Idiopathic intracranial hypertension

Optic disc edema in fibrous dysplasia/McCune-Albright syndrome: Prevalence, etiologies, and clinical implications

BACKGROUND

Fibrous dysplasia (FD) is a rare disorder of expansile fibro-osseous lesions that may be associated with extraskeletal features as part of McCune-Albright syndrome (MAS). Optic disc edema is a potentially serious ophthalmologic finding that has been rarely reported in patients with FD/MAS. The purpose of this study was to investigate the prevalence and potential clinical associations of optic disc edema in a large cohort.

METHODS

Clinical records were reviewed from subjects in an ongoing FD/MAS natural history study. Computed Tomography scans were evaluated for the presence of structural craniofacial abnormalities associated with optic disc edema, including Chiari I malformation and space-occupying lesions. Craniomorphometric analyses were performed to determine optic canal diameter and intracranial volume. Statistical analyses were performed to compare clinical and radiographic features between subjects with and without optic disc edema.

RESULTS

Optic disc edema was diagnosed in 7/187 subjects, for a prevalence of 3.7%. All subjects with optic disc edema were diagnosed before age 18 years and had mild, non-progressive disease. Radiographic structural abnormalities, including Chiari I malformation, aneurysmal bone cysts, and arachnoid cysts, were associated with higher odds of optic disc edema (odds ratio [OR] 24.3; 95% confidence interval [CI], 4.2 to 121.4; p < 0.01) (OR 18.0; 95% CI, 3.4 to 108.2; p < 0.01). Treatment with leuprolide, a gonadotropin releasing hormone analog, was also associated with optic disc edema (OR 26.0; 95% CI 3.3 to 177.5; p < 0.05). There was no significant association of optic disc edema with other MAS endocrinopathies, medications, optic canal diameter, or intracranial volume.

CONCLUSION

Optic disc edema is an uncommon but potentially serious complication of craniofacial FD, which may occur more frequently in pediatric patients and those with structural craniofacial abnormalities. The potential association of leuprolide therapy with optic disc edema in this population warrants further study.

Idiopathic intracranial hypertension in childhood: pitfalls in diagnosis

AIM

Idiopathic intracranial hypertension (IIH) is prone to misdiagnosis. Our aim was to identify the reasons for this in children in our region referred for suspected IIH.

METHOD

We reviewed the records of all children referred with symptoms and/or signs consistent with raised intracranial pressure (ICP) and normal magnetic resonance imaging of the brain to our tertiary neurology unit over 4 years. IIH was confirmed after expert ophthalmology including ultrasound/tomography and advanced cerebrospinal fluid (CSF) pressure studies.

RESULTS

Of 15 children (six males, nine females; median age 12y, range 3-15y), six (five females, one male) were confirmed to have IIH. All weighed above the 91st centile and were over 10 years old. Four of the six had raised ICP secondary to other causes. Four had been misdiagnosed locally with papilloedema, three had drusen, and one had 'crowded discs'. Two had raised CSF pressures on standard lumbar puncture, but 20-minute steady state and infusion studies were normal, with symptoms settling after therapy was withdrawn.

INTERPRETATION

Misdiagnosis of IIH was frequent, but could be reduced by (1) expert ophthalmological fundoscopy, orbital ultrasound, and optical coherence tomography; (2) expert neuroradiology; and (3) assessment of steady state CSF pressure rather than standard opening pressure in centimetres of water.

Brain anomalies in 121 children with non-syndromic single suture craniosynostosis by MR imaging

INTRODUCTION

The aim of this study was to evaluate prevalence of intracranial abnormalities in children with non-syndromic single suture craniosynostosis scheduled for cranial vault remodelling surgery using pre-operative magnetic resonance imaging.

PATIENTS AND METHODS

A retrospective analysis of brain magnetic resonance imaging studies of 129 non-syndromic single suture craniosynostosis children undergoing craniofacial surgery between January, 2004-October, 2010 was conducted. Statistical analysis was performed for child, maternal and sibling related predisposing factors for abnormal brain magnetic resonance imaging findings. The mean age of these 121 patients at the time of imaging was 21.6 months. The majority, 78% were males and 74% of the patients were scaphocephalic.

RESULTS

In 18 (15%) patients abnormal brain findings were noted. The most common finding was Chiari 1 malformation in 11 (9%). Chiari 1 malformation comprised over half (61%) of the brain anomalies identified. None of these findings required any additional surgical procedures. None of the statistical analysis reached statistical significance.

CONCLUSIONS

Brain anomalies in connection with non-syndromic single suture craniosynostosis patients seem to be a coincidental event. We did not establish any specific craniosynostosis form to be regularly associated with abnormal brain magnetic resonance imaging findings. The routine use of pre-operative magnetic resonance imaging in non-syndromic single suture craniosynostosis patients seems to be of limited value in the search for associated intracranial malformations necessitating additional interventions.

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.