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A 13-year follow-up of Finnish patients with Salla disease.

Paavola LE, Remes AM, Harila MJ, Varho TT, Korhonen TT, Majamaa K - J Neurodev Disord (2015)

Bottom Line: Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria.Thus, the results indicate better prognosis in cognitive skills than earlier assumed.The early neurocognitive development predicts the later course of motor and cognitive development.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Oulu University Hospital, P.O. Box 20, 90029 Oulu, Finland ; Department of Clinical Medicine, Neurology, University of Oulu, P.O. Box 5000, 90014 Oulu, Finland ; Department of Clinical Neurology, University of Oulu, P.O. Box 5000, 90014 Oulu, Finland ; Neural Ltd, Center of Neuropsychology, Isokatu 16 B 18, 90100 Oulu, Finland.

ABSTRACT

Background: Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.

Methods: Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16-65 years, 13 years after a similar examination.

Results: The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.

Conclusions: Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development.

No MeSH data available.


Related in: MedlinePlus

Developmental age as a function of chronological age in 24 patients with SD. Developmental age was determined by using the motor tasks (a) or the mental tasks (b) of BSID-II
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Fig3: Developmental age as a function of chronological age in 24 patients with SD. Developmental age was determined by using the motor tasks (a) or the mental tasks (b) of BSID-II

Mentions: The maximal motor developmental age was 27 months, and the maximal mental developmental age was 42 months among the 24 SD patients. The developmental ages of four subjects (age range, 16–34 years) were significantly lower than those of other patients with a similar age. These four patients presented with the severe phenotype of SD, and they were compound heterozygotes harboring the R39C mutation only in one allele. There was a significant inverse correlation between the motor developmental age and the chronological age (Fig. 3a) and between the mental developmental age and chronological age (Fig. 3b). Motor and mental developmental ages at the follow-up visit correlated well with each other (Pearson correlation coefficient r = 0.88, p = 0.001), and this was the case also for the data obtained at the baseline visit. The motor developmental age at the follow-up visit was dependent on that at the baseline visit, but not on age, sex, or baseline mental developmental age. In a similar fashion, the mental developmental age at the follow-up visit was dependent on that at the baseline visit, but not on age, sex, or motor developmental age at baseline.Fig. 3


A 13-year follow-up of Finnish patients with Salla disease.

Paavola LE, Remes AM, Harila MJ, Varho TT, Korhonen TT, Majamaa K - J Neurodev Disord (2015)

Developmental age as a function of chronological age in 24 patients with SD. Developmental age was determined by using the motor tasks (a) or the mental tasks (b) of BSID-II
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4499899&req=5

Fig3: Developmental age as a function of chronological age in 24 patients with SD. Developmental age was determined by using the motor tasks (a) or the mental tasks (b) of BSID-II
Mentions: The maximal motor developmental age was 27 months, and the maximal mental developmental age was 42 months among the 24 SD patients. The developmental ages of four subjects (age range, 16–34 years) were significantly lower than those of other patients with a similar age. These four patients presented with the severe phenotype of SD, and they were compound heterozygotes harboring the R39C mutation only in one allele. There was a significant inverse correlation between the motor developmental age and the chronological age (Fig. 3a) and between the mental developmental age and chronological age (Fig. 3b). Motor and mental developmental ages at the follow-up visit correlated well with each other (Pearson correlation coefficient r = 0.88, p = 0.001), and this was the case also for the data obtained at the baseline visit. The motor developmental age at the follow-up visit was dependent on that at the baseline visit, but not on age, sex, or baseline mental developmental age. In a similar fashion, the mental developmental age at the follow-up visit was dependent on that at the baseline visit, but not on age, sex, or motor developmental age at baseline.Fig. 3

Bottom Line: Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria.Thus, the results indicate better prognosis in cognitive skills than earlier assumed.The early neurocognitive development predicts the later course of motor and cognitive development.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Oulu University Hospital, P.O. Box 20, 90029 Oulu, Finland ; Department of Clinical Medicine, Neurology, University of Oulu, P.O. Box 5000, 90014 Oulu, Finland ; Department of Clinical Neurology, University of Oulu, P.O. Box 5000, 90014 Oulu, Finland ; Neural Ltd, Center of Neuropsychology, Isokatu 16 B 18, 90100 Oulu, Finland.

ABSTRACT

Background: Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.

Methods: Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16-65 years, 13 years after a similar examination.

Results: The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.

Conclusions: Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development.

No MeSH data available.


Related in: MedlinePlus