Clinical Geriatrics

CASE PRESENTATION
An 86-year-old woman presented to the emergency department complaining of left-sided flank pain that had awoken her from sleep earlier that morning. She rated the pain severity as 6 on a scale of 1 to 10, with radiation to the left groin and no relief on position change. She had no hematuria, dysuria, fever, or chills. Past medical history included a stroke at age 83, with no residual deficits, hypertension, atrial fibrillation, depression, and pacemaker for sick sinus syndrome. Her medications were warfarin 5 mg daily, digoxin 0.25 mg daily, fosinopril 10 mg daily, and mirtazapine 15 mg before bed. She had no recent surgery and did not smoke or consume alcohol.

She had no fever, and vital signs remained stable. Heart rhythm was atrial fibrillation with a controlled ventricular rate. Lower thoracic spine was tender to palpation. No costovertebral tenderness was present. Her neurologic examination was entirely normal.

Initial differential diagnoses included nephrolithiasis, abdominal aortic aneurysm, diverticulitis, and compression fracture of the spine. Urinalysis showed moderate leukocytes, trace protein, and trace blood. Erythrocyte sedimentation rate and complete blood count were within normal range. Prothrombin time was 27.7, with international normalized ratio (INR) of 2.71 and partial thromboplastin time of 49. Complete metabolic profile, cardiac enzymes, and serum digoxin level were unremarkable. No fracture was found on plain films of the spine. Computed tomography (CT) scan of the abdomen and pelvis did not show any pathology. She was admitted to the hospital for further evaluation because her back pain worsened and was unrelieved by morphine sulfate 8 mg.

Three hours after admission, she was unable to move her legs. Muscle strength was 1/5 in the right leg and 0/5 on the left. No reflexes were elicited in the legs. Sensation was absent below L1 on the left and L2 on the right. The bladder was distended with 700 cc of clear urine on catheterization.

A CT scan of the thoracic and lumbar spine partially visualized a soft tissue density within the posterior aspect of the thecal sac at the thoracolumbar junction. A repeat scan showed an epidural hematoma extending from T10 to L1.

DISCUSSION
Spinal epidural hematoma has been well documented in association with trauma, bleeding diatheses, tumor, vascular malformation, and anticoagulation therapy.1 To date, there have been about 300 reported cases of spontaneous spinal epidural hematoma.2,3 About 20-30% of these cases have been associated with anticoagulation.4 Several of these were believed to have occurred during sleep.

In 1952, DeVanney and Osher5 described the first case of a spinal epidural hematoma in a patient receiving anticoagulants. Subsequent reports, such as Alderman6 in 1956, have stressed that this diagnosis be considered in any patient receiving anticoagulants in whom back pain or sciatica develop. In addition, spinal epidural hematoma can occur in patients whose INR is within acceptable therapeutic range. This was the case with our patient.

The acute onset of severe local and radicular back pain, motor and sensory deficits below the area of the initial pain, and bowel and bladder dysfunction are the most frequently reported symptoms.1 However, these symptoms are not universally present, and some patients with large epidural hematoma have had no physical symptoms.7 Absence of pain could further delay accurate diagnosis.

Age at time of occurrence in case reports ranged from 14 months to 90 years.1-3 Patients in the sixth and seventh decades of life are the most vulnerable, perhaps related to an increased use of oral anticoagulants.1 Most studies found an equal incidence in men and women.8

The exact mechanism of spontaneous spinal epidural hematoma is unknown.