Hyperthyroid-Induced Chorea in an Adolescent Girl Giovanni Battista Pozzan, MD, Pier Antonio Battistella, MD, Franco Rigon, MD, Lucia Zancan, MD, Gian Luca Casara, MD, Pier Andrea Pellegrino, MD and Franco Zacchello, MD
Hyperthyroidism is invariably accompanied by nervous system dysfunctions. Irritability, emotional lability and hyperkinesia are the signs and symptoms most frequently observed. Chorea or choreoathetosis are only rarely associated with hyperthyroidism. It is the purpose of this work to describe the case of a young girl in whom chorea was the main manifestation of thyrotoxicosis. The chorea receded and disappeared as the patient became euthyroid. Hyperthyroidism, therefore, is to be considered an unusual cause of chorea and every patient with choreiform movements should be examined also for thyroid function. Key words: Chorea, hyperthyroidism. Pozzan GB, Battistella PA, Rigon F, Zancan L, Casara GL, Pellegrino PA, Zacchello F. Hyperthyroid-induced chorea in an adolescent girl. Brain Dev 1992;14:126-7
CASE REPORT A 16-year-old girl, operated on for closure of ventricular septal defect at 5 years of age, was admitted to the Department of Pediatrics of the University of Padova because of the appearance of depression of the mood, tremors, motor incoordination and chorea more evident in the right side. In the last 8 months she had a weight loss of 12 kg associated with emotional lability. Her father was treated 10 years ago for Graves' disease. On admission, physical examination showed blood pressure 120/70 mm/Hg, heart rate 80 beats per min, temperature 36.8°C, and respiratory rate 20 per min. Diarrhea was not present. There was a mild diffuse thyroid enlarge-
From the Department of Pediatrics, University of Padova, Padova. Received for publication: December 12, 1991. Accepted for publication: January 25, 1992. Correspondence address: Dr. Giovanni Battista Pozzan, Department of Pediatrics, University of Padova, via Giustiniani 3, 35100 Padova, Italy.
ment, mild bilateral ptosis and absence of exophthalmos or other ocular signs. The most remarkable finding was incoordinated involuntary movements affecting mainly the right side of the body. There was mild symmetrical muscular hypotonia. The tendon reflexes were decreased. The patient presented also with facial grimacing and dysarthria. No other neurological signs or symptoms were present. The ophthalmoscopic evaluation showed vascular tortuosity with sharply defined disk margins. Visual acuity and fields were normal. Laboratory data were within normal limits except for thyroid function tests and cholesterol serum levels: serum thyroxine (T4) was 167 nmol/L (normal values = 71-154). triiodothyronine (T 3 ), 4.2 nmol/L (1.77-2.93); freeT 4 , 46 pmol/L (7.7-23.2); TSH, < 0.1 mUlL (0.1-,4.5); cholesterol, 2.8 mmol/L (4.1-5.2). Antimicrosomal, antithyroglobulin and thyroid receptor-directed autoantibodies were absent. 99Tc thyroid scanning imaging was compatible with toxic diffuse goiter, while thyroid echography was normal. An awake electroencephalogram was normal except for unusual diffuse fast activity. Other causes of chorea were investigated. There was no history of rheumatic fever, scarlet fever or recent sore throat; in addition, there was no laboratory evidence of recent streptococcal infection. Family history was negative for neurologic disorders and the patient had not taken any drugs during the last year. Finally, the normality of the laboratory fmdings excluded other and rarer causes of chorea such as hypocalcemia, systemic lupus erythematosus and polycythemia. The patient was treated with methimazole 30 mg per day for two weeks, after which the dosage was tapered to 15 mg/day. The neurological symptoms rapidly subsided and two months after the onset of the therapy the patient became euthyroid and disclosed a normal neurological examination. DISCUSSION Choreoathetosis has been infrequently described in the past in patients with hyperthyroidism. In 1988 Shahar and Shenkman [1], reviewing the English literature, found only 11 detailed, well-documented descriptions. Chorea was present in only one patient in the Shahar's large series (over 800 cases) of hyperthyroidism. After this report we were able to collect 2 other cases of this rare association [2, 3]. The mechanism of hyperthyroid-induced chorea is not well understood. It is possible that in hyperthyroid patients there is an enhanced dopaminergic tone as suggested by the successful results of treatment with sulpiride [4] or haloperidol [5] and the reduced response of prolactin toTSH [6,7]. A confirmation of a relationship between hyper-
thyroidism and chorea results from the observation of disappearance of the chorea following resolution of thyrotoxicosis. Furthermore, Drake [2] elegantly described a case of chorea due to thyrotoxicosis factitia cured upon drug discontinuation. In our case, representing a further example of hyperthyroid-induced chorea, the symptomatology was dominated by neurologic manifestations, particularly chorea, while other thyrotoxic features such as tachycardia, elevated blood pressure, diarrhea or ophthalmopathy were either absent or not relevant. In conclusion, hyperthyroidism should be remembered as an uncommon cause of chorea also in the adolescent period, and the diagnostic work-up of choreic patients should be completed by a careful thyroid function evaluation even in the absence of typical thyrotoxic: features. REFERENCES 1. Shahar E, Shenkman L. Hyperthyroid-induced chorea. Case
2. 3.
4.
5.
6.
7.
report and review of the literature. Isr J Med Sci 1988;24: 264-6. Drake MEJr. Paroxysmal kinesigenic choreathetosis in hyperthyroidism. Postgrad MedJ 1987;63:1089-90. Ahronheim JC. Hyperthyroid chorea in an elderly woman associated with sole elevation ofT3. JAm Ceriatr Soc 1988; 36:242-4. Delwaide PJ, Shohenen J. Hyperthyroidism as a cause of persistent choreic movements. Acta Neurol Scand 1978;58: 309-12. Klawans HLJr, Shenker DM. Observations on the dopaminergic nature of hyperthyroid chorea. J Neural Transm 1972; 33:73-81. Scanlon MF, Chan V, Heath M, et al. Dopaminergic control of thyrotropin, alpha-subunit, thyrotropin beta-subunit, and prolactin in euthyroidism and hypothyroidism: dissociated responses to dopamine receptor blockade with metoclopramide in hypothyroid subjects. J Clin Endocnnol Metab 1981;53:360-5. Snjder PJ, Jacobs LS, Utiger BD, Daughaday WH. Thyroid hormone inhibition of the prolactin response to thyrotropinreleasing hormone. J Clin Invest 1973;52:2324-9.
Pozzan et al: Hyperthyroid-induced chorea 127
Hyperthyroidism is invariably accompanied by nervous system dysfunctions. Irritability, emotional lability and hyperkinesia are the signs and symptoms most frequently observed. Chorea or choreoathetosis are only rarely associated with hyperthyroidism. It is the purpose of this work to describe the case of a young girl in whom chorea was the main manifestation of thyrotoxicosis. The chorea receded and disappeared as the patient became euthyroid. Hyperthyroidism, therefore, is to be considered an unusual cause of chorea and every patient with choreiform movements should be examined also for thyroid function. Key words: Chorea, hyperthyroidism. Pozzan GB, Battistella PA, Rigon F, Zancan L, Casara GL, Pellegrino PA, Zacchello F. Hyperthyroid-induced chorea in an adolescent girl. Brain Dev 1992;14:126-7
CASE REPORT A 16-year-old girl, operated on for closure of ventricular septal defect at 5 years of age, was admitted to the Department of Pediatrics of the University of Padova because of the appearance of depression of the mood, tremors, motor incoordination and chorea more evident in the right side. In the last 8 months she had a weight loss of 12 kg associated with emotional lability. Her father was treated 10 years ago for Graves' disease. On admission, physical examination showed blood pressure 120/70 mm/Hg, heart rate 80 beats per min, temperature 36.8°C, and respiratory rate 20 per min. Diarrhea was not present. There was a mild diffuse thyroid enlarge-
From the Department of Pediatrics, University of Padova, Padova. Received for publication: December 12, 1991. Accepted for publication: January 25, 1992. Correspondence address: Dr. Giovanni Battista Pozzan, Department of Pediatrics, University of Padova, via Giustiniani 3, 35100 Padova, Italy.
ment, mild bilateral ptosis and absence of exophthalmos or other ocular signs. The most remarkable finding was incoordinated involuntary movements affecting mainly the right side of the body. There was mild symmetrical muscular hypotonia. The tendon reflexes were decreased. The patient presented also with facial grimacing and dysarthria. No other neurological signs or symptoms were present. The ophthalmoscopic evaluation showed vascular tortuosity with sharply defined disk margins. Visual acuity and fields were normal. Laboratory data were within normal limits except for thyroid function tests and cholesterol serum levels: serum thyroxine (T4) was 167 nmol/L (normal values = 71-154). triiodothyronine (T 3 ), 4.2 nmol/L (1.77-2.93); freeT 4 , 46 pmol/L (7.7-23.2); TSH, < 0.1 mUlL (0.1-,4.5); cholesterol, 2.8 mmol/L (4.1-5.2). Antimicrosomal, antithyroglobulin and thyroid receptor-directed autoantibodies were absent. 99Tc thyroid scanning imaging was compatible with toxic diffuse goiter, while thyroid echography was normal. An awake electroencephalogram was normal except for unusual diffuse fast activity. Other causes of chorea were investigated. There was no history of rheumatic fever, scarlet fever or recent sore throat; in addition, there was no laboratory evidence of recent streptococcal infection. Family history was negative for neurologic disorders and the patient had not taken any drugs during the last year. Finally, the normality of the laboratory fmdings excluded other and rarer causes of chorea such as hypocalcemia, systemic lupus erythematosus and polycythemia. The patient was treated with methimazole 30 mg per day for two weeks, after which the dosage was tapered to 15 mg/day. The neurological symptoms rapidly subsided and two months after the onset of the therapy the patient became euthyroid and disclosed a normal neurological examination. DISCUSSION Choreoathetosis has been infrequently described in the past in patients with hyperthyroidism. In 1988 Shahar and Shenkman [1], reviewing the English literature, found only 11 detailed, well-documented descriptions. Chorea was present in only one patient in the Shahar's large series (over 800 cases) of hyperthyroidism. After this report we were able to collect 2 other cases of this rare association [2, 3]. The mechanism of hyperthyroid-induced chorea is not well understood. It is possible that in hyperthyroid patients there is an enhanced dopaminergic tone as suggested by the successful results of treatment with sulpiride [4] or haloperidol [5] and the reduced response of prolactin toTSH [6,7]. A confirmation of a relationship between hyper-
thyroidism and chorea results from the observation of disappearance of the chorea following resolution of thyrotoxicosis. Furthermore, Drake [2] elegantly described a case of chorea due to thyrotoxicosis factitia cured upon drug discontinuation. In our case, representing a further example of hyperthyroid-induced chorea, the symptomatology was dominated by neurologic manifestations, particularly chorea, while other thyrotoxic features such as tachycardia, elevated blood pressure, diarrhea or ophthalmopathy were either absent or not relevant. In conclusion, hyperthyroidism should be remembered as an uncommon cause of chorea also in the adolescent period, and the diagnostic work-up of choreic patients should be completed by a careful thyroid function evaluation even in the absence of typical thyrotoxic: features. REFERENCES 1. Shahar E, Shenkman L. Hyperthyroid-induced chorea. Case
2. 3.
4.
5.
6.
7.
report and review of the literature. Isr J Med Sci 1988;24: 264-6. Drake MEJr. Paroxysmal kinesigenic choreathetosis in hyperthyroidism. Postgrad MedJ 1987;63:1089-90. Ahronheim JC. Hyperthyroid chorea in an elderly woman associated with sole elevation ofT3. JAm Ceriatr Soc 1988; 36:242-4. Delwaide PJ, Shohenen J. Hyperthyroidism as a cause of persistent choreic movements. Acta Neurol Scand 1978;58: 309-12. Klawans HLJr, Shenker DM. Observations on the dopaminergic nature of hyperthyroid chorea. J Neural Transm 1972; 33:73-81. Scanlon MF, Chan V, Heath M, et al. Dopaminergic control of thyrotropin, alpha-subunit, thyrotropin beta-subunit, and prolactin in euthyroidism and hypothyroidism: dissociated responses to dopamine receptor blockade with metoclopramide in hypothyroid subjects. J Clin Endocnnol Metab 1981;53:360-5. Snjder PJ, Jacobs LS, Utiger BD, Daughaday WH. Thyroid hormone inhibition of the prolactin response to thyrotropinreleasing hormone. J Clin Invest 1973;52:2324-9.
Pozzan et al: Hyperthyroid-induced chorea 127
