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PubMed1990

[The brain stem function in patients with brain bladder--clinical evaluation using dynamic CT scan and auditory brainstem response].

A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presence of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain disease and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD.

Adult↗
PubMed1998

[Brain stem glioma].

Brain-stem gliomas occur mainly in childhood and are localized in the mesencephalon, pons and medulla oblongata. Diagnosis is a domain of MRI, requiring T2, T1 and KM. CT shows hemorrhage and calcification well. The criteria are the primary site, size, tumor growth, brain-stem enlargement, delineation, intralesional structure, exophytic components and enhancement. Secondary criteria are herniation, hydrocephalus and liquorgenic seeding. In CT glioma are hypodense, in MRI hyperintense in T2 and hypointense in T1. Enhancement is seen in 25-60% and does not allow differentiation of tumor vs nontumor or gradings. Factors influencing poor outcome are high grade, a short history, cranial nerve involvement, severe brain-stem enlargement, pontine site, diffuse growth and recurrency. The 5-year-survival rate is 30% (after radiation: focal tumors 85%, diffuse 20%). Most frequent are symptoms of brain pressure, cerebellum, cranial nerves and pyramidal tract. There is no agreement on whether biopsy is necessary or not. A diagnosis of tumor is highly suggestive if classical MRI findings fit the clinical history.

Adolescent↗
PubMed2001

Serotonin elicits long-lasting enhancement of rhythmic respiratory activity in turtle brain stems in vitro.

Brain stem preparations from adult turtles were used to determine how bath-applied serotonin (5-HT) alters respiration-related hypoglossal activity in a mature vertebrate. 5-HT (5-20 microM) reversibly decreased integrated burst amplitude by approximately 45% (P < 0.05); burst frequency decreased in a dose-dependent manner with 20 microM abolishing bursts in 9 of 13 preparations (P < 0.05). These 5-HT-dependent effects were mimicked by application of a 5-HT(1A) agonist, but not a 5-HT(1B) agonist, and were abolished by the broad-spectrum 5-HT antagonist, methiothepin. During 5-HT (20 microM) washout, frequency rebounded to levels above the original baseline for 40 min (P < 0.05) and remained above baseline for 2 h. A 5-HT(3) antagonist (tropesitron) blocked the post-5-HT rebound and persistent frequency increase. A 5-HT(3) agonist (phenylbiguanide) increased frequency during and after bath application (P < 0.05). When phenylbiguanide was applied to the brain stem of brain stem/spinal cord preparations, there was a persistent frequency increase (P < 0.05), but neither spinal-expiratory nor -inspiratory burst amplitude were altered. The 5-HT(3) receptor-dependent persistent frequency increase represents a unique model of plasticity in vertebrate rhythm generation.

Animals↗
PubMed1985

Auditory brain-stem response in determination of brain death.

A diagnosis of brain death requires evidence of irreversible destruction (or dysfunction) of neurons in the brain stem and cerebrum. The physical examination is not a valid index of brain integrity in patients who are drug-intoxicated or receiving therapeutic paralyzing agents or high-dose barbiturates. We evaluated the use of the auditory brain-stem response (ABR) as an ancillary test in the determination of brain death. A total of 100 combined ABR and nuclear cerebral blood flow studies were completed at bedside with 81 acute, severely brain-injured adults. The ABR and cerebral blood flow outcomes were significantly correlated. We conclude that the ABR is a clinically feasible and useful procedure in the determination of brain death, especially in patients whose medical therapy compromises the neurologic examination.

Adolescent↗
PubMed1994

D-amino-acid oxidase is confined to the lower brain stem and cerebellum in rat brain: regional differentiation of astrocytes.

Based on enzymatic activity, the localization and the identification of D-amino-acid oxidase-containing cells in rat whole brain was systematically studied in serial fixed sections. The oxidase activity was absent or scarce in the forebrain, was confined to the brain stem (midbrain, pons and medulla oblongata) and cerebellum, and its localization was extended to the spinal cord. In the brain stem the oxidase was mainly localized in the tegmentum, particularly in the reticular formation. The intense oxidase reactions were present in the red nucleus, oculomotor nucleus, trochlear nucleus, ventral nucleus of the lateral lemniscus, dorsal and ventral cochlear nuclei, vestibular nuclei, nuclei of posterior funiculus, nucleus of the spinal tract of the trigeminal nerve, lateral reticular nucleus, inferior olivary nucleus, and hypoglossal nucleus. In the cerebellum the activity in the cortex was much more intense than that in the medulla. In all the fields described above, the oxidase-containing cells were exclusively astrocytes including Bergmann glial cells, and neither neuronal components, endothelial cells, oligodendrocytes nor ependymal cells showed oxidase activity. These results indicated that the astrocytes regionally differentiated into two distinct types, one of which expressed oxidase in the midbrain, rhombencephalon and spinal cord, and the other which did not in the forebrain. The localization of the oxidase was inversely correlated with the distribution of free D-serine in mammalian brains (Nagata, Y., Horiike, K. and Maeda, T., Brain Res., 634 (1994) 291-295). Based on the characteristic localization of the oxidase-containing astrocytes, we discussed the physiological role of the oxidase.

Animals↗
PubMed1986

[The effect of brain-stem vasomotor centers on the neurogenic control of cerebrovascular tonus--Part 3. The effects of destruction and stimulation of the brain-stem on intracranial pressure in acute subarachnoid hemorrhage].

The purpose of the present study is to clarify the effects of destruction and stimulation of the brain-stem on intracranial pressure (ICP) in experimentally induced subarachnoid hemorrhage (SAH). Using 23 cats, blood pressure (BP), ICP and local cerebral blood volume (CBV) were continuously measured. Acute SAH was produced by injection of autogenous blood (3 to 7 ml) into the cisterna magna. The animals were divided into two groups. Group A: those in which hypothalamic dorsomedial nucleus (DM) and reticular formation of the midbrain (MBRF) were coagulated bilaterally one hour after SAH and Group B: in addition to the procedure of Group A, reticular formation of the medulla oblongata (MORF) was electrically stimulated bilaterally. In 19 out of 23 cats of both groups, transient small increases in ICP and CBV were observed during coagulation and/or stimulation of DM, MBRF and MORF respectively in the animals whose ICP remained approximately 20 mmHg or below and progressive increase in ICP was never evoked. In 3 animals of Group A whose ICPs remained high at more than 20 mmHg, sequential destruction of DM and MBRF induced stepwise increase in ICP to 40 to 80 mmHg and consequently resulted in acute brain swelling. In 1 animal of Group B whose ICP fluctuated around 20 to 40 mmHg, biphasic increase in ICP to 100 mmHg was repeatedly evoked by stimulation of MORF. It is concluded that in the condition of increased ICP produced by SAH, lesions in the DM and MBRF and stimulating condition of MBRF may result in acute brain swelling.

Acute Disease↗
PubMed1980

Click lateralization and the auditory brain stem response.

Auditory brain stem function was evaluated in patients by means of (1) click lateralization thresholds and (2) auditory brain stem responses. In the three cases tested, clear qualitative agreement was seen between the behavioral results and the evoked-response findings.

Adult↗
PubMed1996

Is there a role for high-dose chemotherapy with stem cell rescue for brain stem tumors of childhood?

Diffuse pontine tumors are highly lethal and conventional therapy with irradiation provides long-term survival to a very small proportion of the patients. We have reported promising results using high-dose chemotherapy with autologous stem cell rescue in patients with recurrent high-grade astrocytomas in other anatomic locations, but our results and those of others have been very discouraging in children with brain stem tumors. Alternative strategies need to be developed for this highly lethal disease.

Adult↗