Distinguishing between post-trauma pituitary stalk disruption and genetic pituitary stalk interruption syndrome – case presentation and literature overview

TL;DR

This case report and literature overview contrasts post-traumatic pituitary stalk transection syndrome (PSTS) with genetic pituitary stalk interruption syndrome (PSIS), which can look similar clinically and on MRI but differ in etiology, midline anomalies, and temporal relation to trauma. It presents a 7-year-10-month-old girl with post-traumatic combined pituitary hormone deficiency and MRI findings of absent stalk with a hyperintense distal hypothalamic axon stump (pseudo-posterior lobe), illustrating PSTS rather than PSIS.

Key findings

• PSTS and PSIS can both present with combined pituitary hormone deficiency (CPHD) and MRI findings of absent pituitary stalk and small anterior pituitary, but PSIS is caused by developmental hypoplasia/aplasia, often genetic, while PSTS follows regenerative and regressive changes after trauma. The paper reports PSIS prevalence of approximately 1 per 6000 births, and notes that pituitary stalk transection can be found in about 4% of pediatric traumatic brain injury cases (with pediatric TBI occurrence about 200–235 per 100 000).
• The case: a girl first admitted at 7 years 10 months with severe symptomatic hypoglycemia (lowest glycemia 25 mg%) after gastroenteritis. She had severe head trauma at 3 years 10 months from being hit by a swing, with basilar skull fracture, cerebral edema, subarachnoid hemorrhage, and transient diabetes insipidus. She was diagnosed with secondary adrenal insufficiency (morning cortisol 44.8 ng/ml, ACTH 5.3 pg/ml), growth hormone deficiency (GH 0.13 ng/ml during hypoglycemia; max 0.49 ng/ml in two stimulation tests; IGF1 27.1 ng/ml), and secondary hypothyroidism (fT4 6.6 pmol/l, fT3 1.8 pmol/l, TSH 2.89 uIU/ml).
• MRI was initially described as PSIS but reassessed as PSTS: absent pituitary stalk, hyperintense signal of the distal regenerating hypothalamic axon (pseudo-posterior lobe) at the median eminence, hypotrophic anterior pituitary, and no posterior pituitary bright spot. Hormone replacement with hydrocortisone, L-thyroxine, and recombinant GH resolved hypotonia and hypoglycemia and normalized growth, with growth velocity 16 cm/year.
• The paper highlights differentiation points: extra-pituitary midline malformations occur in 48% of PSIS cases but never as a PSTS consequence; known gene mutations were confirmed in 5% of examined patients. In a series of 67 children with PSIS, invisible pituitary stalk was found in only 6%, while interrupted or thin stalk was reported in 81% and 13%, respectively; anterior pituitary hypoplasia can be found in 86%. At diagnosis, isolated GH deficiency was diagnosed in 52% of PSIS patients and CPHD in 48%, with CPHD confirmed in 83% after 12 years follow-up.

Methods

• Design: single pediatric case report plus literature overview comparing clinical manifestation, MRI images, and extra-pituitary disorders between PSIS and PSTS.
• Case data: 7-year-10-month-old girl born at 41 weeks by elective cesarean section due to breech presentation, birth weight 3600 g, length 58 cm, Apgar 10; severe head trauma at 3 years 10 months; laboratory testing including glucagon stimulation, hormonal assays, and hypothalamo-pituitary MRI (1.5 Tesla; sagittal/coronal T1- and T2-weighted and dynamic post-contrast T1-weighted; 3 mm sections).
• Analysis: descriptive integration of the patient’s clinical, biochemical, and imaging findings with published data on PSTS and PSIS; MRI was reassessed in light of the strict temporal relation between trauma and CPHD.

Limitations

• No formal limitations section is stated in the paper.
• Evident limitations: the report is based on a single case, so findings cannot be generalized; the literature overview is not described as a systematic review; and the patient’s diagnosis of PSTS is supported by clinical temporal association and imaging rather than direct pathological proof.