Brainstem In Children Research Articles

Life-long increase of substantia nigra hyperechogenicity in transcranial sonography

Transcranial ultrasound of the substantia nigra (SN) shows a distinct hyperechogenicity in the majority of patients with Parkinson's disease. Recent studies indicate a larger area of hyperechogenicity in elderly healthy adult subjects. The present study aimed to determine the size of the SN hyperechogenicity and of the mesencephalic brainstem in children and adults without evidence of movement disorders. The areas of echogenicity in the substantia nigra (aSN) and the area of the ipsilateral midbrain (aMid) were assessed in 121 healthy infants and children as well as in 64 healthy adults. Furthermore, the ratio of aSN and aMid was calculated (S/M ratio). We found a positive correlation between age and aSN and between age and the S/M ratio. The values for aSN and S/M ratio were smaller in infants and children compared to healthy adults (aSNmax 0.06±0.05 cm2 vs. 0.13±0.08 cm2). The aSN and S/M ratio grew with increasing age in an almost linear progression. The increase of SN hyperechogenicity over time suggests that the biological process underlying this ultrasound finding may be more dynamic and possibly progressive than previously thought.

Neurophysiologic and Neurocognitive Case Profiles of Andean Patients with Chronic Environmental Lead Poisoning

This report presents case profiles of three siblings in a family of lead (Pb) glazing workers living in a Pb-contaminated Andean village who presented with extreme plumbism (blood Pb levels: 47 to 128 μg/dl) from childhood to adolescence. These cases are examples of persons who have chronic Pb poisoning as a result of prolonged occupational and environmental exposure in a Pb-glazing ceramic cottage industry in the study area. Using behavioral and physiological techniques for measuring the integrity of the peripheral and central auditory systems, including otoacoustic emissions, and replicated auditory brainstem electrophysiological potentials, the authors found normal auditory neurosensory function in each patient, thus ruling out hearing impairment as a basis for adverse neurocognitive outcomes. This finding is contrary to the prevailing view regarding the detrimental effects of Pb poisoning on the cochlear and auditory brainstem of children. Performance on tests of visual spatial intelligence and auditory memory/attention was below average in these patients, which may underlie their reported learning disabilities. In two of the cases, there was an improvement in cognitive performance following a lowering of PbB levels from chelation therapy and Pb prevention education, suggesting some level of reversibility of their neurocognitive deficits. Nevertheless, these case profiles suggest that if the patients persist in Pb-glazing activities, in spite of repeated chelation therapy and family counseling, they may continue to be re-intoxicated and remain at risk for learning disabilities and other neurological impairments.

Morphometric MRI Findings in the Thalamus and Brainstem in Children After Moderate to Severe Traumatic Brain Injury

Generalized whole brain volume loss is well documented in moderate to severe traumatic brain injury. Whether this atrophy occurs in the thalamus and brainstem has not been systematically studied in children. Magnetic resonance imaging (MRI) quantitative analysis was used to investigate brain volume loss in the thalamus and brainstem in 16 traumatic brain injury subjects (age range 9-16 years) compared with 16 age and demo-graphically matched controls. Based on multiple analysis of covariance, controlling for age and head size, reduced volume in the thalamus and the midbrain region of the brainstem were found. General linear model analyses revealed a relation between processing speed on a working memory task and midbrain and brain stem volumes. Reduced volume in thalamic and brainstem structures were associated with traumatic brain injury. Reduction in midbrain and thalamic volume is probably a reflection of the secondary effects of diffuse axonal injury and reduction in cortical volume from brain injury.

An Evoked Potential Study of the Developmental Time Course of the Auditory Nerve and Brainstem in Children Using Cochlear Implants

Central auditory responses to electrical stimulation from a cochlear implant were studied in 75 pre-lingually deafened children and 11 adults. Electrically evoked auditory brainstem response (EABR) latencies significantly decreased with duration of cochlear implant use and were not significantly affected by the age at implant activation. Significant decreases in early latency waves and interwaves occurred within the first 1–2 months of implant use, whereas longer term changes (6–12 months) were found for eV and eIII-eV, which measure activity in the more rostral brainstem. Comparisons to acoustically evoked auditory brainstem response (ABR) in children with normal hearing suggested shorter interwave EABR latencies, reflecting either distinct neural generators or increased neural synchrony, but similar rates of change in the later latency eV and eIII-eV with time in sound. In sum, normal-like development of the rostral auditory brainstem is promoted by cochlear implant use in children of a wide range of ages.

Juvenile pilocytic astrocytoma of the brainstem in children

In reports involving the operative treatment of brainstem tumors, multiple histological types are often grouped together. To determine prognosis after resection, histology-specific data may be helpful. Twenty-eight patients with juvenile pilocytic astrocytoma (JPA) of the brainstem (six in the midbrain, four in the pons, and 18 in the medulla) were identified from the medical records. Initial treatment was resection in 25 and biopsy sampling in three. Postoperative imaging revealed gross-total resection (GTR) or resection with linear enhancement (RLE) in 12 of 25 patients and solid residual tumor in the other 13. In 10 of the 13 patients harboring solid residual tumor, observation was undertaken; the residual lesion disappeared in one, was stable in four, and progressed in five. Of the 12 patients with complete excision or RLE only, seven underwent no further treatment, with tumor progression occurring in one. All patients were alive at last follow-up examination (range 0.3-20.4 years, mean 6 years). New neurological deficits commonly appeared immediately after resection but often resolved. In six of the 28 patients, the new postoperative deficit was still present at last follow-up visit. The 5- and 10-year progression-free survival was 74 and 62%, respectively, after GTR or RLE and 19 and 19%, respectively, when solid residual tumor was present. Long-term survival after resection of JPAs of the brainstem has been observed and appears to be related to the extent of initial excision.

Intra-axial dermoid/epidermoid tumors of the brainstem in children

BACKGROUND Epidermoid and dermoid cysts are rare intracranial space-occupying lesions, which account for about 1% of all intracranial tumors; they are even rarer in the pediatric age group. Among the varius locations, that inside the brain stem is quite exceptional (only 12 cases reported to date in the literature). We report two additional cases occurring in children, underlining their clinical characteristics, the difficulties faced in the diagnostic work-up, and the surgical treatment adopted (which consisted of removal of the cyst contents and partial resection of the cyst membrane, because of its adherence to the surrounding nervous and vascular structures). METHODS We report two cases of intraaxial dermoid/epidermoid cysts observed within the last 5 years. Both patients complained of cervico-nuchal pain, with a remittent/intermittent character in one of them; this patient also exhibited transient 6th and 7th cranial nerve deficit. One lesion was approached through the floor of the fourth ventricle, the second one through the ventrolateral aspect of the brainstem. Results Subtotal tumor resection was achieved in both cases. Both patients had a smooth postoperative course without permanent neurological deficits. In the first patient residual tumor remains stable on follow-up MRI. In the second one, early tumor regrowth necessitated a second operation, after which the residual tumor has remained stable. CONCLUSIONS Based on our experience we suggest that a cautious surgical approach (“conservative” resection) to these lesions is the best choice. In fact, attempts at radical removal carry unacceptably high morbidity and mortality rates.

Glial reaction in periventricular areas of the brainstem in fetal and neonatal posthemorrhagic hydrocephalus and congenital hydrocephalus

This immunohistochemical, neuropathological study was performed on the ventricular wall of the brainstem in children with fetal and neonatal posthemorrhagic and congenital hydrocephalus. In posthemorrhagic hydrocephalus (PHH), hemosiderin deposits, nodular gliosis, ependymal cell loss and subsependymal rosette formation developed subventricularly after 2 weeks of age. Ferritin-positive reactive microglia were well stained until about 2 weeks of age and thereafter diminished as reactive astrocytosis occurred. In congenital hydrocephalus (CH), the damage to the ventricular wall was less than in PHH at all ages and was associated with only mild astrogliosis. These differences in the neuropathological findings of periventricular regions, consisting mainly of glial reactions between PHH and CH, are due to differences in pathophysiology, and the timing of the insult in both conditions. The differences may be due to the effects of intraventricular hemorrhage and/or rapidly increased intracranial pressure in PHH. These results may have implications for the neurological prognosis in children with PHH.

Hyperfractionated radiation therapy for gliomas of the brainstem in children and in adults

Between February 1984 and September 1990, 60 patients with brainstem gliomas were treated with hyperfractionated radiotherapy in the Department of Radiation Oncology at the University of California, San Francisco. Forty-one children (≤ 18 years) and 19 adults were treated with 100 cGy twice daily with 4–8 hr between doses. Thirty-one patients (21 children and 10 adults) received total doses of 66–72 Gy and 29 patients (20 children and nine adults) received 74–78 Gy. Median follow-up was 208 weeks for all patients (214 weeks for children, 157 weeks for adults). Twenty-three patients (14 children and nine adults) were alive at the time of analysis, surviving 59–359 weeks following treatment. Median actuarial survival was 73.6 weeks overall (72 weeks for children, 190 weeks for adults; p = 0.43). Survival at 12 and 24 months was 65% and 38%, respectively (63% and 32%, for children; 68% and 53% for adults). All patients had pretreatment magnetic resonance imaging by which tumors were classified as either focal or diffuse. No significant pretreatment prognostic factors for adults were identified. In children, significant favorable prognostic factors on univariate analysis were older age ( p = 0.001), tumor location in thalamus or midbrain ( p = 0.002), focal appearance on MRI scan ( p < 0.001) and duration of symptoms > 2 months prior to treatment ( p < 0.001). Thirty-five patients had tumor biopsies, leading to a diagnosis in 33 (22 children and 11 adults). Children with moderately anaplastic astrocytomas survived significantly longer than those with glioblastoma multiforme or unbiopsied tumors ( p < 0.001). Only duration of symptoms > 2 months remained significant as a favorable prognostic indicator for children on multivariate analysis ( p < 0.001). Survival was not significantly different for patients receiving < 72 Gy and those receiving > 72 Gy ( p = 0.18). No subgroup of patients showed significantly better survival with the higher dose. These findings indicate that hyperfractionated radiotherapy is effective treatment for adults and a subgroup of better prognosis children with brainstem gliomas. There is a subgroup of pediatric patients with extremely poor prognosis for whom even this aggressive treatment does little to extend survival. We conclude that there is no benefit to increasing total dose above 72 Gy for any of the groups analyzed.

Elevated level and underdeveloped fatty acid composition of brain cholesterol esters in malnourished children

The content and fatty acid composition of cholesterol esters were measured in the forebrain, cerebellum, and brain stem of children who died within the first 2 years of life from severe malnutrition syndrome of kwashiorkor, marasmus, or marasmic kwashiorkor. All three brain regions of the malnourished children had elevated concentrations of cholesterol esters, compared to those of apparently normal, well-nourished children of comparable ages. This was particularly true for the brain stem, in which the elevation in some cases was 10-fold or more. In this brain region, and less pronouncedly also in the cerebellum, the elevations were more marked in the second year of life than in the first year. Fatty acid analysis showed that the developmental changes that are seen in brain cholesterol esters during normal growth, for example, fall in percentage proportions of palmitic and oleic acids and a concomitant rise in the proportion of arachidonic acid, were absent in the brain regions of the malnourished children.

Auditory brainstem responses (ABR) in children with neurological disorders

Auditory brainstem responses (ABR) were studied in 35 children with neurological disorders and 24 controls. Abnormal results were obtained in 16 patients. All 5 of the patients with metachromatic leukodystrophy had evidence of peripheral and/or central delay in transmission in keeping with evidence of demyelination of both peripheral (i.e. auditory nerve) and central (i.e. brainstem) pathways as occurs in this disorder. Two children with lead poisoning had delayed conduction in the peripheral pathways only and in these there was good correlation between the degree of delay and the ulnar nerve conduction velocity; both improved after chelation therapy. One infant with lead poisoning had central delay only. One infant with osteopetrosis manifested progressive damage to the auditory nerves. Delayed conduction was also found in one patient each with hydrocephalus, spinal muscular atrophy, and in 2 infants with cerebral palsy. No responses were obtained in one infant with congenital rubella, one deaf-mute and one child with an undiagnosed degenerative neurological disease. Auditory brainstem responses are of value in detecting disturbances of the auditory nerve or brainstem in children with various neurological disorders.

Hyperexcitable state of the brainstem in children with post-traumatic vomiting as evidenced by brainstem auditory-evoked potentials.

Brainstem auditory-evoked potentials were studied within 6 hours after mild head injury in 17 children with post-traumatic vomiting. Compared with 8 control subjects, the children with frequent vomiting showed a significant shortening of peak latency for wave III. This mechanism appears to be essentially the reverse of that found in the post-concussion syndrome in which significant delay of wave III has been reported. These findings indicate transient facilitatory effects of trauma on brainstem auditory transmission in post-traumatic vomiting.

The movement of the brain stem and vessels around the brain stem in children with hydrocephalus and the Arnold Chiari deformity.

SUMMARYPost‐mortem angiography and dissection of the large vessels and tissues of the brain stem was carried out on 25 children with the Arnold Chiari deformity. An abnormal descent and looping of the basilar arteries was seen, and a very considerable downward looping of the posterior cerebellar vessels occurred in association with the descent of the cerebellum into the spinal cord canal.Measurements at dissection indicated an average descent of the vertebral arteries and pons of 10 mm. in children with thoracolumbar and 3 mm. with lumbosacral meningomyeloceles. There was a comparable descent of the base of the 4th ventricle of 30 mm. with thoracolumbar meningomyeloceles and 23 mm. with lumbosacral meningomyeloceles.RÉSUMÉLe déplacement du tronc cérébral et des vaisseaux autour du tronc cérébral chei les enfants atteints d'hydrocéphalic et de la difformité d'Arnold ChiariAngiographic post‐mortem et dissection des grands vaisseaux et des tissus du tronc cérébral ont été pratiquées chez 25 enfants atteints de la difformité d'Arnold Chiari. Une descente et une courbure anormales ont eacute;té notées dans les artéres basilaires, et une trés importante courbure vers le bas des vaisseaux cérébelleux était associée a la descente du cervelet dans le canal rachidien.Des mesures effectuées lors de la dissection ont indiqué une descente moyenne des artéres vertébrales et des apophyses de 10 mm. chez les enfants atteints de méningomyÉlocéles thoraco‐lombaires, et de 3 mm. chez ceux atteints de myélocéles lombo‐sacrés. II y avait une descente comparable de la base du 4 éne ventricule de 30 mm. avec méningomyÉlocéles thoraco‐lombaires et 23 mm. avec méningomyélocÉles lombo‐sacrés.ZUSAMMENFASSUNGBewegung des Gehirnstamms unci der Gefässe urn den Gehirnstamm bei Kindern mil Hydrocephalus und der Arnold Chiari DeformitätPost‐mortem Angiographic und Dissektion der grossen Gefässe und Gewebe des Gehirnstamms wurden bei 25 mit der Arnold Chiari DeformitÄt behafteten Kindern ausgefÜhrt. Eine abnorme Senkung und Verschleifung der Basilar‐Arterien wurde fest‐gestellt, und eine äusserst bedeutsame Abwärtsverschleifung der posterioren Gehirngefasse trat auf, in Verbindung mit dem Herabsinken des Cerebellums in den Rückenmarkskanal. Messungen bei der Dissektion ergaben eine Durschnitts‐Senkung der vertebralen Arterien und pons von 10 mm. bei Kindern mit thoraco‐lumbarer und 3 mm. bei lumbo‐sacraler Meningomyeloceles. Es gab eine vergleichbare Senkung des Bodens der 4. Gehirnkammer von 30 mm. bei thoraco‐lumbarer Meningomyeloceles und 23 mm. bei lumbo‐sacraler Meningomyeloceles.RESUMENMovimienlos del tronco cerebral y de los vasos alrededor del tronco cerebral en niños que padecen de hidrocefalia o de la defonnidad de Arnold ChiariDespués de la muerte, se hicieron una angiografía y una disección de los vasos grandes y de los tejidos del tronco cerebral en 25 niños que habían padecido de la deformidad de Arnold Chiari. Se vieron un descenso y una curvatura anormales de los troncos basilares, además de un descenso y una curvatura muy considerables de los vasos cerebelosos posteriores, con un descenso del cérebro en el conducto de la medula espinal.Las medidas tomadas durante la disección revelaron un descenso medio de las arterias verticales y del puente de Varolio de 10 mms. en los niños que tenian meningomielocclcs toracico‐lumbares, y de 3 mms. en los niños que tenían meningomieloceles Iumbar‐sacras. Se halló igualmente un descenso de la base del cuarto ventriculo de 30 mms. en los niños que tenian meningomieloceles toracico‐lumbares, y de 23 mms. en los niños que tenían meningomieloceles Iumbar‐sacras.