[Fahr's syndrome: two case report]. / Syndrome de Fahr: à propos de deux cas.

INTRODUCTION: Fahr's syndrome is characterized by symmetrical and bilateral intracerebral calcifications, located in the basal ganglia and mostly associated with a phosphorus calcium metabolism disorder. It must be distinguished from genetic or sporadic Fahr's disease. OBSERVATIONS: We report two cases of this syndrome, the first was revealed by psychotic and cognitive disorders and the other by epilepsy. In both cases, brain imaging and biology resulted in the diagnosis of Fahr's syndrome. The outcome was favorable after treatment in both cases. CONCLUSION: These two observations illustrate various clinical signs of Fahr's syndrome.

Bone mineral analysis using single-energy computed tomography.

We present a new method for evaluating in vivo changes in bone mineralization in the peripheral skeleton, using computed tomography (CT). A set of bone mineralization indices are generated from numerous CT images of the patient's distal radius. The cross-sectional anatomy displayed by the CT scan allows for separate evaluation of the cortical and trabecular bone. Correction for possible drift of the CT number scale (Hounsfield scale) is achieved by scanning standard solutions of dipotassium hydrogen phosphate simultaneously with the forearm. Preliminary data indicate that this is a precise method for evaluating in vivo changes in bone mineralization.

[Hyperechogenicity of the renal medulla in children: clinico-echographic correlations]. / Iperecogenicità della midollare renale nel bambino: correlazioni clinico-ecografiche.

Increased renal medullary echogenicity by renal ultrasound associated with hypercalciuria and nephrocalcinosis is often present in childhood. 17 children, 9 boys and 8 girls, aged from 8 months to 10 years were classified into three groups based on ultrasound findings according to Patriquin and Robitaille: type A faint hyperechogenic rim around the sides and tip of the medullary pyramid; type B more intense echogenic rim of the pyramids; type C intense echoes throughout the pyramid. Clinic-echographic correlations showed a pattern C in 4 children with distal renal tubular acidosis and in an infant treated with furosemide; pattern B in 3 patients having different types of tubulopathy associated with hypercalciuria; pattern A in 6 children with congenital tubulopathy and in 3 children treated with vitamin D. Abdominal X-rays detected medullary calcinosis in 2 (11.7%) of total 17 patients. Ultrasonography appears to be an important tool in early diagnosis of renal medullary nephrocalcinosis.

Superimposition of nutcracker syndrome in a hematuric child with idiopathic hypercalciuria and urolithiasis.

We report a 5-year-old girl with idiopathic hypercalciuria who developed gross hematuria and left flank pain despite normalization of calciuria, a renal stone, and microscopic hematuria. She was found to have nutcracker syndrome by renal Doppler ultrasound, which revealed the significant differences of the peak blood flow velocities in the two portions of the left renal vein.

Disorders of maternal calcium metabolism implicated by abnormal calcium metabolism in the neonate.

Normal fetal and neonatal calcium homeostasis is dependent upon an adequate supply of calcium from maternal sources. Both maternal hypercalcemia and hypocalcemia can cause metabolic bone disease or disorders of calcium homeostasis in neonates. Maternal hypercalcemia can suppress fetal parathyroid function and cause neonatal hypocalcemia. Conversely, maternal hypocalcemia can stimulate fetal parathyroid tissue causing bone demineralization. We report two asymptomatic women, one with previously unrecognized hypoparathyroidism and the other with unrecognized familial benign hypercalcemia, who were diagnosed when their newborn infants presented with abnormalities of calcium metabolism. J.B. was born at 34 weeks' gestation with transient hyperbilirubinemia and thrombocytopenia. At 1 month of age he had severe bone demineralization, cortical irregularities, widening and cupping of the metaphyses, and lucent bands in the scapulae. The total serum calcium and phosphorus were normal with an ionized calcium of 5.4 mg/dL (4.6-5.4). His alkaline phosphatase, parathyroid hormone, and 1,25-dihydroxyvitamin D levels were all increased. P.B., mother of J.B., had no symptoms of hypocalcemia either prior to, or during this pregnancy. She had severe hypocalcemia and hyperphosphatemia, laboratory values typical of hypoparathyroidism. J.N. presented at 6 weeks of age with new onset of seizures and tetany secondary to severe hypocalcemia. The serum phosphorus, creatinine, alkaline phosphatase, and parathyroid hormone levels were normal. At 15 weeks of age his calcium was slightly elevated with a low fractional excretion of calcium. P.N., mother of J.N., had no symptoms of hypercalcemia either prior to, or during this pregnancy. Her serum calcium was 12.7 mg/dL and urine calcium was 66.5 mg/24 hr, with a low fractional excretion of calcium ranging from 0.0064 to 0.0073. P.N. has a brother who previously had parathyroid surgery. Both J.N. and P.N. meet the diagnostic criteria for familial benign hypercalcemia. These cases illustrate the important relationships between maternal serum calcium levels and neonatal calcium homeostasis. They emphasize the need to assess maternal calcium levels when infants are born with abnormal serum calcium levels or metabolic bone disease.

[Paget's disease with osseous demineralization (author's transl)]. / Maladie de Paget avec déminéralisation osseuse

Radiological diagnosis of Paget's disease which is based on hypertrophy of the osseous cortex, osteocondensation and a fibrillary appearance of the cancellous bone, can be rendered difficult when there is superadded demineralization. This is usual in the initial phase of the condition and take on the form of circumscribed osteoporosis. Such an appearance can however be misleading owing to its wide extent or to the number of localizations, as was the case in two of our cases; the diagnosis of Paget's disease must then be established from histological criteria. Besides this demineralization which is directly related to the morbid process in Paget's disease, calcium deficiency is known to modify the clinical and radiological symptomatology of Paget's disease. Our first two cases illustrate this fact and the remarkable effectiveness of "remineralization" therapy in such cases.

Hypercalciuria and ultrasound abnormalities in children with cystinosis.

We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity. The ultrasound scan appearance was graded and correlated with laboratory parameters. It remains unclear as to the aetiology of the ultrasound findings and whether they are a consequence of treatment or a hitherto unrecognised feature of the disease.

Cervical myelopathy in C.P.P.D. deposition disease.

Cervical Myelopathy is a rare manifestation of calcium pyrophosphate dihydrate (C.P.P.D.) deposition disease. A case is presented where radiographically noncalcified extradural masses containing C.P.P.D. crystals were present at the C7 level, producing cord compression and neurological symptoms. These masses are thought to represent para-articular deposits related to the adjacent facet joints.

Hand and wrist arthropathies of hemochromatosis and calcium pyrophosphate deposition disease: distinct radiographic features.

Radiographic features of hand and wrist involvement in 26 patients with hemochromatosis and in 26 patients with idiopathic calcium pyrophosphate dihydrate (CPPD) crystal deposition disease were compared. Two radiologists independently examined the radiographs without knowledge of the specific group to which the patient belonged. The results of this study clearly establish that structural joint diseases in the two disorders are not identical. Characteristic findings allow the radiologist to favor one diagnosis over the other. These radiographic differences indicate that the arthropathy of hemochromatosis is related to factors additional to the presence of CPPD crystals, specifically, the more prevalent narrowing of the metacarpophalangeal joint spaces, including those in the fourth and fifth digits, peculiar hook-like osteophytes on the radial aspect of the metacarpal heads, and less prevalent separation of the scaphoid and the lunate.

Subchondral cysts (geodes) in arthritic disorders: pathologic and radiographic appearance of the hip joint.

A comprehensive study of femoral heads of patients and cadavers with osteoarthritis, rheumatoid arthritis, osteonecrosis, and calcium pyrophosphate dihydrate deposition disease allows insight into the radiographic and pathologic appearance of subchondral radiolucencies in these disorders. The term geode, rather than cyst or pseudocyst, may be a more appropriate decription of these lesions. In osteoarthritis, goedes occur on the pressure segment of the femoral head in association with loss of articular space; in rheumatoid arthritis, they are initially noted at the chondro-osseous junction and subsequently involve the entire femoral head. In osteonecrosis, geodes appear in the necrotic segment of the femoral head. In calcium pyrophosphate deposition disease, geodes resemble those in osteoarthritis but are larger, more numerous, and more widespread.