Clinical myopathy in patients with nephropathic cystinosis.

BACKGROUND: Nephropathic cystinosis is a lysosomal storage disorder. Patient survival years after renal transplantation has revealed systemic complications including distal myopathy and dysphagia. METHODS: We evaluated 20 adult patients with nephropathic cystinosis using patient-reported and clinical outcome measures. Standard motor measures, video fluoroscopy swallow studies, and tests of respiratory function were performed. We also used Rasch analysis of an initial survey to design a 16-item survey focused on upper and lower extremity function, which was completed by 31 additional patients. RESULTS: Distal myopathy and dysphagia were common in patients with nephropathic cystinosis. Muscle weakness ranges from mild involvement of intrinsic hand muscles to prominent distal greater than proximal weakness and contractures. CONCLUSIONS: In addition to further characterization of underlying dysphagia and muscle weakness, we propose a new psychometrically devised, disease specific, functional outcome measures for distal myopathy in patients with nephropathic cystinosis.

Visual and verbal learning and memory in cystinosis.

Cystinosis is a rare genetic lysosomal storage disorder characterized by the accumulation of cystine in lysosomes. Many organ systems are vulnerable to this cystine accumulation including the CNS. A past study demonstrated that children with cystinosis have deficits in visual learning and memory while their verbal learning and memory and global intellectual function are spared (Spilkin, Ballantyne, & Trauner, 2009). However, no related study has been performed to assess the dissociation between visual and verbal learning and memory in adults with cystinosis who have had the benefit of longterm treatment with the cystine-depleting agent, cysteamine. In this study we assessed visual and verbal learning and memory in 15 adults with cystinosis, with a mean age of 30.2 years. The results indicate that adults with cystinosis have no significant deficits in either verbal or visual learning and memory. However, the individuals did perform better on the verbal assessment. The results suggest that if early and continued treatment is given to individuals with cystinosis there is a relative sparing of visual learning and memory that might have otherwise declined. This emphasizes the essential nature of the proper clinical management of cystinosis.

Multidisciplinary approach for patients with nephropathic cystinosis: model for care in a rare and chronic renal disease / Abordagem multidisciplinar para pacientes com cistinose nefropática: modelo para atendimento em uma doença renal rara e crônica

Abstract Care for patients with chronic and rare diseases is complex, especially considering the lack of knowledge about the disease, which makes early and precise diagnosis difficult, as well as the need for specific tests, sometimes of high complexity and cost. Added to these factors are difficulties in obtaining adequate treatment when available, in raising patient and family awareness about the disease and treatment compliance. Nephropathic cystinosis is among these diseases. After more than 20 years as a care center for these patients, the authors propose a follow-up protocol, which has been used with improvement in the quality of care and consists of a multidisciplinary approach, including care provided by a physician, nurse, psychologist, nutritionist and social worker. In this paper, each field objectively exposes how to address points that involve the stages of diagnosis and its communication with the patient and their relatives or guardians, covering the particularities of the disease and the treatment, the impact on the lives of patients and families, the approach to psychological and social issues and guidelines on medications and diets. This protocol could be adapted to the follow-up of patients with other rare diseases, including those with renal involvement. This proposal is expected to reach the largest number of professionals involved in the follow-up of these patients, strengthening the bases for the creation of a national protocol, observing the particularities of each case.

Resumo A assistência a pacientes com doenças crônicas e raras é complexa, principalmente pela falta de disseminação de conhecimento sobre a doença, o que dificulta o diagnóstico preciso e precoce, além da necessidade da realização de exames específicos, por vezes de alta complexidade e custo. Somam-se a esses fatores dificuldades na obtenção de tratamento adequado quando disponível, na conscientização do paciente e da família sobre a doença e na aderência ao tratamento. A cistinose nefropática está entre essas doenças. Após mais de 20 anos como centro de atendimento a esses pacientes, os autores propõem um protocolo de seguimento, o qual vem sendo empregado com melhora na qualidade da assistência e consiste de uma abordagem multidisciplinar, incluindo, principalmente, atendimento prestado por médico, enfermeiro, psicólogo, nutricionista e assistente social. Neste artigo, cada área expõe de maneira objetiva como abordar pontos que envolvem as etapas do diagnóstico e sua comunicação ao paciente e a seus familiares ou responsáveis, abrangendo as particularidades da doença e do tratamento, o impacto na vida do paciente e de sua família, a abordagem das questões psicológicas e sociais e orientações quanto a medicamentos e dietas. Considera-se que este protocolo poderia ser adaptado ao seguimento de pacientes portadores de outras doenças raras, incluindo aquelas com envolvimento renal. Com essa proposta, espera-se alcançar o maior número de profissionais envolvidos no seguimento desses pacientes, fortalecendo as bases para a criação de um protocolo nacional, observando-se as particularidades de cada caso.

Hierarchical processing of visual stimuli in nephropathic cystinosis.

Previous studies have shown that individuals with cystinosis may exhibit difficulty with visuospatial tasks. Global and local (hierarchical) processing are specific types of visuospatial tasks mediated by the right and left parietal lobes respectively. The study objective was to determine whether individuals with cystinosis and carriers of the cystinosin gene mutation show deficits in global and/or local processing. The study included 48 children (32 controls, 16 cystinosis) and 56 adults (25 controls, 25 carriers, and 6 cystinosis). Participants were instructed to replicate 10 hierarchical stimuli to assess global-local processing. The primary outcome measure was mean global and local performance on the hierarchical stimuli task between subgroups. Error subtypes were included to further assess each image. Compared to the control subgroups, adult and child cystinosis patients as well adult carriers demonstrated significant deficits in the global processing of a hierarchical stimulus against a background of unimpaired local processing. Child cystinosis patients performed significantly more poorly than controls on all error subtypes except local shape distortion. Adult cystinosis patients and carriers made significantly more global shape distortion errors than the controls. Our study shows that the cognitive profile documented in cystinosis patients and carriers includes significant difficulties with the global processing of an image. Results of the carrier population are important since they suggest that the cognitive impairments observed in patients cannot be attributed to symptomatic manifestations of the disease. Instead, the global processing deficits observed provide insight into the potential role of the cystinosin gene mutation on neurodevelopmental differences seen in these individuals.

Multidisciplinary approach for patients with nephropathic cystinosis: model for care in a rare and chronic renal disease.

Care for patients with chronic and rare diseases is complex, especially considering the lack of knowledge about the disease, which makes early and precise diagnosis difficult, as well as the need for specific tests, sometimes of high complexity and cost. Added to these factors are difficulties in obtaining adequate treatment when available, in raising patient and family awareness about the disease and treatment compliance. Nephropathic cystinosis is among these diseases. After more than 20 years as a care center for these patients, the authors propose a follow-up protocol, which has been used with improvement in the quality of care and consists of a multidisciplinary approach, including care provided by a physician, nurse, psychologist, nutritionist and social worker. In this paper, each field objectively exposes how to address points that involve the stages of diagnosis and its communication with the patient and their relatives or guardians, covering the particularities of the disease and the treatment, the impact on the lives of patients and families, the approach to psychological and social issues and guidelines on medications and diets. This protocol could be adapted to the follow-up of patients with other rare diseases, including those with renal involvement. This proposal is expected to reach the largest number of professionals involved in the follow-up of these patients, strengthening the bases for the creation of a national protocol, observing the particularities of each case.

Mood and illness experiences of adults with cystinosis.

BACKGROUND: Cystinosis is an autosomal recessive disorder with an estimated incidence of 1/100,000-200,000 live births. The main complications are renal disease, visual impairment, endocrine abnormalities and growth retardation. OBJECTIVE: Our aim was to describe the mood and illness experiences of adults with cystinosis. METHODS: Twenty-three patients attending the adult cystinosis clinic at Guy's Hospital, London were asked to complete the Hospital Anxiety and Depression Scale (HADS) questionnaire anonymously. Eighteen months later, 21 patients who were still alive were invited to participate in a semi-structured interview aimed at exploring illness experience. RESULTS: Eighteen patients completed the HADS questionnaire (means: depression = 7.2; anxiety = 9.2), and 12 participated in the interviews. Three significant themes emerged: (i) the main physical complaints were tiredness, the impact of short stature and side effects of cysteamine medication, especially halitosis, poor taste and nausea. (ii) Cystinosis has a major impact on relationships, autonomy and social life, including reliance on families for support to self-manage, distress at dependence, social anxiety, reduced social involvement and some positive effects on family cohesiveness. (iii) Patients use a range of individual coping strategies to deal with their illness and medication. CONCLUSIONS: Adult cystinosis patients reported comparatively high-anxiety and depression scores. Common complaints related to the complications of cystinosis and the side-effects of cysteamine, which impacted on relationships, autonomy and social life. Patients described a wide range of strategies, including benefit finding, for coping with cystinosis.

Peer Support and Mentorship in a US Rare Disease Community: Findings from the Cystinosis in Emerging Adulthood Study.

PURPOSE: Medical advances have transformed the rare disease cystinosis from fatal in childhood to chronic and manageable into adulthood. Disease-specific advocacy groups and interaction via the Internet create opportunities for peer support, part of the changing experience and outcomes of the illness. METHODS: This study utilized a qualitative grounded theory approach to explore the experience of emerging adults and adults with cystinosis, and their parents. Individuals (n = 49) from 21 families were recruited online and in person for focus groups and/or individual interviews. RESULTS: Individuals participate in the disease community through comfortability, comparing notes, witnessing/scaling, modeling/mentoring, and going/being public. Participants valued connection to others who shared their diagnosis, and seek to provide support and mentorship to younger patients and their families. Adults with cystinosis perceived themselves as role models but also as examples of potential progression and disability. Going/being public about one's health condition carried emotional and social risks. IMPLICATIONS: Individuals and families benefit from peer support and mentorship from others who share their illness experience. Participation in the disease community helps individuals (and caregivers) negotiate living with illness and the transition to adulthood. Further research regarding these processes within other disease communities is needed.

Neurocognitive functions and behavioral profiles in children with nephropathic cystinosis.

Children with nephropathic cystinosis (NCTN) have evidence of defective intellectual functions and behavioral disorders. This prospective study was performed to detect the cognitive dysfunctions in patients with this rare hereditary lysosomal storage disease, define their behavioral phenotypes, and study the findings on magnetic resonance imaging (MRI) of the brain. Thirteen patients with confirmed diagnosis of cystinosis (mean age±SD 5.9±3.0, range 1.5-12 years) were subjected to the Stanford Binet test, Porteus Maze test, Child Behavior Checklist, and MRI brain. Thirteen age- and sex-matched children served as the control subjects (mean age±SD 5.9±2.9, range 1.7-12 years). The intelligence quotient (IQ) was significantly lower in patients with cystinosis (P<0.001), with a significant defect in verbal (language, memory, and comprehension) and non-verbal abilities (visual perception and visiospatial and motor performance). A discrepancy between both abilities was detected--the non-verbal ability being lower; however, it did not reach statistical significance. Furthermore, analysis revealed the visiospatial ability to be significantly lower compared to the visual perception. In comparison to healthy controls, children with NCTN had evidence of increased incidence of behavioral problems, mainly social (P=0.023). An MRI of the brain revealed varying degrees of atrophic changes in seven patients. Patients with NCTN need a wider scope of attention and care, encompassing not only the metabolic multisystem derangement, but also the neuropsychological impairment in the context of multidisciplinary management. This approach is crucial in formulating comprehensive plans for social and educational rehabilitation.

Executive function in nephropathic cystinosis.

OBJECTIVE: We studied executive function (EF) in children and adolescents with cystinosis. BACKGROUND: Cystinosis is a genetic metabolic disorder in which the amino acid cystine accumulates in all organs of the body, including the brain. Previous research has shown that individuals with cystinosis have visuospatial deficits, but normal intelligence and intact verbal abilities. Better understanding of the behavioral phenotype associated with cystinosis could have important implications for treatment. METHODS: Twenty-eight children with cystinosis and 24 control participants (age range 8 to 17 years) underwent selected Delis-Kaplan executive function system tests for neuropsychological assessment of EF, and the participants' parents completed the behavior rating inventory of executive function. RESULTS: Participants with cystinosis performed significantly more poorly than controls on all Delis-Kaplan Executive Function System indices examined and on the behavior rating inventory of executive function metacognition index and global executive composite. CONCLUSIONS: EF is an area of potential risk in cystinosis. Our data have implications not only for the function of affected children and adolescents in school and daily life, but also for disease management and treatment adherence. Our findings can aid in the design and implementation of interventions and lead to a greater understanding of brain-behavior relationships in cystinosis.

Cognition in nephropathic cystinosis: pattern of expression in heterozygous carriers.

Individuals with cystinosis exhibit specific cognitive deficits in visual spatial function. The purpose of the current study was to examine if obligate heterozygotes of the CTNS mutation have the same pattern of cognitive functioning seen in homozygotes, namely aberrant visual-spatial functioning against a background of relatively intact visual-perceptual functioning and overall cognitive ability. Study participants were 254 adults (100 heterozygotes and 154 controls), ages 17 years 10 months through 74 years 9 months. Tests of intelligence, visual perceptual, and visual spatial functioning were administered. Our results showed that cystinosis heterozygotes demonstrated intelligence within the normal range, and performed similarly to controls on tests of visual-perceptual ability. In contrast, the heterozygotes performed significantly more poorly on each of the visual-spatial tests when compared to controls. Obligate heterozygotes for the CTNS mutation display a similar pattern of visual processing decrements as do individuals with cystinosis. Namely, carriers demonstrate relative weaknesses in visual-spatial processing, while maintaining normal visual perceptual ability and intelligence in the normal range. The visual spatial decrements in heterozygotes were not as marked as those found in individuals with cystinosis, suggesting a gene dosing effect. This study provides an impetus for other studies of gene-behavior relationships in recessive disorders, and may stimulate further interest in the role of aberrant genes on "individual differences" in behavior.

Neurocognitive functioning in school-aged cystinosis patients.

INTRODUCTION: Cystinosis is an autosomal recessive disorder leading to intralysosomal cystine accumulation in various tissues. It causes renal Fanconi syndrome and end stage renal failure around the age of 10 years if not treated with cysteamine. Children with cystinosis seem to have a normal intelligence but frequently show learning difficulties. These problems may be due to specific neurocognitive deficits rather than impaired renal function. Whether cysteamine treatment can improve cognitive functioning of cystinosis patients is thus far unknown. We aim to analyze neurocognitive functioning of school-aged cystinosis patients treated with cysteamine in order to identify specific deficits that can lead to learning difficulties. PATIENTS AND METHODS: Fourteen Dutch and Belgian school-aged cystinosis patients were included. Glomerular filtration rate was estimated using the Schwartz formula. Children were tested for general intelligence, visual-motor integration, inhibition, interference, sustained attention, accuracy, planning, visual memory, processing speed, motor planning, fluency and speed, and behavioural and emotional functioning using standardized methods. RESULTS: Glomerular filtration rate ranged from 22 to 120 ml min(-1) 1.73 m(-2). Median full-scale intelligence was below the average of a normal population (87, range 60-132), with a discrepancy between verbal (median 95, range 60-125) and performance (median 87, range 65-130) intelligence. Over 50% of the patients scored poorly on visual-motor integration, sustained attention, visual memory, planning, or motor speed. The other tested areas showed no differences between patients' and normal values. CONCLUSION: Neurocognitive diagnostics are indicated in cystinosis patients. Early recognition of specific deficits and supervision from special education services might reduce learning difficulties and improve school careers.

Intellectual and motor performance, quality of life and psychosocial adjustment in children with cystinosis.

Cystinosis is a rare multisystemic progressive disorder mandating lifelong medical treatment. Knowledge on the intellectual and motor functioning, health-related quality of life and psychosocial adjustment in children with cystinosis is limited. We have investigated nine patients (four after renal transplantation) at a median age of 9.7 years (range 5.3-19.9 years). Intellectual performance (IP) was analysed with the Wechsler Intelligence Scale for Children-III (seven children) and the Kaufman Assessment Battery for Children (two children). Motor performance (MP) was evaluated using the Zurich Neuromotor Assessment Test, and quality of life (QOL) was studied by means of the Netherlands Organization for Applied Scientific Research Academical Medical Center Child Quality of Life Questionnaire. Psychosocial adjustment was assessed by the Child Behavior Checklist. The overall intelligence quotient (IQ) of our patient cohort (median 92, range 71-105) was significantly lower than that of the healthy controls (p = 0.04), with two patients having an IQ < 85. Verbal IQ (93, range 76-118) was significantly higher than performance IQ (90, range 68-97; p = 0.03). The MP was significantly below the norm for pure motor, pegboard and static balance, as well as for movement quality. The patients' QOL was normal for six of seven dimensions (exception being positive emotions), whereas parents reported significant impairment in positive emotions, autonomy, social and cognitive functions. Significant disturbance was noted in terms of psychosocial adjustment. Based on the results from our small patient cohort, we conclude that intellectual and motor performance, health-related QOL and psychosocial adjustment are significantly impaired in children and adolescents with cystinosis.

Behavioral profiles of children with infantile nephropathic cystinosis.

Children with infantile nephropathic cystinosis have evidence of visuospatial and arithmetic deficits on a background of normal intellectual and verbal skills. This study aimed to define further their behavioral phenotype. The Achenbach Child Behavior Checklist was completed by parents of: 64 children and adolescents with cystinosis (33 females, 31 males; mean age 8 y 8 mo, range 4 to 16y, SD 2 y 11 mo); 101 healthy controls (47 females, 54 males; mean age 8 y 4 mo, range 4 to 16 y, SD 2 y 11 mo); 21 children and adolescents with cystic fibrosis (CF), termed chronic-disease controls (9 females, 12 males; mean age 11 y 3 mo, age range 4 to 17 y, SD 3 y 5 mo). Compared with healthy controls, individuals with cystinosis had evidence of a significantly higher incidence of behavioral problems, including social problems, somatic complaints, and attention problems. Compared with the chronic-disease control group, the cystinosis group differed only on the Social Problems scale, with 22% of participants with cystinosis scoring in the 'at risk' range whereas no participant with CF received an elevated score on this scale. We conclude that children and adolescents with cystinosis have evidence of a significant incidence of social difficulties compared with individuals with another chronic illness and healthy participants. The combination of visuospatial problems, difficulty with arithmetic, attention problems, and social difficulties seen in the cystinosis group constitutes a behavioral phenotype of this genetic disorder. This cluster of cognitive and behavioral symptoms is also seen in the nonverbal learning disabilities syndrome, and suggests a possible early difference in brain development in children with cystinosis compared with children who do not share this genetic disorder.

Visuomotor performance in children with infantile nephropathic cystinosis.

Infantile nephropathic cystinosis is a genetic metabolic disorder in which the amino acid cystine accumulates in various organs, including the kidney, cornea, thyroid, and brain. Despite normal intellect, individuals with cystinosis may have specific impairments in the processing of visual information. To examine further the specific types of deficits in visual processing found in individuals with cystinosis, we administered the Development Test of Visual-motor Integration to 26 children with cystinosis (4 to 16 yr. old) and 26 matched controls. The cystinosis group achieved a significantly lower standard score, raw score, and mean ceiling than did the control group. Qualitative analyses showed that in the cystinosis group, size within errors and rotation errors were more prevalent than in the control group. Correlational analyses showed that with advancing age, the cystinosis subjects tended to fall further behind their chronological age. Our data, together with the findings of previous studies, suggest that the visuospatial difficulties in children with cystinosis may be due to inadequate perception or processing of visually presented information. Furthermore, the increasing discrepancy with age may reflect a progressive cognitive impairment, possibly as a result of cystine accumulation in the brain over time.

Global intellectual deficits in cystinosis.

Fourteen families of children with infantile nephropathic cystinosis were evaluated using the Stanford-Binet Intelligence Scale, Fourth Edition [Thorndike et al., 1986: Stanford-Binet Intelligence Scale, Fourth Ed.]. The IQs of 15 children with cystinosis, their 23 sibs and 24 parents were compared in order to evaluate a potential effect of cystinosis on intelligence. Children with cystinosis had a significantly lower mean IQ than their sibs and their parents (P = .001). Thus, even though the mean IQ of the children with cystinosis (94.4 +/- 10) was within the average range, there is evidence that these children have a mild global intellectual deficit relative to their expected IQ based upon the IQs of other relatives. In addition, to a subset of the subjects we administered a measure of scholastic ability, the Wide Range Achievement Test-Revised [Jastak and Wilkinson, 1984: The Wide Range Achievement Test-Revised], which consists of spelling, reading, and arithmetic subtests. The 11 cystinosis subjects scored significantly lower (P = .01) than their 16 sibs and their 14 parents in the area of spelling, whereas they did not significantly differ in their performance in the areas of reading and arithmetic.

Psychosocial and intellectual development in 12 patients with infantile nephropathic cystinosis.

The psychosocial and intellectual development of 12 children with infantile nephropathic cystinosis was investigated longitudinally by use of biographical data, long-term behavioral observations and psychological assessment. Of the 12 patients, eleven suffered terminal renal failure and 7 of these were followed up after renal transplantation. In spite of the severe illness and the resulting unusual life conditions the patients showed normal intellectual capacity and most of them average school performance. The patients were socially adapted, their behavior was predominantly cooperative, shy and reserved, but depressive at times. After transplantation the children became more active and outgoing. However, growing discrepancies between their physical development and their emotional and social age may lead to adaptational problems at adolescence which may require psychological counselling.

[Psychosocial intellectual development of children with infantile cystinosis and cerebral atrophy (author's transl)]. / Psychosozial-intellektuelle Entwicklung bei Kindern mit infantiler Zystinose und Hirnatrophie.

The psychosocial and intellectual development of 4 boys with nephropathic cystinosis and brain atrophy documented by cranial computerized tomography was investigated by use of biographical data and psychological tests (HAWIK, Deutscher Rechtschreibtest). Inspite of the brain atrophy the patients showed low-normal intellectual capacities and mainly average school performance. There were no psychosocial abnormalities correlated to the primary metabolic disease. However, renal dwarfism led to mascotism requiring psychotherapy.