5 children with hypokalemia, hypomagnesemia and hypocalciuria (Gitelman syndrome) in one family

Gitelman's syndrome was diagnosed in five siblings. The parents were relatives in the third remove. Gitelman's syndrome is a rare autosomal recessive hereditary magnesium reabsorption defect in the distal tubule. It is characterized by episodes of muscle weakness, usually accompanied by abdominal pain and vomiting. Tetany may occur during a febrile illness. Patients are of normal height and weight and have normal blood pressures. Sometimes eczematous skin lesions are found. Biochemically there is hypokalaemia, hypomagnesaemia and alkalosis. Urinary excretion rates of potassium and magnesium are elevated, the excretion of calcium is diminished. Treatment consists of oral suppletion of magnesium, sometimes also with oral potassium. A potassium-sparing diuretic may be used. The prognosis appears to be good.     

Hypocalcemia and hypomagnesemia

The occurrence of hypocalcemia is well documented in clinical veterinary medicine. In this article, we have attempted to provide an overview of the established causes as well as information on more recently recognized etiologies such as the ionized hypocalcemia seen in cats with urethral obstruction and the presence of the disorder in critically ill patient populations. Hypomagnesemia has been identified as the most common electrolyte abnormality in canine and feline critically ill patients. Magnesium depletion and experience with supplementation appear to have most significance in diabetic ketoacidotic patients with the development of associated refractory hypokalemia. (N. Dhupa, BVM, MRCVS, unpublished observations, 1997). Although cardiac arrythmias are associated with hypomagnesemia in human patients, documentation of this association in veterinary patients is lacking. Because hypomagnesemia has been associated with other electrolyte abnormalities in human and veterinary populations, the detection of hypokalemia (particularly if refractory to therapy), hyponatremia, hypophosphatemia, or hypocalcemia should indicate the possibility of coexisting hypomagnesemia.     

Hypothermia-induced hypokalemia

Hypothermia may be seen both as a presenting problem and as a part of therapeutic strategy. An illustrative case is presented. In our case of severe head trauma, hypothermia was used as a therapeutic modality to minimize the brain injury. While hypothermic, the patient developed severe hypokalemia and was supplemented with 400 mEq of potassium. Upon rewarming, severe hyperkalemia occurred with resultant fatal arrhythmias. Severe hypokalemia may be seen in hypothermic patients, which represents a shift of potassium rather than a true loss. Careful management of this electrolyte problem must be given to avoid hyperkalemia with rewarming.     

Coexisting psoriatic arthritis, gout, and chondrocalcinosis

BACKGROUND: Constructional impairment following left vs. right hemisphere damage has been extensively studied drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects. METHODS: Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs test. RESULTS: Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand. CONCLUSIONS: The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LDH is due to an elementary motor disturbance related to use of the non-dominant hand.     

Does hypothyroidism increase the prevalence of chondrocalcinosis?

To investigate whether or not there is an association between hypothyroidism (HPT) and chondrocalcinosis (CC) 100 HPT patients and 100 controls matched for the age and sex were evaluated prospectively. All the patients were examined clinically, and X-rays of knees, wrists and pelvis, and biological evaluation of thyroid hormones, calcium, uric acid, iron and alkaline phosphatase levels were recorded. X-rays were assessed independently by two radiologists blind to the thyroid status of the patient. The prevalence of CC was 17% in the HPT patients and 10% in the controls (NS). No correlation was found between CC duration and mechanism or treatment of HPT. We suggest that HPT and CC are two diseases that may co-exist in patients but without any causal or mechanistic relationship.     

Ritodrine- and terbutaline-induced hypokalemia in preterm labor: mechanisms and consequences

The effects of ritodrine and terbutaline on potassium homeostasis, renal function, and cardiac rhythm were assessed in women treated with these drugs for preterm labor. Timed blood and urine samples were obtained for two hours before and during six hours of intravenous ritodrine (N = 5) and terbutaline (N = 5) administered in pharmacologically equivalent doses. No differences were found in any parameters affecting potassium homeostasis or renal function between these drugs. A decrease in mean plasma potassium of 0.9 mEq/liter occurred after 30 minutes of drug infusion (4.2 +/- 0.1 to 3.3 +/- 0.1 mEq/liter, P < 0.005) before any significant changes in plasma glucose (75.0 +/- 4.7 to 93.7 +/- 6.1 mg/dl, P = NS) or plasma insulin (12.4 +/- 6.0 to 28.4 +/- 5.1 mU/ml, P = NS). The mean plasma potassium after four hours of drug infusion was 2.5 +/- 0.1 mEq/liter. Plasma insulin rose to a level known to induce cellular potassium uptake (39.2 +/- 7.7 mU/ml) after 60 minutes of drug therapy and remained at this level for four hours. Hyperlactatemia occurred at four hours (4.7 +/- 0.8 mmol/liter) and the plasma lactate/pyruvate ratio increased in a 10:1 ratio. Both drugs significantly reduced glomerular filtration rate, sodium, potassium, and chloride excretion and urinary flow rate. Changes in acid-base homeostasis, plasma aldosterone, or renal potassium excretion did not contribute to ritodrine-or terbutaline-induced hypokalemia. In 83 women with preterm labor randomly assigned to ritodrine (N = 42) or terbutaline (N = 41), the maximum decrease in plasma potassium occurred after six hours of drug infusion. During Holter monitoring, 3 of 14 women treated with ritodrine or terbutaline developed symptomatic cardiac arrhythmias at the lowest plasma potassium while no women treated with saline and morphine (N = 12) developed cardiac arrhythmias (P = 0.14). We conclude that ritodrine and terbutaline induce profound hypokalemia by stimulating cellular potassium uptake and both drugs cause significant renal sodium and fluid retention and cardiac arrhythmias. Careful monitoring of electrolytes, fluid balance, and cardiac rhythm should occur during tocolytic therapy with ritodrine or terbutaline.     

Palindromic syndrome: appearance of chondrocalcinosis after 47 years of evolution

We describe a case with a very long history of recurrent episodes of arthritis without radiological articular damage. After 47 years of followup, he developed chondrocalcinosis located only in previously affected joints. Our patient illustrates the heterogeneity of palindromic rheumatism, which should more appropriately be considered as a clinical syndrome. Our case gives us the opportunity to discuss the nosologic situation of palindromic rheumatism and the role of primary joint damage in the articular deposition of calcium pyrophosphate dihydrate.     

Familial dermatomyositis

A simple device is described that monitors respiration by sounding an alarm if respiration ceases. It is light and portable and performs well, even in a 60 dB noise environment.     

Familial paraganglioma

Extra-adrenal pheochromocytomas and paragangliomas are rare tumors of neural crest origin, most commonly found in the retroperitoneum. Because these tumors are so uncommon, relatively little is known about their natural history. Comparisons between adrenal pheochromocytomas and extra-adrenal pheochromocytomas have appeared in the medical literature. Like pheochromocytomas, paragangliomas may occur as functional or nonfunctional tumors. Furthermore, although the hereditary occurrence of pheochromocytomas is well documented, the familial nature of paragangliomas is unclear. We present the first report of a mother and son with nonfunctional paragangliomas occurring in the same anatomic location and describe their care and treatment.     

Familial paraganglioma

Non-secreting paragangliomas are rare tumours usually present in the head and neck. We describe an unusual case of familial paraganglioma with cranial nerve palsies. After exhaustive investigation, a vagal paraganglioma, was found and excised. The positive family history of paraganglioma was of significance, although this was only present in one of five generations. The diagnosis and management of non-secreting paragangliomas is discussed.     

Familial cardiomyopathy

Over three generations, several members of a family suffered from cardiomyopathy exhibiting, primarily, rhythm and conduction disturbances and, eventually, congestive heart failure. Certain serum enzymes (SGOT, SGPT, LDH) were elevated. The clinical examination indicated a progressive deterioration with increasing age of the patients, a more serious course in the male members of the family, and the frequent association of mental retardation.