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Biomedical subjects

B Kendall

Publications and source records attributed to B Kendall.

At least 19 recordsLinked to original sources

Cognitive functioning and magnetic resonance imaging in chronic fatigue.

BACKGROUND: This study examines whether cognitive dysfunction in chronic fatigue may be accounted for by depression and anxiety or is due to brain pathology evident on magnetic resonance imaging (MRI). METHOD: Twenty-six subjects with chronic fatigue, with and without coexisting depression, and 18 age-matched normal controls were recruited from primary care following a presumed viral illness six months previously. Comparison was made with 13 psychiatric controls with depressive illness on standardised cognitive tests. MRI determined the presence of cerebral white-matter lesions. RESULTS: No substantial differences in performance were shown between subjects with chronic fatigue, most of whom met the criteria for chronic fatigue syndrome, and controls. Subjective cognitive dysfunction increased with psychopathology. White-matter lesions were found in a minority from all groups. Improvement in fatigue and depression coincided with improved performance on cognitive measures. CONCLUSIONS: Subjective complaints of cognitive impairment are a prominent feature of chronic fatigue, but objective cognitive and MRI abnormalities are not. Such complaints probably reflect psychopathology rather than a post-viral process.

Adolescent

Magnetic resonance imaging in the assessment of craniosynostosis.

Modern interest in craniosynostosis began when clinicians, regardless of their individual specialty but united in their interest in the problems raised by patients with this condition, first realised that if treatment was confined simply to opening up the fused sutures of the skull vault, success in terms of both function and the restoration of a more normal appearance was likely to be limited. Indeed, the grouping together of such specialists into formal craniofacial units was tacit recognition of this, as was the acceptance that many affected children had evidence of clinical problems that could not be explained on simple mechanical grounds alone. It is not surprising, therefore, that the advent of any new method of investigation has been welcomed by craniofacial surgeons eager to learn anything that might lead to an improvement in management, particularly of the more complex syndromes.

Brain

CT and MR imaging in lateral sinus thrombosis.

Establishing a pre-operative diagnosis of lateral sinus thrombosis can be difficult, as the clinical features are non-specific and laboratory tests unhelpful. CT may demonstrate abnormal high density of the lumen of the sinus, which does not enhance after intravenous contrast medium. Enhancement of the dura surrounding the sinus may be prominent, causing the 'empty triangle' or 'delta sign' which may suggest the diagnosis. Magnetic resonance (MR) imaging may show both lack of flow and abnormal signal from the sinus, thus providing definitive evidence of thrombosis.

Adolescent

Pelizaeus-Merzbacher disease: classical or connatal?

The clinical features and investigation results of 7 patients with Pelizaeus-Merzbacher disease (PMD) are described; one patient had a brain biopsy and two patients had an autopsy. This paper tries to differentiate the clinical features of the connatal and classical types of PMD. Transient stridor and nystagmus were early signs in both types of PMD. Our findings support the view that the more severe connatal form shows rapid neurological deterioration from an early age leading to death usually in the first decade. In younger patients in whom the evolution is still unclear, severe feeding problems and extrapyramidal features may suggest the connatal form. By contrast, in the classical form of PMD, cerebellar signs and cognitive deterioration are more prominent with a more slowly progressive course. Nuclear magnetic resonance imaging and brainstem auditory evoked potentials were very helpful in supporting the diagnosis of PMD either in a known affected family or in sporadic cases, but were not useful in distinguishing between the two types of PMD. Genetic counseling in this condition is difficult, particularly in the connatal form in which inheritance may be either X-linked or autosomal recessive.

Age Factors

The clinical significance of seizures in critically ill young infants requiring intensive care.

The aetiology, severity of systemic and biochemical abnormalities, seizure duration, EEGs and CT scans have been reviewed in previously normal young infants with an acute critical illness occurring after the first week of life; none of whom had birth asphyxia. Findings were related to outcome in an attempt to evaluate the significance of seizures during the acute phase of severe illness. In three years seizures occurred in 54/251 (22%) young infants requiring ventilatory support. In these patients the acute illness was most commonly infection and encephalitis/encephalopathy. Twenty-one died, 24 had good or moderate outcome and 9 poor outcome (follow-up 6-27 months). The outcome was not directly related to diagnosis, but to systemic and biochemical changes, the most important being severe hypotension (40/54). After correction of these factors, in survivors, increasing number of days over which seizures occurred during the acute phase of illness was related to worsening outcome (tau(c) = 0.66, p less than 0.0001). In many of these patients one of three abnormal low density changes (generalized, boundary zone and focal) were seen on CT scan and were not uncommonly associated with focal/multifocal clonic seizures and characteristic type, distribution and evolution of EEG discharge. In the 45 patients with EEGs from presentation, severity of encephalopathy assessed by predominant background EEG activity was most closely related to outcome, irrespective of aetiology and seizures. There was a significant relationship between graded severity of background EEG activities and outcome both in the initial and serial recordings (tauB = 0.70, p less than 0.0001 and 0.75, p less than 0.0001 respectively). Seizures are a common occurrence in the previously well young infant with an acute critical illness necessitating intensive care. Prompt recognition and treatment may influence outcome in patients with a potentially reversible encephalopathy. However, in many patients seizures reflect severe, often multifactorial cerebral insult with variable morphological changes, EEG patterns and clinical outcome.

Anticonvulsants

Intracranial neurenteric cysts. Report of two cases.

Two cases of intracranial neurenteric cysts are reported and the literature is reviewed. Neurenteric cysts are rare congenital lesions that tend to occur in the spinal intradural space. An intracranial location is exceptional.

Adult

Neurological deterioration in young adults with phenylketonuria.

7 patients with phenylketonuria who developed neurological disability in adolescence or early adult life are described. 4 had been diagnosed by routine neonatal screening and started a low phenylalanine diet in infancy. 3 were diagnosed in early childhood because of developmental delay, and then started dietary treatment. Dietary control deteriorated in later years and was withdrawn in mid to late childhood. The late neurological deterioration cannot be directly ascribed to poor compliance with or cessation of dietary treatment in this small, retrospective study--but other likely causes have been excluded and 2 patients showed a striking clinical improvement when a strict diet was resumed. Serial magnetic resonance images from one of these patients show abnormalities that appeared after cessation of dietary treatment and resolved after diet was resumed. If these findings are confirmed, strict dietary control into adult life would be indicated for at least some patients with phenylketonuria.

Adult

Convergence nystagmus associated with Arnold-Chiari malformation.

A case of convergence nystagmus associated with an Arnold-Chiari type I malformation is presented. The nystagmus appeared in the absence of fixation, was provoked during Valsalva's maneuver and neck flexion and extension, and attenuated on deep inspiration. Sagittal magnetic resonance images showed that the diameter of the cerebral aqueduct increased with the neck in full flexion and in full extension. Surgical foramen magnum decompression considerably reduced the nystagmus and abolished the postural variation of aqueduct diameter. It is postulated that this nystagmus was due to a combination of mechanical distortion and abnormal transmission of cerebrospinal fluid pressure to the aqueductal region.

Adolescent

Hemifacial spasm in infancy.

Three infants presented with the onset of hemifacial spasm after birth and at the age of 10 months. One patient was found to have occlusion of the straight sinus and large collateral veins at the base of the brain, presumably due to venous sinus thrombosis, supporting the concept of vascular compression of the facial nerve at its exit from the brain stem as a mechanism for the production of hemifacial spasm. The other patients each had an intrinsic mass compressing the fourth ventricle, located in the lower pons and extending into the cerebellar vermis and right cerebellar peduncle in one; in the other patient, the mass involved the cerebellar vermis and right middle cerebellar peduncle alone. These patients widen the etiologic spectrum of the syndrome and show that serious intracranial diseases may underlie hemifacial spasm in infancy.

Brain Neoplasms

Joubert syndrome: a clinico-radiological study.

A characteristic malformation of the cerebellum, including dysgenesis of the vermis and enlargement of the fourth ventricle was observed on computed tomography (CT) in 16 children on review of our consecutive material. Seven of these children underwent magnetic resonance imaging (MRI) which showed hypoplasia of the brainstem in addition to cerebellar vermian dysgenesis. One child had, in addition, dysgenesis of the corpus callosum. All these children were developmentally delayed, and many had neonatal breathing abnormalities, congenital retinal dystrophy and supranuclear ocular motor abnormalities. Joubert's syndrome should be suspected in children in whom dysgenesis of the cerebellar vermis and hypoplasia of the brainstem is shown on CT or MRI.

Brain Stem

Computed tomography in the assessment of raised intracranial pressure in non-traumatic coma.

Cranial computed tomography (CT) scans and invasive intracranial pressure (ICP) measurements were reviewed for 34 children with non-traumatic coma from various causes. CT scan features including focal or generalised changes in density were noted and changes in cerebrospinal fluid (CSF) spaces were graded and correlated with the level of maximum ICP in the first 12 hours of treatment and monitoring. Seven patients had normal findings and 27 had abnormal scans. Nineteen of the 27 patients with abnormal scans had generalised abnormalities with varying degrees of loss of CSF space. Seventeen of these 19 patients had pressures greater than 15 mmHg. The highest pressures being found in those with the greatest degree of CSF space obliteration. In the remaining 8 patients, who had focal abnormalities either within the basal ganglia or cerebral hemisphere, there was no relationship between local CSF space obliteration and the level of ICP. In the 7 patients with normal scans three had ICPs of 20 mmHg or greater in the first 12 hours of monitoring and a further two also developed an ICP of this level 13-36 hours after the initiation of monitoring. In non-traumatic coma of various causes there is an association between loss of CSF space and increased ICP. However, there were two important exceptions to this; firstly in patients with focal abnormalities either within the basal ganglia or cerebral hemisphere, in whom the loss of adjacent CSF spaces was not a good indicator of generalised raised ICP; secondly some patients with normal scans, in whom this finding did not indicate normal ICP nor ensure that it remained at this level.

Adolescent

Ataxia, developmental delay and an extensive neuronal migration abnormality in 2 siblings.

Two siblings with developmental delay and a non-progressive cerebellar ataxia are described. The electroencephalograms in both children showed a rather unusual pattern of high amplitude 10-12/s rhythms maximal anteriorly, while extensive neuronal migration abnormalities were apparent on Magnetic Resonance scans. There were no dysmorphic features, metabolic abnormalities, chromosomal defects or evidence of prenatal environmental toxins. It is considered that these siblings have an autosomal recessive neuronal migration defect which has not previously been reported.

Brain

Neurotoxicity in lymphoblastic leukaemia: comparison of oral and intramuscular methotrexate and two doses of radiation.

Serial cranial computed tomograms were carried out in 136 children with acute lymphoblastic leukaemia who were receiving 24 Gy or 18 Gy of cranial irradiation and continuing treatment with doses of methotrexate given weekly orally or intramuscularly. The findings were correlated with treatment variables, the development of fits, and the intelligence quotient (IQ). Reversible brain shrinkage, attributed to treatment with steroids, was found on 87 of 114 initial scans (76%); 14 showed changes in white matter during treatment (10%), and calcification was found in 13 either during or after treatment (10%). Eight children (6%) had fits, and in six of the eight there were changes in white matter or calcification on the scans. Comparison of the two radiotherapy dosages showed no difference in the incidence of abnormalities seen on computed tomography, fits, or serial IQ measurements, but children receiving intramuscular methotrexate had a higher incidence of calcification and a lower mean IQ at one year than those who received the drug orally, although this difference was not apparent later. Younger children were more likely to develop changes on computed tomograms and fits, and to have low IQs on completion of treatment, with changes most apparent in those less than 2 years of age. There were highly significant correlations between abnormalities on computed tomography, fits, and IQ. These findings confirm the neurological vulnerability of younger children with acute lymphoblastic leukaemia, show an association between abnormalities on computed tomography and intellectual deficit, and suggest that methotrexate is more toxic when given intramuscularly than orally. They provide no evidence that 18 Gy of cranial irradiation is less toxic than 24 Gy, and indicate the need for alternative treatment regimens.

Administration, Oral

Value of CT and NMR imaging in diagnosing of chordomas.

Chordomas usually occur in the axial skeleton and they arise from the remnants of notochord. Their growth is slow and they often give metastases. Such cases are mainly observed among people above 40 years of age. Most frequently chordomas are situated in sacral bone (50%), in spheno-occipital region of the skull base (35%), and in the cervical, dorsal and lumbar spine (15%). Very rarely chordomas are found within sella, paranasal sinuses and nasopharynx, and in the forms of ectopic foci in the pons and spinal canal. Such tumour situated within spine destroys vertebral bodies and arches and can bulge into subdural space causing impression of the dural sac. Despite osteolytic destruction, chordomas cause visible reactive sclerotization and characteristic granular calcifications or ossifications. Intracranial chordomas destroy bony base of skull, specially clivus, pyramids and sphenoid sinuses.

Adolescent