Endocrine Abstracts

JOINT2425

Introduction: Fahr’s syndrome is a rare anatomo-clinical entity, characterised by bilateral and symmetrical intracerebral calcifications in the basal ganglia, most often associated with disorders of phosphocalcium metabolism. Hypoparathyroidism is the most common anomaly. Pseudohypoparathyroidism is exceptionally reported as a cause of Fahr’s syndrome.

Observation: Patient aged 28, followed in psychiatry for delusional psychotic disorders evolving for 3 years, under neuroleptic treatment, without clear improvement. Complicated 1 day after her admission to the medical intensive care unit by the onset of confusion-type consciousness disorders evolving in a febrile and atraumatic context, and by the appearance of tetany crises involving the 4 limbs, the nape of the neck and the chest wall giving rise to respiratory disorders. On admission, the clinical examination revealed a confused patient with a Glasgow score of 13/15, a blood pressure of 100/70 mmhg and a heart rate of 102 bpm. The patient was polypnoeic and had an oxygen saturation of 99% on 4 litres of oxygen therapy, with a temperature of 38.5 C. The patient had a stiff neck and a soft abdomen, and the rest of the clinical examination was unremarkable. A lumbar puncture was performed, which returned normal. Cerebral CT revealed bilateral and symmetrical calcifications involving the basal ganglia. Biological tests showed hypocalcaemia at 61.76 mg/l (N:84-102), hyperphosphaemia at 49 mg/l (N:27-45), and a normal serum parathyroid hormone level of 12.8 pg/ml (N:12-80). Given this picture, the diagnosis of pseudohypoparathyroidism was accepted. Treatment consisted of calcium and vitamin D replacement therapy. Progress was favourable.

Discussion: The clinical manifestations of Fahr’s syndrome include primarily neuropsychiatric signs: behavioural disorders, confusional or delusional syndrome. Other neurological manifestations are possible but less common. Fahr’s syndrome is most often associated with dysparathyroidism: hypoparathyroidism is the most common anomaly. The association of Fahr’s syndrome with hyperparathyroidism or pseudohypoparathyroidism, as in our patient’s case, has rarely been described; a review of the literature found less than a dozen cases. Other pathologies can cause intracerebral calcifications, such as endocrinopathies, systemic diseases and infections, but with different sites and appearances. The diagnostic test of choice is computer tomography. The prognosis for Fahr’s syndrome is good, as the clinical and neuropsychological signs regress once the phosphocalcic disturbances have been corrected.

Conclusion: Although Fahr’s syndrome is a rare entity, this clinical case shows the importance of brain imaging and phosphocalcium assessment in the investigation of neuropsychiatric disorders, with a view to initiating appropriate therapeutic measures.