Classification of Hypoparathyroid Disorders.

The term hypoparathyroidism encompasses a huge group of disorders all characterized by an abnormal mineral homeostasis determined by inadequate secretion of parathyroid hormone. Postsurgical hypoparathyroidism is a complication of neck surgery (thyroidectomy, parathyroidectomy, lymph node, and cancer neck dissection), closely related to the extent of the surgical procedure and the experience of the surgeon. If lasting more than 6 months it is defined as chronic hypoparathyroidism, requiring life-long replacement therapy with active vitamin D metabolites. All the other forms of nonsurgical hypoparathyroidism, previously referred to as idiopathic hypoparathyroidism, have several causes, the majority of them genetic, which can be grouped into 3 main categories: disorder of parathyroid development, disorders of parathyroid function, and acquired damage to the parathyroids. Hypoparathyroidism can manifest as the sole disease in an individual (isolated hypoparathyroidism) or be associated with other manifestations within complex syndromes (syndromic hypoparathyroidism). Functional hypoparathyroidism, which may be caused by magnesium disturbances, has always to be ruled out before commencing the genetic diagnostic workup in nonsurgical forms. The search for signs of autoimmunity can drive the diagnosis towards an autoimmune pathogenesis of the disease, since a routine assessment of parathyroid autoantibodies is neither available nor specific.

Sanjad-Sakati Syndrome: Oral Health Care.

OBJECTIVES: The aim of this report is to describe the orofacial manifestations and dental management of a girl with Sanjad-Sakati syndrome. CLINICAL PRESENTATION AND INTERVENTION: The facial features included microcephaly, thin lips, beaked nose, low set ears, and a retrognathic mandible. An oral examination revealed oligodontia/hypodontia, small dental arches, a high arched palate, and a deep overbite and increased overjet. Oral rehabilitation involved full coverage prosthetic crowns on the upper central incisors, stainless steel crowns on the lower molars, and removable partial prostheses to replace missing teeth. CONCLUSION: Recognition of orofacial features might help in the diagnosis of Sanjad-Sakati syndrome. Dental management of affected patients might be complicated by intellectual, neurological, and endocrine abnormalities.

[Parathyroid and bone. Bone metabolism in hypoparathyroidism].

Hypoparathyoidism is classified into two categories: PTH deficient and PTH refractory (i.e. pseudohypoparathyrodism [PHP]). Bone metabolism is different between the two. In PTH deficient hypoparathyroidism such as post-operative hypoparathyroidism, BMD is increased with relatively low bone turnover markers. In PHP, which characterized by PTH resistance in proximal renal tubules, bone response to PTH is sometimes preserved. In some PHP cases, high bone turnover state is observed, which correlates with serum PTH levels.

[Pathophysiology and classitication of parathyroidism].

Hypoparathyroidism is characterized by decreased actions of parathyroid hormone (PTH) either by reduced secretion of or resistance to PTH. The understanding in the pathogenesis of hypoparathyroidism has been greatly increased by recent findings in genetic abnormalities of patients with hypoparathyroidism. A new classification of hypoparathyroidism based upon these genetic abnormalities is proposed, and a diagnostic approach to patients with hypoparathyroidism is summarized.

[Differential diagnosis of hypoparathyroidism and the Ellsworth-Howard's test].

Presence of hypocalcemia along with normo- or hyper-phosphatemia in the absence of decreased renal function strongly suggests hypoparathyroidism. The first step of differential diagnosis is the measurement of serum intact-PTH level. Less than 30 pg/mL of serum intact-PTH means decreased secretion of PTH, most often associated with post-surgical or idiopathic hypoparathyroidism, and hypomagnesemia. Serum intact-PTH values of 30 pg/mL or more suggest psuedohypoparathyroidism (PHP). In the latter case, to confirm decreased PTH responsiveness, Ellsworth-Howard's test or PTH loading test should be performed.

[Treatment of hypoparathyroidism by active vitamin D].

Oral administration of active vitamin D is used as a standard medication for the treatment of hypoparathyroidism in our country. Although the dose required for the control of serum calcium level might be different dependent on the pathological type of hypoparathyroidism, the determination of maintenance dose and follow-up are performed by the measurements of serum and urinaly calcium levels. In the future, the clinical use of parathyroid hormone is expected for the treatment of hypoparathyroidism, since it is physiological.

[Hypoparathyroidism and syndrome of hypocalcemia]. / Gipoparatireoz i gipokal'tsimicheskii sindrom.

Hypoparathyroidism (HP) is a syndrome caused by insufficient secretion or weak action of parathormone leading to hypocalciemia (HC) and intermittent tetanus. HP is the most frequent cause of HC but not a single one. HC may present in 30 etiopathogenic variants and, consequently, being a problem for many clinical disciplines. Practical aspects of etiopathogenesis, clinical and laboratory diagnosis and treatment of a hypocalciemic syndrome of different nature are considered.

Thyroid surgery and anaesthesia following head and neck irradiation for childhood malignancy.

BACKGROUND: Increasing numbers of adolescents and young adults are undergoing thyroid surgery because of the risk of malignancy following previous irradiation for childhood malignancy. Irradiation to the head and/or neck regions may induce changes in the soft tissues and larynx that are far from normal with respect to both size and mobility. The aim of the present study was to evaluate the possible impact of such changes on both surgical and anaesthetic technique during thyroidectomy. METHODS: This was a retrospective ease study. Thirty consecutive patients undergoing total thyroidectomy following previous irradiation for childhood malignancy formed the study group. RESULTS: There were no permanent surgical or anaesthetic complications in the group. In particular there were no cases of either permanent recurrent laryngeal nerve palsy or permanent hypoparathyroidism. Twenty-eight patients had an uneventful intubation and two were unable to be intubated directly, one requiring fibre-optic bronchoscopic intubation and the other having surgery performed with a laryngeal mask following failed bronchoscopy. Both of these patients had received high-dose direct irradiation to the larynx for solid tumours. CONCLUSIONS: Despite potential difficulties associated with the heavily irradiated larynx, thyroid surgery and anaesthesia can be performed safely with minimal complications in experienced hands.

Pseudohipoparatiroidismo Tipo I

El pseudohipoparatiroidismo es una entidad infrecuente y heterogénea causada por la pérdida heterocigótica de aproximadamente el 50 por ciento de la proteína Gs alfa, caracterizada por losvalores séricos de calcio bajos, grados de fosfatemia variable elevada y resistencia variable de la PTH, con hallazgos clínicos dismórficos y en algunos casos (tipo I) asociado a retardo mental. La alteración descrita es el resultado de la disfunción de la proteína Gs alfa miembro de la superfamilia de proteínas heterotriméricas transductoras de señales intracelulares estimuladoras de la adenil ciclasa intracelular. Se revisan dos casos con el tipo pseudohipo-hiperparatiroidismo y uno de tipo I.

[Idiopathic hypoparathyroidism (isolated)].

X-linked recessive, autosomal dominant and autosomal recessive types of familial isolated hypoparathyroidism have been reported, and there are a variety of syndromes of isolated hypoparathyroidism in association with other developmental anomalies involving dwarfism, cortical thickening of tubular bones, nephropathy, sensoryneural deafness and lymphedema. The molecular genetic basis of these forms of idiopathic hypoparathyroidism has been investigated recently. Several genetic abnormalities were elucidated; mutations of the parathyroid hormone gene in some families of autosomal dominant and autosomal recessive familial isolated hypoparathyroidism, a defect at the Xq 26-q 27 region on the long arm of the X chromosome in X-linked recessive familial isolated hypoparathyroidism, and chromosomal deletions at 22q 11 in DiGeorge syndrome. Although adult onset idiopathic hypoparathyroidism may be caused by autoimmune mechanism as a part of polyglandular autoimmune syndrome or as isolated hypoparathyroidism, this type of idiopathic hypoparathyroidism is relatively rare in Japan. Etiology of sporadic cases of adult onset idiopathic hypoparathyroidism still remains to be elucidated.

Pseudoidiopathic hypoparathyroidism: report of a case and review of the literature in Japan.

A case of pseudoidiopathic hypoparathyroidism is described. The patient, 47-year-old male, developed numbness and muscle spasms in the extremities in July 1980. Physical and laboratory examinations revealed positive Chvostek and Trousseau's signs, hypocalcemea, mild hyperphosphatemia, normal serum magnesium, prolongation of QTc on EKG, normal reaction to Ellsworth-Howard test and high levels of serum PTH. Treatment with calcium lactate and vitamin D was successful. The literature regarding 16 cases reported in Japan was reviewed.

Hypoparathyroidism and pseudohypoparathyroidism in childhood.

Although relatively uncommon, the conditions of hypoparathyroidism and pseudohypoparathyroidism in childhood provide an exciting diagnostic and therapeutic challenge. Knowledge of calcium-phosphate homeostasis has progressed rapidly over the past few years so that our understanding of the basic pathophysiological mechanisms has increased tremendously. However, further clinical and basic scientific research will, no doubt, unravel further variations of the various disease entities described.

[Radiologic aspects of osteopathy in parathyroid gland diseases and their differential diagnosis]. / Radiologische Aspekte der Osteopathien bei Nebenschilddrüsenerkrankungen und ihre Differentialdiagnose.

The different disturbances of these organs resulting from the relative endocrine autonomy of the parathyroid glands obtain a manifold symptomatology often with an only later diagnosing. In increased activity of the parathyroid glands hypercalcaemia as well as generalized osteodystrophy are indicating the target in combination with subperiostal resorptions of the corticalis at the phalanges. As a rule underfunction distinguishes itself by hypocalcaemia, hyperphosphataemia and osteoscleroses due to increased mineral fixation in bones. Pseudoparathyreotic conditions are to be differed from actual pictures of the disease only in typical expression. In the paraneoplastic syndromes appearing within this boundary only the proof of a malignoma allows a secure demarcation. On account of the often uncharacteristic X-ray picture, the variable symptomatology and the in many cases lacking directive paraclinical findings practically all pathological bone processes which are based on deviations in the calcium and phosphate metabolism are to be included in differential-diagnostic considerations.