An unrecognized cause of paralysis in ED: thyrotoxic normokalemic periodic paralysis

Atypical Normokalemic Case of Thyrotoxic Periodic Paralysis in a Pediatric Patient

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism characterized by typical muscular symptoms, ranging from paresis to complete paralysis, commonly associated with low potassium blood levels (<3 mmol/l). It is more commonly reported in adult Asian individuals and can lead to life-threatening situations. Therefore, early clinical diagnosis and targeted therapy are of crucial importance. In this article, we report the case of a 17-year-old adolescent with a Vietnamese background and known Graves' disease who was admitted with typical TPP-related symptoms but no hypokalemia. After treatment with an antithyroid medication and oral potassium supplementation, no new episode of TPP was observed. Using next-generation sequencing, a genetic analysis of TPP-related ion channel genes (KCNJ2, KCNJ18, KCNE3, SCN4A, and CACNA1S) found no known/likely pathogenic variants or variants of unknown significance. To the best of our knowledge, this is only the second reported case of quite normokalemic TPP in the pediatric population. Prompt diagnosis of TPP is essential to prevent harmful complications. Supplementation with potassium appears to be successful alongside non-selective beta-blockers. Normalization of thyroid function should be pursued to prevent new attacks, which is considered the best preventive measure.

Case report: Hyperthyroid hypokalemic periodic paralysis

Introduction and importance

HHPP is a rare type of hypokalemic PP that can occur when there is hyperthyroidism.Thyrotoxic periodic paralysis is due to increased influx of potassium into skeletal muscle cells which leads to profound hypokalemia and paralysis. Insulin and Epinephrine are also responsible for stimulating the Na–K-ATPase pumps which are over expressed during hyperthyroid state. Laboratory hypokalemia in the background of hyperthyroidism with sudden symmetric paralysis point toward the diagnosis.

Case

We present a case of 25 year old male with limb weakness for 3hours following heavy dinner.He felt weakness after waking up in the morning where he could not move his both lower limbs. He also had difficulty moving upper limbs.

Clinical findings and investigations

Examination revealed proximal muscle weakness with power of 2/5, decreased muscle tone, diminished deep tendon reflexes in all four limbs and equivocal plantar reflex bilaterally. Investigation sent were Total Leukocyte count, Hemoglobin, Renal function test, Liver Function test,Thyroid function test, Vitamin B12, Serology, ACTH, Serum calcium, Serum phosphate, Serum magnesium, Urine R/ME and Stool R/ME.

Intervention and outcome

Patient is treated with 10mEq/L/hr infusion of potassium chloride, methimazole and beta-blockers. He is stable and is in regular followup in medicine OPD.

Relevance and impact

Early diagnosis of HHPP is very essential to prevent fatal complications (cardiac and respiratory).

It can be treated by timely potassium supplementation, methimazole and beta-blockers.

Clinicians must be concerned about Hyperkalemia while supplementing Potassium in bed side.

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HHPP is a rare life-threatening complication of hyperthyroidism which is characterized by episodes of acute muscle weakness due to hypokalemia.

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Periodic paralysis (PP) is a muscle disease, characterized by episodes of painless muscle weakness. These episodes can be triggered by strenuous exercise, fasting, or consuming high-carbohydrate foods.

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Treatment cand be done by potassium supplementation until normalized serum potassium level. Patient must be kept in cardiac monitoring and serum potassium monitoring.

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Hyperthyroidism can be treated with methimazole. Patient must be kept under regular follow up in endocrinology department.

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Relapses can be prevented by treatment with radioactive iodine or surgery. Beta-blocking drugs have also been proven to reduce the frequency and severity of episodes.

Periodic paralysis with normokalemia in a patient with hyperthyroidism: A case report

RATIONALE

Thyrotoxic periodic paralysis is characterized by a sudden onset of hypokalemia and paralysis. This condition mainly affects the lower extremities and is secondary to thyrotoxicosis. The underlying hyperthyroidism is often subtle without typical symptoms such as palpitations, tremors, anxiety, and weight loss; this causes a difficulty in early diagnosis. Here, we reported a case of periodic paralysis in a patient with hyperthyroidism whose potassium level was within the normal range.

PATIENT CONCERNS

A 33-year-old Taiwanese man presented to the emergency department with bilateral limb weakness (more severe in the lower limbs than in the upper limbs). On arrival, the patient's vital status was stable with clear consciousness. He denied experiencing recent trauma, back pain, chest pain, abdominal pain, headache or dizziness, or a fever episode. Physical examination showed no specific findings. Neurological examination showed weakness in the muscles of the bilateral upper and lower limbs. Muscle weakness was more severe in the proximal site than in the distal site.

DIAGNOSIS

Blood examination showed normal complete blood count, normal renal and liver function, and normal potassium (3.5 mmol/L, normal range 3.5-5.1 mmol/L), sodium, and calcium levels; however, the examination showed impaired thyroid function (thyroid stimulating hormone: 0.04 uIU/mL, normal range 0.34-5.60 uIU/mL; free T4: 1.96 ng/dL, normal range 0.61-1.12 ng/dL). Brain computed tomography without contrast showed no obvious intra-cranial lesion.

INTERVENTIONS

Intravenous potassium infusion (20 mEq/L) with normal saline was prescribed for the patient.

OUTCOMES

After treatment, the patient felt a decrease in limb weakness. He was discharged from our emergency department with a scheduled follow-up in the endocrine outpatient department.

LESSONS

TPP should be considered as a differential diagnosis in young Asian men presenting with limb paralysis that is more severe in the proximal site and in the lower limbs than in the distal site and in the upper limbs, respectively. It is important for emergency department physicians to consider TPP as a differential diagnosis as it can occur even if the patient's potassium level is within the normal range.

Hyperthyroid hypokalemic periodic paralysis

Hyperthyroid periodic paralysis (HPP) is a rare life threatening complication of hyperthyroidism commonly occurring in young Asian males but sporadically found in other races. It is characterised by hypokalemia and acute onset paraparesis with prevalence of one in one hundred thousand (1 in 100000). The symptoms resolve promptly with potassium supplementation. Nonselective beta blockers like propranol can also be used to ameliorate and prevent subsequent paralytic attack. We report a case of 22 year old male presenting with hyperthyroid periodic paralysis (HPP) having very low serum potassium level.

Normokalemic thyrotoxic periodic paralysis with preserved reflexes- a unique case report

Although serum potassium levels are usually subnormal in Thyrotoxic Periodic Paralysis (TPP), but in exceptionally rare circumstances, it may be normal leading to the entity called normokalemic TPP. The diagnosis of normokalemic TPP is more often overlooked and/or delayed due to lack of awareness among the physicians and associated mild symptoms of hyperthyroidism. Here, the author describes the case of a 27-year-old male with newly diagnosed but untreated Grave's disease and TPP who was normokalemic during the acute phase of paralysis. Hypokalemia was documented only after resolution of paralytic attacks during subsequent days of admission. The importance of the case report is to highlight upon the fact that TPP should always be considered in an "previously asymptomatic" young Asian individual with acute paralysis with or without hypokalemia , and thyroid function and serial potassium values should be evaluated for diagnosing the usual hypokalemic type or the more rarer variant normokalemic TPP. This case report also deserves mention as the patient of TPP had a notable feature of having preserved reflexes in the face of hypokalemia.

[Thyrotoxic periodic paralysis: a case series of four patients and literature review]

PURPOSE

Periodic thyrotoxic hypokalemic paralysis (TPP) is a neuromuscular complication of hyperthyroidism. It is more common in young Asian males than in Caucasian and African patients. We report four new cases and review the literature.

CASE REPORTS

Four consecutive patients were diagnosed with TPP. They were all men with a median age of 34.5 years at presentation. Two patients originated from the Philippines, one was African and one was Caucasian ethnic background. They all presented with a paresis or flaccid paralysis, without respiratory failure. Previous similar episodes in their past medical history, the presence of profound hypokalemia (mean serum potassium level of 2 mmol/L) and the presence of clinical and biological signs of hyperthyroidism led to the diagnosis of TPP. All four patients were diagnosed with Graves' disease. Outcome was favourable in all four patients with the symptomatic treatment of TPP and treatment of Graves' disease.

CONCLUSION

TPP is a severe condition, due to a dysfunction of the Na(+)-K(+) ATPase pump. Initial management relies on β-blocker treatment and careful potassium supplementation. Then, medical or surgical etiological treatment of the thyrotoxicosis is essential to prevent a recurrence. The disease is probably underdiagnosed: it must be suspected when a profound hypokaliema resolves very quickly (<12hours); hyperthyroidism should always be included in the differential diagnosis of a paresis associated with hypokalemia.

Concurrent Graves disease thyrotoxicosis and myasthenia gravis: the treatment of the former may dangerously reveal the latter

Autoimmune thyroxicosis and myasthenia gravis are often associated. In both diseases, clinical features may include neuromuscular weakness, making their distinction challenging. We report a patient with known Graves disease who presented with generalised fatigue, initially attributed solely to thyrotoxicosis, and who experienced severe respiratory failure linked to associated myasthenia gravis that was unmasked by medication used in the perioperative management of his thyroxicosis. Anaesthetists should always consider myasthenia gravis in cases of hyperthyroidism presenting with neuromuscular features.

Hypokalemic thyrotoxic periodic paralysis: clinical characteristics and predictors of recurrent paralytic attacks

BACKGROUND AND PURPOSE

To study the clinical characteristics of hypokalemic thyrotoxic periodic paralysis (hoTPP) and identify the predictors of recurrent paralytic attacks before achieving the euthyroid status.

METHODS

We retrospectively analyzed 45 hoTPP patients who were admitted during the 7-year study period.

RESULTS

A tendency towards male predominance was observed among the 45 patients (91.1%, 41/45). The mean onset age was 32.9 +/- 10.0 years (range: 16-54 years). No significant differences were observed in the onset age between male and female patients. Precipitating factors included rest/sleep at night, hot weather, upper respiratory tract infections (URIs), and excessive physical activities. Atypical weakness was observed in nine (20%, 9/45) patients. One patient initially diagnosed with sporadic periodic paralysis eventually developed hoTPP.

DISCUSSION

In provocative tests, hypokalemia was not a consistent finding during paralytic attacks. Before achieving the euthyroid status, the rate of recurrent attacks was as high as 62.2%, and peaked in the first 3 months after hoTPP was diagnosed. Patients with URIs exhibited a higher incidence of recurrent paralytic attacks than those without (odds ratio = 13.00; 95% confidence interval = 1.08-156.08; P = 0.04).

Thyrotoxic hypokalaemic periodic paralysis in a Turkish population: three new case reports and analysis of the case series

OBJECTIVE

Thyrotoxic hypokalaemic periodic paralysis (THPP) is an uncommon condition with intermittent episodes of muscle weakness and occasionally severe paralysis. THPP is a common complication of hyperthyroidism in Asian populations, and has also been reported in other ethnic groups including Caucasians. This study aimed to conduct an analysis of THPP in a Turkish population, and is to our knowledge the first analysis of a homogeneous Caucasian group.

SUBJECTS

Forty cases with THPP were identified in the Turkish population. Three out of the 40 were new cases and were assigned as index cases. Two cases were not included in the analysis because of lack of data.

RESULTS

THPP was diagnosed in 10 cases during the first attack and was observed to have a significant shorter complete recovery time statistically in this group (P < 0.01). The majority of cases were hypokalaemic, while there were two normokalaemic cases. Classification of the cases according to their potassium (K) levels revealed that the group with K levels < 2.5 mEq/l had a statistically longer amelioration time than the group with K levels > or = 2.5 mEq/l. When the cases were classified according to intravenous or oral application of K, the mean amelioration time was 6.8 +/- 3.6 h for the intravenous group and 13.1 +/- 7.6 for the oral group. Mean complete recovery times of the groups were 29.4 +/- 16.2 h and 52.8 +/- 18.0 h, respectively. The intravenous group had a shorter amelioration time and complete recovery time, and both were statistically significant (P < 0.05 for each).

CONCLUSIONS

THPP may be seen among Caucasians. Diagnosing THPP during the first attack might decrease the recovery time. The level of hypokalaemia seems to affect the recovery time and initial low K levels may lead to more deterioration in a patient's health compared with mild or near-normal levels. Intravenous, rather than oral, application of K may be advantageous for shortening both the amelioration and complete recovery times.

Fatal thyrotoxic periodic paralysis with normokalemia

We present a 10-year-old girl who presented to our emergency services with difficulty in breathing of 2-days duration and progressive weakness of a month's duration. In a previous admission elsewhere, she had not been detected to have hyperthyroidism or electrolyte abnormalities. On admission, the child was in hypercapnic respiratory failure with tachycardia and hepatomegaly. A small goiter as well as signs of thyrotoxicosis were present. Laboratory investigations showed anemia, mildly elevated liver enzymes and serum potassium of 4.8mEq/L. Despite intubation and ventilation and other supportive management including propranolol, the patient could not be saved. Post-mortem biopsy of the thyroid showed diffuse hyperplasia of the follicles and muscles showed evidence of thyroid myopathy.

Evaluation of neurologic deficit without apparent cause: the importance of a multidisciplinary approach

BACKGROUND/OBJECTIVE

A patient presenting with an acute neurologic deficit with no apparent etiology presents a diagnostic dilemma. A broad differential diagnosis must be entertained, considering both organic and psychiatric causes.

METHODS

A case report and thorough literature review of acute paraplegia after a low-energy trauma without a discernible organic etiology.

RESULTS

Diagnostic imaging excluded any bony malalignment or fracture and any abnormality on magnetic resonance imaging. When no organic etiology was identified, a multidisciplinary approach using neurology, psychiatry, and physical medicine and rehabilitation services was applied. Neurophysiologic testing confirmed the absence of an organic disorder, and at this juncture, diagnostic efforts focused on identifying any psychiatric disorder to facilitate appropriate treatment for this individual. The final diagnosis was malingering.

CONCLUSIONS

The full psychiatric differential diagnosis should be considered in the evaluation of any patient with an atypical presentation of paralysis. A thorough clinical examination in combination with the appropriate diagnostic studies can confidently exclude an organic disorder. When considering a psychiatric disorder, the differential diagnosis should include conversion disorder and malingering, although each must remain a diagnosis of exclusion. Maintaining a broad differential diagnosis and involving multiple disciplines (neurology, psychiatry, social work, medical specialists) early in the evaluation of atypical paralysis may facilitate earlier diagnosis and initiation of treatment for the underlying etiology.

Thyrotoxic periodic paralysis in Caucasian patients: a diagnostic challenge

Secondary hypokalemic periodic paralysis is rare. However, when it occurs, it is usually associated with Graves' disease and it is mostly diagnosed in Asiatic male patients. In this report, we analyze the diagnostic procedure in three cases of hypokalemic periodic paralysis associated with Graves' disease, diagnosed in three different emergency care units over the last 3 years. Three Caucasian men (26, 30, and 39 years of age) came to the emergency care unit for acute tetraparesia. One of them had suffered 15 stereotypical episodes of tetraparesia during the last 2 years. Goiter was present in each case. Kalemia was 1.8, 2.1, and 3 mmol/l, respectively. Triggering events such as considerable sugar intake and physical exercise were present in two cases. In all cases, low TSH levels, high FT4 levels, and anti-TSH receptor antibodies led to the diagnosis of Graves' disease. All patients were treated with potassium supplementation and neomercazole. Outcome was good with a follow-up of 6, 9, and 24 months, respectively. Emergency care practitioners should be aware of this diagnosis, which may affect Caucasian patients presenting with transient tetraparesia in a primary care unit.

Thyrotoxic periodic paralysis: an overview

Thyrotoxic periodic paralysis (TPP) is a fairly common manifestation of hyperthyroidism in Asian populations, with an incidence of about 1.9% in thyrotoxic patients, but it is rarely diagnosed among Caucasians and blacks in the Western world. The diagnosis often can be made on the basis of the clinical manifestations alone. Sometimes, periodic paralysis precedes hyperthyroidism or occurs in silent hyperthyroidism. As a result, physicians may easily overlook it even when life-threatening hypokalemia is present. The pathophysiology of this disorder is still not well understood. Correction of the thyrotoxic state is the definitive treatment. Potassium supplementation, propranolol, and spironolactone may be helpful both in the acute state and in preventing attacks.