Etiologic and therapeutic analysis in patients with hypokalemic nonperiodic paralysis

Clinical features and recovery pattern of secondary hypokalaemic paralysis

PURPOSE

Information regarding frequency, details of neurological signs and recovery patterns of patients with secondary hypokalaemic paralysis (HP) is limited. This study aimed to analyse the frequency, aetiology, clinical features and recovery patterns of patients with secondary HP.

METHODS

The clinical and laboratory records of 18 consecutive patients with secondary HP aged ≥ 18 years admitted to our hospital between April 2011 and March 2022 were reviewed. Patients with inherited hypokalaemic periodic paralysis were excluded.

RESULTS

Of the 18 patients, 16 had a common aetiology: chronic alcoholism, diarrhoea or an imbalanced diet. Initial symptoms, such as fatigue, were often atypical. Three patients had prominent asymmetric limb weakness and four had predominant upper limb weakness. On admission, the mean serum potassium and creatine kinase (CK) levels of the patients were 1.90 mmol/L and 4488 U/mL, respectively. Ten patients (56%) had decreased potassium levels after admission, despite potassium replacement treatment (rebound hypokalaemia). Twelve patients presented with increased CK levels even after 2-5 days (delayed hyperCKaemia). Low serum magnesium levels significantly correlated with rebound hypokalaemia.

CONCLUSIONS

Secondary HP can be caused by a variety of conditions, but mainly occurs due to lifestyle conditions/disorders. Secondary HP often presents with atypical symptoms, and the initial symptoms can be non-specific. Rebound hypokalaemia and delayed hyperCKaemia are common in secondary HP, despite potassium replacement. As such, careful serial monitoring is needed for patients with secondary HP.

Thyrotoxic periodic paralysis in two sexagenarian men: A case report

RATIONALE

Thyrotoxic periodic paralysis (TPP) characterized by the triad of muscle paralysis, acute hypokalemia, and the presence of hyperthyroidism is often reported in young adults but rarely reported in age >60 year-old.

PATIENT CONCERNS

Two sexagenarian males (age 61 and 62) presenting to the emergency department with progressive muscle paralysis for hours. There was symmetrical flaccid paralysis with areflexia of lower extremities. Both of them did not have the obvious precipitating factors and take any drugs.

DIAGNOSIS

Their Wayne scores, as an objective index of symptoms and signs associated with thyrotoxicosis, were <19 (7 and 14, respectively). Their blood pressure stood 162/78 and 170/82 mm Hg, respectively. Their thyroid glands were slightly enlarged. Both of them had severe hypokalemia (1.8 and 2.0 mmol/L). Their presumptive diagnosis of mineralocorticoid excess disorders with severe potassium (K+) deficit were made. However, low urine K+ excretion and relatively normal blood acid-base status were suggestive of an intracellular shift of K+ rather than K+ deficit. Hormone studies confirmed hyperthyroidism due to Graves disease.

INTERVENTIONS

A smaller dose of K+ supplementation (only a total of 50 and 70 mmol K+, respectively) were prescribed for the patient.

OUTCOMES

After treatment, their serum K+ levels became normal with a full recovery of muscle strength.

LESSONS

Our 2 cases highlight the fact that thyrotoxic periodic paralysis must be still kept in mind as the underlying cause of hypokalemia with paralysis and hypertension in elderly patients to avoid missing curable disorders.

Hypokalemic paralysis in hyperthyroidism: Not all that glitter are gold

Abnormal acid-base status (metabolic acidosis or alkalosis), inappropriate urine electrolytes excretion (high or low Na+ and Cl-), and higher required dose of potassium supplement (4-5 mmol/kg) are suggestive of non-TPP causes of hypokalemia.

A Case of Thiazide-induced Hypokalemic Paralysis

We describe the case of a patient presenting with odd neurologic symptoms initially thought to represent somatization who was found to have critical hypokalemia manifesting as hypokalemic non-periodic paralysis. It was determined that the patient had baseline hypokalemia as a function of alcohol abuse, exacerbated by self overmedication with hydrochlorothiazide for elevated blood pressure readings at home. The diagnosis was suspected when an electrocardiogram was obtained demonstrating a pseudo-prolonged QT interval with ST depression, consistent with T-U wave fusion and a QU interval with an absent T wave.1 The patient received oral and intravenous potassium and magnesium supplementation with resolution of symptoms.

An atypical presentation of high potassium renal secretion rate in a patient with thyrotoxic periodic paralysis: a case report

Background

Hypokalemia is one of the most common clinical electrolyte imbalance problems, and thyrotoxic periodic paralysis (TPP) is a leading cause of presentation to the emergency department. Low renal potassium secretion rates, a normal acid–base balance in the blood, and hyperthyroidism are the hallmarks of suspected TPP.

Case presentation

Here we report the case of a 36-year-old man who presented to the emergency department with a sudden onset of acute muscle weakness at 5 h prior to admission. Biochemistry tests revealed hypokalemia with hyperthyroidism and renal potassium wasting. TPP was initially not favored due to the presence of renal potassium wasting. However, his serum potassium level rebounded rapidly within several hours after potassium supplementation, indicating that the intracellular shifting of potassium ions was the main etiology for his hypokalemia. The early stage of TPP development may have contributed to this paradox.

Conclusion

Therefore, it is premature to rule out TPP based on the presentation of high renal potassium secretion rates alone. This finding may result in an incorrect impression being made in the early stage of TTP and may consequently lead to an inappropriate potassium supplementation policy.

Spectrum of Hypokalemic Paralysis from a Tertiary Care Center in India

Hypokalemic paralysis is an important and reversible cause of acute flaccid paralysis. The treating physician faces unique diagnostic and therapeutic challenges. We did a prospective study and included all patients with acute flaccid weakness and documented serum potassium of <3.5 mEq/L during the period between January 2009 and August 2015. We studied the incidence, etiology, clinical profile, and acid-base disturbances in patients presenting with hypokalemic paralysis and analyzed the significance of periodic and non-periodic forms of hypokalemic paralysis on patient's outcome. Two hundred and six patients were studied with a mean follow-up of 3.6 ± 1.2 years. Mean age was 37.61 ± 2.2 years (range 18-50 years). Males were predominant (M:F ratio 2.1:1). The nonperiodic form of hypokalemic paralysis was the most common (61%). Eighty-one (39%) patients had metabolic acidosis, 78 (38%) had normal acid-base status, and 47 (23%) patients had metabolic alkalosis. The most common secondary cause was distal renal tubular acidosis (RTA) (n = 75, 36%), followed by Gitelman syndrome (n = 39, 18%), thyrotoxic paralysis (n = 8, 4%), hyperaldosteronism (n = 7, 3%), and proximal RTA (n = 6, 4%). Patients with non-periodic paralysis had more urinary loss (40.1 vs. 12.2 mmol, P = 0.04), more requirement of potassium replacement (120 vs. 48 mmol, P = 0.05), and longer recovery time of weakness (48.1 vs. 16.5 h, P = 0.05) than patients with periodic paralysis. Non-periodic form of hypokalemic paralysis was the most common variant in our study. Patients with periodic paralysis had significant incidence of rebound hyperkalemia.

Hypokalemic Paralysis Complicated by Concurrent Hyperthyroidism and Hyperaldosternoism: A Case Report

Patient: Female, 38

Final Diagnosis: Primary hyperaldosteronism

Symptoms: Paralysis

Medication: —

Clinical Procedure: —

Specialty: Nephrology

Mutation profile and treatment of Gitelman syndrome in Chinese patients

BACKGROUND

Gitelman syndrome (GS) is a rare autosomal recessive disease caused by loss-of-function mutations in the SLC12A3 gene, and is characterized by hypokalemia and metabolic alkalosis. In this study, we aimed to study the genotype, phenotype, and treatment in 42 GS patients, the largest sample size so far in mainland China.

METHOD

We retrospectively studied the clinical data and genetic characteristics of 42 patients diagnosed with GS in Peking Union Medical College Hospital from 2012 to 2015. Therapeutic efficacy of spironolactone and potassium supplements was also studied retrospectively.

RESULTS

Eighty-one mutation alleles were found in 42 patients, and total of 52 distinctly different mutation alleles were identified, of which 15 were new mutation alleles. p.Asp486Asn was a hotspot in our series, with the allele frequency being 19.7 % (16/81), and was found in 13 patients (31.0 %). Treatment with spironolactone or potassium supplements alone significantly increased serum potassium concentration by 0.36 ± 0.37 and 0.45 ± 0.35 mmol/l, respectively (both P < 0.05), and combined therapy with spironolactone and potassium increased serum potassium concentration by 0.69 ± 0.64 mmol/l (P < 0.05).

CONCLUSIONS

18.5 % (15/81) mutation sites identified in 42 Chinese GS patients are novel. p.Asp486Asn mutation is a hotspot, which is different from the reports from other countries. Spironolactone could moderately elevate serum potassium level, and spironolactone in combination with potassium supplements tended to be more effective.

[A woman with pareses of the arms and legs]

BACKGROUND

Hypokalemic pareses are caused by low extracellular potassium levels which reduce the resting membrane potential of muscle cells and make them less excitable. It may be caused by an intracellular shift of potassium, renal potassium loss, reduced potassium intake or increased gastrointestinal loss.

CASE PRESENTATION

A woman in her 60s presented with rapid-onset tetraparesis and hyporeflexia starting the day before admission. The patient history revealed several months of low food intake, increased alcohol consumption and diarrhoea. Laboratory tests showed severe hypokalemia (1.5 mmol/l) and hypomagnesemia (0.38 mmol/l), and ECG showed atrial fibrillation. She was admitted to the medical intensive care unit and treated with intravenous normal saline with added potassium and magnesium, with good effect on her symptoms. Urine tests showed high potassium-creatinine ratio (4.22 mmol/mmol creatinine) and increased fractional excretion of magnesium (18.6%). Abdominal CT scan revealed colonic wall thickening, and colonic biopsies showed mild inflammation. Faecal calprotectin was moderately elevated (294 mg/kg).

INTERPRETATION

The patient had hypokalemic pareses for which there were several contributing factors. The renal causes were augmented excretion of magnesium and potassium, probably due to increased alcohol consumption. The extrarenal causes were increased gastrointestinal loss, with ulcerative colitis being the presumed explanation, and reduced food intake.

Hypokalemic Paralysis Complicated by Concurrent Hyperthyroidism and Chronic Alcoholism: A Case Report

Thyrotoxic periodic paralysis (TPP) is characterized by the presence of muscle paralysis, hypokalemia, and hyperthyroidism. We report the case of a young man with paralysis of the lower extremities, severe hypokalemia, and concurrent hyperthyroidism. TPP was suspected; therefore, treatment consisting of judicious potassium (K+) repletion and β-blocker administration was initiated. However, urinary K+ excretion rate, as well as refractoriness to treatment, was inconsistent with TPP. Chronic alcoholism was considered as an alternative cause of hypokalemia, and serum K+ was restored through vigorous K repletion and the addition of K+ -sparing diuretics. The presence of thyrotoxicosis and hypokalemia does not always indicate a diagnosis of TPP. Exclusion of TPP can be accomplished by immediate evaluation of urinary K+ excretion, acid-base status, and the amount of potassium chloride required to correct hypokalemia at presentation.