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At least 721 records · Page 40Linked to original sources
PubMed2006

Measuring brain stem and cerebellar damage in parkinsonian syndromes using diffusion tensor MRI.

OBJECTIVE: To use diffusion tensor MRI to quantify and compare degeneration of the pons and cerebellar peduncles in multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and Parkinson disease (PD) and to relate changes in diffusion measures to clinical features and localized atrophy. METHODS: We used a region-of-interest approach to measure changes in fractional anisotropy and mean diffusivity in the middle cerebellar peduncles, decussation of the superior cerebellar peduncles, and pons in 17 patients with MSA, 17 with PSP, 12 with PD, and 12 healthy volunteers. We also evaluated atrophy of the cerebellar peduncles and pons on T2-weighted magnetic resonance images in patients with MSA and PSP. RESULTS: In MSA, fractional anisotropy was markedly reduced in the middle cerebellar peduncles, and mean diffusivity increased both here and in the pons compared with other groups, whereas in PSP, mean diffusivity was strikingly increased in the decussation of superior cerebellar peduncles. Cerebellar ataxia was related to mean diffusivity in the middle cerebellar peduncles (r = 0.71, p = 0.001) and pons (r = 0.60, p = 0.01) in MSA. Diffusion measures were related to localized atrophy in both MSA and PSP. CONCLUSIONS: Diffusion tensor MRI can be used to quantify neurodegenerative processes in different brain stem and cerebellar structures in multiple system atrophy and progressive supranuclear palsy during life, and may have diagnostic value. Larger studies of early, undifferentiated parkinsonian syndromes are indicated to provide estimates of the relative diagnostic value of diffusion measures, atrophy measures, and visual assessment of scans.

Aged↗
PubMed2000

Effect of aging on tryptophan hydroxylase in rat brain: implications on serotonin level.

Tryptophan hydroxylase (TrpH) catalyzes a rate-limiting step in the biogenesis of serotonin. The main objective of this study is to investigate the effect of aging on the activity of TrpH in serotonergic-enriched brain regions such as midbrain, pons, and medulla. TrpH activity was monitored by incubating various concentrations of tryptophan in a fixed amount of brain homogenate from midbrain, pons, and medulla of 2-month (young), 12-month (mature), and 24-month (old) rats (pH 7.4, 37 degrees C). The product 5-hydroxytryptophan was quantitated using a reversed phase HPLC equipped with an electrochemical detection system. Michaelis-Menton constants, K(m) and V(max), were calculated using the Lineweaver-Burk plot. The affinity (K(m)) of the enzyme significantly declined in midbrain and pons of old rats (141.1 +/- 2. 6, 126.0 +/- 10.8 microM) relative to mature rats (22.4 +/- 7.7, 38. 2 +/- 4.7 microM). However, no change was observed in medulla of old rats. The V(max) of TrpH in pons of all three age group rats was fairly constant. However, the V(max) of midbrain was significantly elevated, whereas that of medulla was reduced in old rats relative to mature rats. Clearance formation, a ratio of V(max) to K(m), of 5-hydroxytryptophan declined significantly in midbrain, pons, and medulla of old rats relative to mature rats. A combined effect of inefficient phosphorylation and oxidative damage of TrpH enzyme may be responsible for lower TrpH activity in aging brain. Such alterations in TrpH activity may reduce the level of serotonin in brain, which may be linked to late-life depression and other brain disorders, such as Alzheimer and Parkinson diseases.

Aging↗
PubMedDate not supplied

Effect of diisopropylfluorophosphate and atropine or mecamylamine on acetylcholine levels in the central nervous system of the rat.

The effect on acetylcholine levels caused by diisopropylfluorophosphate, either alone or in combination with atropine or mecamylamine, has been studied in the olfactory brain, medulla pons and cortex of the rat. At sublethal doses (0.25 and 0.5 mg/kg), diisopropylfluorophosphate reduced the acetylcholine levels. This effect was completely antagonized by atropine in the medulla pons and by mecamylamine in the medulla pons, olfactory brain and partly in the cortex. These observations suggest that the reduction of acetylcholine levels at low doses of diisopropylfluorophosphate is mediated by a muscarinic system in the medulla pons and by a nicotinic system in the medulla pons, the olfactory brain and also, in part, in the cortex.

Acetylcholine↗
PubMedDate not supplied

[CLinico-morphologic correlations in cases of fatal outcome following removal of acoustic nerve neuromas].

The clinical findings were compared with the results of morphological examination of the brain in 32 patients who had died in different periods after surgery for removal of neurinoma of the acoustic nerve. In all cases vessels supplying the brain stem were injured during removal of the tumor. In 5 cases all three groups of arteries of the pons varolii were injured, which led to the development of infarction of half of the pons. The short circumflex pons arteries and the anterior inferior cerebellar artery were injured in 18 patients, which caused the formation of an infarct in the lateral part of pons varolii. The distal segment of the anterior inferior cerebellar artery was injured in 9 patients, as a result of which a small focus of infarction formed in the dorsolateral parts of the pons.

Arteries↗
PubMed1993

Simultaneous pontine and basal forebrain microinjections of carbachol suppress REM sleep.

This study was performed to test the hypothesis that cholinoceptive basal forebrain systems can significantly influence cholinoceptive pontine mechanisms known to be important for generating rapid eye movement (REM) sleep. This hypothesis was examined by microinjecting the cholinergic agonist carbachol or saline (vehicle control) into the pons, the basal forebrain, or simultaneously into the pons and basal forebrain, while quantifying the effects on sleep and wakefulness in unanesthetized, chronically instrumented cats. All microinjections were made during wakefulness and were followed by 2 or 4 hr of recording. Polygraphic records were scored for wakefulness, non-REM sleep, REM sleep, and the REM sleep-like state evoked by pontine administration of carbachol (DCarb). Dependent variables quantified following each microinjection included the percentage of recording time spent in each state, the latency to onset of non-REM, REM, and DCarb, the number of episodes per hour of each state, and the duration of the longest episode of each state. A total of 149 microinjections were made into 15 forebrain and 11 pontine sites in eight cats. Basal forebrain administration of carbachol significantly increased wakefulness. Pontine microinjection of carbachol produced a state that polygraphically and behaviorally resembled REM sleep. This REM sleep-like state occurred in amounts significantly greater than natural REM sleep. Pontine carbachol also significantly decreased wakefulness and non-REM sleep. Simultaneous injection of carbachol into the pons and basal forebrain enhanced REM sleep, but the magnitude of this enhancement was significantly less than the increase in REM sleep evoked by carbachol injection into the pons alone. The results show that cholinoceptive regions of the basal forebrain can increase wakefulness and reduce the ability of pontine carbachol to evoke the REM sleep-like state. These findings suggest that basal forebrain administration of carbachol activates an arousal-generating system that can successfully compete with the powerful cholinergic REM sleep-generating system of the pons.

Animals↗
PubMed1998

[Histological and morphometrical studies on small arteries in normal brainstems with special reference to the pathogenesis of the hypertensive brainstem hemorrhage].

Plasmatic arterial necrosis and microaneurysm of small arteries are preceded by smooth muscle cell loss and the rupture of these arterial lesions is a direct cause of hypertensive intracerebral hemorrhage. The hypertensive brainstem hemorrhage occur exclusively in the pons. To elucidate whether there are differences of underlying arterial lesions between each part of the brainstem or not, small arteries in normal 34 autopsied brainstems were investigated histologically and morphometrically. Histological study revealed the predilection of the occurrence of plasmatic arterial necrosis, microaneurysms and fibronodular arterial lesions in the hypertensive pons. These lesions occurred predominantly in the small arteries 100-300 microns in diameter in the basal part of hypertensive pons, and were rare in the other parts of hypertensive brainstems and in normotensive brainstems. A negative correlation between the ratio of number of smooth muscle cell nuclei to the area of tunica media and age was demonstrated morphometrically. The ratio in the hypertensive group was significantly lower than that of the normotensive group. In addition the mean ratio in the pons was significantly lower than that in the midbrain and the medulla oblongata in the hypertensive group. These results are consistent with the fact that the hypertensive brainstem hemorrhage predominantly occur in the pons and primary bleedings in the other parts of the brainstem are rare.

Aged↗
PubMed1996

Olfactory glomeruli are innervated by more than one distinct subset of primary sensory olfactory neurons in mice.

The rodent olfactory epithelium consists of a mosaic of primary sensory olfactory neurons (PONs) which express distinct putative olfactory receptor proteins. Recent evidence suggests that individual subsets of these sensory neurons project to separate glomeruli in the olfactory bulb (Vassar et al., [1994] Cell 79:981-991). In the present study we have identified two distinct subsets of primary sensory olfactory neurons (PONs) in the H-OMP-LacZ-6 transgenic mouse. In these transgenic mice, a LacZ reporter gene under the control of a 294 base pair element from the 5' promoter region of the olfactory marker protein (OMP) gene was expressed in a subset of PONs located in a discrete band of neuroepithelium in the nasal cavity. These LacZ positive neurons were not randomly located within this band but were more concentrated within a locus between endoturbinates IIb and III. The axons of these neurons densely innervated three adjacent and bilaterally symmetrical glomeruli present in the ventromedial olfactory bulb. Labeling of tissue sections with the plant lectin Dolichos biflorus (DBA) revealed an independent subset of PONs in the transgenic mice. These neurons were present in a wide region of the nasal cavity that included the neuroepithelial band containing the LacZ expressing neurons. The DBA labeled axons terminated in glomeruli in the rostromedial and dorsolateral olfactory bulb surfaces. Although the glomeruli innervated by the LacZ and DBA positive axons were predominantly non-overlapping there were glomeruli in the ventral olfactory bulb that were labeled by both DBA and LacZ markers. Eight different types of glomeruli were characterized. Most notably, glomeruli were identified which were innervated partially by both or by either subset alone. In these cases, axon subsets were observed to terminate within discrete subregions of a glomerulus. These results support the hypothesis that phenotypically distinct subsets of PONs converge on to the same glomeruli but also indicate that some glomeruli are innervated by more than one subset of sensory neuron. These findings have implications for understanding how the olfactory projection is formed and how olfactory information is processed.

Animals↗
PubMed1998

New aspects in the reaction mechanism of phenol with peroxynitrite: the role of phenoxy radicals.

The decomposition of peroxynitrite (PON) in aqueous solutions was investigated by monitoring the release of dioxygen as a function of pH together with the various reaction products generated from phenol. This substrate was used as a mechanistic model for tyrosine nitration in prostacyclin synthase for which we have reported a highly efficient nitration and inhibition by PON (Zou, M., Martin, C., and Ullrich, V. (1997) Biol Chem. 378, 707-713). Nitrite as a contaminant and product of PON generated 4-nitrosophenol and some nitrophenols in the acidic pH range. In the alkaline range high amounts of 4-nitrosophenol originated from the disproportionation of PON yielding dioxygen and NOx species. The hydroxylation of phenol occurred between pH 3 and 8 with a maximum at 4.5. The nitration by PON also required a pH between 4 and 8 but had a second maximum between 10 and 12, suggesting that in this pH range phenolate was the reacting species. All isomeric biphenols were found as dimerization products as well as 4-phenoxyphenol (4-hydroxydiphenyl ether), indicating phenoxy radicals as intermediates. Since anisol when incubated under the same conditions yielded only hydroxylation but virtually no nitration products, it was concluded that nitration of phenolic compounds requires a one-electron oxidation as a primary step, followed by addition of the nitrogen dioxide radical.

Anisoles↗
PubMed1996

Behavior of luminance neurons in the pretectal olivary nucleus during the pupillary near response.

In cats and monkeys, extrastriate visual areas that have been reported to be involved in the near triad of pupilloconstriction, convergence, and accommodation have well-defined projections to the pretectal olivary nucleus (PON), the retinorecipient pretectal nucleus mediating the pupillary light reflex in mammals. We have therefore used alert, behaving primates to investigate the possibility that PON neurons are involved in the pupillary near response in addition to the pupillary light reflex. Single-unit recording revealed that PON luminance neurons significantly increased their firing rate with increases in retinal illumination and the resultant pupilloconstriction. In contrast, their activity did not significantly increase during pupilloconstriction elicited by near viewing. Thus the behavior of PON luminance neurons is appropriate for their participation in the pupillary light reflex, but is inappropriate for any proposed role in the pupillary near response. This result strongly suggests that neurons in the primate PON are solely related to the pupillary light reflex and that the cortical projections to this pretectal nucleus are related to this reflex and do not play a role in the pupillary near response.

Accommodation, Ocular↗
PubMed1975

[Influence of repetition rate and pause upon the cortical potential evoked by various acoustic stimulation in man (author's transl)].

In agreement with earlier experiments an increase of amplitude of the medium components (80-250 ms: Non-Pon) with decreasing repetition rate or increasing interval between the stimuli (sinusoidal tones, white noise, craftsman noise) is observed. There is no influence of the variable intervals upon the off-effect, if sinusoidal tones and white noise are used. A small increase of the amplitude difference Noff-Poff results if bursts of craftsman noise are used for stimulation. The amplitude of a peak in the range 300-400 ms which can be regarded approximatively as the peak of the long lasting dc-component, related to the positive peak (Pon) around 200 ms shows also an increasing tendency if the interval between stimuli is enlarged. Pon itself is augmented if related to the preceding section before stimulus on-set. Therefore the increase of the slow component expresses only an increase of the positive component Pon or is based upon a dc-shift which is added to the preceding section as well as to the range of the dc-component beginning around 300 ms after stimulus on-set. Using only sinusoidal tones a reduction takes place of the amplitude of the potential evoked by a tone of constant duration if the silent pauses are smaller than 2500 ms. If the pause preceding a tone of constant duration is reduced down to 300 ms the decrease of the amplitude is around 50-60%. The amplitude of the off-effect however is not affected. Only if related on the positive component Pon the slow component shows a small decrease. If related on the preceding section there is no change caused by different pauses preceding a tone of constant duration. Both, the latency of on- and off-components is also not influenced by the variable pause. Only the peak of the slow component shows a shift in the way that there is a maximum if the duration of the pause corresponds to half of the interval. In this case there is also a clear maximum of the amplitude of the potential evoked by the tone of variable duration. The results throw some light upon the different origin of the components of the evoked response and the overlapping of dc-shifts.

Acoustic Stimulation↗
PubMed1976

Effects of glutamic acid relatives on the electrical activity of an identified molluscan giant neurone (Achatina fulica Férussac).

Effects of glutamic acid and its relatives were examined on the electrical activity of two kinds of neurones (the PON, periodically oscillating neurone, and the TAN, tonically autoactive neurone) identified in the suboesophageal ganglia of an African giant snail, Achatina fulica Férussac. L- and D-Glu, L-Asp, Gly and beta-Ala did not show any effect on the two neurones. However, beta-hydroxyglutamic acid (BHGA) showed a remarkable inhibitory effect on the PON. Erythro-L-BHGA had the strongest effect of these stereoisomers, and the critical concentration of this substance to produce the effect was 10(-6)-3 X 10(-5) g/ml (6-18 muM) when administered in the bath application. We confirmed by the microdrop application that erythro-L-BHGA directly hyperpolarized the PON neuromembrane. When the curve of current-voltage relationships (I-V curve) of the PON neuromembrane measured under erythro-L-BHGA at 10(-5) g/ml (61 muM) was superimposed on the curve of the normal state using the firing level as the common standard, these two curves showed concordance in a wide range of membrane polarization level. This concordance implies that the membrane resistance was maintained normally under erythro-L-BHGA at this concentration. A higher concentration of 10(-4) g/ml (0.61 mM) of this substance caused a decrease of PON membrane resistance and a remarkable elevation of its firing level. The TAN was not sensitive to BHGA, but sensitive to GABA and its derivatives.

Amino Acids↗
PubMed1988

Turning responses evoked by stimulation of visuomotor pathways.

Lateral eye, head, and body movements are produced by electrical stimulation of many brain regions from frontal cortex to pons. A new collision method shows that at least 5 separate axon bundles mediate stimulation-elicited lateral head and body movements in rats. One bundle passes between the rostromedial tegmentum and medial pons, with conduction velocities of 0.8-18 m/s. A second bundle passes between the superior colliculus and contralateral medial pons, with conduction velocities of 1.7-13 m/s. A third bundle passes between the superior colliculus and ventrolateral pons, with conduction velocities of 1.3-20 m/s. A fourth bundle passes between the internal capsule and medial substantia nigra, with conduction velocities of 0.9-4.4 m/s. A fifth bundle passes between the anteromedial cortex and rostral striatum, with conduction velocities of 2.4-36 m/s. Collision effects have not been observed between the anteromedial cortex and the internal capsule, medial substantia nigra, superior colliculus, rostromedial tegmentum, or medial pons, which suggests that these sites are not connected by axons mediating turning. Possible synaptic linkages between the 5 bundles and possible transmitters are discussed.

Animals↗
PubMed2004

Incidence of and risk factors for perioperative optic neuropathy after cardiac surgery.

BACKGROUND: Visual loss from optic neuropathy rarely occurs in the perioperative period in patients who have undergone nonocular surgery. We performed a retrospective, matched, case-control study to determine the incidence of perioperative optic neuropathy (PON) after cardiac surgery with the use of cardiopulmonary bypass (CPB) and to determine risk factors that may lead to this potentially devastating complication. METHODS: Medical records of all patients undergoing cardiac surgery during a 9-year period were reviewed retrospectively to identify visual loss from acute unilateral and bilateral optic neuropathy during the perioperative period that had developed in patients. Data were collected from these patients and compared with data from control subjects matched for age, gender, risk factors for vascular disease, and type of surgery to determine the incidence of and potential risk factors for PON. RESULTS: Of 9701 surgical patients requiring CPB, 11 patients (0.113%) with PON were identified. Although both the absolute and relative drop in hemoglobin during the perioperative period approached statistical significance, no other putative risk factors were identified. CONCLUSIONS: The risk of PON associated with cardiac surgery in which CPB is used is low but substantial. The factors that lead to the condition remain unknown, although the presence of systemic vascular disease and both the absolute and relative drop in hemoglobin during the perioperative period seem to be important. Because PON often causes profound permanent visual loss, we recommend that patients, particularly those with systemic vascular disease, for whom cardiac surgery with CPB is planned, be made aware of this potential complication.

Acute Disease↗
PubMed2005

Effect of nandrolone decanonate on paraoxonase activity in hemodialysis patients.

OBJECTIVES: This study was designed to determine the effect of nandrolone decanonate (ND) on HDL-C, apolipoproteins and paraoxonase (PON) activity in stable hemodialysis patients. DESIGN AND METHODS: 64 hemodialysis patients were treated with ND at a dose of 100 mg/I.M./week for 4 months. HDL-C, Apo-AI, Apo B, concentrations and PON activity were measured before and after 2 and 4 months of treatment as well as 2 months after withdrawing the treatment. RESULTS: After 4 months of treatment, an elevation in the serum levels of Apo B (P<0.0001) and a marked decrease in the concentration of HDL-C (P<0.0001), Apo-AI (P<0.0001) and PON activity (P<0.0001) were found. A significant correlation between PON and both Apo-AI (r=0.270, P<0.04) and HDL-C (r=0.455, P<0.0001) and also between HDL-C and Apo-AI (r=0.305, P<0.02) were found. CONCLUSION: Results revealed the adverse effects of ND on apolipoprotein levels in our study population. It is possible that ND reduces PON activity mostly by reducing both the HDL-C and Apo-AI levels.

Apolipoprotein A-I↗
PubMed2004

Changes of serum paraoxonase (an HDL-cholesterol-associated lipophilic antioxidant) and arylesterase activities in severe preeclamptic women.

OBJECTIVE: To determine the serum lipid profile, the activity of paraoxonase (PON, the lipophilic antioxidant component of HDL-cholesterol), and alterations of the arylesterase activity in preeclamptic women. STUDY DESIGN: This cross-sectional study included 28 severe preeclamptic, and 24 healthy pregnant women. Fasting venous blood samples were collected during the antepartum period for spectrophotometric determination of the PON and arylesterase activities. RESULTS: In the severe preeclamptic group, the mean levels of total cholesterol, triglycerides, and LDL-cholesterol were 4, 5 and 9.8% higher, respectively, and HDL-cholesterol 9% lower than in the healthy controls. The PON and arylesterase activities were significantly lower in the severe preeclamptic women than in the controls, P<0.001 and P=0.000, respectively. A moderately positive correlation was detected between the serum levels of HDL-cholesterol and PON (r=0.49, P<0.02, n=52) and between HDL-cholesterol and arylesterase (r=0.42, P<0.05, n=52). CONCLUSIONS: Our results suggest that an abnormal lipid profile and decreased PON and arylesterase activities may have a role in pathogenesis of preeclampsia.

Adult↗
PubMed2006

Inverse correlation of serum paraoxonase and homocysteine thiolactonase activities and antioxidant capacity of high-density lipoprotein with the severity of cardiovascular disease in persons with type 2 diabetes mellitus.

Atherosclerotic risk is increased in diabetes partly because of increased plasma levels of the oxidized low-density lipoprotein and homocysteine, 2 independent and important cardiovascular disease (CVD) risk factors. Paraoxonase (PON) is a multifunctional antioxidant enzyme component of high-density lipoprotein (HDL), which can protect against low-density lipoprotein (LDL) oxidation. It also exhibits homocysteine thiolactonase (HCTL) activity that detoxifies homocysteine thiolactone, which can damage proteins by homocysteinylation of the lysine residues, thus leading to atherosclerosis. We conducted a cross-sectional study to correlate PON-1, HCTL activities, and the lag time of LDL oxidation in 15 healthy control subjects and in 55 subjects with type 2 diabetes mellitus with different degrees of CVD. Compared with healthy controls and diabetic subjects without evidence of overt CVD, we not only found 47% (P < .005) decrease in PON-1 activity, but also for the first time, 30% (P = .019) decrease in HCTL activity in subjects with a prior coronary artery bypass surgery. There was corresponding decreased effectiveness of HDLs from diabetic groups (with and without CVD) in protecting against LDL oxidation. Moreover, the PON-1 activity was significantly inversely correlated to the extent of intracoronary lesions determined at catheterization (ie, a high Gensini score). These decreases in PON-1 and HCTL activity were not due to any bias in preferential distribution of low-activity QQ homozygotes in the diabetic groups compared with the control group because QQ allele was equally distributed in all the experimental groups, whereas RR allele tended to increase in the diabetic subjects with coronary artery bypass surgery compared with the other groups. Therefore, clinical intervention to restore the impaired antiatherogenic activities of HDL should be considered an important goal in the treatment of persons with diabetes.

Aged↗
PubMed2006

Paraoxonase gene polymorphism and vitamin levels during pregnancy: Relationship with maternal oxidative stress and neonatal birthweights.

The aim of this study was to determine the association between maternal oxidative stress and adverse birth outcome, and serum vitamin levels and paraoxonase (PON) polymorphism during pregnancy. We investigated 276 pregnant women who visited a hospital for prenatal care during gestational weeks 24 and 28. We measured serum Vitamins C and E levels and urinary levels of 8-hydroxy-2-deoxyguanosine (8-OH-dG). We determined the presence of a maternal PON polymorphism (Q-to-R substitution at a nucleotide located on 7q21.3) using a polymerase chain reaction-restriction fragment length polymorphism assay. High levels (relative to the median) of Vitamins C and E were associated with a reduced concentration of urinary 8-OH-dG, but increased birthweight and gestational age in subjects with the Q/Q and Q/R types of PON polymorphism. Even with the high-risk PON polymorphism (R/R), the results show that birthweight increased with high levels of Vitamins C and E. Our data demonstrate that oxidative stress and neonatal birthweight are affected by maternal levels of Vitamins C and E in subjects with a PON polymorphism.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2006

Brainstem and trigeminal nerve changes after radiosurgery for trigeminal pain.

PURPOSE: To evaluate the significance of radiological changes on follow-up MRIs after SRS for TN. MATERIALS AND METHODS: Thirty-seven patients with follow-up MRI because of paresthesias, bilateral treatment, or failure were analyzed regarding pain outcome and complications. Mean age was 64.4 years; 14 underwent previous treatment. Twenty-nine had ETN, 5 secondary TN due to tumor or multiple sclerosis, and 3 had atypical TN. Ninety gray was prescribed for 20 patients, 70 Gy for 5, and 80/85 Gy for 2. A 5-mm collimator was used in 32 (88.9%) cases. Mean follow-up was 15 months (range, 4-52 months). RESULTS: Excellent/good pain relief was sustained in 67% of cases at 13 months' follow-up. Enhancement on MRIs was observed in 21 cases (56.75%) with nerve enhancement in 9, pons enhancement in 4, pons-nerve enhancement in 4, and tumor enhancement in 4. Magnetic resonance images were unremarkable in 16 cases. Pain recurred in 4 cases (5.5-10 months). Pons enhancement correlated with pain relief (P = .0087) but not with nerve enhancement (P = .22). Incidence of slight paresthesias was 66.6%. No anesthesia dolorosa or ophthalmologic problems were observed. Paresthesias correlated with enhancement (P = .02), but not with brainstem volume encompassed by the 20%, 30%, and 50% isodoseline (P = .689, .525, .908). Enhancement free probability at 12 months was 48.5% (Kaplan-Meier). CONCLUSIONS: Pons enhancement seems to be prognostic for pain relief without higher incidence of complications. Pons volume irradiated did not predict enhancement occurrence. Radiation delivery to the brainstem-REZ interface seems to improve pain outcome, although more paresthesias should be expected.

Adult↗