Category: Thyroid

Monitor: 7


Thursday, Apr 25
11:30 AM – 12:00 PM

Objective :

Thyrotoxic Periodic Paralysis (TPP) is a rare, severe, and potentially lethal but reversible complication of hyperthyroidism, characterized by flaccid muscle paralysis and hypokalemia caused by a massive intracellular shift of potassium. TPP has a genetic background, causing skeletal muscle ion channel defects. The most common mechanism is episodic intracellular shift of potassium causing rapid onset hypokalemia and muscle weakness. The incidence is largely unknown in Western countries. Among the most common precipitating factors known are: high carbohydrate diet, strenuous exercise, stress, and corticosteroid therapy. Its most common presentation is proximal asymmetric lower extremity weakness, although it may present with symmetric weakness and diffuse myalgia. Almost invariably, TPP presents with intact sensation, and bowel and bladder functions are typically unaffected.

Methods :

This is the case of a 26-year-old man without significant medical history, who presented with bilateral lower extremity weakness of both of his proximal lower extremities. Symptoms started one day before, and progressed to compromise his upper extremities. He denied presenting with any similar episodes in the past. He denied any other neurologic, respiratory, urinary, digestive or flu-like symptoms. Neurologic exam showed symmetric loss of deep tendon reflexes in the upper and lower extremities, diminished power of 3/5 in his upper extremities and 2/5 in lower extremities; he had normal higher function and grossly intact cranial nerves. The rest of the exam was unremarkable.

Results : Pertinent ancillaries revealed hypokalemia, without hyperkaluria. Electrocardiogram (EKG) showed diffuse T wave flattening. Thyrotropin level was found suppressed, and free thyroxine significantly elevated. Computed tomography of the brain, and of all spine levels were unremarkable. He was treated with intravenous potassium, followed by rapid improvement of quadriparesis, with no residual weakness. 

Discussion : A thyroid uptake and scan showed diffuse increased uptake consistent with Graves' disease. He was treated with methimazole and atenolol orally. If TPP is suspected, investigations to rule out other causes of hypokalemia and flaccid paralysis should be sought. The treatment focuses on correction of hypokalemia with acute management of thyrotoxicosis.

Conclusion : Flaccid paralysis and hypokalemia are features of both, TPP and hypokalemic periodic paralysis, hence it is imperative to search for clinical features of thyrotoxicosis and obtain thyroid function tests as part of the work up immediately upon presentation, in order to direct therapy accordingly.


Alberto A. Franco-Akel

Chief of Endocrinology
New York City H+H/ Metropolitan, New York Medical College
New York

Dr. Alberto Franco-Akel is an endocrinologist, currently working as chief of the endocrinology section of the department of medicine, at NYC H+H/Metropolitan, New York City. Dr. Franco-Akel graduated from medical school at Universidad Catolica de Santiago de Guayaquil, Ecuador in 2005. He did his internal medicine residency at NYC H+H/Metropolitan after which he served as Chief Medical Resident, until 2014. Dr. Franco-Akel completed his endocrinology fellowship training at Mount Sinai Beth Israel, New York in 2016. Afterwards, he started working as an internist and endocrinologist at NYC H+H/Metropolitan in 2016, taking charge of patients in the general endocrinology clinic, HRT-LGBT clinics, and Diabetes clinics, as well as the inpatient endocrinology consultation services. He was promoted to Chief of Endocrinology in July 2017. Dr. Franco has an academic affiliation with New York Medical College as an Assistant Professor of Medicine. As such, he participates in mentorship of residents and medical students. Dr. Franco-Akel is actively involved in quality improvement projects, performance improvement projects, as well as programs for the enhancement of care for patients at Metropolitan, including the Diabetes Prevention Program, and Diabetes Self Management Program. Dr. Franco-Akel received the award of The Best Physician Teacher In A Sub-specialty Rotation, and the recognition by New York Medical College medical students for teaching and preceptor-ship in 2018.

Janpreet S. Bhandohal

Internal Medicine resident
New York H+H/Metropolitan - New York Medical College

Currently internal medicine PGY3.

Mohammad Saeed

Internal Medicine attending, assistant professor of medicine
New York H+H/Metropolitan - New York Medical College

Internal Medicine physician

Devendra Tripathi

PGY3 internal medicine resident
New York H+H/Metropolitan - New York Medical College

Currently internal medicine PGY3 resident