Idiopathic intracranial hypertension in cystinosis

A systematic review of cognition in idiopathic intracranial hypertension

Background: Cognitive disturbance is not pathognomonic of idiopathic intracranial hypertension (IIH), and therefore is not routinely assessed unless it presents as a major complaint. Consequently, cognition has been slow to gain substantial traction in IIH-related research, despite its notable impact on a subset of patients. We completed a systematic review of the literature examining the neurocognitive profile of patients with IIH. Methods: A PRISMA compliant literature search was conducted in Ovid Medline, PubMed, PsycInfo, Embase, Web of Science, Cochrane, Cinahl, and Scopus databases. The initial query yielded 1376 unique articles. These articles were narrowed to those including empirical analyses of cognitive assessment in adult patients with IIH. Results: A final cohort of nine articles resulted, comprising the findings from 309 patients with IIH and 153 healthy control subjects. Although there was considerable variability in methodology particularly with respect to cognitive assessment, fairly consistent deficits were observed across studies in the domains of processing speed, working memory, sustained and complex attention, set-shifting, and confrontation naming. Body mass index and body weight were not associated with cognitive performance. Pertinent limitations of the literature were identified, most notably failure to report trial-level cognitive testing data, the need for more comprehensive testing batteries with less reliance on screening tools, and not controlling for variables that may impact cognition. Conclusions: A more complete understanding of the cognitive profile in patients with idiopathic intracranial hypertension could lead to the increased -relevance of cognitive screening in disease management, and therefore more appropriate neuropsychological referral, earlier identification of functional limitations, and targeted neurorehabilitation.

Neurologic involvement in cystinosis: Focus on brain lesions and new evidence of four-repeat (4R-) Tau immunoreactivity

Nephropathic cystinosis is a rare autosomal recessive storage disorder caused by CTNS gene mutations, leading to autophagy-lysosomal pathway impairment and cystine crystals accumulation. Neurologic involvement is highly variable and includes both neurodevelopmental and neurodegenerative disturbances, as well as focal neurologic deficits. By presenting longitudinal data of a 28-year-old patient with a large infratentorial lesion, we summarized the pathology, clinical and imaging features of neurological involvement in cystinosis patients. Brain damage in form of cystinosis-related cerebral lesions occurs in advanced disease phases and is characterized by the accumulation of cystine crystals, subsequent inflammation with vasculitis-like features, necrosis, and calcification. Epilepsy is a frequent comorbidity in affected individuals. Steroids might play a role in the symptomatic treatment of "stroke-like" episodes due to edematous-inflammatory lesions, but probably do not change the overall prognosis. Lifelong compliance to depleting therapy with cysteamine still represents the main therapeutic option. However, consequences of CTNS gene defects are not restricted to cystine accumulation. New evidence of four-repeat (4R-) Tau immunoreactivity suggests concurrent progressive neurodegeneration in cystinosis patients, highlighting the need of innovative therapeutic strategies, and shedding light on the crosstalk between proteinopathies and autophagy-lysosomal system defects. Eventually, emerging easily accessible biomarkers such as serum neurofilament light chains (NfL) might detect subclinical neurologic involvement in cystinosis patients.

Posterior Segment Involvement in Infantile Nephropathic Cystinosis - A Review

Cystinosis is a rare lysosomal storage disease with a prevalence of 1 : 100 000 - 1 : 200 000 cases. It is caused by biallelic mutations in the CTNS gene, which encodes cystinosin, that transport cystine out of the lysosomes. Due to its dysfunction, cystine crystals accumulate in the lysosomes and ultimately cause apoptosis of the cell. Since cystinosin is ubiquitously present in the body, cystine crystals are deposited in every body structure and lead to the dysfunction of various organ systems in the course of time. Cystine crystals deposited in the cornea are a clinical hallmark of the disease, while there is less awareness of concomitant posterior segment alterations. Symmetrical pigment epithelial mottling and patches of depigmentation frequently start in the periphery and progress towards the posterior pole and can be encountered upon fundus biomicroscopy. Spectral-domain optical coherence tomography (SD-OCT) is an elegant tool for visualizing chorioretinal cystine crystals at the posterior pole. An SD-OCT-based clinical grading of the severity of the chorioretinal manifestation can potentially be applied as a biomarker for systemic disease status and for monitoring oral therapy adherence in the future. Along with previous histological examinations, it may also give information about the location of cystine crystals in the choroid and retina. This review aims to increase the awareness of vision-threatening retinal and choroidal changes in cystinosis and the concomitant findings in SD-OCT.

Cystinosis

Cystinosis is a very rare autosomal recessive lysosomal storage disorder with an incidence of 1 : 150,000 - 1 : 200,000, and is caused by mutations in the CTNS gene encoding the lysosomal membrane protein cystinosin, which transports cystine out of the lysosome into the cytoplasm. As a result, accumulation of cystine occurs in almost all cells and tissues, especially in the kidneys, leading to multiple organ involvement. Introduction of drug therapy with cysteamine in the mid 1980s, along with the availability of renal replacement therapy in childhood, have dramatically improved patient outcome. Whereas patients used to die without therapy with end-stage renal failure during the first decade of life, nowadays most patients live well into adulthood without renal replacement therapy, and several reach 40 years. There is robust evidence that early initiation and sustained lifelong therapy with cysteamine are both essential for morbidity and mortality. The rarity of the disease and the multi-organ involvement present an enormous challenge for those affected and the providers of care for this patient group.

Relationship between age at initiation of cysteamine treatment, adherence with therapy, and glomerular kidney function in infantile nephropathic cystinosis

Infantile nephropathic cystinosis, due to impaired transport of cystine out of lysosomes, occurs with an incidence of 1 in 100-200,000 live births. It is characterized by renal Fanconi syndrome in the first year of life and glomerular dysfunction progression to end-stage kidney disease by approximately 10 years of age. Treatment with oral cysteamine therapy helps preserve glomerular function, but affected individuals eventually require kidney replacement therapy. This is because glomerular damage had already occurred by the time a child is diagnosed with cystinosis, typically in the second year of life. We performed a retrospective multicenter study to investigate the impact of initiating cysteamine treatment within the first 2 months of life in some infants and comparing two different levels of adherence in patients diagnosed at the typical age. We collected 3983 data points from 55 patients born between 1997 and 2020; 52 patients with 1592 data points could be further evaluated. These data were first analyzed by dividing the patient cohort into three groups: (i) standard treatment start with good adherence, (ii) standard treatment start with less good adherence, and (iii) early treatment start. At every age, mean estimated glomerular filtration rate (eGFR) was higher in early-treated patients than in later-treated patients. Second, a generalized additive mixed model (GAMM) was applied showing that patients with initiation of treatment before 2 months of age are expected to have a 34 ml/min/1.73 m² higher eGFR than patients with later treatment start while controlling for adherence and patients' age. These data strongly suggest that oral cysteamine treatment initiated within 2 months of birth preserves kidney function in infantile nephropathic cystinosis and provide evidence of the utility of newborn screening for this disease.

Beneficial effects of starting oral cysteamine treatment in the first 2 months of life on glomerular and tubular kidney function in infantile nephropathic cystinosis

Nephropathic cystinosis is a rare lysosomal storage disease whose basic defect, impaired transport of cystine out of lysosomes, results in intracellular cystine storage. Affected individuals exhibit renal Fanconi Syndrome in infancy, end-stage kidney disease at approximately 10 years of age, and many other systemic complications. Oral cysteamine therapy mitigates the detrimental effects on glomerular function and prevents most of the late complications of the disease but has not shown benefit with respect to the early tubular damage of cystinosis. This is because cystinosis is generally diagnosed in the second year of life, after the damage to kidney tubular function has already occurred. We longitudinally evaluated 6 infants diagnosed and treated with cysteamine from before 2 months of age. The 4 infants with good compliance with cysteamine and consistently low leucocyte cystine levels maintained normal eGFR values, exhibited only minor degrees of renal Fanconi Syndrome, and maintained normal serum levels of potassium, bicarbonate, phosphate, and calcium without electrolyte or mineral supplementation through 2, 4, 10 and 16 years of age. Thus, renal Fanconi syndrome can be attenuated by early administration of cysteamine and renew the call for molecular-based newborn screening for cystinosis.

Central Nervous System Complications in Cystinosis: The Role of Neuroimaging

Despite improvement in the specific treatment, clinical and anatomo-functional central nervous system (CNS) abnormalities of various severities are still observed in cystinosis patients. Patients who develop CNS complications today have a worse compliance to cysteamine treatment. Radiological studies have shown that cortical or central (ventriculomegaly) atrophy is observed in more than two thirds of cystinosis patients’ magnetic resonance imaging (MRI) and correlates with the intelligence quotient score. Half of cystinosis patients have marked aspecific white matter hyperintensities. The development of advanced neuroimaging techniques provides new tools to further investigate CNS complications. A recent neuroimaging study using a voxel-based morphometry approach showed that cystinosis patients present a decreased grey matter volume in the left middle frontal gyrus. Diffusion tensor imaging studies have shown white matter microstructure abnormalities in children and adults with cystinosis, respectively in areas of the dorsal visual pathway and within the corpus callosum’s body. Finally, leucocyte cystine levels are associated with decreased resting cerebral blood flow, measured by arterial spin labelling, in the frontal cortex, which could be associated with the neurocognitive deficits described in these patients. These results reinforce the relevance of neuroimaging studies to further understand the mechanisms that underline CNS impairments.

Renal and Extra Renal Manifestations in Adult Zebrafish Model of Cystinosis

Cystinosis is a rare, incurable, autosomal recessive disease caused by mutations in the CTNS gene. This gene encodes the lysosomal cystine transporter cystinosin, leading to lysosomal cystine accumulation in all cells of the body, with kidneys being the first affected organs. The current treatment with cysteamine decreases cystine accumulation, but does not reverse the proximal tubular dysfunction, glomerular injury or loss of renal function. In our previous study, we have developed a zebrafish model of cystinosis through a nonsense mutation in the CTNS gene and have shown that zebrafish larvae recapitulate the kidney phenotype described in humans. In the current study, we characterized the adult cystinosis zebrafish model and evaluated the long-term effects of the disease on kidney and extra renal organs through biochemical, histological, fertility and locomotor activity studies. We found that the adult cystinosis zebrafish presents cystine accumulation in various organs, altered kidney morphology, impaired skin pigmentation, decreased fertility, altered locomotor activity and ocular anomalies. Overall, our data indicate that the adult cystinosis zebrafish model reproduces several human phenotypes of cystinosis and may be useful for studying pathophysiology and long-term effects of novel therapies.

Adult complications of nephropathic cystinosis: a systematic review

While nephropathic cystinosis is classically thought of as a childhood disease, with improved treatments, patients are more commonly living into adulthood. We performed a systematic review of the literature available on what complications this population faces as it ages. Nearly every organ system is affected in cystinosis, either from the disease itself or from sequelae of kidney transplantation. While cysteamine is known to delay the onset of end-stage kidney disease, its effects on other complications of cystinosis are less well determined. More common adult-onset complications include myopathy, diabetes, and hypothyroidism. Some less common complications, such as neurologic dysfunction, can still have a profound impact on those with cystinosis. Areas for further research in this area include additional study of the impact of cysteamine on the nonrenal manifestations of cystinosis, as well as possible avenues for new and novel treatments.

Neuropsychological and neuroanatomical phenotype in 17 patients with cystinosis

Background

Cystinosis is a rare autosomal recessive disorder caused by intracellular cystine accumulation. Proximal tubulopathy (Fanconi syndrome) is one of the first signs, leading to end-stage renal disease between the age of 12 and 16. Other symptoms occur later and encompass endocrinopathies, distal myopathy and deterioration of the central nervous system. Treatment with cysteamine if started early can delay the progression of the disease. Little is known about the neurological impairment which occurs later. The goal of the present study was to find a possible neuroanatomical dysmorphic pattern that could help to explain the cognitive profile of cystinosis patients. We also performed a detailed review of the literature on neurocognitive complications associated with cystinosis.

Methods

17 patients (mean age = 17.6 years, [5.4–33.3]) with cystinosis were included in the study. Neuropsychological assessment was performed including intelligence (Intelligence Quotient (IQ) with Wechsler’s scale), memory (Children Memory Scale and Wechsler Memory Scale), visuo-spatial (Rey’s figure test) and visuo-perceptual skills assessments. Structural brain MRI (3 T) was also performed in 16 out of 17 patients, with high resolution 3D T1-weighted, 3D FLAIR and spectroscopy sequences.

Results

Intellectual efficiency was normal in patients with cystinosis (mean Total IQ = 93). However the Perceptual Reasoning Index (mean = 87, [63–109]) was significantly lower than the Verbal Comprehension Index (mean = 100, [59–138], p = 0.003). Memory assessment showed no difference between visual and verbal memory. But the working memory was significantly impaired in comparison with the general memory skills (p = 0.003). Visuospatial skills assessment revealed copy and reproduction scores below the 50th percentile rank in more than 70% of the patients. Brain MRI showed cortical and sub-cortical cerebral atrophy, especially in the parieto-occipital region and FLAIR hypersignals in parietal, occipital and brain stem/cerebellum. Patients with atrophic brain had lower Total IQ scores compared to non-atrophic cystinosis patients.

Conclusions

Patients with cystinosis have a specific neuropsychological and neuroanatomical profile. We suggest performing a systematic neuropsychological assessment in such children aiming at considering adequate management.

Short-cut diagnostic tool in cystinosis: Bone marrow aspiration

BACKGROUND

Cystinosis is a rare metabolic genetic disorder caused by a mutation in cystinosin lysosomal cystine transporter (CTNS). The diagnosis of nephropathic cystinosis (NC) is made by observing corneal cystine crystals and/or measuring the cystine content of leukocytes. CTNS mutation analysis confirms the diagnosis of cystinosis, but leukocyte cystine measurement and CTNS analysis have not been widely available, and cystine crystals in the cornea may not be apparent in the first months of life. Cystine crystal deposition can be seen in the bone marrow earlier than corneal deposition, in patients with NC.

METHODS

Ten patients with cystinosis diagnosis were enrolled in the study. Medical records were reviewed retrospectively to collect demographic and clinical data such as age at diagnosis, disease presentation, parental consanguinity, family history, corneal cystine deposition, leukocyte cystine level, bone marrow cystine deposition, presence of renal failure, follow-up time and prognosis.

RESULTS

Cystine crystals were seen in all of the patients' fresh bone marrow aspiration samples. Eight patients had corneal cystine deposition. Leukocyte cystine measurement could have been performed in four patients who had come from another center. Complications such as pulmonary hypertension and idiopathic intracranial hypertension (IIH) were observed in two patients.

CONCLUSIONS

Bone marrow aspiration might be an easy and short-cut diagnostic tool for NC especially when it is not possible to measure fibroblast cystine content. Additionally some rare complications such as pulmonary hypertension and IIH can be encountered during the course of NC.

Nephropathic cystinosis: an update

PURPOSE OF REVIEW

Over the past few decades, cystinosis, a rare lysosomal storage disorder, has evolved into a treatable metabolic disease. The increasing understanding of its pathophysiology has made cystinosis a prototype disease, delivering new insights into several fundamental biochemical and cellular processes.

RECENT FINDINGS

In this review, we aim to provide an overview of the latest advances in the pathogenetic, clinical, and therapeutic aspects of cystinosis.

SUMMARY

The development of alternative therapeutic monitoring strategies and new systemic and ocular cysteamine formulations might improve outcome of cystinosis patients in the near future. With the dawn of stem cell based therapy and new emerging gene-editing technologies, novel tools have become available in the search for a cure for cystinosis.

Intracranial Hypertension in Cystinosis Is a Challenge: Experience in a Children's Hospital

BACKGROUND

Cystinosis is a rare systemic lysosomal disease affecting mainly the kidney and eye. Ocular involvement in cystinosis is universal being the presence of cystine crystals in the cornea a diagnostic criterion and one of the earliest manifestations of the disease. Neuro-ophthalmologic manifestations are considered a rare and late complication in these patients. The aim of this article is to report the unexpectedly high incidence of intracranial hypertension in children with cystinosis at our centre.

METHODS

This study included eight children (0-16 years of age) with cystinosis seen at the paediatric ophthalmology department, Hospital Universitari Vall d'Hebron (Barcelona, Spain), a tertiary hospital, over the last 5 years.

RESULTS

Three girls and five boys, mean age: 9.6 years (range: 5-14 years), were studied. During follow-up, 4 out of 8 developed papilledema and confirmed high cerebrospinal fluid (CSF) pressure. The only symptomatic child presented an Arnold-Chiari anomaly with enlarged ventricles, whereas the other three, all asymptomatic, were diagnosed by scheduled fundoscopy and had normal neuroimaging studies. All four patients had at least one known risk factor for developing intracranial hypertension: initiation of growth hormone therapy, tapering of corticosteroids, acute renal failure and Arnold-Chiari malformation. Two of them required a ventriculoperitoneal shunt.

CONCLUSIONS

Our results show that intracranial hypertension can occur more frequently than expected in patients with cystinosis. Furthermore, visual prognosis depends on early diagnosis and prompt treatment. A multidisciplinary approach is necessary, and we recommend fundoscopic examinations in all paediatric patients with cystinosis whether or not they present symptoms.

Cystinosis: a review

Cystinosis is the most common hereditary cause of renal Fanconi syndrome in children. It is an autosomal recessive lysosomal storage disorder caused by mutations in the CTNS gene encoding for the carrier protein cystinosin, transporting cystine out of the lysosomal compartment. Defective cystinosin function leads to intra-lysosomal cystine accumulation in all body cells and organs. The kidneys are initially affected during the first year of life through proximal tubular damage followed by progressive glomerular damage and end stage renal failure during mid-childhood if not treated. Other affected organs include eyes, thyroid, pancreas, gonads, muscles and CNS. Leucocyte cystine assay is the cornerstone for both diagnosis and therapeutic monitoring of the disease. Several lines of treatment are available for cystinosis including the cystine depleting agent cysteamine, renal replacement therapy, hormonal therapy and others; however, no curative treatment is yet available. In the current review we will discuss the most important clinical features of the disease, advantages and disadvantages of the current diagnostic and therapeutic options and the main topics of future research in cystinosis.

Chiari I Malformation in Nephropathic Cystinosis

OBJECTIVE

To determine the relative incidence of Chiari I malformations in children with cystinosis compared with those in the general population.

STUDY DESIGN

Magnetic resonance imaging scans were performed on 53 patients with nephropathic cystinosis and 120 controls, age range 3-18 years.

RESULTS

Ten of 53 (18.9%) patients with cystinosis had Chiari I or tonsillar ectopia, and only 2 of 120 controls (1.6%) had a similar finding. At least 2 of the patients had symptoms or signs thought to be related to the malformation, and one had surgical decompression. Two had an associated cervical syrinx.

CONCLUSIONS

Children with cystinosis have a 12-fold higher prevalence of Chiari I malformations than the general pediatric population. Chiari I malformations should be high on the differential diagnosis when individuals with cystinosis develop neurologic signs and symptoms, and magnetic resonance imaging scans should be performed on children with cystinosis who present with new-onset headache, ataxia, incontinence, or other unexplained neurologic symptoms.

Cystinosis in adult and adolescent patients: Recommendations for the comprehensive care of cystinosis

INTRODUCTION

Cystinosis is a rare lysosomal systemic disease that mainly affects the kidney and the eye. Patients with cystinosis begin renal replacement therapy during the first decade of life in absence of treatment. Prognosis of cystinosis depends on early diagnosis, and prompt starting and good compliance with cysteamine treatment. Kidney disease progression, extra-renal complications and shorter life expectancy are more pronounced in those patients that do not follow treatment. The objective of this work was to elaborate recommendations for the comprehensive care of cystinosis and the facilitation of patient transition from paediatric to adult treatment, based on clinical experience. The goal is to reduce the impact of the disease, and to improve patient quality of life and prognosis.

METHODS

Bibliographic research and consensus meetings among a multidisciplinary professional team of experts in the clinical practice, with cystinotic patients (T-CiS.bcn group) from 5 hospitals located in Barcelona.

RESULTS

This document gathers specific recommendations for diagnosis, treatment and multidisciplinary follow-up of cystinotic patients in the following areas: nephrology, dialysis,renal transplant, ophthalmology, endocrinology, neurology, laboratory, genetic counselling,nursing and pharmacy.

CONCLUSIONS

A reference document for the comprehensive care of cystinosis represents a support tool for health professionals who take care of these patients. It is based on the following main pillars: (a) a multi-disciplinary approach, (b) appropriate disease monitoring and control of intracellular cystine levels in leukocytes, (c) the importance of adherence to treatment with cysteamine, and (d) the promotion of patient self-care by means of disease education programmes. All these recommendations will lead us, in a second phase, to create a coordinated transition model between paediatric and adult care services which will contemplate the specific needs of cystinosis.

Association of Nephropathic Cystinosis and Pseudotumor Cerebri with Bilateral Duane Syndrome Type I

A 15-year-old girl, a known case of nephropathic cystinosis with a history of kidney transplantation, presented for evaluation of lid drooping in lateral gaze and a recent-onset headache. Examination of ocular movements showed bilateral limitation of abduction combined with narrowing of palpebral fissure in adduction. Deposition of polychromatic crystals in the conjunctiva and corneal stroma of both eyes was evident. Both optic discs were oedematous and intracranial pressure was 270 mm CSF, which responded to oral acetazolamide. The patient developed metabolic imbalances and multiple organ failure, from which she expired 3 months after presentation.

Cystinosis: the evolution of a treatable disease

Cystinosis is a rare autosomal recessive disorder involving lysosomal storage of the amino acid cystine due to a defect in the membrane transport protein, cystinosin. Since the introduction of kidney transplants and the availability of cystine-depleting medical therapy, this previously fatal disease was transformed into a treatable disorder. Renal allografts and medical therapy targeting the basic metabolic defect have altered the natural hisotry of cystinosis so drastically that patients have a life expectancy extending past 50 years. Consequently, early diagnosis and appropriate therapy are critically important. In this article, we offer a review of the manifestations of cystinosis, including the proximal tubular dysfunction of renal Fanconi syndrome, and discuss the prevention and treatment of the disorder's systemic complications. We focus on the nephropathic forms of cystinosis, aiming to assist nephrologists and other physicians to develop early recognition and appropriate management of cystinosis patients.

Cystinosis: practical tools for diagnosis and treatment

Cystinosis is the major cause of inherited Fanconi syndrome, and should be suspected in young children with failure to thrive and signs of renal proximal tubular damage. The diagnosis can be missed in infants, because not all signs of renal Fanconi syndrome are present during the first months of life. In older patients cystinosis can mimic idiopathic nephrotic syndrome due to focal and segmental glomerulosclerosis. Measuring elevated white blood cell cystine content is the corner stone for the diagnosis. The diagnosis is confirmed by molecular analysis of the cystinosin gene. Corneal cystine crystals are invariably present in all patients with cystinosis after the age of 1 year. Treatment with the cystine depleting drug cysteamine should be initiated as soon as possible and continued lifelong to prolong renal function survival and protect extra-renal organs. This educational feature provides practical tools for the diagnosis and treatment of cystinosis.

Increased intracranial pressure in patients with cystinosis

Patients with cystinosis have risk factors known to be associated with secondary increased intracranial pressure. The authors report a series of patients with cystinosis and describe their experience in the diagnosis and management of increased intracranial pressure in this population. The ophthalmologist should be aware of this vision-threatening association.

Nephropathic cystinosis: late complications of a multisystemic disease

Cystinosis is a rare autosomal recessive disorder due to impaired transport of cystine out of cellular lysosomes. Its estimated incidence is 1 in 100,000 live births. End-stage renal disease (ESRD) is the most prominent feature of cystinosis and, along with dehydration and electrolyte imbalance due to renal tubular Fanconi syndrome, has accounted for the bulk of deaths from this disorder. Prior to renal transplantation and cystine-depleting therapy with cysteamine for children with nephropathic cystinosis, their lifespan was approximately 10 years. Now, cystinotic patients have survived through their fifth decade, but the unremitting accumulation of cystine has created significant non-renal morbidity and mortality. In this article we review the classic presentation of nephropathic cystinosis and the natural history, diagnosis, and treatment of the disorder's systemic involvement. We also emphasize the role of oral cysteamine therapy in preventing the late complications of cystinosis.

Pediatric idiopathic intracranial hypertension

Our understanding of pediatric idiopathic intracranial hypertension has been refined since Dr. Simmons Lessell's review in 1992. The use of rigorous methodologies and standard definitions in recent studies has demonstrated distinct demographic trends. Specifically, the incidence of idiopathic intracranial hypertension seems to be increasing among adolescent children, and among older children its clinical picture is similar to that of adult idiopathic intracranial hypertension (female and obese). Within younger age groups there are more boys and nonobese children who may develop idiopathic intracranial hypertension. The pathogenesis of the disease has yet to be elucidated. Idiopathic intracranial hypertension among young children has been associated with several new etiologies, including recombinant growth hormone and all-trans-retinoic acid. More modern neuroimaging techniques such as MRI and MRI-venograms are being used to exclude intracranial processes. Although most cases of pediatric idiopathic intracranial hypertension improve with medical treatment, those who have had visual progression despite medical treatment have undergone optic nerve sheath fenestration and lumboperitoneal shunting. Because idiopathic intracranial hypertension in young children appears to be a different disorder than in adolescents and adults, separate diagnostic criteria for younger children are warranted. We propose new criteria for pediatric idiopathic intracranial hypertension in which children should have signs or symptoms consistent with elevated intracranial pressure, be prepubertal, have normal sensorium, can have reversible cranial nerve palsies, and have an opening cerebrospinal fluid pressure greater than 180 mm H(2)O if less than age 8 and papilledema is present, but greater than 250 mm H(2)0 if age 8 or above or less than 8 without papilledema.

Growth hormone producing prolactinoma in juvenile cystinosis: a simple coincidence?

Juvenile cystinosis was diagnosed in a patient who presented with severe headache attacks and photophobia. Treatment with oral cysteamine and topical cysteamine eye drops was started. One-and-a-half years later, he developed unilateral gynecomastia and elevated prolactin and growth hormone levels. A pituitary macroprolactinoma was discovered and successfully treated with the dopamine agonist cabergoline. Increased serum growth hormone levels were attributed to enhanced growth hormone production by the prolactinoma and somatostatin inhibition by cysteamine. Although the occurrence of prolactinoma in this patient could be a simple coincidence, it might also be a rare yet unrecognised complication of cystinosis.

Pseudotumor cerebri from sinus venous thrombosis, associated with polycystic ovary syndrome and hereditary hypercoagulability

OBJECTIVE

The association of pseudotumor cerebri, visual impairment, hypothyroidism, polycystic ovary syndrome (PCOS), and a hypercoagulable state due to a factor V and a prothrombin mutation has not been reported previously.

CASE REPORT

A 20-year-old obese woman developed menstrual cycle irregularities since age 14 years, initially bitemporal and latter diffuse headache since age 14 years, and bilateral visual impairment, described as sparkling black points. Ophthalmologically there was a recurrent papilledema. Clinical neurologic investigations revealed sore neck muscles and hirsutism. Magnetic resonance imaging of the brain, orbita and cervical spine, and investigations of cerebrospinal fluid were non-informative. Visually evoked potentials revealed demyelination of the optic nerves. Gynecologic investigations revealed PCOS and endocrinologic investigations hypothyroidism and hyperandrogenism. Tests for thrombophilia disclosed a heterozygote state for the G1.697A factor V Leiden and the G20.210A prothrombin mutation. A possible relationship between pseudotumor cerebri and the ophthalmologic, gynecologic, endocrinologic and coagulation abnormalities is discussed.

CONCLUSIONS

For the first time we describe the association of pseudotumor cerebri, optic nerve demyelination, PCOS, other endocrinologic abnormalities, and thrombophilia due to a factor V and prothrombin mutation. A causal relationship between these abnormalities remains elusive.

Ophthalmic manifestations and histopathology of infantile nephropathic cystinosis: report of a case and review of the literature

Cystinosis is a rare autosomal recessive metabolic disorder characterized by the intracellular accumulation of cystine, the disulfide of the amino acid cysteine, in many organs and tissues. Infantile nephropathic cystinosis is the most severe phenotype. Corneal crystal accumulation and pigmentary retinopathy were originally the most commonly described ophthalmic manifestations, but successful kidney transplantation significantly changed the natural history of the disease. As cystinosis patients now live longer, long-term complications in extrarenal tissues, including the eye, have become apparent. A case of an adult patient with infantile nephropathic cystinosis is reported. He presented with many long-term ocular complications of cystinosis. After 4 years of follow-up, the patient died from sepsis. Pathology of the phthisical eyes demonstrated numerous electron-transparent polygonal spaces, bounded by single membrane, in corneal cells, retinal pigment epithelial cells, and even choroidal endothelial cells. The ophthalmic manifestations and pathology of infantile nephropathic cystinosis are discussed and reviewed in light of the current report and other cases in the literature.

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension is common in obese women and can lead to significant visual impairment. First described more than 100 years ago, the cause of the disorder remains unknown. Despite a multitude of proposed links, the aetiology has never been established. Impairment of cerebrospinal-fluid reabsorption is the most likely underlying pathophysiological cause of the raised pressure, but this notion has yet to be proven. Cerebral venous sinus abnormalities associated with the disorder need further exploration. Although the major symptoms of headache and visual disturbance are well documented, most data for disease outcome have been from small retrospective case series. No randomised controlled trials of treatment have been done and the management is controversial. The importance of weight loss needs clarification, the role of diuretics is uncertain, and which surgical intervention is the most effective and safe is unknown. Prospective trials to examine these issues are urgently needed.

Nodular regenerative hyperplasia and severe portal hypertension in cystinosis

BACKGROUND & AIMS

Cystinosis is a rare autosomal-recessive disorder characterized by the intralysosomal accumulation of cystine, which is responsible for widespread tissue destruction. Liver biopsy specimens of patients with cystinosis show cystine crystal formation in Kupffer cells. However, significant liver disease and portal hypertension is not a common complication of cystinosis. We report the case histories of 2 young men with poorly treated nephropathic cystinosis who developed noncirrhotic portal hypertension with evidence of nodular regenerative hyperplasia (NRH).

METHODS

Liver biopsy examinations, upper and lower endoscopy with biopsy examination, imaging studies, venous pressure measurements, and laboratory investigations were used to evaluate the causes of the liver disease and portal hypertension.

RESULTS

Histologic examination of liver biopsy specimens from both patients showed changes characteristic of NRH with portal hypertension documented by measurement of pressure gradients. In addition, endoscopy in the first patient showed varices and portal hypertensive gastropathy.

CONCLUSIONS

NRH was confirmed by histologic examination of the liver in both patients and is the likely cause of their portal hypertension. NRH may represent a rare, late complication of cystinosis, although the mechanism remains undefined.

Optic atrophies in metabolic disorders

Optic nerve involvement in metabolic disorders often results from apoptosis of cells that form or support the optic nerve, the retinal ganglion cell (RGC) axons, the myelin-forming oligodendrocytes, or the supporting vascular system. Given their high energy demands and the long course of their axons, RGCs are particularly sensitive to intracellular metabolic defects. Defects in energy metabolism, formation of reactive oxygen species, and storage of metabolites can all cause apoptosis of RGCs, decreased myelin formation of oligodendrocytes and increased pressure on the optic nerve. Clinically, the loss of RGC axons manifests as pale optic nerves. In general, the ophthalmologist can identify the underlying cause of an optic atrophy by careful examination, neuro-imaging, and family history. In some cases, however, the diagnosis proves elusive. In these instances, and especially when optic atrophy is accompanied by other systemic involvement, a metabolic disorder should be considered. Here, we review the underlying mechanisms of optic atrophy and its significance in metabolic disorders. Early identification of optic atrophy aids the diagnosis and subsequent management of the underlying condition, including anticipation of symptoms, genetic counseling, and possible therapeutic interventions. For many metabolic disorders, molecular testing is available.