Hypoparathyroidism mimicking ankylosing spondylitis
Arzu Gedik, Merve Yilmaz, Ayten Eraydin, Mustafa Gunes & Sevinc Eraslan
Idiopathic hypoparathyroidism (IHP) is an uncommon disease in which soft tissue calcifications may be seen. We report a case with IHP with asymptomatic hypocalcemia and features of ankylosing spondylitis (AS).
Case: A 58-year-old male patient was referred to our department due to incidentally discovered hypocalcemia when admitted with blurred speech, gait and posture abnormalities. He had had a generalized convulsion 19 years ago. On physical examination, patients posture was typical for AS. Cervical and lumbal vertebral motion and chest expansion were limited. Trousseaus and Chvosteks signs were both negative. Laboratory findings were as follows: calcium: 5.4 mg/dl (8.410.2), inorganic phosphorus: 6 mg/dl (2.34.7), albumin: 4.2 g/dl (3.55), PTH: <3 pg/ml (1565). Lumbosacral radiographs revealed bamboo spine appearance of thoracal and lumbal vertebrae with calcification of anteriorposterior longitudinal and interspinous ligaments mimicking ankylosing spondylitis. But unlike AS, sacroiliac joints were spared. Cranial computarized tomography showed severe parenchymal calcification of cerebellum, basal ganglia and corona radiata, giving the image of a rocky brain. The extreme calcification of paravertebral structures and the brain were attributable to the long duration of the disease before the diagnosis. Calcitriol and supplemental calcium were initiated.
Conclusion: Idiopathic hypoparathyroidism, when undiagnosed for a long period, may result in extreme calcification of soft and bony tissues. The vertebral calcification may be so intense that it may result in an AS like clinical picture. Patients may present with clinical and radiographic findings of skeletal changes with no evidence of hypocalcemic symptoms. In a patient with spondyloarthropathy with vertebral involvement without sacroiliitis, IHP may come into mind as an alternative cause.