decrease in SBP. They were induced by stimulation of 2 points in the mesencephalic reticular formation 2 mm lateral to the red nucleus, where slow waves had been induced at the early stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[A case of cavernous angioma extended from the ventral part of the pons to the midbrain: subtemporal and trans-tentorial approach].

The authors presented a surgically treated case of cavernous angioma extending from the ventral part of the pons to the midbrain. A 20-year old man was admitted to our service with left motor weakness, dysarthria and consciousness disturbance. CT scan revealed a round well-circumscribed high density lesion in the pons and midbrain. This was diagnosed preoperatively as a cryptic vascular malformation with hemorrhage. The right temporal craniotomy with keel form skin incision and subtemporal & trans-tentorial approach was performed in an attempt to remove the hematoma and the angioma. Histological examination of the surgical specimen revealed abnormal vessels as a cavernous angioma. The postoperative course was uneventful.

Adult↗
PubMed1979

[Myelinolysis of the pons Varolli].

A case of myelinolysis of pons varolli which was diagnosed only after a microscopic examination of the brain is described. Certain morphological features of the focus in pons varolli were observed. It is assumed that in this observation the development of central pontine myelinosis was influenced by the abuse of alcohol as well as by exacerbation of pulmonary tuberculosis.

Alcoholism↗
PubMed1984

VIP-like and GFAP-like immunoreactivities in the chicken brain stem. II. The pons and the tegmentum of the mesencephalon.

An immunocytochemical analysis was performed on the chicken pons and mesencephalon (except the optic tectum) according to the PAP-DAB procedure, to study the distribution here of the neurons reacting to anti-VIP antibodies and the gliocytes reacting to anti-GFAP antibodies. Positive and negative controls were carried out in both the immunoreactions. The VIP-immunoreactive neurons showed a distribution essentially corresponding to that observed in other species by various Authors. They appeared scattered mainly in 3 sites: (a) the subventricular grey between pons and mesencephalon; (b) the periaqueductal grey, up to the diencephalon; (c) the rostro-ventral portion of the mesencephalic tegmentum, up to the diencephalon. Furthermore, some perivascular VIP-immunoreactive neuronal processes were seen. No differences have so far been detected as regards the GFAP-like immunoreactivity distribution, in comparison with the data reported by the authors in the chicken medulla and by others in in the brain stem of some other species.

Animals↗
PubMed1980

Histological and histoenzymological studies on the medulla oblongata and pons of hedgehog (Paraechinus micropus).

A comparative study of the acid and alkaline phosphatases within the medulla oblongata and pons of the hedgehog revealed the following facts: 1. All the cellular elements are positive for acid phosphatase, irrespective of their sensory or motor nature, and the large neurons of all the nuclei are more strongly positive than the small cells. Furthermore, the nuclei which contain a dense population of neurons, appear to be more strongly positive than areas containing scattered neurons. 2. Alkaline phosphatase preparations show a strong activity in the walls of blood capillaries of all the nuclei of the medulla oblongata and pons. Reaction of this enzyme in the neuropil varies from strong (NNH, NPH, VSP, VM, VS, VL, OLS, NI, NRM), over moderate (reticular nuclei, NS, TSN), mild (NA, NRL) to absent (AP). A few nuclei such as OLS, NT, VM, VL, VS, NPH, and NI also show activity in neurons, which appears to be localized at the periphery of the cells only. The significance of the distribution of these enzymes at the various locales are discussed from a functional point of view.

Acid Phosphatase↗
PubMed1981

Hemifacial spasm: treatment by microvascular decompression of the facial nerve at the pons.

Hemifacial spasm is a syndrome of intermittent and tonic unilateral facial muscular contraction; mild facial weakness on the same side is also frequently present. Hemifacial spasm can be differentiated clinically from habit spasms, blepharospasm, facial synkinesis following Bell's palsy, facial myokymia, and masticatory spasm. The syndrome of hemifacial spasm is caused by a variety of lesions; the common feature appears to be compression of the facial nerve at the pons. Diagnostic studies do not usually add significant information to that gained from the history and physical examination. The best current treatment (aside from removing an etiologic lesion such as a posterior fossa tumor in the small percentage of cases with such lesions) is microvascular decompression of the facial nerve at the pons through a retromastoid craniectomy. Of 30 patients treated in this manner, 28 have been satisfied with the results. On the most recent follow-up examination, 16 had no hemifacial spasm, nine had only slight periodic twitching about the eye, and three had occasional mild episodes of hemifacial spasm.

Adult↗
PubMed1980

[Vessel work development phases in the neural part of the pons in chick embryos].

By means of intravascular India ink injections we have analyzed the early developmental phases of the vessel network in the cranial part of the chick embryo pons. At four and one half days of incubation the first radial endoneural vessels have already entered the ventral portion of the pons and formed with their branches a perigerminative network. Both the external and deep network progressively extend during the subsequent days, and at the 7th day the previously segregated cell groups begin to be encircled by tiny branches from the radial vessels. On the 8th day vessels appear also within the cellular groups and differences in vascular density between the various groups become detectable, apparently depending on their different cell density and differentiation degree. From this stage until the 12th day the vessel denseness undergoes a gradual, general increase, although differences in the vascularization degree between various groups are still appreciable.

Animals↗
PubMed1993

Recordings of the evoked auditory wave P1 from the pons during natural and drug-induced REM.

A positive component of the middle latency auditory evoked response recorded from the vertex, the P1 wave, was found to be sensitive to changes in the wakefulness-sleep states. We report here that this wave can be recorded from the pons of chronically prepared cats. During natural REM sleep and REM induced by micro-injections of carbachol and neostigmine into the pons the pontine P1 had amplitudes much higher than during slow wave sleep (SWS). The increase in amplitude was dose dependent. Scopolamine had a profound and long-lasting weakening effect on the wave. These results indicate a relation between the P1 wave and the cholinergic generator mechanism for REM sleep. Also, our results support the role of an increased recruitment of the pontine neurones in the generation of REM sleep.

Animals↗
PubMed1996

Slow-flow vascular malformations of the pons: capillary telangiectasias?

PURPOSE: To report clinical and MR features that suggest telangiectatic vascular malformations of the pons: METHODS: The MR scans and clinical data of 12 patients demonstrating an enhancing pontine lesion with minimal or no signal abnormality on T2-weighted images were reviewed. None of the patients underwent angiography or biopsy. Follow-up scans, available for all patients between 3 weeks and 40 months (range, 11.5 months), were reviewed. RESULTS: The patients presented with a variety of symptoms including headache (n = 4), vertigo (n = 3), gait abnormality (n = 3), and hearing loss (n = 2). Two were referred for biopsy or treatment of presumed pontine glioma. On precontrast MR, 3 of 12 lesions were isointense on both T1- and T2-weighted images. Three of 12 lesions were slightly hypointense on T1-weighted images and 8 of 12 were slightly hyperintense on T2-weighted images. Postgadolinium images showed a discrete focus of enhancement with irregular or brushlike borders. Eight of 12 had an anomalous draining vessel from the lesion to the surface of the pons. None demonstrated mass effect or hemorrhage. Gradient-echo sequences in 7 patients all showed marked T2 shortening, despite the absence of hemorrhage on either T1- or T2-weighted images. None of the follow-up scans showed radiographic or clinical progression. CONCLUSION: The benign clinical course, lack of mass effect, and minimal or no T2 prolongation argue against neoplasm and instead indicate a vascular cause. We suspect the decreased signal on gradient-echo sequences represents elevated intravascular deoxyhemoglobin from stagnant blood flow. The findings are atypical for cavernous angioma or classic venous malformation. Although pathologic confirmation is lacking, the radiographic features are most consistent with capillary telangiectasia or a transitional capillary-venous malformation. Despite the absence of progression or hemorrhage in any of the patients to date, the long-term prognosis currently is unknown. We emphasize the importance of recognizing the nonneoplastic nature of these lesions.

Adolescent↗