KVS Hari Kumar¹, Sangeeta Jha², Ratan Jha³, KD Modi^1
1 Departments of Endocrinology, Medwin Hospitals, Chirag Ali Lane, Nampally, Hyderabad, India
² Departments of Surgical Endocrinology, Medwin Hospitals, Chirag Ali Lane, Nampally, Hyderabad, India
³ Departments of Nephrology, Medwin Hospitals, Chirag Ali Lane, Nampally, Hyderabad, India

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Abstract

Primary hyperaldosteronism (Conns' syndrome) commonly presents with a combi­nation of clinical features of hypokalemia and hypertension. Atypical presentations like normo­tension, normokalemia and neurological ailments are described in few cases. We encountered two such cases, the first presenting with acute neurological complaint and second case having insig­nificant hypertension. Both the patients had a characteristic biochemical and imaging profile consistent with primary hyperaldosteronism and responded to surgical resection of adrenal adenoma.

Keywords: Paralysis, Hyperaldosteronism, Adrenal adenoma

Introduction

Case Reports

(1.4-2.6) and post saline plasma aldosterone was 62 ng/dL (not suppressible). CT scan abdomen revealed a minimally en­hancing isodense mass of 1.2 × 1.2 cms in­volving medial limb of left adrenal gland.

He was treated initially with potassium sup­plements and spironolactone 100 mg twice a day for 4 weeks resulting in good BP control. He underwent left adrenalectomy and intra­operative period was uneventful. On gross examination the tumor was well circumscribed and histopathological examination revealed fea­tures of both zona reticularis and glomerulata in the tumor. Post operatively patient had com­plete recovery of weakness and was not re­quiring any antihypertensive drugs. Serum po­tassium on follow up was normal.

Case 2

33 year old lady presented with recurrent episodic muscle weakness of 4 years duration associated with myalgia and backache. Patient gave history of a hypertensive record on a couple of occasions during past 2 years but was not prescribed with antihypertensives and advised follow up. She gave no symptoms to suggest previous history thyroid illness, co­nnective tissue disease and similar complaints in family members. She had regular menstrual cycles and her only son is 4 years old. Clinical examination revealed normotensive lady with no edema or palpable abdominal mass. Neuro­logical examination revealed Grade IV power in all groups of muscles with normal deep tendon jerks. BP monitoring in hospital ranged between a maximum of 150/90 mmHg and a minimum of 110/80 mmHg without any anti­hypertensive drugs. Serum sodium, potassium and chloride were 141, 1.9, and 102 meq/L res­pectively. Arterial blood gas analysis showed metabolic alkalosis with pH - 7.493 and HCO3 - 28.1 mmol/L. Thyroid function tests were normal. ECG showed presence of U waves and there were no hypertensive changes. Spot urine potassium showed 46 meq/L and because of hypokalemia with kaliu­resis she was investigated for primary hyper­aldosteronism. Ultrasonography of the abdomen revealed 3.6 × 2.7 cm round, hypoechoic le­sion in right adrenal gland. CT scan abdomen confirmed the right adrenal adenoma of 3.2 × 2.5 cms in size with non homogenous en­hancement. Plasma Renin Activity was 0.04 ng/mL.hr and plasma aldosterone was 51.6 ng/dL. Overnight dexamethasone test revealed suppressible cortisol levels. Diagnosis of Conns' syndrome was established by:

1. presentation with episodic weakness
2. Hypokalemia
3. increased plasma aldosterone and low plasma renin activity and
4. adrenal adenoma on imaging

The patient was managed with potassium replacement initially followed by Spironolac­tone in a daily dose of 200 mg for 4 weeks preoperatively, which improved her weakness and hypokalemia. She underwent right adrena­lectomy and intraoperative period was un­eventful. On gross examination the tumor was well circumscribed and histopathological exa­mination confirmed the typical features of adrenal adenoma. Post operatively patient had no features of weakness and her serum potassium normalized without any drugs.

Discussion

Primary aldosteronism is a common, often undiagnosed cause of hypertension requiring a high index of suspicion in identification. Nor­mokalemic variant is described in majority of patients but acute neurological ailment as presenting feature is an extremely rare asso­ciation. ^[5] Severe hypokalemia goes unnoticed in otherwise healthy persons but can often present with severe manifestations in some patients. Paralytic myopathy in association with hypokalemia is a recognized feature of Conns' syndrome and is seen more commonly in Asian patients. ^[6] The possible provocative factors are high carbohydrate intake, heavy exercise. The severity of hypokalemia is re­lated to dietary sodium intake and our patient had severe hypokalemia despite a low sodium diet. This increased prevalence of hypokalemic paralysis in Oriental subjects appears to be related to dietary habits rather than underlying genetical difference. Thus, spontaneous hypo­kalemia or diuretic induced hypokalemia asso­ciated with hypertension is a strong indicator of underlying hyperaldosteronism and should be evaluated.

The classical recommendation in patients with significant hypertension requiring 2 or more drugs with poor control, young hypertensives and hypertension associated with hypokalemia is to investigate for the presence of primary hyperaldosteronism. Our second patient recor­ded mild hypertension intermittently and was not treated with antihypertensives throughout her illness. Primary hyperaldosteronism is now increasingly being seen as the underlying cause in patients with hitherto diagnosis of essential hypertension. ^[7] The likelihood of de­monstration of primary hyperaldosteronism appears directly related to the severity of hypertension with increased incidence in pa­tients with more severe hypertension and less common (< 2%) with mild hypertension. The arterial hypertension of primary hyperaldoste­ronism is usually explained by an initial in­crease in sodium reabsorption related to the effect of aldosterone on distal renal tubules. Blood pressure remains high because of in­creased peripheral vascular resistance, a direct hypertensive effect of aldosterone on the cen­tral nervous system, and increased vascular sensitivity to vasopressors such as angiotensin and adrenalin.

The occurrence of normotension in primary hyperaldosteronism is exceedingly rare and mostly described in Eurasians (especially Ja­panese). The patients are mostly middle-aged females and the diagnosis is usually raised by signs of hypokalemia (fatigue, paresthesia, tetany). The mechanisms proposed for normal blood pressure are early diagnosis, absence of volemic expansion or a low salt diet and vasodilator production. ^[3] Postoperative ambula­tory BP monitoring after removal of the adrenal adenoma revealed that these patients had a marked fall in blood pressure. Therefore, the normal blood pressure corresponds to relative hypertension in subjects with low spontaneous blood pressure.

In conclusion, primary hyperaldosteronism with its varied clinical characteristics presents a diagnostic dilemma to the clinicians. Earlier approach of hypertension with hypokalemia to suspect this condition may be missing many borderline hypertensive or normotensive cases. Atypical presentations are increasingly being described in literature and screening for this condition should be undertaken in all cases of hypertension with spontaneous or secondary hypokalemia and in patients with hypokalemic paralysis without hypertension.

 

References

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Correspondence Address:
KVS Hari Kumar
Department of Endocrinology, Medwin Hospitals, Nampally, Hyderabad
India

Source of Support: None, Conflict of Interest: None

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PMID: 19237819