methimazole and Seizures

A 54-years-old patient coming from Guinea, who presented fever, diarrhoea, consciousness disorders and severe haemolytic anaemia, was admitted to resuscitation unit in France. Despite many explorations carried out (evaluation of traumatic causes, infection, neoplasia, vascular, toxic causes, vitamin deficiency), it was not possible to explain neurological symptomatology. Besides, haemolytic anaemia was due to the ingestion of metamizole in a context of glucose-6-phosphate dehydrogenase deficit. This drug's marketing has been suspended in France since 2006. Despite appropriate treatment, after seven days of hospitalization, the patient died of multi-organ failure and hemophagocytic syndrome. This clinical case illustrates the difficulties encountered to set a diagnosis and manage patients coming from overseas. Uncommon aetiologies for French healthcare professionals should be evoked in the absence of comprehensive clinical information.

Topics: Anemia, Hemolytic; Antithyroid Agents; Diagnosis, Differential; Diarrhea; Fatal Outcome; Glucosephosphate Dehydrogenase Deficiency; Guinea; Headache; Humans; Lymphohistiocytosis, Hemophagocytic; Malaria, Falciparum; Male; Methemoglobinemia; Methimazole; Middle Aged; Multiple Organ Failure; Paris; Psychomotor Agitation; Seizures; Vomiting

Thyroid hormone lowers the seizure threshold. We present the case of a female patient who developed generalized convulsions emerging with Graves' disease, and clarified the clinico-electroencephalographic characteristics. Before treatment, electroencephalography (EEG) showed 2- to 2.5-Hz diffuse spike and wave (SW) bursts, apparent during and after hyperventilation without any distinct absence seizure. Thiamazole treatment without any anticonvulsant led to a euthyroid state, convulsions resolved and EEG abnormalities normalized promptly. Clinical seizures were generalized tonic-clonic convulsions during sleep, and EEG showed diffuse SW bursts induced by hyperventilation. These characteristics suggested that epilepsy might correspond to idiopathic generalized epilepsy (IGE). IGE might be susceptible to hyperthyroidism. Cases of IGE emerging with hyperthyroidism, even if EEG paroxysms are advanced, may be improved using antithyroid pharmacotherapy alone.

Topics: Adolescent; Antithyroid Agents; Electroencephalography; Female; Follow-Up Studies; Graves Disease; Humans; Methimazole; Seizures

The effects of 3,5,3'-triiodothyronine (T3) levels on threshold, latency and duration of pentylenetetrazole-induced seizures were tested in rats treated with thyroxine (300 micrograms/kg.day, N = 9) or methimazole (60 mg/kg.day, N = 5) dissolved in drinking water. Compared to controls (N = 7), methimazole treatment reduced T3 levels (45.4 +/- 2.0 vs. 33.0 +/- 4.8 ng/dl) and increased seizure duration (36.2 +/- 22.4 vs. 289.6 +/- 24.4 s) and threshold (29.0 +/- vs. 45.5 mg/kg). Thyroxine treatment increased T3 levels (45.4 +/- 2.0 vs. 67.7 +/- 4.8 ng/dl), but had no significant effect on seizures.

Topics: Animals; Antithyroid Agents; Colon; Convulsants; Drug Overdose; Male; Methimazole; Pentylenetetrazole; Rats; Rats, Wistar; Seizures; Temperature; Thyroxine; Time Factors; Triiodothyronine

The feeding of goitrogens during pregnancy and lactation causes the offspring of rats to be partially deaf and persistently sensitive to audiogenic seizures. The most potent goitrogen, propylthiouracil, caused severe dysfunction and disorganization of the organ of Corti. Adult seizure-susceptible rats showed increased sensitivity to audiogenic seizures when they were fed propylthiouracil.

Topics: Acoustic Stimulation; Animals; Animals, Newborn; Antithyroid Agents; Cochlea; Female; Iodine; Lactation; Methimazole; Perchlorates; Pregnancy; Propylthiouracil; Rats; Seizures; Thiocyanates

A patient with hyperthyroidism is described who developed grand mal seizures when anth-thyroid medication was withdrawn. Pyramidal signs were also present. The EEG reverted to normal and the clinical signs and symptoms disappeared when his thyroid status was again controlled.

Topics: Adult; Humans; Hyperthyroidism; Male; Methimazole; Phenytoin; Seizures

Topics: Aminobutyrates; Animals; Brain; Brain Chemistry; Depression, Chemical; Electroshock; Glutamates; Male; Methimazole; Rats; Seasons; Seizures; Thyroid Gland; Thyroidectomy