Biomedical subjects

A Hellström

Publications and source records attributed to A Hellström.

At least 19 recordsLinked to original sources

PubMed2006

Visual function and ocular features in children and adolescents with attention deficit hyperactivity disorder, with and without treatment with stimulants.

AIMS: To investigate visual function and ocular features in children with attention deficit hyperactivity disorder (AD/HD) and establish whether treatment with stimulants is reflected in functioning of the visual system. METHODS: Detailed ophthalmologic evaluations without and with stimulants were performed in 42 children (37 boys) with AD/HD, mean age 12 years, and compared with a reference group (ref; n=50; mean age 11.9 years; 44 boys). For a comparison between two groups, Mann-Whitney's U-test was used for ordered and continuous variables; for dichotomous variables, Fisher's exact test was used. For paired comparison (with and without treatment), sign test was used. RESULTS: In all, 83% had visual acuity of >0.8 (<0.1 logMAR) without treatment, 90% with stimulants (ref 98%; P=0.032 and n.s., respectively). Heterophoria was found in 29% without, and in 27% with, stimulants (ref 10%; P=0.038 and n.s., respectively) and subnormal stereovision (>60 s of arc) in 26% (ref 6%; P=0.016) without stimulants, and in 27%, with (P=0.014). Abnormal convergence (>6 cm or absent) was noted in 24% (ref 6%; P=0.031) without treatment and in 17%, with (n.s.). Astigmatism (> or =1.0 D) was observed in 24% (ref 6%; P=0.03), and signs of visuoperceptual problems in 21% (ref 2%; P=0.007). We found smaller optic discs (n=8/38) and neuroretinal rim areas (n=7/38) (P<0.0001) and decreased tortuosity of retinal arteries (n=6/34) (P=0.0002) than that of controls. CONCLUSIONS: Children with AD/HD had a high frequency of ophthalmologic findings, which were not significantly improved with stimulants. They presented subtle morphological changes of the optic nerve and retinal vasculature, indicating an early disturbance of the development of these structures.

Adolescent↗

PubMed2004

Subnormal visual perception in school-aged ex-preterm patients in a paediatric eye clinic.

PURPOSE: The aim of this study was to assess visual perception at school age of children born preterm with known lesions to the posterior visual pathways or with ophthalmologic signs that might indicate such lesions. METHODS: The study group consisted of 91 patients born before the 37th gestational week. Visual perception was assessed using the TVPS-R (Test of Visual Perceptual Skills - Revised) and a structured interview. In addition, ophthalmologic and orthoptic examinations were performed. RESULTS: On the test of visual perception, 67% of the patients had results below the third percentile of the American reference group. This is to be compared with 10% of Swedish full-term controls. Scores below the third percentile were observed in 87% of the patients with known brain lesions, 48% of those with strabismus without known brain lesion, and 86% of those with reduced visual acuity in the absence of strabismus and known brain lesion. CONCLUSIONS: Reduced visual perception is common among children born preterm who have strabismus and/or reduced visual acuity, as well as in those with known brain lesions. This study emphasises the need to find tools to identify and assess those patients who have visual perceptual problems that may restrict their ability to meet the demands of daily life.

Child↗

PubMed2004

Visual and ocular findings in children adopted from eastern Europe.

AIMS: To evaluate ophthalmological findings in children adopted from eastern Europe. METHODS: A prospective study on 72/99 children, born 1990-5 and adopted from eastern Europe to western Sweden during 1993-7 was performed. The children (41 boys; mean age 7.5 years) were compared with an age and sex matched reference group ("ref") of Swedish children. RESULTS: 78% of the adopted children had abnormal ocular findings. 26% (ref 4%) had visual acuity (VA) of the better eye < or = 0.5 (> or = 0.3 logMAR) (p = 0.0001) and 8% (ref 0%) were visually impaired (p = 0.01). Amblyopia was found in 15% (ref 2%) (p = 0.005). 22% (ref 10%) were hyperopic (> or = 2.0 D SE) (NS) and 10% (ref 1%) were myopic (> or = 0.5 D SE) (p = 0.03). Astigmatism (> or = 0.75 D) was found in 51% (ref 23%) (p = 0.004). 32% (ref 2%) had strabismus (p<0.0001), mostly esotropia. Four cases had bilateral optic nerve hypoplasia, in three of whom a history of suspected prenatal alcohol exposure was documented. One child had congenital glaucoma. Signs of visuoperceptual problems were recorded in 37% (ref 1%) (p<0.0001). CONCLUSION: In this study, children adopted from eastern Europe had a high frequency of ophthalmological findings. Consequently, it is strongly recommended that an ophthalmological examination be performed in these children after arrival in their new home country.

Adoption↗

PubMed2003

Posterior ocular malformations in children: somatic, neuroradiological and cognitive aspects.

AIM: To investigate associated neurological, endocrinological and cognitive dysfunctions in children with visual impairment caused by optic nerve hypoplasia or optic nerve/fundus coloboma and/or microphthalmus. METHODS: Forty children born between 1990 and 1998 were assessed by neurological examination, re-evaluation of neuroradiological investigations, review of medical records and examination of cognitive levels. RESULTS: Neurological dysfunctions (epilepsy and/or motor impairment) were found in 13/28 children with optic nerve hypoplasia and in 3/12 children with coloboma/microphthalmus. The optic pathways were thin in 22/24, an abnormal posterior pituitary gland and/or thin infundibulum was found in 16/22 and absence of septum pellucidum in 14/27 children with optic nerve hypoplasia. Other types of cerebral abnormalities occurred in 9/26 children. Among children with coloboma/microphthalmus, the optic pathways were thin in 4/8 children but none had pituitary or cerebral midline abnormalities. Sixteen children with optic nerve hypoplasia were receiving hormone substitution but none of the children with coloboma/microphthalmus. Thirteen of the 16 children with optic nerve hypoplasia and with an abnormal pituitary region had endocrinological deficiencies. Mental retardation was found in 9/24 of the children with optic nerve hypoplasia and in 5/10 of the children with coloboma/microphthalmus. CONCLUSION: Endocrinological. neurological and neuroradiological defects seem more common in children with optic nerve hypoplasia than in children with coloboma. A pituitary region that appears abnormal in magnetic resonance imaging seems to predict endocrinological deficits in children with optic nerve hypoplasia.

Blindness↗

PubMed2003

Knee-heel length measurements in preterm infants: evaluation of a simple electronically equipped instrument.

AIM: To compare and evaluate a mini-knemometer with a simple and inexpensive electronic caliper with regard to precision, handling error (technical error) and estimation of growth velocity. METHODS: Thirty-five prematurely born infants, with a median gestational age of 29 (range 24-33) wk and a median birthweight of 960 (range 480-2,480) g, were measured on 409 different occasions with both instruments. On each occasion, five independent readings were made. RESULTS: There was no significant difference in precision between the two instruments, when measuring growth velocity over a 4 wk period (median 0.41, range 0.10-0.59 mm d(-1)). The handling error in this study, calculated as the mean standard deviation, was 0.36 (SD 0.18, coefficient of variation 0.38%) mm for the simple electronic caliper and 0.59 mm for the mini-knemometer. Short-term growth was detectable within 2 d when growth velocity was normal. CONCLUSION: Longitudinal measurement of lower leg length is a gentle and useful complementary method for assessing growth in preterm infants. An inexpensive electronic caliper is well suited for routine use in clinical practice, with measurements taken once or twice a week.

Anthropometry↗

PubMed2003

Optic disc morphology may reveal timing of insult in children with periventricular leucomalacia and/or periventricular haemorrhage.

AIMS: To evaluate the relation between optic disc morphology and timing of periventricular white matter damage, defined as either periventricular leucomalacia (PVL) or periventricular haemorrhage (PVH), as estimated by neuroradiology. METHODS: 35 children with periventricular white matter damage who had had neuroradiology performed and ocular fundus photographs taken had their photographs analysed by digital image analysis and compared with a control group of 100 healthy full term children. Timing of brain lesion was estimated by analysis of the brain lesion pattern on neuroradiological examinations (magnetic resonance imaging or computed tomography). RESULTS: Four of 35 children had a small optic disc area; these four children had a brain lesion estimated to have occurred before 28 weeks of gestation. Nine of 11 children with a large cup area had a PVL/PVH estimated to have occurred after 28 weeks of gestation. The children with PVL/PVH had a significantly larger cup area (median 0.75 mm(2)) than the control group (median 0.33 mm(2)) (p = 0.001) and a significantly smaller neuroretinal rim area (median 1.58 mm(2)) than the controls (median 2.07 mm(2)) (p = 0.001). CONCLUSION: In a child with PVL/PVH and abnormal optic disc morphology, the possibilities of timing of the lesion should be considered.

Case-Control Studies↗

PubMed2002

Large variability in performance IQ associated with postnatal morbidity, and reduced verbal IQ among school-aged children born preterm.

AIM: To assess cognitive ability in a population-based group of prematurely born school-aged children and to relate these findings to postnatal morbidity. METHOD: The study group consisted of a cohort of 51 children born preterm, 43 (26 boys, 17 girls) of whom were available for psychological evaluation At evaluation, their median age was 10 y (range 8-11 y). They were all born between 1988 and 1991, with gestational age less than 29 wk (median 27, range 24-28). Their median birthweight was 1060g (range 450-1450). The Wechsler Intelligence Scale for Children (WISC-III) was used, and the test results were compared with those of a standardized, age-matched, normative group of children. RESULTS: Thirteen children (30%) performed below average [intelligence quotient (IQ) < 80] for Full Scale IQ (FSIQ). Thirty-six children had a Verbal IQ (VIQ) below the mean value of 100 [84%, 95% confidence interval 73-95%], p < 0.0001. The Performance IQ (PIQ) was within the expected range of a normal population, although a large variability was observed. Discrepancies between VIQ and PIQ of more than 15 IQ units were found in 42% of the children. High postnatal morbidity (days with assisted ventilation, number of blood transfusions) and low birthweight standard deviation scores (SDS) were associated with lower PIQ than VIQ, while low postnatal morbidity and high birthweight were associated with higher PIQ than VIQ. CONCLUSION: This cohort of preterm children had reduced overall verbal capacity independent of morbidity, and a large variability in performance capacity that was associated with postnatal morbidity. The findings suggest that there are different mechanisms influencing the outcome of verbal and performance capacity in preterm children.

Blood Transfusion↗

PubMed2001

Association between visual impairment and functional and morphological cerebral abnormalities in full-term children.

PURPOSE: To characterise the nature and degree of ocular disorders and cerebral morphological and functional abnormalities in a population-based group of visually impaired full-term pre-school children. METHODS: Forty-five children who were born at full-term between 1989 and 1995 in Värmland, Sweden, were reported as being visually impaired. An ophthalmological examination was performed and clinical data regarding mental development and neurological disease were obtained for all children. Cerebral imaging was performed in 35 children. RESULTS: Twenty-six per cent of the children were found to have ocular disorders only. Forty-two per cent had cerebral morphological abnormalities, verified by cerebral imaging, and 65% had signs of cerebral functional abnormalities. In total, 74% were found to have cerebral morphological and/or cerebral functional abnormalities. CONCLUSION: The majority of children with visual impairment, including children with ocular disorders, were found to have cerebral morphological and/or cerebral functional abnormalities. We suggest that any child with visual impairment should therefore undergo cerebral imaging and be examined by a paediatrician in order to establish the correct diagnosis.

Brain↗

PubMed2001

Association between urinary tract infection, renal damage and birth size.

UNLABELLED: The aim of this study was to investigate whether birth size is associated with permanent renal damage in children with urinary tract infection (UTI). A cohort of 1221 children under 16 y of age was diagnosed with their first symptomatic UTI between 1970 and 1979. Of these, 74 had urographic renal scarring in childhood and 57 were re-examined as adults. The birth files of 48 of these patients (35F, 13M) were available, and birthweight and birthlength in relation to gestational age were analysed and compared with a Swedish reference population. Children who had renal damage without vesicoureteric reflux were significantly smaller at birth (median weight, -0.76 SDS) compared with both children who had renal damage and reflux (median weight, -0.01 SDS) and the reference population. CONCLUSION: The demonstration of low birthweight among children with UTI and renal damage but no reflux suggests that low birthweight may be a risk factor for the development of renal damage.

Adolescent↗

PubMed2000

Visual function in school-aged children born before 29 weeks of gestation: a population-based study.

The aim of this study was to assess visual function, including visual perception, in a geographically-based population of school-aged children, with a median age of 7.2 years (range 5.1 to 9.3 years), born before 29 weeks of gestation to mothers living in Goteborg, Sweden. Fifty-one preterm children participated in the study, six of whom had known brain lesions. Visual acuity, visual fields, stereoacuity, and visual perception were tested. The Test of Visual Perceptual Skills Revised (TVPS-R, Gardner 1996) was used to measure visual perception, and the results were compared with those of 50 term (control) subjects. Six percent of the preterm children were visually impaired, with a visual acuity of less than 0.3 (6/18), while 42% of all the preterm children and 34% of those without known brain lesions had a total score below the 5th centile of the reference material for the test, compared with 14% of the control subjects. In conclusion, visual-perceptual problems seem to be common among very preterm children and should be screened for and assessed before the children start school.

Child↗

PubMed2000

Sensation weighting in comparison and discrimination of heaviness.

Participants lifted pairs of successively presented weights and compared them for heaviness, using the constant method with 2, 3, or 6 judgment categories. The standard weight (St) was 100, 200, or 300 g, either roving or fixed within a block. For each St, there were 5 comparison (Co) weights. The lifting orders were St-Co and, with 6 categories, Co-St. Time-order errors were negatively related to St magnitude, particularly with roving St. In terms of Hellström's sensation-weighting theory, this result was accounted for by a smaller weighting coefficient for the first-presented stimulus than for the second. Time-order errors were negative on average, which was explained as the result of this weighting in conjunction with a low position of the reference level because of light background heaviness. With roving St, the dispersion of the subjective intrapair difference increased with St magnitude, providing evidence for Ekman's law (G. Ekman, 1956, 1959).

Adult↗

PubMed2000

Ocular fundus abnormalities in children born before 29 weeks of gestation: a population-based study.

PURPOSE: Preterm birth has been found to be associated with increased morbidity of the central nervous and vascular tissues. To investigate the influence of preterm birth on the optic disc and retinal vessels, we examined the ocular fundus in school-aged children born very preterm. METHODS: A prospective, population-based study was performed in 50 very preterm children (median age 7 years, range 5-9 years) with a median gestational age at birth of 27 weeks (range 24-28 weeks) and a median birth weight of 1055 g (range 450-1520 g). The ocular fundus was examined by ophthalmoscopy in 50 children, and the optic nerve and retinal vessel morphology was evaluated by digital image analysis of ocular fundus photographs in 45 of these children. RESULTS: The median optic disc area was significantly smaller (p = 0.0002) in the preterm children compared with a reference group. There was no difference in cup area and, consequently, the rim area was significantly smaller (p = 0.0002) in the preterm children. Children with early signs of brain lesions commonly had a rim area below the median of the reference group. Preterm children also commonly had an abnormal retinal vascular pattern that was independent of a previous history of retinopathy of prematurity. CONCLUSION: Very preterm birth was associated with subnormal optic disc and rim areas and an abnormal vascular pattern. The findings clearly demonstrate the effect of preterm birth on the development of these structures. The long term clinical prognosis of these findings has yet to be determined.

Adolescent↗

PubMed2000

Children with septo-optic dysplasia - how to improve and sharpen the diagnosis.

The data in this article are based on investigations performed in 25 children with suspected septo-optic dysplasia (SOD). There are many signs and methods that help in the diagnosis of SOD. In particular, the ocular fundus, abnormalities of the hypothalamo-pituitary axis and other midline brain structures should be described. In order to achieve a more holistic and functional diagnosis, the degree of neurological, neuropsychiatric and psychological involvement should also be stated. It has been suggested that SOD is associated with autosomal recessive inheritance, and it can be speculated that it is the result of genetic and environmental influences early in gestation. An early diagnosis can favourably influence the outcome of the affected child.

Blindness↗

PubMed2000

Discrimination of tone durations across the menstrual cycle.

Discrimination of tone duration was studied as a function of menstrual cycle phase. In three phases of their menstrual cycle, 12 women compared the durations of 64 pairs of tones. They discriminated the tone durations least well in the premenstrual phase and tended to speed up their responding over sessions. In contrast, a control group of 12 men tended to improve their performance over sessions while response time remained constant.

Acoustic Stimulation↗

PubMed1999

Optic nerve hypoplasia with isolated tortuosity of the retinal veins: a marker of endocrinopathy.

OBJECTIVE: To investigate whether children with optic nerve hypoplasia and pituitary hormone insufficiencies have specific ocular fundus characteristics that may facilitate early diagnosis and treatment. DESIGN: From May 15, 1995, through December 15, 1997, 17 children (8 girls and 9 boys, aged 0.3 to 13 years) with optic nerve hypoplasia were referred to the Department of Pediatric Ophthalmology, Children's Hospital, Göteborg, Sweden, and divided into 2 groups dependent on the presence (n = 8) or absence (n = 9) of pituitary deficiency. Morphological characteristics of the ocular fundus were evaluated by digital image analysis of fundus photographs, and the morphological characteristics of the brain structures were studied by magnetic resonance imaging. RESULTS: An isolated venous tortuosity noted among the children with optic nerve hypoplasia and endocrinopathy was the morphological ocular fundus variable that discriminated between the 2 groups of patients with optic nerve hypoplasia. Both groups of children demonstrated significantly reduced optic disc, cup, and neuroretinal rim area and few vascular branching points. CONCLUSION: Optic nerve hypoplasia with isolated tortuosity of the retinal veins may potentially help the ophthalmologist in identifying children who should undergo a thorough diagnostic workup of endocrine function.

Adolescent↗

PubMed1999

Optic nerve morphology may reveal adverse events during prenatal and perinatal life--digital image analysis.

OBJECTIVE: To evaluate optic nerve morphology in children with various conditions caused by adverse events during prenatal and/or perinatal life and to investigate whether optic nerve morphology can reveal brain lesions associated with these conditions, as well as provide insight into the etiology and timing of the prenatal and perinatal damage. METHODS AND PATIENTS: A digital image analysis technique was used to analyze fundus photographs. One hundred healthy Swedish individuals of various ages from childhood to adolescence constituted a reference group. The following patient groups were chosen to represent various clinical conditions affecting the newborn or fetus at different stages of development: children born preterm (N = 39), children with fetal alcohol syndrome (FAS [N = 16]), children with periventricular leukomalacia (PVL [N = 17]), and children with septo-optic dysplasia (SOD [N = 6]). RESULTS: Preterm children without known brain lesions demonstrated normal optic disk morphology but abnormal retinal vascular pattern; children born preterm with an acquired brain lesion late in gestation (PVL) demonstrated normal disk size with enlarged cups in addition to the abnormal vascular pattern. Children with prenatal alcohol exposure (FAS) had a subnormal optic disk area with increased tortuosity of both arteries and veins, whereas children born at term with an early acquired brain lesion (SOD) had a markedly reduced optic disk area with isolated tortuosity of the retinal veins. CONCLUSIONS: Evaluation of optic nerve morphology, by digital image analysis, demonstrated that differences in ocular fundus morphology were correlated with differences in etiology and timing of the adverse event occurring in prenatal and perinatal life. In addition, digital image analysis may be a helpful tool for understanding variations in optic nerve and retinal vessel morphology and their relationship with central nervous pathology.

Adolescent↗

PubMed1999

The clinical and morphologic spectrum of optic nerve hypoplasia.

PURPOSE: The purpose of this study was to characterize the clinical and morphologic spectrum of all children referred for optic nerve hypoplasia to a tertiary referral hospital in Sweden during a 9-year period. SUBJECTS AND METHODS: A retrospective review was undertaken of the charts of 117 children (age range, 0.25-16 years), treated at the Children's Hospital, Göteberg between 1988 and 1996, after the diagnosis of optic nerve hypoplasia. Ocular fundus morphologic condition was evaluated by digital image analysis of fundus photographs in 50 children, and neuroimaging was performed in 57 children. RESULTS: Of the 117 children with optic nerve hypoplasia, 66 (56%) were boys and 51 (44%) were girls. Preterm birth occurred in 24 (20%), and 14 (12%) were born small for gestational age. Additional diagnoses, such as fetal alcohol syndrome, septo-optic dysplasia, perinatal adverse events, and neuropsychiatric disorders, were made in 88%; 7% had unilateral optic nerve hypoplasia. Most of the children had small optic disc, cup, and neuroretinal rim areas, as well as retinal vascular abnormalities; 75% were visually impaired, and a high incidence of nystagmus and strabismus was found among these children. CONCLUSION: This study indicates that optic nerve hypoplasia has a wide clinical and morphologic spectrum and is associated with a broad range of disorders of the central nervous system. It is suggested that differences in the etiology and timing of the lesion as well as associated lesions may explain this spectrum of optic nerve hypoplasia in children.

Adolescent↗

PubMed1999

Diagnostic value of magnetic resonance imaging and planimetric measurement of optic disc size in confirming optic nerve hypoplasia.

PURPOSE: This study set out to evaluate magnetic resonance imaging (MRI) and measurement of optic disc size as diagnostic tools for confirming the diagnosis of optic nerve hypoplasia (ONH) in children with impaired growth. METHODS: MRI was performed to study the size of the intracranial visual pathways, and image analysis measurements of fundus photographs were performed to determine the size of the optic disc. Results from these investigations were compared with those using the gold standard for diagnosis of ONH, which was the clinical eye examination (visual function, ophthalmoscopic signs, or both). Forty children (median age, 9 years; range, 3 to 19 years) with impaired growth were included in the study. RESULTS: The prevalence of ONH among the children was 15%. MRI classification of the visual pathways had a higher positive predictive value than image analysis measurement of the optic disc size (1.0 vs 0.6). CONCLUSIONS: MRI is a good tool for confirming the diagnosis of ONH and may thus facilitate early detection. On the other hand, a small optic disc per se is not a definite indicator of ONH but should encourage further investigation with MRI, especially if there is a clinical suspicion of ONH.

Adolescent↗