A new study published by medical journal "Epilepsia" explains that there was a considerable spike in the number of seizure patients in a northern Japanese fishing community weeks after the tsunami on March 11, 2011.
According to Reuters, the study looked at 440 patient records from Kesennuma City Hospital. The city was one of the many left devastated by the tsunami.
In the eight weeks after the tsunami, 13 people were admitted for seizures. In the two months before it, only one was admitted.
Research has linked stressful life-threatening situations with an increased risk of seizures, but there has been a lack of clinical data with multiple patients.
Lead author Ichiyo Shibahara, staff neurosurgeon at Sendai Medical Center, said they "suggest that stress associated with life-threatening situations may enhance seizure generation."
Shibahara also said stress itself is "not a universal risk factor for seizures."
He also explained that most of the patients admitted had a neurological disease before the disaster.
In total, 11 of the 13 admitted had preexisting brain disorders, including epilepsy, head injuries or stroke. Eight of them took anti-convulsive medication.
But five of them were not admitted because of a lack of anticonvulsants. Shibahara said they were admitted "because of stress."
William Theodore, senior investigator of the clinical epilepsy section at the National Institute for Neurological Disorders and Stroke, said he is not totally convinced by the study.
"This is interesting, but I'm not 100 percent convinced," he said, and also explained that the study was too small and that random variation could explain the spike in seizures.
Other factors, like head trauma, infections from polluted water, and lack of sleep could also have caused seizures, Theodore said.
But he said the study did prove one thing: "If you already have seizures and you're taking medication, always make sure you have a decent supply just in case some natural disaster occurs."