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Biomedical subjects

R Riikonen

Publications and source records attributed to R Riikonen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Pons tumour behind a phenotypic Rett syndrome presentation.

We describe a girl with a brain-stem tumour and symptoms very similar to those of Rett syndrome (RS). Her early history was uneventful and development was normal (except for hypotonia). At the age of 6 months her development slowed. Subsequently, deterioration occurred and the features characteristic of RS were seen: loss of purposeful hand use, stereotypic hand movements, impaired social contact, decelerated head growth, and ataxia. Cerebral CT at the age of 3 years and 4 months revealed a tumour in the region of the pons and hydrocephalus. We suggest that a pons/midbrain tumour appearing at an early age may affect the developing CNS and cause symptoms similar to those of RS. A possible causal connection between midbrain pathology and RS is supported by this case.

Brain Neoplasms↗
PubMed1998

Neurotrophic factors in cerebrospinal fluid and serum of patients with Rett syndrome.

Rett syndrome is now considered to be a neurodevelopmental disease. Its cause is unknown, but it has been suggested that neuronal growth factors and neurotransmitters play important roles. We measured levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid, and nerve growth factor and brain-derived neurotrophic factor in serum in child and adolescent patients with Rett syndrome. Levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid were below the limit of sensitivity of the methods used. Serum levels of nerve growth factor and brain-derived neurotrophic factor did not differ from control values. In Rett syndrome, the normal serum levels of nerve growth factor together and previously reported low levels of the factor in cerebrospinal fluid indicate that the latter may reflect low levels of nerve growth factor in the central nervous system.

Adolescent↗
PubMed1996

Long-term otucome of West syndrome: a study of adults with a history of infantile spasms.

To our knowledge, ours is the first study to evaluate the outcome of infantile spasms (IS) in adult patients. We analyzed 214 children born between 1960 and 1976 who had been followed for 20-35 years or until death at 3 months to 30 years of age. Mortality was 31% (67 of 214 patients). Thirty-six of the surviving patients (24%) had normal (25 patients) or only slightly impaired (11 patients) intelligence as assessed by their educational abilities. Four had academic occupations. Eight were married or living unmarried with a partner. Five had healthy children. At follow-up, the EEGs of the 25 normal persons were either normal or slightly abnormal, demonstrated focal findings in 9 (36%), and had unspecific changes in 1. Focal abnormalities were not more common in patients with less good outcomes (37%). In patients with normal neurological outcomes, IS had been classified as cryptogenic only in 9 of 25 (36%) cases. Therefore, some patients with IS apparently have normal intelligence and socioeconomic status as adults, including patients whose spasms were either symptomatic or associated with focal EEG findings.

Adrenocorticotropic Hormone↗
PubMed1996

Low levels of nerve growth factor in cerebrospinal fluid of children with Rett syndrome.

A role of neurotrophic factors has been postulated in some human neurodegenerative disorders such as Alzheimer's and Parkinson's disease. The known developmental effects of these substances suggested that, in some neurologic diseases affecting children, neurotrophic factors might be inadequate. Using a sensitive, two-site enzyme-linked immunoassay, we examined the content of nerve growth factor in the cerebrospinal fluid of 11 children with Rett syndrome and of 24 control patients with various neurologic diagnoses or suffering from other diseases. Nerve growth factor levels were significantly lower in the cerebrospinal fluid of the patients with Rett syndrome than in control patients. The lower level of cerebrospinal fluid nerve growth factor in Rett syndrome suggests that lack of nerve growth may be involved in the pathogenesis of this disease or reflect the underlying brain damage present.

Adolescent↗
PubMed1995

Decreasing perinatal mortality: unchanged infantile spasm morbidity.

The present study examined whether changes in the incidence of infantile spasms could be used to evaluate changes in the quality of pre- and perinatal care over time. 107 children in 1960 to 1976, and 102 in 1977 to 1991, developed infantile spasms in southern Finland. The number of small-for-gestational age (SGA) infants and infants with neonatal hypoglycaemia decreased significantly. Brain malformations, malformation syndromes and patients with tuberous sclerosis increased; this probably reflects the development of more refined neuroradiological screening methods. SGA infants are probably more apt to develop infantile spasms than preterm infants appropriate for gestational age. Early prenatal factors seem to play a major role in the genesis of infantile spasms. Little can be done to reduce the incidence of infantile spasms, but every effort should be made to reduce the number of SGA infants by good prenatal care. Treatment of hypoglycaemia is important because infantile spasms might be preventable in these infants.

Brain↗
PubMed1994

Hereditary and acquired risk factors for childhood stroke.

Forty-four patients aged from one month to 16 years suffering from arterial stroke were carefully studied for any hereditary and acquired risk factors for stroke. No physiologic anticoagulant deficiency or antiphospholipid syndrome was found. Two patients had mitochondrial disease (MELAS). Six patients had migraineous stroke. Migraine and thrombotic disease in the families of the patients were not more prevalent than in the families of the controls. Preceding infections occurred in 34% of the patients, that is, significantly more common than in the age-matched controls. Two children had borreliosis. Repeat strokes occurred particularly in patients with migraine (n = 4) and MELAS (n = 2). The hereditary factors studied here seem to play only a minor role in pediatric patients. Repeated strokes have a varied etiology and are difficult to prevent. Important triggers of strokes are infections.

Adolescent↗
PubMed1993

Infantile spasms: infectious disorders.

Infections were considered to be etiological factors in 29 patients (10%) with infantile spasms; congenital CMV (n = 5), congenital or acquired CMV (n = 1), acquired CMV (n = 5), congenital rubella (n = 2), herpes simplex virus (n = 5), enterovirus (n = 1), adenovirus (n = 1), viral encephalitis of unknown agent (n = 3), meningococcus (n = 4), pneumococcus (n = 1) and pertussis (n = 1). The children with congenital infections had long-lasting tremor and convulsions from birth. Early EEG pattern was characteristic for children with herpes encephalitis but not for other patients. Infantile spasms appeared only some weeks after viral encephalitis. One patient with enterovirus and another with probable adenovirus infection had necrotic changes in their brain CT resembling those of herpes encephalitis. The response to ACTH was poor (38%) compared to the whole series (60%). The long-term outcome was also poor compared to the whole series; mental retardation in 90%, convulsions in 62%, abnormal EEG in 89%. Four children died during the follow-up of 7 years. Autopsy showed disseminated CMV infection in one patient and chronic CMV infection in another. The outcome of children with infectious etiology appears to be particularly poor. Thus, the prevention and specific diagnosis and treatment are important. Steroid therapy should be avoided in children with a history of herpes virus encephalitis (CMV, herpes simplex) in the past.

Adolescent↗
PubMed1992

The concentrations of GABA, 5-HIAA and HVA in the cerebrospinal fluid of children with infantile spasms and the effects of ACTH treatment.

Children with infantile spasms (IS) are generally treated with ACTH although little is known of the biochemical basis of the symptoms and the mechanism of this therapy. We have measured the concentrations of gamma-aminobutyric acid (GABA), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the CSF of IS children, followed the effect of ACTH treatment on these parameters and correlated CSF GABA values with the cause of IS, cranial CT findings and antiepileptic treatment. While significant differences in GABA concentrations were found between the children with IS and those with febrile seizures or nonconvulsive symptoms, these could be accounted for by age, not the disease present. The CSF GABA level was highest in the IS children with normal CT, cryptogenic cause and no antiepileptic treatment, and lowest in those with abnormal CT, symptomatic cause and antiepileptic treatment. The basal level of CSF 5-HIAA in the IS children was higher than that in the nonconvulsive children, but HVA levels did not differ. ACTH therapy did not change the CSF levels of GABA, 5-HIAA and HVA significantly.

Adolescent↗
PubMed1990

Tuberous sclerosis and infantile spasms.

The short- and long-term outcome and special problems of 24 children with infantile spasms and tuberous sclerosis (TS) was studied. The diagnosis of TS is frequently missed: white spots on the skin have to be carefully looked for. In the present study, these spots were always found, and calcifications or hypodense areas of the brain were revealed by CT scans before one year of age. In addition to epilepsy, manifestations of TS included: giant cell astrocytoma, iridic heterotopia, cardiac rhabdomyoma, brain cysts, polycystic kidneys with severe arterial hypertension, retinal phakomas, angiofibroma and white spots on the skin. Long-term outcome was poor. None of the children had normal intelligence and all but one had epilepsy, which was often intractable. Behavioural problems were common. The prognosis, in terms of later intelligence, epilepsy and behavioural problems, was worse than in those with 'idiopathic' infantile spasms or in those with simultaneous neurological disorders. An early diagnosis of TS in patients with infantile spasms clarifies the prognosis and avoids some of the hazards of ACTH therapy. TS children have a high relapse rate after ACTH therapy, so prolonged courses may be indicated.

Adolescent↗
PubMed1989

Hormonal background of the hypertension and fluid derangements associated with adrenocorticotrophic hormone treatment of infants.

We studied the hormonal background of the fluid derangements and arterial hypertension associated with adrenocorticotrophic hormone (ACTH) treatment for infantile spasms in ten infants aged 5-22 months. They received a 6 week course of (carboxymethyl-cellulose-)ACTH: 80 IU at 0800 hours daily in weeks 1-3, then tapering, and termination at the end of week 6. The infants showed large, variable increases in 24 h urine cortisol during treatment. The mean plasma cortisol concentration (24 h after ACTH injection) was not significantly increased, but was correlated with the relative dose of ACTH. The mean plasma aldosterone concentration decreased. No significant change occurred in plasma renin activity (PRA), or in the concentrations of renin substrate (RS) or arginine vasopressin (AVP). Seven infants developed arterial hypertension, which was severe in three. This severe hypertension was associated with the highest relative ACTH doses and the highest plasma RS and cortisol concentrations. In the group as a whole, systolic blood pressure correlated with plasma RS and cortisol concentrations, but not with the other parameters. At the end of treatment urine and plasma cortisol dropped below the pretreatment levels and stayed low for greater than 2 weeks. There was a sharp peak in PRA and plasma aldosterone concentration, and a decrease in plasma RS. Plasma AVP levels dropped markedly. The mean body weight increased sharply and urine flow decreased. Mean plasma electrolyte levels remained unaltered. The danger at termination of ACTH treatment appears to be associated with a sudden transition from hypercortisolism to hypocortisolism, activation of the renin-angiotensin-aldosterone axis, and suppression of AVP secretion.

Adrenocorticotropic Hormone↗
PubMed1989

Long-term persistence of intrathecal viral antibody responses in postinfectious diseases of the central nervous system and in Rett syndrome.

Twenty patients: seven with herpes simplex virus encephalitis (HSVE), six with other severe central nervous system (CNS) infections and 7 with Rett syndrome were studied to determine whether they showed any intrathecal synthesis of virus-specific or total IgG in CNS. The study of the postinfectious patients was made a mean of 20 years after the primary infection in childhood. Four of seven patients with HSVE had an elevated IgG index and four showed intrathecal viral antibody production which was both specific (against HSV) and non-specific. One patient with congenital syphilis and one with tuberculotic meningitis showed non-specific intrathecal viral antibody synthesis. In three of seven patients with Rett syndrome intrathecal antibody production was observed. The clarification of the mechanism of polyclonal immunoactivation in postinfectious diseases would be of interest since similar persistent immunoactivation is a common feature in multiple sclerosis. In Rett syndrome the immunoactivation may also have pathogenetic significance.

Adolescent↗
PubMed1989

The role of infection and vaccination in the genesis of optic neuritis and multiple sclerosis in children.

This article describes the association between previous infection and/or vaccination and the development of optic neuritis (ON) in 18 children. Ten of these children subsequently developed clinically definite multiple sclerosis (MS), while in 8 patients a clinically definite etiology could not be confirmed. Vaccination preceded the first ON attack in 6 patients, all but one of whom subsequently developed MS. It also preceded subsequent demyelinating events in 6 patients. Ten of the patients had a bacterial or viral infection within the 2 weeks prior to the first symptoms of ON. Intrathecal antibody synthesis against 2 or more viruses could be shown in 5 out of 8 patients studied; 5 out of 6 patients had oligoclonal antibodies in CSF and 12 out of 16 patients a high IgG index. Neither intrathecal antibody synthesis against 2 or more viruses nor elevated IgG indexes could be found in the control patients. Measles and mumps occurred at a significantly later age in the children who subsequently developed MS than in the control children, and these patients had significantly more events that might have impaired the blood-brain barrier than the controls. These results indicate that immunological events leading to MS may be triggered during childhood. Vaccination and infection often precede ON in childhood. Intrathecal viral antibody production can occur already in childhood at the time of the first symptoms of MS.

Adolescent↗
PubMed1989

Changing pattern of cerebral palsy in the southwest region of Finland.

The prevalence of cerebral palsy (CP) increased significantly from 1968-72 to 1978-82 in the region of the University Central Hospital of Turku, Finland, from 1.6/1,000 live births during the first five-year period to 2.5/1,000 live births during the second. The increase was due to an increase of CP in low birthweight children (p = 0.0002). The distribution of CP patterns did not change significantly. During the second period the diagnosis was made earlier in all groups (except that of spastic tetraplegia), though it reached statistical significance only in the hemi- and diplegic groups. While the perinatal mortality rate declined greatly during this period (especially in low birthweight groups), the increase in CP prevalence was due to increased survival rather than to a real change in prevalence. As a net gain, the decline resulted in an increased absolute figure in non-CP children, in spite of the rising prevalence of the disease.

Birth Weight↗
PubMed1989

Two cases of Dandy-Walker syndrome and chronic polyneuropathy.

The paper describes a so far unreported combination of Dandy-Walker syndrome and chronic hereditary polyneuropathy in 2 boys. One of the boys has a de- and remyelinating motor and sensory polyneuropathy, with either an autosomal recessive mode of inheritence or a sporadic occurrence. The other has an autosomal dominant form of mild polyneuropathy with tomaculum formations in myelinated fibers, corresponding to hereditary neuropathy with liability to pressure palsies.

Adult↗