Idiopathic intracranial hypertension revealing severe hypoparathyroidism in the context of autoimmune polyglandular syndrome type 1: a case report

¹Department of Endocrinology, Diabetes and Metabolic Diseases, Mohammed VI University Hospital of Tangier, Tangier, Morocco, ²Faculty of Medicine and Pharmacy of Tangier, Abdelmalek Essaadi University, Tangier, Morocco

^&Corresponding author
Wiam Ftouh, Department of Endocrinology, Diabetes and Metabolic Diseases, Mohammed VI University Hospital of Tangier, Tangier, Morocco

Introduction    

Hypoparathyroidism is an uncommon endocrine disorder resulting in inadequate parathyroid hormone (PTH) secretion, leading to chronic hypocalcaemia and hyperphosphataemia [1]. Clinical manifestations range from neuromuscular symptoms (paresthesias, cramps, tetany) to multisystemic complications, including basal ganglia calcifications, neuropsychiatric disturbances, and early-onset cataracts [2]. Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is defined as elevated intracranial pressure without mass lesions, hydrocephalus, vascular malformations, or central nervous system infections, typically presenting with headaches, papilloedema, and visual disturbances [3]. While IIH most commonly affects obese women of reproductive age, atypical presentations necessitate a rigorous search for secondary causes [3,4]. We report a rare case of IIH secondary to severe primary hypoparathyroidism in the context of probable APS-1, highlighting a pathophysiologically coherent but underrecognised association.

Patient and observation     

Patient information: a 34-year-old woman with no significant past medical or surgical history was under neurology follow-up for presumed IIH. She reported chronic daily morning headaches, transient visual obscurations, tinnitus, progressive visual blurring, and a one-year history of depressive symptoms (low mood, anhedonia, insomnia, low self-esteem). She had a history of recurrent oral ulcers since adolescence, enamel hypoplasia, onychomycosis, and Hashimoto's thyroiditis. No family history of endocrine or autoimmune disease was reported. Despite symptomatic treatment with acetazolamide, her visual blurring progressed.

Clinical findings: vital signs were normal. Neuromuscular examination revealed a positive Chvostek's sign and a positive Trousseau's sign, both consistent with latent hypocalcaemic tetany. Ophthalmological examination revealed bilateral papilloedema and the unexpected finding of bilateral subcapsular cataracts.

Timeline: the patient's symptoms began approximately one year before hospital admission. During that period she experienced gradual onset of daily morning headaches and progressive visual blurring that failed to improve with acetazolamide introduced by her neurologist. Oral ulcers and enamel hypoplasia had been present since adolescence, and Hashimoto's thyroiditis had been diagnosed in the years preceding the current episode. Hospital admission led to the incidental discovery of severe hypocalcaemia and suppressed PTH.

Diagnostic assessment: laboratory testing confirmed severe hypocalcaemia (corrected calcium 1.65 mmol/L), hyperphosphataemia (1.80 mmol/L), hypomagnesaemia (0.60 mmol/L), and markedly suppressed intact PTH (2.5 pg/mL), establishing primary hypoparathyroidism (Table 1). An electrocardiogram showed borderline QTc prolongation (Figure 1). Brain MRI revealed a partially empty sella turcica without a mass lesion (Figure 2). Lumbar puncture confirmed elevated opening pressure (380 mmH₂O) with normal cerebrospinal fluid (CSF) composition (Table 2), fulfilling diagnostic criteria for IIH. End-organ assessment showed no significant renal, cardiac, or skeletal complications. The constellation of primary hypoparathyroidism, ectodermal manifestations, and Hashimoto's thyroiditis fulfilled criteria for probable APS-1; however, AIRE mutation analysis was unavailable.

Therapeutic interventions: urgent intravenous calcium gluconate was administered under continuous ECG monitoring, co-administered with calcitriol (1 µg/day) and intravenous magnesium. After biochemical stabilisation, the patient was transitioned to oral calcium (2 g/day) and continued on calcitriol. Fluoxetine was initiated for a moderate depressive disorder identified on psychiatric evaluation.

Follow-up and outcomes: at three-month follow-up, serum calcium normalised (2.10 mmol/L) with improvement in phosphate and magnesium levels (Table 1). Headaches, visual disturbances, and neuromuscular irritability substantially resolved. Mood improved significantly, with only residual ruminative thoughts persisting. No adverse events or treatment intolerance were reported.

Patient perspective: the patient reported that after years of unexplained headaches and progressive visual decline, obtaining a diagnosis and initiating treatment was transformative. She noted considerable improvement in her symptoms.

Informed consent: oral informed consent was obtained from the patient following a full explanation of the purpose of this clinical case report and the associated images. All data have been anonymised to preserve patient confidentiality.

Discussion     

This case illustrates a rare but pathophysiologically coherent triad of primary hypoparathyroidism, secondary IIH, and probable APS-1. Hypoparathyroidism has been rarely reported as a secondary cause of intracranial hypertension, presenting with a clinical and radiological picture indistinguishable from IIH [4]. Chronic hypocalcaemia is believed to contribute to elevated intracranial pressure by impairing calcium-dependent CSF absorption at the arachnoid granulations and by promoting cerebral vasodilation, thereby increasing cerebral blood volume [5]. Hyperphosphataemia may further disrupt normal CSF dynamics. Sustained intracranial hypertension subsequently led to a partially empty sella turcica through herniation of the subarachnoid space into the sella in the setting of an incompetent diaphragma sellae [6]. The coexistence of these findings represents a pathophysiologically coherent continuum rather than a coincidental association.

Autoimmune polyglandular syndrome type 1 (APECED) is a rare autoimmune condition caused by AIRE gene mutations, classically characterised by the Whitaker triad of chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency [7]. In our patient, isolated hypoparathyroidism combined with enamel hypoplasia, onychomycosis, and Hashimoto's thyroiditis fulfilled criteria for a probable diagnosis [8]. Definitive confirmation would require AIRE mutation analysis or anti-interferon autoantibody testing, which were unavailable.

Regarding treatment, conventional management with oral calcium and active vitamin D can produce biochemical fluctuations and may inconsistently improve neuropsychiatric outcomes. The 2025 revised international recommendations now position PTH replacement therapy (e.g., palopegteriparatide) as a more physiological option with potential neuropsychiatric and neurological benefits in patients with an inadequate response to, or complications of, conventional therapy [9]. Furthermore, empty sella syndrome has been associated with mood disorders, possibly through subclinical disruption of the hypothalamic-pituitary-adrenal axis, which may explain the prodromal depressive symptoms in our patient [6,10]. The main limitation of this report is its single-case nature and the absence of genetic confirmation of APS-1. This case nonetheless underscores the need for systematic endocrine screening in atypical IIH and provides a framework for multidisciplinary management of this complex association.

Conclusion     

This case highlights hypoparathyroidism as a secondary cause of IIH that should be considered in atypical presentations, particularly when early-onset cataracts or electrolyte abnormalities are present. Early correction of hypocalcaemia combined with multidisciplinary management involving neurology, endocrinology, ophthalmology, and psychiatry can lead to significant neurological, visual, and psychiatric improvement.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Patient management: all authors. Data collection and case description: Wiam Ftouh, Meryem Smouni, and Dalia Kaadan. Manuscript drafting: Wiam Ftouh and Meryem Smouni. Critical revision of the manuscript: Fatima Aziouaz and Mariem Benkacem. Supervision: Fatima Aziouaz and Mariem Benkacem. All authors have read and approved the final version of this manuscript.

Tables and figures     

Table 1: laboratory values at admission and three-month follow-up

Table 2: cerebrospinal fluid analysis

Figure 1: electrocardiogram at admission showing borderline QTc prolongation associated with severe hypocalcaemia

Figure 2: brain MRI showing indirect signs of chronic intracranial hypertension

References