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Biomedical subjects

H E Persson

Publications and source records attributed to H E Persson.

At least 19 recordsLinked to original sources
PubMed2006

The nervous system in early HIV infection: a prospective study through 7 years.

In this study 28 patients with early stage HIV infection (CD4 >280 x 10(6)/l) were subjected to yearly examinations of the nervous system up to 7 years in order to detect any deterioration. Clinical neurological as well as neuropsychological performance was evaluated. The patients also underwent yearly neurophysiological tests (digital EEG, visual evoked potentials, somatosensory evoked potentials, auditory evoked potentials P300 and electroneurography). Every other year, SPECT with (99m)Tc-D,L-hexamethylpropylene amine oxime and brain MRI were performed. Originally, 38 patients were included in the study but only the results of 28 patients who complied with three of more yearly check-ups are presented. The results of yearly investigations of cerebrospinal fluid (CSF) have been presented earlier [Eur J Neurol4 (1997) 1]. All the patients showed signs of HIV in the CSF. Yet, no major deterioration in the neurological, psychological performance, neurophysiological or neuroimaging examinations could be discerned.

Adult↗
PubMed2003

"Maturational lag" hypothesis of attention deficit hyperactivity disorder: an update.

UNLABELLED: This article discusses the relationship of maturation to ADHD and hyperkinetic disorder (HKD), with an emphasis on current research in ADHD and HKD, persistence and remission of ADHD symptoms over time and brain maturational trajectories. CONCLUSION: ADHD is a broad, heterogeneous syndrome and only a subgroup of subjects has a diagnosis of HKD, which is a subset of individuals with severe ADHD combined subtype. Children showing symptoms above the threshold for a diagnosis of ADHD are at risk of developing comorbid conditions and increasing stress in both parents and teachers. In some subjects, ADHD symptoms can improve over time during maturation and development. These children with a diagnosis of ADHD could be viewed as showing variants of normal childhood behaviour with maturational trajectories that are lagging behind but will catch up. ADHD could therefore represent a continuum from normality at one extreme to a severe disorder, HKD according to ICD-10, at the other extreme.

Adolescent↗
PubMed1998

Poisoning severity score. Grading of acute poisoning.

BACKGROUND: A standardized and generally applicable scheme for grading the severity of poisoning allows a qualitative evaluation of morbidity and facilitates comparability of data. Working from a simple grading scale proposed by the European Association of Poisons Centres and Clinical Toxicologists, a Poisoning Severity Score has been developed jointly with the International Programme on Chemical Safety and the European Commission. METHODS: The Poisoning Severity Score has been elaborated, tested, and gradually revised during a project running 1991-1994. Fourteen poisons centers from various countries have participated. Each center independently graded 371 cases of acute poisoning by ten different toxic agents. The data were then analyzed and compared. RESULTS: The concordance in grading the severity increased during the study period, and in the last phase there was an acceptable concordance among centers in 80% or more of the cases. Given the condition and quality of the original case records, this result was considered satisfactory and agreement was reached on the scoring scheme presented here. The Poisoning Severity Score grades severity as (0) none, (1) minor, (2) moderate, (3) severe, and (4) fatal poisoning. It is intended to be an overall evaluation of the case, taking into account the most severe clinical features. Use of the Poisoning Severity Score normally requires a follow-up of all cases, but may be used on admission or other times during the course of poisoning if this is clearly stated when data are presented. CONCLUSIONS: A Poisoning Severity Score has been developed and found applicable for grading the severity of poisoning. It is foreseen that the Poisoning Severity Score will meet the expectations and be used in practice, but its future use and evaluation may result in some further revision and refinement.

Acute Disease↗
PubMed1996

Topography of auditory evoked cortical potentials in children with severe language impairment: the N1 component.

Topographic maps of late auditory evoked potentials (AEPs) were obtained in a group of 20 children, aged 9-15 years, with severe language impairment (LI) and an age-matched control (C) group of 20 normal children. The study was focused on differences in the latency, amplitude and topography of the N1 component between the two groups and the potential diagnostic value of these variables. The stimulus was a pure tone at 500 Hz with a duration of 100 msec and a rise and fall time of 20 msec. The intensity was 75 dB HL. Six test sequences of 50 stimuli at an interval of 1.0 sec were presented to the left and right ear separately. The AEPs were recorded and analyzed with the Bio-Logic Brain Atlas III program. In the topographic maps a focus corresponding to N1 (FN1) was seen in 15 subjects after left-ear stimulation and in 17 subjects after right-ear stimulation in the LI group. In the C group FN1 was identified in all 20 subjects after left-ear stimulation and in 19 subjects after right-ear stimulation. The position of FN1 was in front of the interaural line and with a dominance on the side contralateral to the ear stimulated in both groups. Among the subjects with an FN1, 6 in the LI group and 4 in the C group had deviating topography. Non-focal maps were seen in 5 LI subjects and 1 C subject. The latencies of N1 were longer in the LI group and there was no decrease in latency with age. There were no differences in FN1 amplitudes between groups. The prolonged latencies in the LI subjects compared to the C subjects may be explained by a slower processing in central auditory pathways and the lack of decrease in latencies with age in the LI subjects might indicate that the disturbance persists and is not a pure delay of maturation. The diagnostic sensitivity of N1 latency, amplitude and topography, in selecting the LI subjects, was 40% with a specificity of 90%. Statistical mapping of a time epoch of 70-140 msec and corresponding to FN1 in the map showed regions of > or = 3 S.D. in 10 LI and 2 C subjects, which corresponds to a sensitivity of 50% and a specificity of 90%. The variability of results within the LI group may reflect different pathophysiological factors underlying the language impairment. In conclusion, topographic evaluation of auditory long-latency potentials may become a diagnostic tool in speech and language disorders.

Adolescent↗
PubMed1996

Sleep deprivation worsens obstructive sleep apnea. Comparison between diurnal and nocturnal polysomnography.

Daytime polysomnography (DPG) has been suggested for diagnosis of obstructive sleep apnea syndrome (OSAS), because it is less expensive than whole-night polysomnography investigation (NPG). To ensure sleep during day recordings, patients are often instructed to stay awake the night preceding DPG. This procedure has been validated against NPG, and also against apnea mattress recordings combined with ear oximetry (AMO). Twenty patients with OSAS symptoms were examined with NPG and simultaneous AMO and 2 to 3 weeks later with DPG 3 to 4 h in the morning after 1 nights sleep deprivation. Median apnea-hypopnea index (AHI) of DPG was 37 (95% confidence interval [CI], 19 to 44), significantly higher than median AHI of NPG (14; 95% CI, 12 to 27), whereas median nocturnal oxygen desaturation index (ODI) (11; 95% CI, 9 to 25) did not differ significantly from median AHI of NPG. Sensitivity values for DPG increased from 81 to 100% when the criteria AHI greater than 5, greater than 10, greater than 15, and greater than 20 were used, respectively. Specificity values also increased with the AHI used as cutoff point, from 50% (AHI>5) to 75% (AHI>20). In AMO, there were one false-negative case and four nonclassifiable borderline cases. If these types of simplified tests for OSAS are used for diagnosis, the risk of both false-negative and positive results (DPG) or nonclassifiable borderline cases (AMO) must be considered. Since there was a significant increase in AHI in DPG after sleep deprivation in comparison to conventional NPG, the former procedure should not be used for staging of the disease. These results also stress the importance of advice to OSAS patients concerning regular sleeping habits.

Adult↗
PubMed1995

Receptor and neural visual readaptation after exposure to colored flash.

The time needed to recover optokinetic nystagmus or electroretinography complexes after a glare inducing flash was measured to study the receptor and neural visual readaptation. Electroretinographs and optokinetic nystagmus were evoked with low intensity stimuli. The light from a flash tube was filtered with an interference filter (Tmax = 536 or 622 nm) and evenly distributed into a Goldmann hemisphere observed by the subject. The Recovery of the amplitude of the a-wave of the electroretinography is quicker than the recovery of optokinetic nystagmus after a low intensity glare inducing flash. The recovery time was shorter for a red than for a green flash of equivalent dose for both recovery modalities. The time difference between electroretinography a-wave and optokinetic nystagmus recovery was the same and independent of glare inducing flash wavelength. The recovery of the amplitude of the a-wave of the electroretinography was quicker than the recovery of optokinetic nystagmus after a low intensity glare inducing flash. This time difference between the recovery modalities may in part be due to the difference between the physiological stimuli used, but it is believed that most of the time difference is because the recovery of optokinetic nystagmus monitors more of the afferent visual pathway with complex post receptor neural mechanisms than the recovery of the a-wave.

Adaptation, Ocular↗
PubMed1992

Preliminary report: validity of symptom analysis and daytime polysomnography in diagnosis of sleep apnea.

The aim of this study was twofold: first, to see if the prevalence of the sleep apnea syndrome (SAS) in a given population could be fairly estimated by our patient questionnaire, mainly based upon the 1979 American Sleep Association definition of SAS; and second, to investigate whether the severity of SAS could be similarly accurately measured by daytime polysomnography (DPSG), as an alternative to the more demanding all-night polysomnography (NPSG). Of 42 patients consecutively examined due to rhonchopathy, 18 had the clinical diagnosis of SAS, which was based on the three symptoms--snoring, sleep disturbances and diurnal hypersomnia--if reported to occur habitually. In 11 patients the diagnosis was established by NPSG [apnea index (AI) greater than 10]. However, in only 10 of the 18 cases NPSG indicated the diagnosis giving a positive predictive value of 56%. When comparing DPSG versus NPSG in 36 patients, the AI ranged from -23 to +65, and the mean AI value was found to be twice as high in the former (mean difference 9.0 +/- 18.4; p less than 0.01). The positive predictive value of DPSG was 63% (10/16). Both the self-report and DPSG were burdened with some 25% false-positive results, and DPSG gave far too variable AI values to be reliable in staging the disease. On the other hand, the negative predictive values were high, 96% (23/24) and 100% (20/20), respectively, indicating their usefulness for screening purposes.

Adult↗
PubMed1991

The sleep apnoea syndrome in obesity: risk of sudden death.

A total of 34 severely obese men with a history of heavy snoring and excessive daytime sleepiness indicative of obstructive sleep apnoea syndrome (OSAS) were studied prospectively. Their mean age was 46 years, and mean body mass index was 41.6 kg m-2. During a 4-year follow-up, 15% (5/34) of these subjects died (three cases of acute myocardial infarction and two cases of pulmonary oedema), all of them suddenly and unexpectedly, outside hospital. On autopsy the degree of atherosclerosis was found to be moderate in all cases. In 68% (15/22) of the men a pathological apnoea index (mean value 46 +/- 20) confirmed the OSAS diagnosis. Exercise tests and neurological examinations did not reveal any other causes of daytime sleepiness. Mean blood pressure at rest and during exercise was normal, and mean serum lipid and blood glucose levels were normal. Spirometry revealed intrapulmonary restrictive changes that could not be attributed to the heavy thoracic wall. Compliance was reduced to about 50% of reference values, and the mean pCO2 level (5.8 kPa) was close to the upper reference limit. Blood tests suggested that high alcohol consumption may be an important factor contributing to OSAS. These results demonstrate that morbidly obese men with a history of OSAS have a high risk of sudden cardiovascular death, despite the absence of other conventional risk factors.

Adult↗
PubMed1991

Simulated long-term driving performance before and after uvulopalatopharyngoplasty.

To investigate whether automobile drivers with the clinical features of sleep apnea syndrome (SAS) perform worse than controls in a simulated long-term test drive, and to see if their driving improves after uvulopalatopharyngoplasty (UPPP), 15 male drivers with SAS, suffering from sleep spells whilst driving, and 10 matched controls without a history of SAS or hypersomnia at the wheel were tested in an advanced driving simulator. Brake reaction time, lateral position deviation and off-road episodes were measured during a 90-min rural drive at twilight conditions. The clinical evaluation was made by a questionnaire scoring symptoms of snoring, sleep disturbances and diurnal sleepiness before and after surgery. Before UPPP the patient group showed impaired performance in all three effect measures compared to controls. UPPP resulted in improved reaction time performance (average mean improvement: 0.5 s, average 90th percentile improvement 0.8 s). Furthermore, 12 of the 15 patients reported a marked improvement regarding sleepiness whilst driving. For these clinically successful cases the number of off-road episodes decreased substantially. We conclude that most patients improve their long-term driving performance as a result of UPPP.

Accidents, Traffic↗
PubMed1991

The effect of excessive weight reduction on peripheral and central nervous functions. A study in obese patients treated by gastric banding.

Twenty-four obese patients were studied before and 3, 6, and 12 months after gastric banding to see if the excessive weight reduction caused any dysfunction of the peripheral or central nervous system or both. Postoperatively the patients were assumed to be able to keep their intake to 800-1000 kcal/day together with a multivitamin supplement. Electromyography, electroneurography and vibratory thresholds were used to assess the peripheral, somatosensory and visual evoked potentials to assess the central nervous and synaptic functions. Regular clinical and neurological assessments were made as well as laboratory examinations including total potassium estimations to calculate lean body mass. The mean weight loss and the mean lean body mass reduction amounted to 20.5% and 18.4% at 3 months, and to 30.3% and 10.2% at 12 months, respectively. Electromyography showed signs of acute denervation in the anterior tibial muscle in one patient 3 and 6 months after operation, but restitution after 12 months despite continuous weight loss. In the left peroneal nerve the electroneurography showed a trend with slight successive reduction of the conduction velocity in the postoperative period. No abnormalities of the vibratory thresholds were found postoperatively. Somatosensory and visual evoked potentials were normal in all patients and no significant changes were observed during the postoperative period. The present study did not reveal any significant dysfunction of the peripheral or central nervous system as a result of excessive weight loss in obese adults undergoing weight reducing surgery.

Adult↗
PubMed1990

Does Swedish amateur boxing lead to chronic brain damage? 3. A retrospective clinical neurophysiological study.

The aim of the present study was to investigate possible chronic brain damage due to Swedish amateur boxing. Forty seven former amateur boxers, 22 with many (HM = high-matched) and 25 with few matches (LM = low-matched) during their career were examined and compared with two control groups of 25 soccer players and 25 track and field athletes in the same age-range. No severe EEG abnormality was found. There was a somewhat higher incidence of slight or moderate EEG deviations among HM-(32%, 7/22) and LM-(36%, 9/25) boxers than among soccer players (20%, 5/25) and track and field athletes (12%, 3/25). Brain electric activity mapping (BEAM), brainstem auditory evoked potential (BAEP) and auditory evoked P 300 potential (P 300) did not differ significantly between the groups. No neurophysiological variable was correlated to the number of bouts, number of lost fights or length of boxing career. Thus, no signs of serious chronic brain damage was found among the amateur boxers or the soccer players and the track and field athletes. However, it cannot be excluded that the EEG differences between the groups may be a sign of slight brain dysfunction in some of the amateur boxers.

Adult↗
PubMed1987

Pattern-reversal electroretinograms and high-pass resolution perimetry in suspected or early glaucoma.

Twenty-one patients, age 28 to 78 years, with elevated intraocular pressure (IOP) in one or both eyes, were examined with pattern-reversal electroretinograms (PERG), high-pass resolution perimetry (HRP), and conventional computer-assisted perimetry (CAP). Among the 42 eyes, 33 were hypertensive (IOP greater than or equal to 22 mmHg) and nine were normotensive (IOP less than or equal to 20 mmHg). The optic disc was judged abnormal in 14 of the hypertensive and one of the normotensive eyes. Fourteen abnormal PERGs and 19 abnormal HRPs were observed in the 33 hypertensive eyes. Conventional CAP gave abnormal results in three of the hypertensive eyes. Seven of the nine normotensive eyes were normal in all examinations. HRP was abnormal in one of the normotensive eyes and conventional CAP was abnormal in another. Thus, PERG and HRP showed a high incidence of optic nerve dysfunction in suspected or early glaucoma. These new methods should be clinically useful for diagnosis and management of conditions with increased IOP.

Adult↗
PubMed1987

Subnormal visual acuity in children: prognosis and visual evoked cortical potential findings.

Seventy-one children, age 4-12 years, with subnormal visual acuity (VA) in at least one eye (0.7 or less) were examined using visual evoked cortical potentials (VECPs) to pattern-reversal stimulation. Twenty-eight children with squint had mean VA 0.3 in squinting and 0.7 in non-squinting eyes. Thirty-one children had unexplained subnormal VA, mean 0.6. Twelve children with mild unclassifiable fundus abnormalities had mean VA 0.5. In the squinting eyes and the eyes with fundus abnormalities the mean latency of the VECP was significantly prolonged. In squinters the mean amplitude to stimulation of the squinting eyes and to binocular stimulation was significantly reduced. Statistically significant increase in the mean VA was observed in all groups except in the cases with visible fundus abnormalities. There was no statistically significant correlation between VECP parameters and final VA. In conclusion, VA prognosis could not be predicted from VECP data in individual cases.

Child↗
PubMed1987

Pattern-reversal electroretinograms from normotensive, hypertensive and glaucomatous eyes.

Pattern-reversal electroretinograms (PERG) were recorded from 67 subjects, age 55-77 years, with normotensive (n = 19), hypertensive (n = 37) or glaucomatous (n = 11) eyes. The pathological intraocular pressure (IOP) ranged from 23 to 29 mm Hg in 21 eyes and from 30 to 43 mm Hg in 16 eyes. In 11 eyes (11 patients) manifest glaucoma was present (excavated optic disk, visual field defect). All examined subjects had normal visual acuity and clear optic media. The amplitude of the positive component of the PERG was measured. The mean PERG amplitude was 2.8 +/- 1.2 microV in the eyes with normal IOP (19 +/- 3 mm Hg), 2.2 +/- 1.0 microV in the eyes with moderately elevated IOP (26 +/- 2 mm Hg), 2.0 +/- 0.9 microV in the eyes with IOP above 30 mm Hg (33 +/- 4 mm Hg) and 1.1 +/- 0.6 microV in the glaucomatous eyes. Regression lines of PERG amplitudes versus age were calculated in all groups and showed a decrease in amplitude with increasing age. However, the correlation coefficients were not statistically significant. The decline with age was similar in all groups. The results indicate that the PERG amplitude is reduced in glaucomatous eyes and may be reduced also in ocular hypertension as well as with increasing age.

Aged↗
PubMed1985

Pattern-reversal electroretinograms in ocular hypertension.

Pattern-reversal electroretinograms (ERGs) were recorded from seven patients, aged 50 to 69 years, with clinical diagnosis of unilateral ocular hypertension. In four of the seven patients the pattern ERG amplitude from the hypertensive eye was reduced below the normal level of variability, when compared with the amplitude from the opposite normotensive eye (ratio less than 0.8). In three of these four cases excavation of the optic disk in the hypertensive eye was observed 6 to 15 months after the recording of reduced pattern ERG. The finding suggests that pattern ERG may be an useful objective method for early detection of functional damage in eyes with increased intraocular pressure.

Adult↗
PubMed1985

Hereditary essential myoclonus.

A Scandinavian family whose members have suffered from hereditary essential myoclonus for five generations are presented. Three patients showed a uniform clinical picture with myoclonic jerks located in the upper trunk, the neck and proximal parts of the upper extremities without any other symptom or sign of CNS-dysfunction. The laboratory findings including EEG and somatosensory evoked potentials (SEP) were normal. Diagnostic criteria are discussed. Treatment was relatively ineffective.

Adult↗
PubMed1985

Early diagnosis of retinal changes in diabetes: a comparison between electroretinography and retinal biomicroscopy.

The present study was undertaken in order to find out whether electroretinographic examinations could reveal signs of functional abnormalities before morphological changes are detected in the diabetic retina. Pattern-reversal and flash electroretinograms (ERG) and oscillatory potentials (OP) were recorded in 24 diabetics and 10 age-matched normal controls. The diabetic group consisted of 11 patients without retinopathy and 13 patients with background retinopathy. No significant changes in pattern-reversal or flash ERG or OP amplitudes were observed in the diabetic group with normal fundus or with background retinopathy. The findings imply that ERG examination with the described techniques does not reveal retinal dysfunction in diabetics before retinopathy can be detected by means of retinal biomicroscopy.

Adult↗