Neurocognitive functioning in school-aged cystinosis patients: general effects of chronic disease or specific deficits?

According to a limited number of studies patients with cystinosis are assumed
to be normal intelligent (Wolff et al.1982; Williams et al.1994, Colah et
al.1997; Ballantyne et al.1997). However neuropsychological research performed
by the latter investigators, all participants in the group of Doris Trauner,
San Diego, showed problems in visual- and tactile information processing (Colah
et al., visual-spatial functioning (Williams et al.) resulting into impaired
school performance e.g. spelling and arithmatic (Ballantyne et al.) Our pilot
study showed disturbances in fine-motor functioning in 6 out of 9 children.
Williams et al. hypothesized a relation between these "minor symptoms" and a
neurotoxic effect of cystine accumulation in the brain. Moreover it has to be
referred to global effects of chronic renal failure, side effects of medication
an the psychosocial impact of chronic ilness in general. Recent literature
mentionede late adverse effects of renal disease and treatment on cognitive
functioning in general and a-specific neurocognitive defects: attention,
memory, visual-motor functioning, but also verbal abilities (Groothoff et al.
2002; Gipson et al. 2004). A rather high percentage of children from our
patient group has been referred because of school problems. Neuropsychological
investigation showed a specific neurocognitive profile. Learning problems
resulting from specific defects have not or insufficiently been recognized by
parents and teachers, because the child is assessed as normal intelligent or
even "smart". Identification of "minor"neurological symptoms,visual and
perceptual disorders and schoolproblems by neuropsychological screening in all
school-aged cystinosis patients is strongly recommended.

The aim of the study is to improve the quality of life of cystinosis patients.
Part of it forms neuropsychological screening in order to identify specific
defects in the neurocognitive development and learning abilities. The results
will contribute to an early recognition of specific problems, information and
advices to parents and teachers.

Neuropsychological screening of all school-aged cystinosis patients treated in
the Netherlands (age 6-16 yrs., n=20)
-cognitive functioning WISC-lll, verbal and performal intelligence
-neurocognitive functioning (ANT,Stroop,Bourdon)
-perceptual (visual)- motor functioning (VMI and experimental drawing- and
writing tasks by an electronic digitizer identifying an analyzing pressure,
tremors, fluency, speed and pauses
-behavioural- and school problems (CBCL (parents)and TRF (teachers)

The tests , as well as reports are executed by a psychological assistant,
supervised by a clinical psychologist. The junior investicator/psychologist
will analyze the data writing the manuscript. The results will be discussed
personally and reported by written with the patient and the parents and if
indicated (after having obtained permission) information and advice will be
provided to the school.
See enclosed appendix

see under section E2