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T Aärimaa

Publications and source records attributed to T Aärimaa.

At least 19 recordsLinked to original sources
PubMed2005

Enrichment of the R77C alpha-sarcoglycan gene mutation in Finnish LGMD2D patients.

Limb-girdle muscular dystrophy 2D (LGMD2D) is caused by mutations in the alpha-sarcoglycan gene (SGCA). The most frequently reported mutation, 229CGC>TGC (R77C) in exon 3 of SGCA, results in the substitution of arginine by cysteine. We present here the clinical, immunohistochemical, and genetic data of 11 Finnish patients with LGMD2D caused by mutations in SGCA. Mutational analysis showed 10 patients homozygous and 1 compound heterozygous for R77C. A wide spectrum of SGCA mutations has been reported previously. Our results show an enrichment of R77C in Finland, further underlined by the observed carrier frequency of 1 per 150. According to the annual birth rate of approximately 60,000 in Finland, one LGMD2D patient with a homozygous mutation is expected to be born every 1 or 2 years on average. The presence of an ancient founder mutation is indicated by the fact that all patients shared a short common haplotype extending > or = 790 kilobases. Our results emphasize the need to include the SGCA gene R77C mutation test in routine DNA analyses of severe dystrophinopathy-like muscular dystrophies in Finland, and suggest that the applicability of this test in other populations should be studied as well.

Adolescent↗
PubMed2004

Five new cases of a recently described leukoencephalopathy with high brain lactate.

BACKGROUND: A new leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate was recently defined. The authors describe five new patients with this entity. METHODS: Brain MRI was performed in all patients and spinal MRI and proton magnetic resonance spectroscopy (1H-MRS) in four patients. Laboratory examinations ruled out classic leukodystrophies. RESULTS: MRI showed signal abnormalities in the periventricular and deep white matter, in the pyramidal tracts, mesencephalic trigeminal tracts, in the cerebellar connections, and in dorsal columns of the spinal cord. MRS showed decreased N-acetylaspartate and increased lactate in the white matter of all patients. In one patient choline-containing compounds were elevated. A slowly progressive sensory ataxia and tremor manifested at the age of 3 to 16 years and distal spasticity in adolescence. One 13-year-old patient was asymptomatic. CONCLUSIONS: A slowly progressive sensory ataxia is a typical feature in this new leukodystrophy. MRS favors a primary axonal degeneration.

Adolescent↗
PubMed2002

Focal and global cortical hypometabolism in patients with newly diagnosed infantile spasms.

OBJECTIVE: To evaluate the occurrence and prognostic importance of focal defects in cerebral cortical glucose metabolism in infants with newly diagnosed symptomatic and cryptogenic infantile spasms. PATIENTS AND METHODS: Ten children with symptomatic and seven with cryptogenic infantile spasms underwent MRI, video-EEG, and PET using fluorodeoxyglucose as a tracer within 2 weeks of diagnosis. PET was repeated at 1 year of age in 12 patients. RESULTS: Cortical hypometabolic foci were found in 13 children (77%) with newly diagnosed spasms (six cryptogenic and seven symptomatic). The hypometabolic foci disappeared in seven of nine reexamined at age 1. The occipital foci disappeared in all (n = 6). Focal findings on PET correlated well with focal findings on video-EEG. There was no difference in quantitative cortical or subcortical glucose metabolic rate at the onset of infantile spasms between children with cryptogenic and symptomatic etiology of spasms. The glucose metabolic rate at the onset of spasms or focal lesions in glucose metabolism did not have prognostic value for seizure outcome. CONCLUSIONS: Infantile spasms are often associated with transient cortical, especially occipital, hypometabolic foci that are not necessarily associated with structural lesions and do not indicate a poor prognosis.

Cerebral Cortex↗
PubMed2000

Cerebral glucose metabolism in survivors of childhood acute lymphoblastic leukemia.

BACKGROUND: Cranial radiation therapy (CRT) has been suggested to be a principal factor responsible for long term neurocognitive deficits in survivors of acute lymphoblastic leukemia (ALL). However, neither reduction of the irradiation dose nor the elimination of irradiation entirely appear to have abolished neurocognitive impairment in long term ALL survivors. Positron emission tomography (PET) and [(18)F]-fluorodeoxyglucose (FDG) can be used to quantitate cerebral glucose metabolism, a potential indicator of treatment-induced adverse central nervous system (CNS) effects. The purpose of this study was to assess whether CRT is associated with defects in cerebral glucose metabolism in long term ALL survivors. The authors also studied whether chemotherapy and/or the severity of disease have deleterious effects on glucose metabolism. METHODS: Forty long-term survivors of childhood ALL were studied using FDG PET. All subjects went through an elaborate neurocognitive assessment. In 20 of these children, the prophylactic treatment of the CNS had been CRT combined with methotrexate (MTX), and it was MTX only in the remaining 20 children. RESULTS: No major differences were found in the regional cerebral glucose utilization or in neurocognitive performance between the irradiated and nonirradiated groups. A high leukocyte count at the time of diagnosis was found to be associated inversely with cerebral glucose utilization. CONCLUSIONS: CRT does not appear to affect cerebral glucose metabolism in long term survivors of ALL. By contrast, the association between the leukocyte count and glucose utilization implies that disease severity may be partly responsible for adverse CNS effects in long term survivors of childhood ALL.

Adolescent↗
PubMed1999

Increased brain glucose utilization in Salla disease (free sialic acid storage disorder).

UNLABELLED: Salla disease is an autosomal recessive lysosomal free sialic acid storage disorder characterized by psychomotor retardation and ataxia. MRI studies have revealed evidence of dysmyelination, but the biological mechanism of the brain dysfunction is unknown. METHODS: Nine patients with Salla disease (age 2.5 mo-42 y) presenting the disease in varying degrees of severity were studied by PET using 2-fluoro-2-deoxy-D-glucose (FDG) as a tracer. Local cerebral metabolic rates for glucose (LCMRGlc) in individual brain regions were compared with controls. RESULTS: The FDG PET results showed significantly increased LCMRGlc values in the frontal and sensorimotor cortex and especially in the basal ganglia of the patients. Cerebellar hypometabolism was present in all seven patients with marked ataxia, whereas the less severely affected patients without obvious ataxia had normal or even high glucose uptake in the cerebellum. CONCLUSION: The increased cerebral glucose utilization is a constant finding in Salla disease and may reflect the basic defect of the sialic acid metabolism in this disorder. The FDG PET findings in the cerebellum suggest a correlation between glucose uptake and the severity of the clinical symptoms.

Adolescent↗
PubMed1997

Cerebral metabolic rate for glucose after neonatal hypoglycaemia.

OBJECTIVE: We studied the effect of neonatal hypoglycaemia on the local cerebral metabolic rate for glucose (LCMRglc). MATERIALS AND METHODS: Eight newborn infants with neonatal hypoglycaemia were studied. The LCMRglc in the whole brain, in five cerebral regions and in skeletal muscles were quantitated using positron emission tomography (PET) and 2-[18F]Fluoro-2-deoxy-D-glucose (FDG). The PET studies were performed at the age of 5.3 +/- 6.2 days during normoglycaemia. The LCMRglc of these infants were compared to the age-adjusted LCMRglc of eight infants with suspected hypoxic-ischaemic brain injury but with normal neurological development. RESULTS: After neonatal hypoglycaemia the age-adjusted LCMRglc in the whole brain was not lower than LCMRglc of the control infants (5.33 +/- 0.60 mumol/100 g/min vs. 6.71 +/- 0.60 mumol/100 g/min). Also the metabolic rate for glucose (MRglc) in the skeletal muscles was similar in hypoglycaemic and control infants (5.56 +/- 2.48 mumol/100 g/min vs. 6.99 +/- 2.41 mumol/100 g/min). CONCLUSION: MRglc in brain and in skeletal muscle seems to be normal after neonatal hypoglycaemia, although larger group of patients with more severe hypoglycaemia are needed to confirm this finding.

Animals↗
PubMed1997

Reactivity of skin blood flow and heart rate to external thermal stimulation in anencephaly.

Oscillations of skin blood flow and heart rate can be synchronised using external rhythmic thermal stimulation in healthy adults and infants. We examined the effect of thermal stimulation on the cutaneous circulation and heart rate of an anencephalic neonate using cutaneous laser Doppler flowmetry and ECG monitoring. The results suggest that synchronisation of SBF and HR to thermal stimulation can also be induced in an anencephalic newborn.

Anencephaly↗
PubMed1997

CNS tumours in south-western Finland: high location, high incidence.

The Department of Paediatrics at the University Central Hospital of Turku, Finland has 130,000 children under 17 y of age within its catchment area. We collected all 103 cases of newly diagnosed CNS tumours from the 15-y period of 1981-95. The incidence was 5.3:100,000, a figure twofold those usually presented. During the period 1981-85 the incidence was lower (4) than during the subsequent 5-y periods (5.7 and 6.2). There were no statistical differences between the incidences of the supra- vs infratentorial brain tumours. Optic glioma was unusually common (17%, CI 13.9-20%).

Adolescent↗
PubMed1996

CT, MRI, and PET in a case of intractable epilepsy.

We report the case of a child with drug-refractory partial epilepsy in whom computed tomography showed no abnormality and magnetic resonance imaging showed a noninvasive cystic lesion in the left hippocampus. The finding in the positron emission tomography study with L-[methyl-11C]-methionine as a tracer suggested a tumor. This finding was confirmed histologically.

Brain Neoplasms↗
PubMed1996

Cerebral metabolic rate for glucose during the first six months of life: an FDG positron emission tomography study.

AIM: To measure the local cerebral metabolic rate for glucose (LCMRGlc) in neonatal brains during maturation using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG). METHODS: Twenty infants were studied using PET during the neonatal period. The postconceptional age ranged from 32.7 to 60.3 weeks. All infants had normal neurodevelopment and were normoglycaemic. The development of the infants was carefully evaluated (follow up 12-36 months) clinically, and by using a method based on Gesell Amatruda's developmental diagnosis. LCMRGlc was quantitated using PET derived from FDG kinetics and calculated in the whole brain and for regional brain structures. RESULTS: LCMRGlc for various cortical brain regions and the basal ganglia was low at birth (from 4 to 16 mumol/100 g/minute). In infants 2 months of age and younger LCMRGlc was highest in the sensorimotor cortex, thalamus, and brain stem. By 5 months, LCMRGlc had increased in the frontal, parietal, temporal, occipital and cerebellar cortical regions. In general, the whole brain LCMRGlc correlated with postconceptional age (r = 0.90; P < 0.001). The change in the glucose metabolic pattern observed in the neonatal brain reflects the functional maturation of these brain regions. CONCLUSION: These findings show that LCMRGlc in infants increases with maturation. Accordingly, when LCMRGlc is measured during infancy, the postconceptional age has to be taken into account when interpretating the results.

Age Factors↗
PubMed1995

Cerebral circulation assessed by transcephalic electrical impedance during the first day of life--a potential predictor of outcome?

Pulsatile changes in intracranial blood volume (transcephalic electrical impedance, delta Z), arterial blood pressure (aBP) and respiration were studied during the first day after birth in 42 neonates with a birth weight of 1040-3850 g and gestational age of 26-36 weeks. The neurological outcome was assessed at 1 year of age to study the predictive ability of delta Z. delta Z, ECG, respirogram and direct aBP were recorded at 8-h intervals. Outcome was adverse in seven infants of whom two died from severe peri-intraventricular haemorrhage. PCO2 was higher (6.2 kPa) in the infants with adverse outcome than in those infants with favourable outcome (5.0 kPa) (P = 0.004). Blood glucose (4.5 vs. 3.3 mmol/l, P = 0.030) and first day administration of fluid (80 vs. 63 ml/kg/day, P = 0.003) behaved, respectively. Of the infants receiving dopamine therapy, 60% had adverse outcome while only 11% of those not receiving dopamine had adverse outcome (P = 0.016). Of the infants with high diastolic blood pressure levels, 32% had adverse outcome, while none with low diastolic blood pressure levels had adverse outcome (P = 0.031). Spectral analysis was used to examine signal variabilities in the frequency domain. During the first 24 h of life, the variabilities of aBP and respiration were equal in all the infants. The high-frequency delta Z signal variability (1.50-4.00 Hz, heart rate level) was found to be lower in the infants with adverse outcome (330 units) than in the infants with favourable outcome (1280 units, P = 0.017). The low delta Z variability allowed us to assume that there is a decrease of pulsatile cerebral blood flow (CBF) in the infants with adverse outcome. We speculate that this may result from the 'no reflow phenomenon', increased tissue pressure due to ischaemia and/or PIVH, the 'brain sparing effect' or constriction of main cerebral arteries due to increased pressure support or metabolic factors (PCO2, glucose). We believe that transcephalic impedance provides a potential cot-side method for monitoring cerebral circulation in the neonatal period with an ability to predict outcome.

Blood Glucose↗
PubMed1994

Phenotypic variation and magnetic resonance imaging (MRI) in Salla disease, a free sialic acid storage disorder.

Salla disease (SD) is a recessively inherited lysosomal storage disorder particularly common in the Finnish population. Patients with SD are normal at birth, but develop psychomotor delay and ataxia during the first year of life. Phenotypic variation of SD is wide, ranging from severely disabled children to mentally retarded adults capable of living under sheltered conditions. In the present study four unusually severely affected patients were investigated by detailed clinical examination, magnetic resonance imaging (MRI) and analysis of the excretion of free sialic acid in urine. MRI study, reported here for the first time, revealed a similarly defective myelination pattern in seven patients. The myelination process seemed to cessate at the level of an infant of a few months of age. Genetic linkage study of the families of the severely affected patients suggested linkage to the recently discovered SD locus on the long arm of chromosome 6. Locus heterogeneity therefore is an unlikely explanation of the phenotypic variation in SD.

Adolescent↗
PubMed1994

Ring chromosome 20 mosaicism in a girl with complex partial seizures.

The authors report an 11-year-old girl with epilepsy, poor school-performance and minor behavioural disorders. The epilepsy is characterized by complex partial seizures, sometimes progressing secondarily into generalized tonic-clonic seizures, and is poorly controlled by medical treatment. Chromosomal analysis revealed a ring chromosome 20 mosaicism. The affected patient shows signs of ring chromosome 20 syndrome, characterized in the present case by poor school-performance, behavioural disorders and epilepsy.

Child↗
PubMed1988

Spectral analysis of impedance respirogram in newborn infants.

Respiratory rate (RR), transthoracic electric impedance (TEZ) and transcutaneous PO2 and PCO2 were monitored during the 5 first postnatal days in 54 neonates on three separate occasions. There was no difference in the overall RR between the term and healthy preterm babies on different days of recordings but RR of the babies with RDS (who were all ventilated) was lower on day 1 (p less than 0.01). When the power spectrum of the TEZ respirogram was computed and the spectral density was divided into low-frequency (LF, less than 0.20 Hz) and high-frequency (HF, greater than 0.20 Hz) areas, the LF/HF ratio of healthy preterm babies was greater than that of term babies on day 1 (p less than 0.01). The preterm babies with RDS did not differ from the term babies in this respect. The LF/HF ratio was negatively correlated with gestational age and it had a positive correlation to PtcO2 (p less than 0.05) and PtcCO2 (p less than 0.01) (R2 = 0.07). The result evidences that the control of respiration changes in relation to maturity and the LF/HF ratio is a quantitative indicator of respiratory variability reflecting this development.

Blood Gas Monitoring, Transcutaneous↗