Generalized Convulsions After Consuming a Large Amount of Gingko Nuts

Abstract

Summary:We report a 36-year-old woman, without any past or family histories of epilepsy, who presented frequent vomiting and generalized convulsions. About 4 h before the convulsion, she had consumed ∼70-80 gingko nuts, seeds of Gingko biloba, in an attempt to improve her health. It is important to know that convulsion may be induced if a large amount of gingko nuts is consumed. The neurotoxicity of gingko nuts, particularly their convulsion-inducing effect, should be recognized. Key Words: Gingko biloba-Gingko nutConvulsion-Neurotoxicity.Leaf extracts of Gingko biloba have various useful pharmacologic actions, such as improvement of cerebral blood flow (1), and neuroprotection against ischemic brain damage (1). Conversely, it must be noted that seeds of Gingko biloba (gingko nuts or gin-nan) also have dangerous poisoning effects (2). Because Japanese, as well as Chinese, often eat gingko nuts as an ordinary food, there is a tendency to be less cautious of their toxicity. We encountered an adult patient who had convulsions after consuming a large amount of gingko nuts. Here, we report on the patient and emphasize the clinical importance of recognizing the neurotoxicity of gingko nuts. CASE REPORTA previously healthy 36-year-old woman without any past or family histories of epilepsy had frequent vomiting and generalized tonic and clonic convulsions. During the first 24 h, she experienced generalized convulsions twice and vomiting several times. About 4 h before the onset of her first episode of convulsion, she had consumed ∼70-80 gingko nuts during lunch, after cooking them in a microwave oven, because she had heard of a favorable effect of ginkgo nuts on health. Soon after the first episode of convulsion, she was transferred to the emergency room of our hospital in an ambulance. During the transfer, her consciousness had returned.In the emergency room, her general conditions were normal, and no neurologic abnormality was noted. Results of routine blood tests, chest and abdominal radiographs, and ECG were all normal. The brain computed tomography (CT) scan was also normal. However, she soon again experienced a generalized convulsion for a period of 10 s with vomiting. Then a possible diagnosis of epileptic seizure was made, and 100 mg of phenobarbital (PB) was administered intramuscularly in the emergency room. The next morning, she was transferred to the neurologic section. On admission, she was alert and oriented, but complained of a dull headache. Her neurologic examination result was normal. Her EEG and cerebrospinal fluid (CSF) were normal. Results of magnetic resonance imaging (MRI) and MR angiography of the brain were all normal. Because she experienced generalized convulsions twice in 1 day, carbamazepine (CBZ) was administered to prevent further convulsions, but she stopped taking the medication within a few days because of marked daytime sleepiness. After stopping the medication, EEGs were repeatedly taken but were found to be normal, and there has been no recurrence of convulsions for 2 years ever with...

Identification and quantification of biomarkers to confirm the poisoning by Ginkgo biloba seeds in a 2-year-old boy

“…As known from in vivo studies, 4′-O-methylpyridoxine (MPN) competes with vitamin B 6 , which is a cofactor of glutamate decarboxylase; as a consequence, MPN indirectly inhibits the activity of this enzyme resulting in a decrease of the γ-aminobutyric acid (GABA) level in brain, which predisposes to convulsions. 9,17,18 The study reported in this paper describes a case of ginkgo poisoning which occurred in Switzerland in a 23-months-old boy, where the association with the ingestion of ginkgo seeds was confirmed by measuring biomarkers both in blood and urine.…”

“…7,8 Even though they are infrequent, clinical cases of ginkgo seed poisoning show severe symptoms, including tonic or clonic convulsion, vomiting, irritability and loss of consciousness. [7][8][9] Poisoning by ginkgo seeds is due to the neurotoxic compound 4′-O-methylpyridoxine (MPN), which is chemically related to vitamin B 6 and interfere with its biosynthesis, metabolism and function. The chemical structures of MPN and vitamin B 6 are reported in Fig.…”

“…Similarly, a case of poisoning was described in another 2-year-old girl who had eaten about 50 ginkgo seeds 4 hours before the onset of symptoms 8 and a case of poisoning with ginkgo nuts was observed in a healthy 36-year-old woman, who consumed 70-80 seeds cooked in a microwave oven. 9 The pathophysiologic mechanisms responsible for convulsions related to ginkgo poisoning are not fully understood. As known from in vivo studies, 4′-O-methylpyridoxine (MPN) competes with vitamin B 6 , which is a cofactor of glutamate decarboxylase; as a consequence, MPN indirectly inhibits the activity of this enzyme resulting in a decrease of the γ-aminobutyric acid (GABA) level in brain, which predisposes to convulsions.…”

Review of the use of botanicals for epilepsy in complementary medical systems — Traditional Chinese Medicine

“…Ginkgo biloba comprises a variety of biologically active chemical constituents, including components that induce [47,48] and inhibit [49][50][51][52] seizure activity. The principal antiepileptic compounds in the ginkgo plant are ginkgolides and bilobalide.…”

The importance of botanical treatments in traditional societies and challenges in developing countries

“…This herbal tea is believed to be safe, however, it can be toxic when taken in excessive doses with some of the constituents of hyssop oil thought to aggravate seizures [103]. Ginkgo biloba nuts [104] and Chinese ginseng [105] have also been suggested to be proconvulsant. Ginkgo seeds contain a seizure-promoting neurotoxin called 4-methoxypyridoxine (MPN) [106] (also termed as "Ginkgotoxin") that indirectly inhibits GABA A formation.…”