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Keywords:

  • Earthquake;
  • Nutrition;
  • Stress;
  • Epilepsy;
  • Tsunami

Summary

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

In the afternoon of March 11, 2011, Kesennuma City was hit by the Great East-Japan Earthquake and a devastating tsunami. The purpose of this retrospective study is to document possible changes in the number of patients with distinct neurologic diseases seeking treatment following this disaster. Because of Kesennuma's unique geographical location, the city was isolated by the disaster, allowing for a study with relatively limited population selection bias. Patients admitted for neurologic emergencies from January 14 to May 5 in 2011 (n = 117) were compared with patients in the corresponding 16-week periods in 2008–2010 (n = 323). The number of patients with unprovoked seizures was significantly higher during the 8-week period after the earthquake (n = 13) than during the same periods in 2008 (n = 6), 2009 (n = 3), and 2010 (no patients) (p = 0.0062). In contrast, the number of patients treated for other neurologic diseases such as stroke, trauma, and tumors remained unchanged. To our knowledge, this is the first report of an increase in the number of patients with seizures following a life-threatening natural disaster. We suggest that stress associated with life-threatening situations may enhance seizure generation.

Natural disasters may result in the destruction of tangible property, but they also affect the mental and physical health of survivors. Previous reports have documented an increase in the number of sudden cardiac deaths after the Northridge earthquake of 1994 (Leor et al., 1996), and a deterioration of glycemic control in patients with diabetes mellitus after the Kobe earthquake of 1995 (Inui et al., 1998). These reports concluded that life-threatening stress contributed to disease or symptom onset. Stress has been reported as an inducer of seizures (Joels, 2009; Gilboa, 2012); however, the effect of stress resulting from an actual life-threatening natural disaster on patients with neurologic diseases such as epilepsy has not been studied in a large and stable patient population.

Kesennuma in Miyagi Prefecture, Japan, is a city of 73,000 inhabitants. It is located on the northeastern part of the main island facing the Pacific Ocean and is situated between mountains and ria coasts, resulting in relative isolated area. This city was shaken by an earthquake of magnitude 9.0 and hit by a subsequent tsunami on March 11, 2011 (Shibahara, 2011). As a result, 15,590 houses were damaged, 1,032 inhabitants lost their lives, and 317 are still missing (as of March 2012). In addition, there were more than 600 aftershocks with a magnitude exceeding 5.0 (as of March 2012, Japan Meteorological Agency); therefore, survivors suffered prolonged physical deprivation and mental stress. The 451-bed Kesennuma City Hospital is the only local hospital with a surgical suite for neurosurgical entities, and staff neurosurgeons not only perform surgery but also treat patients with neurologic diseases that are usually treated by neurologists such as cerebral infarctions and epilepsy.

This retrospective study included almost all local neurologic emergency cases and investigated changes in the number of patients with different neurologic diseases treated after the Great East-Japan Earthquake. Results indicated a specific increase in the number of patients with seizures.

Methods

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

This study conformed to the protocols approved by the ethics committee of Kesennuma City Hospital. In contrast to most hospitals in Kesennuma, our medical records were not damaged by the tsunami. Accordingly, we investigated the number of patients with acute neurologic events admitted to the Department of Neurosurgery from January 14 to May 5 in 2008–2011. This period encompasses the 8 weeks before and after March 11. The patients were categorized into five groups: epilepsy, stroke, trauma, tumors, and others, and the weekly occurrence of each entity was recorded and evaluated. Weekly occurrences in 2011 were compared with those in 2008–2010 using the Kruskal-Wallis test as reported previously (Watanabe et al., 2005). The category “epilepsy” included idiopathic/cryptogenic epilepsy and symptomatic epilepsy. Epilepsy was diagnosed based on either repeated unprovoked seizures or at least one seizure with a high propensity for relapse. In this study, we focused on patients with unprovoked seizures and excluded those with acute symptomatic seizures (Beghi et al., 2010). “Stroke” included all types of cerebrovascular diseases. “Trauma” included subdural or epidural hematoma, contusions, and concussions. “Tumors” included brain tumors. “Others” included meningitis, hydrocephalus, and pneumonia due to preexisting neurologic diseases. These diagnoses were based on findings from computed tomography, magnetic resonance imaging, and blood tests.

To compare the basic clinical characteristics before and after the earthquake, we obtained each patient's Barthel index and blood test results including blood urea nitrogen/serum creatinine ratio, total protein (TP), albumin, C-reactive protein, sodium, creatine kinase, and blood glucose levels. The Barthel index was calculated from medical records and family reports of patient performance on daily activities before admission. Blood test results were obtained on admission. Data from the 8-week periods after March 11 between 2011 and 2008–2010 was compared using the Mann-Whitney U and Fisher's exact tests. Statistical tests were performed using Prism (GraphPad Software, La Jolla, CA, U.S.A.). A p-value <0.05 was considered statistically significant.

Results

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

We analyzed the medical records of 440 patients. During the 8-week periods after March 11, we admitted 55 patients in 2008, 57 in 2009, 48 in 2010, and 66 in 2011. During the 8-week periods before March 11, we admitted 51 in 2008, 52 in 2009, 60 in 2010, and 51 in 2011. The slight increase in the number of admission after March 11, 2011, did not reach statistical significance (p = 0.60). Mean baseline clinical characteristics (age, sex, and Barthel index scores) of patients admitted after March 11, 2011, were not significantly different from those in 2008–2010 (p = 0.57, 0.30, and 0.81, respectively). Among the blood parameters tested, only TP was significantly different in patients after the earthquake compared with that in 2008–2010 (2011: 6.3 g/dl vs. 2008–2010: 6.7 g/dl, p = 0.0010).

The fraction of patients in each disease category is presented in Fig. 1. Significant increase in the number of patients with seizures were treated after March 11, 2011 (n = 13) (Fig. 2A, p = 0.0062). Of the 13 patients after March 11, 2011, 11 had preexisting brain diseases without an acute central nervous system (CNS) insult (5 cases of idiopathic/cryptogenic epilepsy, 4 of post–head trauma, 1 of post-surgical meningioma, and 1 of old cerebral infarction), and of which 8 were currently on anticonvulsant therapy. Of the remaining two, one was on hemodialysis and the other's condition was not specified in the records. Among the 13 patients, 9 were diagnosed with simple partial seizures (propagating to generalized seizure in eight cases) and 3 with complex partial seizures, whereas 1 was unidentified in the records. Of the nine patients with seizures after March 11 in 2008–2010, eight had preexisting brain diseases without acute CNS insult (one of post-head trauma, four of old cerebral infarction, and three of old intracerebral hemorrhage) and the remaining one was not specified. Of these nine patients, four were on anticonvulsant therapy and all cases were simple partial seizures (propagating to generalized seizure in six cases).

image

Figure 1. Fraction of patients in each neurologic disease category (epilepsy, stroke, trauma, tumors, and others) at the time of admission to the Department of Neurosurgery, Kesennuma City Hospital from March 11–May 5 in 2008, 2009, 2010, and 2011. The total number of neurologic patients admitted was 55 in 2008, 57 in 2009, 48 in 2010, and 66 in 2011. In 2011, 20% of these patients experienced seizures.

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image

Figure 2. Plot displaying the number of patients with seizures (A) and stroke (B) admitted each week during the 16-week periods from January 14–May 5 in 2008, 2009, 2010, and 2011. (A) Note the significant increase in the number of patients with seizures admitted after March 11, 2011, and a large peak during the week of March 11–17. (B) The number of stroke patients treated revealed no consistent trend in the 8 weeks before and after March 11 for any of the years evaluated.

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The patients with seizures after March 11, 2011, had a high Barthel index (mean 79.6 in 2011, range 10–100 vs. mean 48.9 in 2008–2010, range 0–100, p = 0.034), a male preponderance (9/13 vs. 2/9, p = 0.040), and low TP (6.2 vs. 7.0 g/dl, p = 0.026). In contrast to patients with seizures, there was no increase in the number of patients admitted for stroke (Fig. 2B), trauma, or tumors after the earthquake.

Discussion

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

This is the first report to demonstrate the effect of life-threatening natural disasters on emergency admissions for seizures. The total number of patients with seizures was significantly increased during the 8-week periods after the Great East-Japan Earthquake and tsunami compared with other 8-week periods. In particular, during the first week after the disaster, there was a high peak in the number of patients with seizures (Fig. 2A), indicating a causal relationship between life-threatening stress and seizures.

Neurologic patients treated after the earthquake exhibited lower TP than those in previous years, which could be explained by a change in diet. Foods high in carbohydrates, such as bread and rice, can be stored and thus, these were the main dietary constituents. In fact, a study following the March 11 earthquake reported that this inappropriate diet resulted in the deterioration of glycemic control and blood pressure in patients with diabetes mellitus (Ogawa et al., 2012). Therefore, low TP could be a consequence of deprivation of healthy diet, indicating low TP as objective measures of stress levels experienced.

Most patients with seizure after the earthquake had preexisting brain diseases but relatively high Barthel index scores. One possible interpretation is that life-threatening stress is not a universal risk factor for seizure generation, but affects those with a preexisting brain disease who are relatively independent. Furthermore, one patient, a 63-year-old male, was unable to obtain anticonvulsant drugs and experienced seizures 6 weeks after the earthquake. As expected, the lack of anticonvulsant therapy could contribute to an increase in seizure generation and emphasizes the need to deliver these medications to disaster-stricken areas as soon as possible. On the other hand, we observed no changes in the frequency of stroke and trauma; this observation may reflect the “all or nothing” feature of tsunami disasters and the quake-resistance of buildings in Japan (Shibahara, 2012).

The main limitation of this study was the single-site retrospective design that limited the total number of patients included. However, we observed a significant increase in patients with seizures; this strongly suggests that the stress from life-threatening natural disaster is a risk factor for seizures. These observations suggest important measures for better preparation in case of future disasters.

Acknowledgments

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

We remember the victims of this tragedy and we thank the staff of Kesennuma City Hospital for their selfless help at the time of this disaster. The authors are grateful to Dr. Takashi Watanabe (Department of Public Health, Tohoku University Graduate School of Medicine, Sendai, Japan) for his advice on our statistical analyses and Dr. Masaki Iwasaki (Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan) for critical review of the manuscript.

Disclosure

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References

None of authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.

References

  1. Top of page
  2. Summary
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Disclosure
  8. References