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Biomedical subjects

R E Nordgren

Publications and source records attributed to R E Nordgren.

At least 19 recordsLinked to original sources

Timing of prenatal stressors and autism.

Recent evidence supports a role for genetics in autism, but other findings are difficult to reconcile with a purely genetic cause. Pathological changes in the cerebellum in autism are thought to correspond to an event before 30-32 weeks gestation. Our purpose was to determine whether there is an increased incidence of stressors in autism before this time period. Surveys regarding incidence and timing of prenatal stressors were distributed to specialized schools and clinics for autism and Down syndrome, and to mothers of children without neurodevelopmental diagnoses in walk-in clinics. Incidence of stressors during each 4-week block of pregnancy was recorded. Incidence of stressors in the blocks prior to and including the predicted time period (21-32 weeks gestation) in each group of surveys was compared to the other prenatal blocks. A higher incidence of prenatal stressors was found in autism at 21-32 weeks gestation, with a peak at 25-28 weeks. This does support the possibility of prenatal stressors as a potential contributor to autism, with the timing of stressors consistent with the embryological age suggested by neuroanatomical findings seen in the cerebellum in autism. Future prospective studies would be needed to confirm this finding.

Autistic Disorder↗

Brief report: macrographia in high-functioning adults with autism spectrum disorder.

The initial description of Asperger syndrome commented on the poor handwriting and motor coordination difficulties of individuals with this condition. Early descriptions of autism do not remark upon such difficulties. Recent evidence, however, suggests that individuals with both conditions have a similar motor control impairment. Handwriting has not been formally assessed in this context. Our study compared handwriting size between individuals with autism spectrum disorder and age- and IQ-matched control subjects. Macrographia was observed among subjects with autism spectrum disorder which remained statistically significant when covaried with educational level. This finding may correlate with the anatomical abnormalities present in the cerebellum of individuals with autism spectrum disorder.

Adolescent↗

The caudal infrasylvian surface in dyslexia: novel magnetic resonance imaging-based findings.

OBJECTIVE: To detect anatomic abnormalities of auditory association cortex in dyslexia by measuring the area of the perisylvian region known as the caudal infrasylvian surface(s) (cIS) in dyslexic and control subjects. BACKGROUND: Several quantitative morphometric investigations of cortical areas in dyslexia have focused on the cIS, which encompasses the supratemporal plane and the inferior bank of the posterior ascending ramus of the sylvian fissure. Inconsistencies in the results of these studies may be attributable in part to the use of measurement methods that do not account fully for surface undulations of the cIS. METHODS: The authors used an MRI-based surface reconstruction technique that models the curvature of the cerebral cortex in three dimensions to obtain whole-hemisphere and regional surface area estimates. Measurements were obtained in both hemispheres of eight right-handed male dyslexic subjects and eight right-handed male control subjects. RESULTS: The cIS area of dyslexic subjects was significantly larger than that of control subjects, and this result was not attributable to a difference in whole-hemisphere surface area. Neither the dyslexic nor control subjects showed a left or right asymmetry in this region, although there was a trend toward less variance of the asymmetry scores in dyslexic subjects. CONCLUSIONS: The gross anatomic organization of this region is different in dyslexic subjects, and elucidation of the precise nature of these differences may be aided by surface modeling techniques.

Adult↗

Long-term seizure outcome following corpus callosotomy in children.

INTRODUCTION: The long-term outcome of pediatric patients undergoing corpus callosotomy (CC) for palliative control of medically intractable seizures is presented. METHODS: During a 27-year period, 43 patients, 20 years of age or younger, underwent CC for seizure palliation and had a minimum of 1 year follow-up. Seizure reduction and stability of that outcome for individual seizure types and for most disabling seizure were reviewed. RESULTS: Overall, 63% of the seizures documented showed a good response. For the most disabling seizure, 56% of the patients had good outcomes. Changes in outcome status occurred within the first 6 months, and outcome was largely maintained after that point. CONCLUSION: Callosotomy achieves the goal of seizure palliation in more than half of the patients, with stable, good outcomes being maintained in the majority of patients.

Adolescent↗

The effect of semantic and emotional context on written recall for verbal language in high functioning adults with autism spectrum disorder.

OBJECTIVE: Several deficits have been proposed to account for cognitive impairment in autism including an inability to comprehend the perspectives of others ("theory of mind"), an inability to process emotional information, and difficulty drawing together diverse information in context ("central coherence"). Because context (central coherence) and emotion can influence memory, a study was designed to show if autism spectrum disorder was associated with impaired utilisation of context and emotion in recall; and if impairments in theory of mind processing would influence recall in autism spectrum disorder. METHODS: Ten high functioning subjects with autism spectrum disorder and 13 age and IQ matched controls were tested using recall tests. In the first coherence memory test, subjects listened to a series of word lists that were in varying degrees of syntactic and semantic (coherent) order and were asked to recall the words. In the second coherence memory test, subjects listened to stories consisting of sentences that were, or were not, in logical (coherent) order. In the emotional memory test, the subjects listened to sentences that were highly emotional or non-emotional. In the theory of mind test, the subjects listened to stories requiring varying levels of understanding of the perspectives of others. RESULTS: There were no significant differences between groups in recall of coherent versus incoherent word lists, nor was there a significant difference between groups in recall of coherent versus incoherent stories. However, the control subjects recalled more of the emotional than non-emotional sentences, whereas the autism spectrum disorder group did not show such a difference. No significant difference existed in recall of stories requiring varying levels of understanding of the perspectives of others among subjects with autism spectrum disorder, and subjects with autism spectrum disorder did not differ from control subjects in the influence of theory of mind content on story recall. CONCLUSION: The study shows that memory in high functioning adults with autism spectrum disorder is facilitated by emotional content to a lesser degree than it is facilitated by coherence. Therefore, impairments in emotional processing cannot be considered as simply an effect of the "weak central coherence" theory in autism spectrum disorder. Whereas the reasons for this emotional deficit are unknown, evidence of abnormalities of the limbic structures in autism spectrum disorder may provide an anatomical explanation.

Adult↗

Turner's syndrome.

Explore the source record for details and available documents.

Airway Obstruction↗

Arthrogryposis due to infantile neuronal degeneration associated with deletion of the SMNT gene.

To determine whether SMNT deletion may be associated with arthrogryposis, we tested DNA extracted from paraffin blocks for deletion of SMNT (exons 7 and 8). Analysis of the DNA showed an SMNT deletion in two of four infants with neurogenic arthrogryposis. In addition to loss of anterior horn cells, patients with SMNT deletion had degeneration of central sensory neurons in Clarke's column and the thalamus. Although one of the patients with no deletion also had cortical pathology, clinical and pathologic characteristics of the two patients without deletion were otherwise similar to the two patients with deletion. Arthrogryposis and degeneration of sensory neurons may be associated with deletion of SMNT.

Anterior Horn Cells↗

Glutaric aciduria: improved MR appearance after aggressive therapy.

Advances in understanding the metabolic abnormalities which cause glutaric aciduria allow biochemical diagnosis on the basis of deficient enzyme and the potential for therapy. Brain abnormalities associated with this inborn error of metabolism have been demonstrated with CT and MR. The findings typically described are atrophy of the fronto-temporal regions with large insular cisterns and diffuse white matter hypodensities. We present a patient with glutaric aciduria, confirmed by enzymatic assay, who had these findings on CT and MR examination. Repeat imaging demonstrated significant improvement after dietary therapy and aggressive prevention of catabolism during febrile illness.

Amino Acid Metabolism, Inborn Errors↗

Vertical gaze paralysis and intermittent unresponsiveness in a patient with a thalamomesencephalic stroke.

A patient with paralysis of upward gaze and downward gaze, absent oculocephalic reflexes, and absent vertical saccades also demonstrated intermittent stupor over the first 9 days of presentation. Magnetic resonance imaging (MRI) demonstrated an infarct in the tegmentum of the mesencephalon including the right red nucleus and the periaqueductal area, superior to the oculomotor nucleus, and contiguous through the left thalamus. The infarct included the area around the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), as well as the midbrain reticular formation. Mechanisms are proposed for the unusual concurrent sign of intermittent unresponsiveness in this case.

Aged↗

The persistent vegetative state in children: report of the Child Neurology Society Ethics Committee.

Increasing concern about children in a persistent vegetative state (PVS) prompted a survey of members of the Child Neurology Society regarding aspects of the diagnosis and management of this disorder. Major findings of those responding to this survey (26% response rate) were as follows: (1) 93% believed that a diagnosis of PVS can be made in children, but only 16% believed that this applied to infants younger than 2 months and 70% in the 2-month to 2-year group; (2) a period of 3 to 6 months was believed to be the minimum observation period required before a diagnosis of PVS could be made; (3) 86% believed that the age of the patient would affect the duration of time needed to make the diagnosis of PVS; (4) 78% thought a diagnosis of PVS could be made in children with severe congenital brain malformations; (5) 75% believed that neurodiagnostic studies would be of value and supportive of the clinical diagnosis of PVS; (6) members' opinions as to the average life expectancy (in years) for the following age groups after the patients were considered vegetative were: newborn to 2 months, 4.1; 2 months to 2 years, 5.5; 2 to 7 years, 7.3; and more than 7 years, 7.4; (7) 20% believed that infants and children in a PVS experience pain and suffering; and (8) 75% "never" withhold fluid and nutrition from infants and children in a PVS and 28% "always" give medication for pain and suffering.(ABSTRACT TRUNCATED AT 250 WORDS)

Advisory Committees↗

Corpus callosotomy for intractable seizures in the pediatric age group.

The results of corpus callosotomy in 18 patients 16 years old and younger are presented. Eighty-three percent of our patients have had a significant improvement from the surgery (a decrease in seizure frequency of greater than 80% or no longer having generalized atonic, tonic, or tonic-clonic seizures). The procedure seems to be well tolerated in young patients, and we have not noted a postoperative deterioration in behavior, memory, or language function in our patients. One of our patients died in status epilepticus 3 months after surgery. Nevertheless, we have not encountered any serious morbidity in our other patients. Corpus callosotomy can be considered for children with intractable seizures, especially when generalized atonic, tonic, or tonic-clonic (whether primary or secondary) seizures are the major seizure type.

Adolescent↗

Neuroleptic malignant syndrome: occurrence in a child after reconstructive surgery.

The occurrence of the rare but potentially fatal neuroleptic malignant syndrome must be considered by the surgeon treating a patient who develops hyperthermia, mental abnormalities, autonomic instability, and muscle rigidity after exposure to phenothiazines or other neuroleptic drugs. The dopamine agonist bromocriptine appears to be the treatment of choice in adults and seemed to be effective and well tolerated in our patient. Although the syndrome cannot be prevented, recognition is crucial, since effective general and specific therapy is available. Differentiating neuroleptic malignant syndrome from malignant hyperthermia allows early appropriate treatment with bromocriptine.

Child↗

Spinal cord tethering after traumatic paraplegia with late neurological deterioration.

The case of a 49-year-old man with traumatic complete T-5 paraplegia of 30 years' duration is presented. Over the last 10 years, he developed cervical myelopathy suggestive of syringomyelia. Work-up, including metrizamide myelography and delayed computerized tomography scanning, revealed an atrophic cord without a syrinx, and a complete block to contrast material at T-5. At operation, the cord was found to be tethered at the original injury site, and was released by transection. This resulted in immediate improvement in the somatosensory evoked potentials and marked postoperative clinical improvement. It is postulated that cord tethering can cause delayed myelopathy in patients with traumatic cord injury. Release of the tethered cord should be considered if a posttraumatic syrinx is not found.

Adult↗

Transient global amnesia associated with bradycardia and temporal lobe spikes.

This paper presents electroencephalographic evidence of bilateral independent temporal lobe spiking during an episode of transient global amnesia. The amnesia occurred during a period of hypotension secondary to sinus bradycardia. The amnesia recurred in absence of bradycardia and hypotension. The temporal lobe spiking leads credence to the thought that transient global amnesia occurs as the result of seizure activity.

Aged↗

Dandy-Walker malformation in identical twins.

The mother of a stillborn anencephalic child subsequently had twins with macrocephaly due to a cystic malformation of posterior brain structures, compatible with the Dandy-Walker syndrome.

Dandy-Walker Syndrome↗