A small study in Japan has found that the number of seizure patients increased in the weeks following the tsunami in March 2011.
The report is published in Epilepsia and refers to Kesennuma City, a small fishing community in north-eastern Japan. It found that 13 people were admitted with seizures in the eight weeks after the natural disaster. Only one person had been admitted in the eight weeks before.
Compared to the three previous years, this is nearly twice the average of 7.3 seizure patients for the same 16-week period. Five of the seizure patients were admitted to the hospital in the first week after the earthquake and tsunami.
Lead author Dr Ichiyo Shibahara said that previous research has linked stressful life-threatening disasters with an increased risk of seizures, but that earlier reports lacked clinical data.
He added: “Most of the seizure patients had some sort of neurological disease before the earthquake.” Eleven of the 13 people admitted to Kesennuma City Hospital had existing brain disorders including epilepsy. Eight of them took epilepsy medicines.
Shibahara stated that the five people admitted in the week after the disaster had nothing to do with a lack of epilepsy medicinces, but was due to stress.
Dr William Theodore, senior investigator at the National Institute of Neurological Disorders and Stroke in Maryland said that he is “not 100 per cent convinced” by the study. He said that due to the small patient size, random variation could explain the spike in numbers.
Also, Dr Theodore claimed that there are other ways that natural disasters could cause seizures other than stress. These are head trauma, infections from polluted water, lack of sleep or if people forget to take or are unable to find their epilepsy medicines.
Dr Sunao Kaneko, neuropsychiatry professor and president of the Japan Epilepsy Society spoke about the study. He said that it highlights the necessity of local treatment and information networks in Japan.
After the 2011 disaster, Japan began to develop a nationwide epilepsy treatment network. This includes over a thousand doctors as well as information and centres for epilepsy patients.