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Biomedical subjects

R Riikonen

Publications and source records attributed to R Riikonen.

At least 55 records · Page 3Linked to original sources
PubMed1988

Can barbiturate anaesthesia cure infantile spasms?

Five patients with infantile spasms and hypsarrhythmia and one with Lennox-Gastaut syndrome were treated with brief thiopentone anaesthesia as the primary treatment of infantile spasms. Thiopentone (30 mg/kg) was given intravenously and burst suppression was reached in EEG in three patients by this dose. The results were disappointing. In three patients a transient beneficial effect on spasms and hypsarrhythmia was seen, but all patients relapsed. Three other patients had anaesthesia for surgery. The spasms ceased and hypsarrhythmia disappeared dramatically, and the effect was permanent. The possible mechanisms of the therapeutic effect are discussed. It seems advisable to give anaesthesia and surgery prior to steroid treatment in any case where the both are needed.

Anesthesia↗
PubMed1988

Optic neuritis in children and its relationship to multiple sclerosis: a clinical study of 21 children.

The optic neuritis of 21 children aged between four and 14 years generally was characterized by bilateral involvement (62 per cent) and papillitis (76 per cent). Often acute infections or vaccinations were preceding events. Frequently there was pleocytosis during the disease process, with production of IgG, oligoclonal and viral antibodies, which increased during follow-up. Nine of these children (eight female) later developed multiple sclerosis, with unilateral involvement of the optic nerves and HLA Dr2 positivity. Disseminated effects on the central nervous system were similar to those of adults with multiple sclerosis. In all cases these relapses occurred within one year of the optic neuritis. EEGs did not differentiate those who developed multiple sclerosis from those who did not, but four of five patients with multiple sclerosis who were followed-up for a year or more had paroxysmal discharges, and one of the four had manifest epilepsy. Magnetic resonance imaging, visual and sensory evoked potentials and CSF studies were helpful in diagnosing multiple sclerosis. The visual prognosis was good in most cases. 17 children had no or only slight neurological disability at the end of follow-up; the other four had moderate to severe disability. This study suggests that optic neuritis is a diffuse disease, not merely affecting the optic nerves, and that the immunological events typical of multiple sclerosis can start in childhood.

Adolescent↗
PubMed1988

Lymphocytes subclasses and function in patients with optic neuritis in childhood with special reference to multiple sclerosis.

Ten patients with childhood optic neuritis (5 with a single attack of ON and 5 with later MS) were studied at various stages of the disease. Lymphocyte count and function were analysed in the peripheral blood of all patients, 3 repeatedly, and in one they were also analysed in the CSF. T-lymphocytes counts were normal in all but 2 MS cases who had high counts. In acute stages the T4/T8 ratio were high in 1/3 determinations, in recovery low in 2/2 determinations, and in stable stages normal in 6/8 determinations. Lymphocyte function, measured by PHA, ConA and PWM stimulation, was normal in all but one. One patient showed significantly higher T-cell percentages and a high number of stimulated lymphocytes in CSF but a lower count of suppressor cells than in the blood. We found no abnormalities specific to MS nor to childhood MS or to disease activity stage. Rather than peripheral blood, it would seem more worthwhile to study CSF to clarify the pathogenesis of ON and MS.

Adolescent↗
PubMed1988

Magnetic resonance imaging, evoked responses and cerebrospinal fluid findings in a follow-up study of children with optic neuritis.

Fourteen patients with previous optic neuritis (ON) in childhood were examined by magnetic resonance (MR) imaging from two months to 14 years after the onset of symptoms. Five patients had a single monosymptomatic course of ON but 7 developed multiple sclerosis (MS); 2 had another demyelinating disease. Eight patients had high signal intensity areas in the T2 weighted images compatible with MS plaques in MR scan; 2 with monosymptomatic ON, 5 with MS and one with another demyelinating disease. The plaques were periventricular or in the optic radiation. The plaques could already be seen during the first symptoms of ON. All 7 MS patients had abnormal visual evoked response, 3/4 abnormal somatosensory evoked response and 5/6 intrathecal immunoglobulin production, when examined at onset of optic neuritis or at follow-up. All patients except one, with lesions in MR, had either oligoclonal CSF antibodies or Dr2 HLA antigen. We suggest that MR is a very sensitive test showing MR abnormalities in children with ON. It is an important tool in the early assessment of MS.

Adolescent↗
PubMed1987

The effect of ACTH therapy on serum dehydroepiandrosterone, androstenedione, testosterone and 5 alpha-dihydrotestosterone in infants.

Serum concentrations of dehydroepiandrosterone (DHEA), androstenedione, testosterone, 5 alpha-dihydrotestosterone and cortisol were measured in 10 infants (age 5-22 months) before, during and after 6-weeks of ACTH therapy for infantile spasms. During therapy, their mean DHEA concentrations increased 2.3-fold, androstenedione 12.3-fold, testosterone 2.7-fold, 5 alpha-dihydrotesterone 2.5-fold and cortisol 2.9-fold compared to pre-therapy values. Serum dehydroepiandrosterone sulphate (DHEA-S) concentrations were also increased during ACTH therapy above the normal prepubertal range. Three days after the cessation of ACTH treatment, all androgens had returned to the pre-therapy level. We conclude: At least in pharmacologic doses ACTH alone stimulates adrenal androgen secretion in infants, excluding the necessity of a separate adrenal androgen stimulating hormone.

Adrenocorticotropic Hormone↗
PubMed1987

Advances in therapy of infantile spasms. Current knowledge of actions of ACTH and corticosteroids.

The anticonvulsant actions of ACTH and corticosteroids in the treatment of infantile spasms have been well documented during the past 29 years. In the past decade neuropeptides have been studied intensively and an understanding of their actions has been gained. Most of the actions of ACTH are well documented in animal experiments and cytochemical studies. Some proceedings of modern steroid research are here reviewed. In the treatment of infantile spasms, the principal mechanism of the therapeutic action of ACTH and corticosteroids is unknown. Clinical data concerning their effects, site and mode of action, on brain and CSF neurochemical activity are still scant and controversial. Some mechanisms probably involved in the therapeutic effects are reviewed. It seems that a disturbance of the central neural transmitter regulation at a specific phase of brain development may be the underlying cause for infantile spasms.

Adrenal Cortex Hormones↗
PubMed1987

Chronic relapsing course of encephalomyeloradiculopathy in a 6-year-old boy.

We present a young child with an illness characterized by remissions and exacerbations and signs of disseminated lesions in the central nervous system. Visual evoked response and brainstem auditory evoked potential gave abnormal findings showing lesions also of the optic nerves and brainstem. The CSF IgG index was slightly elevated and myelin basic protein was high. There was also intrathecal antibody production against different viruses, the highest against measles. The HLA type was A3, B7, Dr2. The T4/T8 ratio reflected an immunological active disease. All these signs could have been diagnosed as multiple sclerosis. However, there were also lower motoneuron lesions and metabolic studies showed disturbances in pyruvate metabolism as in Leigh's disease. Cerebral tomography and magnetic resonance imaging showed scattered lesions in the nuclei lentiformis and capsula interna. We would like to stress the importance of careful etiological studies in cases of MS in childhood.

Brain Diseases, Metabolic↗
PubMed1986

Serum steroids and success of corticotropin therapy in infantile spasms.

Serum levels of 8 steroids and urinary cortisol excretion were determined in 10 infants before and during corticotropin therapy for infantile spasms. High serum dehydroepiandrosterone-androstenedione concentration ratio distinguished the 6 infants with good therapeutic response from the 4 with poor response (p = 0.001). No such distinction was obtained directly by any of the serum steroid levels, 24-hour urinary cortisol, or serum pregnenolone-progesterone concentration ratio. This suggests that the therapeutic effect of corticotropin may be mediated by steroid factors other than cortisol. Inhibition of the 3 beta-hydroxysteroid dehydrogenase system in zona reticularis might be beneficial during the corticotropin therapy.

Adrenocorticotropic Hormone↗
PubMed1986

Disturbed calcium and phosphate homeostasis during treatment with ACTH of infantile spasms.

Kidney histology of five infants who died during or immediately after treatment with adrenocorticotrophic hormone (ACTH) showed severe tubular and interstitial calcinosis. We therefore studied serum concentrations of calcium, inorganic phosphate, and parathormone, serum activities of alkaline phosphatase, and urinary excretion of calcium, inorganic phosphate, and cyclic adenosine monophosphate (cAMP) in 16 other children with infantile spasms before, during, and after 6 weeks of treatment with ACTH. During the treatment the following observations were made: hypocalcaemia developed in three infants; the mean daily urinary excretion of calcium in the group increased threefold and seven infants had hypercalciuria; the excretion of phosphate increased but its tubular reabsorption remained stable; and in most infants serum parathormone and urinary cAMP excretion increased, and in four infants they increased to supranormal concentrations. These biochemical changes were reversible in most infants. Radiographs suggested loss of bone mass by 3-4 weeks of treatment, with rapid recovery after treatment. We conclude that infants treated with ACTH for infantile spasms are at risk of suffering disturbance in calcium and phosphate homeostasis, which leads to nephrocalcinosis.

Adrenocorticotropic Hormone↗
PubMed1986

Adrenocortical hyporesponsiveness after treatment with ACTH of infantile spasms.

The hypothalamic-pituitary-adrenocortical axis was studied in 10 infants before and during a six week period of treatment with adrenocorticotrophic hormone (ACTH) and three days and one and two weeks after its stopping. During the treatment 24 hour urinary cortisol excretion increased 20 to 350-fold (mean 100) above the basal value. Mean morning serum cortisol concentration, measured 24 hours after the preceding ACTH dose, did not increase. After the treatment mean urinary cortisol excretion was subnormal and mean morning serum cortisol concentration was below the pretreatment value. The mean serum cortisol response to a vasopressin test was reduced and shortened throughout the post-treatment observation period. The mean serum cortisol response to an intravenous ACTH test was not significantly different from the pretreatment response three days after treatment but was clearly reduced thereafter. At one and two weeks after treatment the basal concentrations of serum cortisol of one third of the patients and the post-ACTH concentrations of two thirds were subnormal. We conclude that in infants treatment with ACTH may cause adrenocortical hyporesponsiveness.

Adrenocorticotropic Hormone↗
PubMed1984

An unusual case of recovery from infantile spasms.

A six-month-old boy with an uneventful early history and normal development was admitted for treatment of infantile spasms and hypsarrhythmia lasting for a week. Sagittal craniosynostosis was corrected surgically, in preference to a course of ACTH. Large doses of short-acting barbiturates were given during anaesthesia. The child recovered promptly after the operation: there have been no relapses and development was normal when he was seen two years later.

Barbiturates↗
PubMed1984

Infantile spasms: modern practical aspects.

Data on incidence, aetiology, therapy and prognosis of infantile spasms are reviewed. In a large proportion of cases the aetiological factors of infantile spasms can now be established with some certainty. Especially the new neuroradiological and virological investigative methods have enabled a more accurate diagnosis. There have been changes in the aetiologic pattern over the years. The optimal dosage and duration of ACTH or glucocorticoid therapy have not yet been established. In the Finnish study the large ACTH doses (120-160 IE) generally used in many Nordic countries did not carry a better prognosis than the smaller doses (20-40 IE). Side-effects of ACTH therapy are relatively common. They are more frequent with large doses than with smaller ones. Measures can be taken to prevent or treat part of them. The prognosis and related factors in infantile spasms as well as some recommendations to improve them are reviewed.

Adrenocorticotropic Hormone↗
PubMed1983

Infantile spasms: some new theoretical aspects.

Infantile spasms begin in a very active phase of brain development. The new neuropathological techniques have shed light on changes in the fine structure of brain in children with infantile spasms. An understanding of the action of adrenocorticotropic hormone on the biochemistry and development of the brain provides, in an indirect way, a partial explanation of the biochemical events in this syndrome; most of these actions are well documented in animal experiments. Some anticonvulsants are also effective in treating infantile spasms, and modern research has explained many actions of these agents as well. The principal mechanism causing retardation in most children is unknown. Some future aspects of the research are reviewed.

Adrenal Cortex Hormones↗
PubMed1982

A long-term follow-up study of 214 children with the syndrome of infantile spasms.

The long-term prognosis of 192 surviving children with the syndrome of infantile spasms was evaluated. The children had been admitted to three paediatric hospitals in Helsinki at the time of initial diagnosis. The aetiological factors of the syndrome were carefully studied in each case. ACTH therapy was employed in 162, usually for about six weeks. The follow-up study 3-19 (mean 10.4) years later was made at the Children's Hospital, University of Helsinki. The rate of mortality was 19.6 per cent. Normal development was seen in 12 per cent and slightly subnormal in 10.4 per cent of the surviving children. Psychiatric disorders were seen in 27.6 per cent of the survivors. Sensory defects were also common. Severe cerebral palsy was seen in 4 per cent. Other seizures after cessation of the infantile spasms were seen in 60 per cent. Serial EEG studies showed that the temporal lobe was the most common site of abnormality. Abnormalities in the temporal lobes were seen frequently in children with symptomatic neonatal hypoglycaemia as a probable cause of the spasms. Prognostically favourable factors were "idiopathic" aetiology, normal development and not other fits prior to the spasms, short treatment lag, good response to ACTH and short duration of the spasms. In this study early treatment seemed to be of great importance even with regard to mental development. The factors connected with a bad outcome were: symptomatic aetiology (especially brain malformations, early infections and tuberous sclerosis), slow development before spasms, other seizures before infantile spasms, early onset of the spasms, long treatment lag, long duration of the spasms and other later occurrence of myoclonic-astatic seizures (Lennox-Gastaut). Large doses of ACTH (120-160 units) were not associated with a better prognosis than the smaller doses (20-40 units). The benefit of long versus short treatment schedules could not be evaluated in this study. The relapse rate here was 32 per cent.

Adolescent↗
PubMed1981

Psychiatric disorders in children with earlier infantile spasms.

In order to evaluate the occurrence of psychiatric disorder following infantile spasms, a long-term follow-up study (between three and 19 years) was made of 192 children in Finland. Psychiatric disorders were found in 53 of the children. 24 had infantile autism (transient in 14 cases), 16 of whom were also hyperkinetic, as were an additional 29 cases from the whole group. Considerable muscular hypotonia was frequently combined with infantile autism, but both tended to decrease with age. Autistic children often had psychomotor epilepsy and temporal lobe abnormalities, which suggests that organic lesions with a specific localization may be a pathophysiological basis for autism. In addition, the hyperkinetic children had more focal temporal abnormalities in their EEGs than did the children without psychiatric disorders.

Adolescent↗
PubMed1980

ACTH therapy in infantile spasms: side effects.

162 children with infantile spasms were treated with ACTH at the Children's Hospital, Helsinki, and at the Aurora Hospital, Helsinki, during 1960--76. In a large proportion (37%) of the children the treatment caused pronounced side effects, and the mortality was 4.9%. The most common complications were infections: septic infections, pneumonias, and urinary and gastrointestinal infections. Other side effects were arterial hypertension (11), osteoporosis (2), hypokalaemic alkalosis (2), and other marked electrolyte disturbances (10). In children necropsy showed fresh intracerebral haemorrhages. Four children developed oliguria and hyperkalaemia during and after withdrawal of ACTH. One of them had tubular necrosis confirmed by renal biopsy. Infections were significantly more common with large doses (120 units) of ACTH than with small ones (40 units). It is concluded that side effects, even severe ones, are more common during treatment than had been assumed. Careful watch is important before and after treatment. The benefit of very high dosages should also be reconsidered.

Acute Kidney Injury↗