1 / 22

SEPTO-OPTIC DYSPLASIA

SEPTO-OPTIC DYSPLASIA. SOD: Definition. Variable combination of midline forebrain abnormalities, eye abnormalities and pituitary abnormalities Rare: reported incidence 1/50000; probably commoner 2/3 features to make the diagnosis Commoner in younger mothers. Forebrain abnormalities.

nevina
Télécharger la présentation

SEPTO-OPTIC DYSPLASIA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SEPTO-OPTIC DYSPLASIA

  2. SOD: Definition • Variable combination of midline forebrain abnormalities, eye abnormalities and pituitary abnormalities • Rare: reported incidence 1/50000; probably commoner • 2/3 features to make the diagnosis • Commoner in younger mothers

  3. Forebrain abnormalities • In 75-80% of patients • Absence of septum pellucidum • Absence of corpus callosum • Cerebellar hypoplasia • Schizencephaly

  4. Consequences of forebrain anomalies • Fits • Behavioural difficulties • Learning difficulties • Developmental delay • Hemiplegia

  5. Optic nerve hypoplasia • Unilateral/bilateral • Bilateral commoner • Associated with anopthalmia/micropthalmia • Visual impairment variable - complete to compensated

  6. Pituitary gland • Develops from the oral cavity in the embryo and the brain (hypothalamus) • 5 different cell types in anterior pituitary producing 6 different hormones • Secretion of hormones regulated by hypothalamus

  7. Anterior pituitary gland • Growth hormone: growth and helps maintain normal blood sugar levels in children; increases bone strength, muscle mass and decreases fat mass and heart disease in adults • ACTH: regulates production of cortisol and androgens from adrenal glands; cortisol essential for normal well-being and to fight stress and infection

  8. Anterior pituitary gland • Prolactin: important for lactation, ?immune system • FSH, LH: important for puberty and fertility; LH important for normal development of males and for descent of testes into scrotum • TSH: important for regulation of thyroid gland and thyroxine production

  9. Posterior pituitary gland • Vasopressin: important for normal fluid balance - retains water by controlling reabsorption of water in kidney tubules • Oxytocin: important for parturition (birth) and ejection of milk

  10. Pituitary Hormone Deficiency • GH: poor growth with eventual short stature, possibly increased incidence of myocardial infarction • Prolactin: no lactation • ACTH: low cortisol leading to low blood sugar, lethargy, inability to fight stress and infection, low blood pressure, low sodium level in blood, collapse

  11. Pituitary Hormone Deficiency • FSH, LH: inadequate sexual development in males, lack of puberty, lack of fertility • TSH: lack of thyroxine with slowness, cold intolerance, constipation, growth failure, mental retardation if not picked up early • Vasopressin: diabetes insipidus with excessive urinary output

  12. Complexity of hypothalamo-pituitary development • Early puberty: can be explained on basis of hypothalamic involvement • Occasionally mixed involvement of hypothalamus and pituitary

  13. Clinical features of SOD • Conjugated jaundice • Neurological features • Variable visual loss • Impaired sense of smell • Endocrine features • Behavioural disturbances eg. autism • Sleep disturbance

  14. MRI SCANS OF SOD PATIENTS CONTROL SIBLING 2 SIBLING 1

  15. Management of SOD • Support from Neurologists and Opthalmologists: treatment of convulsions • Mainstay of treatment: endocrine

  16. Endocrine replacement • Growth hormone: daily subcutaneous injections • Hydrocortisone: X3 doses daily; adjustment with illness/stress • DDAVP: nasal/oral • Thyroxine • Ethinyloestradiol/testosterone

  17. Investigations • MRI scan of brain • Visual evoked responses/electroretinogram • Routine electrolyte measurement • Thyroid function tests • Pituitary function tests: glucagon/insulin/LHRH/TRH - in tertiary centres ideally • Fluid balance

  18. Monitoring • Evolving - new endocrine features may develop • Monitoring of growth rate at regular intervals • Monitoring through puberty • Regular checks of thyroid function, watch fluid balance

  19. Long-term outlook • Short stature • Developmental/intellectual impairment • Fits, hemiparesis etc • Impaired fertility • Visual impairment • Sleep/behavioural difficulties • Obesity

  20. Why do you get SOD? • Development of pituitary gland, forebrain, olfactory bulbs and eyes all from the same part of the early embryo. Problems occur at 3-6 weeks of gestation • Environment and teratogens • Familial cases: dominant or recessive

  21. Genetics of SOD • Mutations in HESX1: Dominant or recessive • Occasionally, one abnormal copy of gene carried with no phenotype in parent but child affected • Number of other developmental genes may also be involved: all extrapolated from animal studies

  22. Research • New genes involved in SOD: what is their function • Why the variability in severity • Sleep/wake cycles in children with SOD and hypothalamic involvement and the use of melatonin (10-18 year olds)

More Related