Department of Neurology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
Thyroid. 2010 Sep;20(9):955-8. doi: 10.1089/thy.2009.0276.
Central nervous system dysfunction, such as hyperexcitation, irritability, and disturbance of consciousness, may occur in patients with thyrotoxicosis. There are also a few case reports of seizures attributed to thyrotoxicosis. The objective of the present study was to determine the prevalence of seizures that appeared to be related to the thyrotoxic state in patients with thyrotoxicosis.
We retrospectively determined the prevalence and clinical features of seizures in 3382 patients with hyperthyroidism. Among patients with seizures, we excluded those with other causes of seizures or a history of epilepsy. We did not exclude two patients in whom later work-up showed an abnormal magnetic resonance imaging, as their seizures resolved after they became euthyroid.
Among the 3382 patients with hyperthyroidism, there were seven patients (0.2%) with seizures who met our criteria. Primary generalized tonic-clonic seizures occurred in four patients (57%), complex partial seizures with secondary generalized tonic-clonic seizures occurred in two patients (29%), and one patient had a focal seizure (14%). The initial electroencephalography (EEG) was normal in two patients (29%), had generalized slow activity in four patients (57%), and had diffuse generalized beta activity in one patient (14%). On magnetic resonance imaging, one patient had diffuse brain atrophy, and one had an old basal ganglia infarct. After the patients became euthyroid, the EEG was repeated and was normal in all patients. During follow-up periods ranging from 18 to 24 months, none of the patients had seizures.
Hyperthyroidism is the precipitating cause of seizures in a small percentage of these patients. In these patients, the prognosis is good if they become euthyroid. The prevalence of thyrotoxicosis-related seizures reported here can be used in conjunction with the prevalence of thyrotoxicosis in the population to estimate the prevalence of thyrotoxicosis-related seizures in populations.
甲状腺功能亢进症患者可能出现中枢神经系统功能障碍，如过度兴奋、烦躁和意识障碍，也有少数报道称甲状腺功能亢进症与癫痫有关。本研究旨在确定甲状腺功能亢进症患者中似乎与甲状腺功能亢进状态相关的癫痫发作的患病率。
我们回顾性确定了 3382 例甲状腺功能亢进症患者中癫痫发作的患病率和临床特征。在癫痫发作的患者中，我们排除了其他原因引起的癫痫发作或有癫痫病史的患者。我们没有排除两名患者，他们后来的检查显示磁共振成像异常，但在甲状腺功能正常后癫痫发作得到缓解。
在 3382 例甲状腺功能亢进症患者中，有 7 例（0.2%）符合我们的标准的癫痫发作患者。4 例（57%）患者出现原发性全面强直阵挛发作，2 例（29%）患者出现复杂部分性发作伴继发性全面强直阵挛发作，1 例患者出现局灶性发作（14%）。2 例（29%）患者的初始脑电图正常，4 例（57%）患者有广泛的慢波活动，1 例（14%）患者有弥漫性广泛β活动。磁共振成像显示 1 例患者有弥漫性脑萎缩，1 例患者有陈旧性基底节梗死。患者甲状腺功能正常后，重复进行脑电图检查，所有患者均正常。在 18 至 24 个月的随访期间，无患者出现癫痫发作。
在这些患者中，一小部分癫痫发作是甲状腺功能亢进的诱发原因。如果这些患者甲状腺功能正常，预后良好。此处报告的与甲状腺功能亢进相关的癫痫发作的患病率可与人群中甲状腺功能亢进的患病率结合使用，以估计人群中与甲状腺功能亢进相关的癫痫发作的患病率。
