tpp is a rare complication of thyrotoxicosis , mostly due to graves disease but rarely due to thyroxine overdose , toxic multinodular goiter , toxic adenoma , and thyroiditis . we present three cases of tpp due to painless thyroiditis who presented with acute onset quadriparesis . a 21-year - old male presented with sudden onset flaccid quadriparesis with no preceding history of fever , dysphagia , dysphonia , diplopia , bladder , or bowel involvement . there was no relation with heavy carbohydrate meal , exercise or diarrhea , and no past history of similar episode . examination revealed lower limb proximal muscle power of 3/5 , diminished deep tendon reflexes ( dtr ) in all four limbs , bilateral flexor plantar responses , no cranial nerve palsy , and no respiratory muscle involvement . mmol / l ( normal [ nl . ] 3.5 - 5 ) , and esr 38 mm / h ( nl.1 - 25 ) . 0.72.0 ) , t3 210 ng / dl ( normal 70190 ) , and tpo antibody 54 iu / ml ( nl . < 35 ) . a 35-year - old male presented with sudden onset quadriparesis with a history identical to that of case 1 . he had upper limb proximal muscle powers mrc 3/5 , distal muscles 4/5 , lower limbs proximal , and distal muscles 2/5 . dtr on all limbs were diminished with bilaterally flexor plantar responses and no cranial nerve palsy . / l , esr 42 mm / h , tsh 0.005 u / l , free t4 2.5 ng / dl , tpo antibody 68 iu / ml , and decreased uptake ( 0.1% ) on tc scan . a 32-year - old male presented with acute onset flaccid paraparesis , tremors of both hands and palpitations . he had power 2/5 in proximal muscles , depressed jerks on all four limbs , bilateral flexor plantar responses , and no signs of cranial nerve palsy . / l , esr 30 mm / h , tsh 0.03 u / l , free t4:3.2 ng / dl , tpo antibody 117 iu / ml ( nl < 35 ) , and there was decreased uptake ( 0.21% ) on tc scan . all three cases had normal tsh receptor antibodies , serum creatine kinase ( ck ) and collagen vascular profile . ncv was normal but emg showed a myopathic pattern with no decremental muscle action potential . in all three cases fine - needle aspiration cytology ( fnac ) was consistent with lymphocytic thyroiditis . based on clinical features and investigations our diagnosis for each patient was thyrotoxic periodic paralysis secondary to painless or silent thyroiditis . case 1 was managed with oral potassium chloride ( kcl ) at the rate of 0.2 - 0.4 mmol / kg and propanolol 120 mg / day . all patients were discharged after a week with oral propranolol ( 80 - 120 mg / day ) . after 4 weeks of mean follow - up none had any residual paralysis . at the end of 2 months case 1 presented with normal thyroid profile and propranolol the thyroid profile became completely normal in cases 2 and 3 and propanolol was stopped . there was no relapse in any of the three cases even at 6-month follow - up . a 21-year - old male presented with sudden onset flaccid quadriparesis with no preceding history of fever , dysphagia , dysphonia , diplopia , bladder , or bowel involvement . there was no relation with heavy carbohydrate meal , exercise or diarrhea , and no past history of similar episode . examination revealed lower limb proximal muscle power of 3/5 , diminished deep tendon reflexes ( dtr ) in all four limbs , bilateral flexor plantar responses , no cranial nerve palsy , and no respiratory muscle involvement . mmol / l ( normal [ nl . ] 3.5 - 5 ) , and esr 38 mm / h ( nl.1 - 25 ) . 0.72.0 ) , t3 210 ng / dl ( normal 70190 ) , and tpo antibody 54 iu / ml ( nl . < 35 ) . a 35-year - old male presented with sudden onset quadriparesis with a history identical to that of case 1 . he had upper limb proximal muscle powers mrc 3/5 , distal muscles 4/5 , lower limbs proximal , and distal muscles 2/5 . dtr on all limbs were diminished with bilaterally flexor plantar responses and no cranial nerve palsy . u / l , free t4 2.5 ng / dl , tpo antibody 68 iu / ml , and decreased uptake ( 0.1% ) on tc scan . a 32-year - old male presented with acute onset flaccid paraparesis , tremors of both hands and palpitations . he had power 2/5 in proximal muscles , depressed jerks on all four limbs , bilateral flexor plantar responses , and no signs of cranial nerve palsy . his serum potassium was 1.8 mmol / l , esr 30 mm / h , tsh 0.03 u / l , free t4:3.2 ng / dl , tpo antibody 117 iu / ml ( nl < 35 ) , and there was decreased uptake ( 0.21% ) on tc scan . all three cases had normal tsh receptor antibodies , serum creatine kinase ( ck ) and collagen vascular profile . ncv was normal but emg showed a myopathic pattern with no decremental muscle action potential . in all three cases fine - needle aspiration cytology ( fnac ) was consistent with lymphocytic thyroiditis . based on clinical features and investigations our diagnosis for each patient was thyrotoxic periodic paralysis secondary to painless or silent thyroiditis . case 1 was managed with oral potassium chloride ( kcl ) at the rate of 0.2 - 0.4 mmol / kg and propanolol 120 mg / day . cases 2 and 3 initially required intravenous kcl at 10 meq / h . all showed marked improvement of paralysis within a week of treatment . all patients were discharged after a week with oral propranolol ( 80 - 120 mg / day ) . after 4 weeks of mean follow - up none had any residual paralysis . at the end of 2 months case 1 presented with normal thyroid profile and propranolol the thyroid profile became completely normal in cases 2 and 3 and propanolol was stopped . there was no relapse in any of the three cases even at 6-month follow - up . diagnosis at initial presentation may be delayed because of the subtleness of the clinical features of thyrotoxicosis . cases of painless thyroiditis presenting with tpp as seen in our series have rarely been reported , although thyrotoxicosis is more common in females tpp is more common in 20- to 40-year - old males , as observed in our series . many patients of tpp may not have obvious signs and symptoms of thyrotoxicosis , as seen here . in tpp , involvement is mostly proximal and motor resulting in quadriparesis without bowel and bladder affection as in our cases . impairment of bulbar or respiratory muscles is rare except in a severe attack of tpp , like our second case . the hallmark of tpp is hypokalemia , usually less than 3.0 mmol / l , present in all our cases . the degree of initial hypokalemia has a direct correlation with the severity of paralysis but not with the thyroid hormone level . hypokalemia is most likely due to high levels of thyroid hormone causing overactivity of the na + k atpase pump triggering intracellular shift of the potassium causing muscle hyperpolarization . in cases of acute attacks of tpp , immediate restoration of serum potassium via intravenous route and oral propranolol is necessary . because tpp does not recur once the patient is euthyroid , adequate control of hyperthyroidism by antithyroid drugs , radioiodine therapy , or thyroidectomy is imperative . quadriparesis due to tpp may be the first presentation of thyrotoxicosis of any etiology including painless thyroiditis . the painless nature of thyroiditis and absence of clinical signs of thyrotoxicosis can delay diagnosis and treatment . a thyroid function assay should be done routinely while evaluating patients with hypokalemic paralysis to distinguish tpp from other forms of hypokalemic paralysis .
we present three cases of thyrotoxic periodic paralysis ( tpp ) due to painless thyroiditis presenting as acute quadriparesis . 
 all responded to potassium supplementation and propranolol . 
 tpp may be due to thyrotoxicosis of any etiology , commonly grave 's disease . 
 the absence of clinical signs of thyrotoxicosis can delay diagnosis and treatment . 
 thyroid function tests should be a routine evaluation in all cases of hypokalemic periodic paralysis .