Pituitary stalk interruption syndrome (PSIS) is a congenital disorder characterised by the triad of an absent or exceedingly thin pituitary stalk, an ectopic or absent posterior pituitary and/or absent or hypoplastic anterior pituitary. Presentation
Affected individuals may present with hypoglycaemia during the neonatal period, or with growth retardation during childhood (those diagnosed in the neonatal period appear to be affected by a particularly severe form of the disorder). PSIS is a common cause of congenital hypopituitarism, and causes a permanent growth hormone deficit. Some PSIS-affected individuals may also present with adrenal hypoplasia (5-29%), diabetes insipidus (5-29%), primary amenorrhea (5-29%), hypothyroidism (30-79%), failure to thrive (80-99%), septooptic dysplasia (5-29%), and Fanconi anaemia. PSIS may be isolated, or, commonly, present with extra-pituitary malformations.PSIS features in neonates (may) include:
hypoglycaemia (30-79%)
(prolonged) jaundice
micropenis (30-79%)
cryptorchidism (5-29%)
delayed intellectual development
death in infancy (5-29%)
congenital abnormalitiesPSIS features in later childhood (may) include:
short stature (80-99%)
seizures (5-29%)
hypotension
delayed intellectual development
delayed puberty (30-79%)PSIS is associated with a higher frequency of breech presentation, Caeserian section, and/or low Apgar score, though these are likely consequences rather than causes. Cause
The cause of the condition is as of yet unknown. Rare genetic mutations may cause familial cases, however, these account for less than 5% of cases. Diagnosis
The diagnosis is confirmed through MRI. Management
Treatment should commence as soon as a diagnosis is established to avoid complications, and consists of hormone replacement, particularly with growth hormone. Prognosis
Prognosis is generally good in cases of prompt diagnosis and management.
History
AMAN, also known as Chinese Paralytic Syndrome, was first described by a group of Johns Hopkins University and University of Pennsylvania neurologists in collaboration with neurologists from the Second Teaching Hospital of Hebei Medical School and Beijing Childrens Hospital. In 1991, Guy Mckhann, Jack Griffin, Dave Cornblath and Tony Ho from Johns Hopkins University and Arthur Asbury from University of Pennsylvania visited China to study a mysterious epidemic of paralytic syndrome occurring in northern China. Every summer, hundreds of children from rural China developed acute paralysis and respiratory failure. Hospitals were overwhelmed with number of cases and often ran out of ventilators and hospital beds. Examination of these children showed that many of them had acute flaccid paralysis and areflexia but with little or no sensory loss. Electrophysiological testing of these children showed motor axonal loss with occasional conduction block with a lack of demyelinating features and normal sensory potentials. In contrast, the common form of Guillain–Barré syndrome in the West often presents with sensory loss and demyelination on electrophysiology testing and is more common in adults. Later, several autopsies confirmed the focus of the immune attack was at the motor axolemma especially around the nodes of Ranvier. These cases showed deposition of antibody and complement along the motor axolemma and associated macrophage infiltration. References


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