Case Report

Acute aortic dissection presenting as case of accidental falling with flaccidity of Left lower extremity

Abstract

Aortic dissection is often a catastrophic, life-threatening condition that may not always present with symptoms. Without intensive treatment, the mortality within the first 2 weeks of onset is reportedly as high as 80%. Acute aortic dissection classically presents with the symptoms of abrupt chest pain that sometimes radiates to the back, abdominal pain, or back pain alone. The patient may be cool and clammy, which is indicative of a Shock syndrome. It can be associated with neurologic sequelae in as many as one third of all patients. Painless dissection occurs in approximately 5% of patients, and the diagnosis may often be delayed. We report a case of aortic dissection where the patient presented with a history of accidental fall and a new onset of flaccidity of the left lower limb

A 90-year-old woman with a 15-year history of hypertension suddenly developed a left lower leg weakness while bowing to wash her lower leg in the bath. She fell and developed mild flank pain. Subsequently, she was unable to walk and was brought to us for an examination approxi- mately 30 minutes after the onset of the symptoms. On admission, she was alert. She complained of severe left lower leg weakness and could not stand, but only mild flank pain developed after falling. Systolic blood pressure, measured on the right upper arm, was 158 mm Hg on admission. Neurologic examination showed loss of sensation at the level of the left first lumbar spinal cord segment but only mild weakness, and no definite numbness over the right lower limb. Muscle strength was normal in the upper extremities, but flaccidity was observed in the left lower limb. Only mild weakness without numbness was present in the right lower limb. The pulsation of femoral artery was clearly observed in the inguinal area, and the pulsation of the dorsalis pedis artery was also clearly observed over the bilateral forefoot. Suspecting a cerebrovascular accident or traumatic herniated intervertebral disk (HIVD), a computed tomography (CT) scan of the brain was performed, but it showed no unusual lesions. Magnetic resonance imaging (MRI) of the lumbar spine also did not show any abnormal patterns. Immediately after the magnetic resonance imaging

examination, the patient experienced a severe overall discomfort and was irritable. She experienced overall pain of considerable intensity; the source of the pain could not be determined. The mismatch between the clinical symptoms and the radiologic findings was evident. Subsequently, CT scanning was performed based on the assumption of aortic dissection or other acute vascular conditions. The CT scan showed type B aortic dissection with left renal artery impairment (Fig. 1) but that did not involve the iliac arteries. Then, the patient was transferred to a medical center for further evaluation and management. The patient was diagnosed with type B aortic dissection and right common iliac artery occlusion, and she underwent bypass surgery. She died 2 weeks later because of pneumonia and septic shock. Aortic dissection is a rare event, and it accounts for about only 1 in 10,000 hospital admissions [1]. However, not all aortic dissections present with Classic symptoms, and the diagnosis may be missed. Pain may be absent or

intermittent in as many as 5% to 10% of patients [2-4]. A literature review revealed a few reports of painless aortic dissection that presented with neurologic sequelae. Gerber

[4] described 3 patients with acute neurologic syndromes who experienced no pain arising from an aortic dissection. Rosen [5] presented a case report of a patient with transient ischemic myelopathy as the only symptom of aortic dissection. Donovan et al [6] reported a case of painless aortic dissection that presented as acute para- plegia. Joo and Cummings [7] demonstrated a case of aortic dissection that presented as a transient neurological syndrome. In this study, we demonstrate a rare case of aortic dissection that presented as a simple accidental fall with HIVD-like symptoms that was diagnosed in triage as a condition affecting the lower extremities.

Aortic dissection can associate with neurologic sequelae in as many as one third of all patients [3,5]. These sequelae can be divided into 3 categories: cerebral ischemia, ischemic peripheral neuropathy, and spinal cord ischemia, depending on the site of the dissection [8]. Cerebral ischemia presents as a stroke or encephalopathy and occurs when the Ascending aorta dissects. Dissection involving the iliac arteries may result in painful peripheral neuropathy [8]. Paraplegia with or without sensory loss also called anterior artery syndrome occurs when the descending aorta dissects. It is a rare phenomenon and occurs in 2% to 8% of patients [1,3,8]. Furthermore, considering the history of the patient,

0735-6757/$ - see front matter (C) 2009

127.e2 Case Report

diagnosis. After observing the patient over a period of time, it was found that the patient’s condition had dramatically changed and it forced us to suspect the possibility of aortic dissection. In this case, although the patient’s complaints at triage did not appear to be serious, adequate History taking and a close follow-up of the changes in the patient were key in diagnosing the rare and life- threatening condition of aortic dissection.

Bao-Fang Lin MD¹ Yi-Shan Chen RN¹ Hsiao-Fen Weng RN Wei-Tso Chia MD

Department of Emergency, Hsin Chu General Hospital

Hsinchu City 300, Taiwan ROC Department of Health, Executive Yuan, Taiwan ROC E-mail address: [email protected]

doi:10.1016/j.ajem.2008.03.051

References

Fig. 1 Computed tomographic scan of the chest delineates dis- section of the aortic arch of the aorta. A, Right renal artery occlusion. B, Blood flow of bilateral femur arteries was unobstructed.

the initial fall may have been caused by a brain lesion or a true spinal lesion. The fall also may have caused HIVD or the traumatic Spinal injury. The neurologic deficit in the bilateral limbs without pain and the normal arterial blood flow to the lower limbs in the initial presentation resulted in an incorrect choice of triage, and later, an incorrect

1. Archer AG, Choyke PL, Zeman RK, Green CE, Zuckerman M. Aortic dissection following Coronary artery bypass surgery: diagnosis by CT. Cardiovasc Intervent Radiol 1986;9:142-5.
2. Isselbacher KJ, Braunwald E, editors. Harrison’s principles of internal medicine. 13th Ed. New York: McGraw-Hill; 1994.
3. Zull DN, Cydulka R. acute paraplegia: a presenting manifestation of aortic dissection. Am J Med 1998;84:765-70.
4. Gerber O, Heyer EJ, Vieux U. Painless dissections of the aorta presenting as acute neurologic syndromes. Stroke 1986;17:644-7.
5. Rosen SA. Painless aortic dissection presenting as spinal cord ischemia. Ann Emerg Med 1988;17:840-2.
6. Donovan EM, Seidel GK, Cohen A. Painless aortic dissection presenting as high paraplegia: a case report. Arch Phys Med Rehabil 2000 Oct;81(10):1436-8.
7. Joo JB, Cummings AJ. Acute thoracoabdominal aortic dissection presenting as painless, transient paralysis of the lower extremities: a case report. J Emerg Med 2000;19(4):333-7.
8. Weisman AD, Adams RD. The neurological complications of dissecting aortic aneurysm. Brain 1944;67:6-91.

¹ These authors contributed equally to this study.