J Pediatr Endocr Met 2015; 28(1-2): 157–161
Hiba Al-Zubeidi, Carla Demeterco and Kenneth Lee Jones*
Thyrotoxic, hypokalemic periodic paralysis (THPP) in adolescents Introduction
Abstract Introduction: Periodic paralysis associated with hyperthyroidism and hypokalemia is an uncommon disorder reported primarily in Asian males and rarely in children. We report three Hispanic adolescent males who were seen with Graves’ disease (GD) and THPP. Methods: The method used was chart review. Results: Two of these boys presented with episodes of paralysis and were diagnosed with GD. The third was initially seen with hyperthyroidism and developed weakness and paralysis when his disease progressed because of therapeutic noncompliance. Hypokalemia was documented in two of the three patients with the third not seen during paralysis. Intravenous K+ was required in only one case. All three boys were treated with antithyroid medications and β blockers, and the musculoskeletal symptoms resolved in all three when hyperthyroidism was controlled after 2 weeks of treatment. The duration for each episode of weakness and paralysis varied in each case and resolved within 15 min to 2 h in case 1, 1–5 h in case 2, and 24 h in case 3. Conclusions: THPP is considered uncommon except in Asian males and rare in childhood and adolescence. Its occurrence in these three Hispanic boys suggests that it may occur more frequently in the young and in the USA than has been suspected, especially with the changing national demographics. We believe that our experience should raise the awareness of THPP among pediatric care providers. Keywords: Graves’ disease; hyperthyroidism; weakness. DOI 10.1515/jpem-2014-0016 Received January 13, 2014; accepted July 8, 2014; previously published online August 12, 2014
*Corresponding author: Kenneth Lee Jones, MD, MC5103 3020 Children’s Way, San Diego, CA 92123-4282, USA, Phone: +1-858-966-4032, Fax: +1-858-966-6227, E-mail: [email protected] Hiba Al-Zubeidi, Carla Demeterco and Kenneth Lee Jones: Department of Pediatrics, University of California, San Diego, San Diego, CA, USA; and Rady Children’s Hospital, San Diego, San Diego, CA, USA
Thyrotoxic hypokalemic periodic paralysis (THPP) is an uncommon but serious complication of hyperthyroidism, usually associated with Graves’ disease (GD). Presentations range from transient weakness to a flaccid paralysis which may last from hours to days. If patients are evaluated during an episode, hypokalemia can be documented. This condition is unfamiliar to most pediatricians because it is rarely seen in children, having been primarily diagnosed and reported in young Asian men, including Chinese, Japanese, Vietnamese, Filipino, and Korean men. Although some of the earliest cases described were from California (1), the incidence of thyrotoxic patients in the USA is only 0.1%–0.2% (2) in contrast to 1.8% in reported Chinese (3) and 1.9% in Japanese patients (4). It may be anticipated that this disorder will be seen more frequently in the USA and Europe because of its changing demographics and also because of recent recognition of THPP in Hispanics (5), Blacks (6), and in American Indians (7). We have recently seen three Hispanic teenage boys with GD and periodic paralysis and report their presentations and clinical courses here.
Case reports Patient 1 This 17-year-old Hispanic male was first seen by us after having had three episodes of paralysis which lasted for 15 min to 2 h before resolving. The first episode followed a period of skating and was described as weakness in his lower extremities and inability to walk. The second was similar and happened spontaneously while he was standing. The third episode was noted when he awoke, involved both the upper and lower extremities, and was associated with urinary incontinence. When these attacks were occurring, he was being evaluated by his primary care physician for weight loss and elevated liver enzymes and had been scheduled for a liver biopsy. Following the third
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158 Al-Zubeidi et al.: THPP in adolescents event, he was referred to Endocrinology for evaluation of weight loss and paralysis. He was also having difficulty sleeping and was anxious and tired. Physical examination revealed a clinically hyperthyroid, cachectic adolescent with a BMI of 17.56 kg/m2. He was tachycardic and diaphoretic and had a goiter measuring 6 × 6 cm with no bruit. He had lid retraction and a stare. He also had marked proximal muscle weakness in all extremities with little ability to resist opposing force and difficulty rising from a sitting position to stand. His initial thyroid function tests (Table 1) confirmed GD. Treatment was initiated with a β blocker in combination with methimazole. After diagnosis was made, he had two episodes of weakness that occurred at rest and lasted 15 min each. He improved markedly with a gain of 20 lb, resolution of his anxiety and fatigue, and no further paralysis after 2 weeks of treatment. His thyroxine level normalized to 10.9 μg/dL. He remains euthyroid and without neuromuscular symptoms more than a year after diagnosis and initiation of therapy.
Patient 2 This 18-year-old Hispanic male presented to the emergency department (ED) after developing lower extremity weakness requiring assistance to walk. He was found to have a serum potassium level of 3.2 meq/L (normal 3.5–5.5 mmol/L). He reported weight loss of 50 lb over 4–5 months and complained of heat intolerance and anxiety. In the ED, hyperthyroidism was diagnosed; he was started on methimazole at 5 mg bid and was referred to Endocrinology. When seen, he was clinically hyperthyroid with a goiter measuring 11 × 8 cm. He had continued to have lower extremity weakness. Laboratory evaluation (Table 1) revealed an elevated total thyroxine and a suppressed thyroid-stimulating hormone (TSH). Thyroidstimulating immunoglobulin was elevated, confirming GD. Treatment with 10 mg tid of propranolol was started, the dose of methimazole was increased to 15 mg bid, and his lower extremity weakness resolved in 2 weeks. His hyperthyroxemia persisted for 8 months, requiring an additional increase in methimazole to 30 mg bid. Ten Table 1 Thyroid function in patients at initial presentation. Patient
Total T4 (4.5–12)
Total T3 (84–179)
TSH (0.5–4.3)
TSI ( 800 ng/dL > 800 ng/dL
Hiba Al-Zubeidi, Carla Demeterco and Kenneth Lee Jones*
Thyrotoxic, hypokalemic periodic paralysis (THPP) in adolescents Introduction
Abstract Introduction: Periodic paralysis associated with hyperthyroidism and hypokalemia is an uncommon disorder reported primarily in Asian males and rarely in children. We report three Hispanic adolescent males who were seen with Graves’ disease (GD) and THPP. Methods: The method used was chart review. Results: Two of these boys presented with episodes of paralysis and were diagnosed with GD. The third was initially seen with hyperthyroidism and developed weakness and paralysis when his disease progressed because of therapeutic noncompliance. Hypokalemia was documented in two of the three patients with the third not seen during paralysis. Intravenous K+ was required in only one case. All three boys were treated with antithyroid medications and β blockers, and the musculoskeletal symptoms resolved in all three when hyperthyroidism was controlled after 2 weeks of treatment. The duration for each episode of weakness and paralysis varied in each case and resolved within 15 min to 2 h in case 1, 1–5 h in case 2, and 24 h in case 3. Conclusions: THPP is considered uncommon except in Asian males and rare in childhood and adolescence. Its occurrence in these three Hispanic boys suggests that it may occur more frequently in the young and in the USA than has been suspected, especially with the changing national demographics. We believe that our experience should raise the awareness of THPP among pediatric care providers. Keywords: Graves’ disease; hyperthyroidism; weakness. DOI 10.1515/jpem-2014-0016 Received January 13, 2014; accepted July 8, 2014; previously published online August 12, 2014
*Corresponding author: Kenneth Lee Jones, MD, MC5103 3020 Children’s Way, San Diego, CA 92123-4282, USA, Phone: +1-858-966-4032, Fax: +1-858-966-6227, E-mail: [email protected] Hiba Al-Zubeidi, Carla Demeterco and Kenneth Lee Jones: Department of Pediatrics, University of California, San Diego, San Diego, CA, USA; and Rady Children’s Hospital, San Diego, San Diego, CA, USA
Thyrotoxic hypokalemic periodic paralysis (THPP) is an uncommon but serious complication of hyperthyroidism, usually associated with Graves’ disease (GD). Presentations range from transient weakness to a flaccid paralysis which may last from hours to days. If patients are evaluated during an episode, hypokalemia can be documented. This condition is unfamiliar to most pediatricians because it is rarely seen in children, having been primarily diagnosed and reported in young Asian men, including Chinese, Japanese, Vietnamese, Filipino, and Korean men. Although some of the earliest cases described were from California (1), the incidence of thyrotoxic patients in the USA is only 0.1%–0.2% (2) in contrast to 1.8% in reported Chinese (3) and 1.9% in Japanese patients (4). It may be anticipated that this disorder will be seen more frequently in the USA and Europe because of its changing demographics and also because of recent recognition of THPP in Hispanics (5), Blacks (6), and in American Indians (7). We have recently seen three Hispanic teenage boys with GD and periodic paralysis and report their presentations and clinical courses here.
Case reports Patient 1 This 17-year-old Hispanic male was first seen by us after having had three episodes of paralysis which lasted for 15 min to 2 h before resolving. The first episode followed a period of skating and was described as weakness in his lower extremities and inability to walk. The second was similar and happened spontaneously while he was standing. The third episode was noted when he awoke, involved both the upper and lower extremities, and was associated with urinary incontinence. When these attacks were occurring, he was being evaluated by his primary care physician for weight loss and elevated liver enzymes and had been scheduled for a liver biopsy. Following the third
Brought to you by | University of California - San Francisco Authenticated Download Date | 2/14/15 2:38 PM
158 Al-Zubeidi et al.: THPP in adolescents event, he was referred to Endocrinology for evaluation of weight loss and paralysis. He was also having difficulty sleeping and was anxious and tired. Physical examination revealed a clinically hyperthyroid, cachectic adolescent with a BMI of 17.56 kg/m2. He was tachycardic and diaphoretic and had a goiter measuring 6 × 6 cm with no bruit. He had lid retraction and a stare. He also had marked proximal muscle weakness in all extremities with little ability to resist opposing force and difficulty rising from a sitting position to stand. His initial thyroid function tests (Table 1) confirmed GD. Treatment was initiated with a β blocker in combination with methimazole. After diagnosis was made, he had two episodes of weakness that occurred at rest and lasted 15 min each. He improved markedly with a gain of 20 lb, resolution of his anxiety and fatigue, and no further paralysis after 2 weeks of treatment. His thyroxine level normalized to 10.9 μg/dL. He remains euthyroid and without neuromuscular symptoms more than a year after diagnosis and initiation of therapy.
Patient 2 This 18-year-old Hispanic male presented to the emergency department (ED) after developing lower extremity weakness requiring assistance to walk. He was found to have a serum potassium level of 3.2 meq/L (normal 3.5–5.5 mmol/L). He reported weight loss of 50 lb over 4–5 months and complained of heat intolerance and anxiety. In the ED, hyperthyroidism was diagnosed; he was started on methimazole at 5 mg bid and was referred to Endocrinology. When seen, he was clinically hyperthyroid with a goiter measuring 11 × 8 cm. He had continued to have lower extremity weakness. Laboratory evaluation (Table 1) revealed an elevated total thyroxine and a suppressed thyroid-stimulating hormone (TSH). Thyroidstimulating immunoglobulin was elevated, confirming GD. Treatment with 10 mg tid of propranolol was started, the dose of methimazole was increased to 15 mg bid, and his lower extremity weakness resolved in 2 weeks. His hyperthyroxemia persisted for 8 months, requiring an additional increase in methimazole to 30 mg bid. Ten Table 1 Thyroid function in patients at initial presentation. Patient
Total T4 (4.5–12)
Total T3 (84–179)
TSH (0.5–4.3)
TSI ( 800 ng/dL > 800 ng/dL
![[Thyrotoxic hypokalemic periodic paralysis. A case report].](/assets/img/hold.png)
