Paraplegia due to Spinal Epidermoid Cyst Rupture at Asthma Attack
This 22-year-old male patient intermittently suffered from hay fever in summer with symptoms of cough and dyspnea, however as his symptoms were minor, he did not undergo any special check-up, evaluation or treatment. When he was studying in college, he had symptoms of gradual backache and radiating pain in both lower limbs, but as symptoms were minor, he did not seek any examination. In November 2011, he started his military service as a conscripted policeman and experienced several rounds of difficulty in breathing and received conservative treatment. In January 2012, he showed severe dyspnea, coughing, chest pain, and muscular weakness in the lower limbs. After the pulmonary function test in a private hospital, he was diagnosed with asthma, so he was hospitalized and treated with a β-agonist and steroid injection. After 2 days, the symptoms continued so he was transferred to the emergency room of our hospital. After treatment in our hospital, his symptoms improved compared to the results of the private hospital's pulmonary function test, as shown by the forced expiratory volume of subnormal 1 second (FEV1) from 1.13 L (32% of predicted value) to 3.50 L (78% of predicted value), the FEV1/forced vital capacity (FVC) from 46% to 77% and forced expiratory flow (FEF; range, 25%-75%) from 11% to 67%. His symptoms of dyspnea and chest pain gradually improved, but he continued to show muscular weakness in both lower limbs. The muscle tone of both upper limbs was within the normal level, but the muscle tone of both lower limbs was accelerated, showing increased deep tendon reflex in the knee and ankle joints, while exhibiting ankle clonus for both ankles. A neurogenic lesion in the upper part was suspected. According to manual muscle test, muscular strength of both upper limbs was normal, and there was no difference in muscular strength between both sides of lower limbs. However, the flexor/extensor muscles of the hip and knee joints were 1/5, and the flexor muscle of the instep/sole had been decreased to 0/5. Moreover, spasticity of both lower limbs was level 1 for ankle dorsiflexion on the modified Ashworth Scale.\nBlood test during his hospitalization showed a potassium level of 3.8 mEq/L; thyroid function test did not show any unusual findings with T3 of 57.7 ng/dL, thyroid-stimulating hormone of 1.15 µIU/mL, and free T4 of 1.38 ng/dL. He did not have a high fever, headache or meningism symptoms including Kernig's sign and Brudzinski's sign, so lumbar puncture test was not performed. From lumbar magnetic resonance imaging (MRI) which was done on the third day of hospitalization in our hospital, a severe stricture and compression were observed from L2 to S1 due to synechia and a cystic mass of posterior intraspinal space (). After 1 day of test, neurosurgical department of our hospital diagnosed him with lumbar cord damage, and then conducted emergency decompression surgery. Since a space between L2 and S1 was filled with a ruptured epidural cystoma, dead skin cells, and cholesterol type substances, they compressed severely the dura mater and nerves. Adhesion in the dura mater and the back spinal cord was also observed, however as it was located outside the dura mater, compressing substances were comparably easily and perfectly removed. Histological examination of the removed substances confirmed a ruptured epidermoid cyst together with simple squamous cells, dead skin cell components, and dystrophic calcification (). As the patient did not undergo back surgery or rachicentesis, he was diagnosed with a congenital epidermoid cyst.\nSeven days since the operation, the patient was transferred to our rehabilitation department; when he was transferred, manual muscle test showed no big difference in the muscular force of both lower limbs, while the flexor/extensor muscles of the hip and knee joints was 2/5 and the flexor muscle of instep/sole was 1/5. He was recovering, but, except for changing positions, sitting by himself and moving around in the wheel chair, his physical strength became weaker such that he needed help from other people to perform everyday activities.\nWhen he was transferred, the Functional Independence Measure (FIM) was 94, the Korean version of Medified Barthel Index (K-MBI) was 56 and the Spinal Cord Independence Measure (SCIM) was 58. According to results of his neurologic examination, he showed hypesthesia and muscle weakness from the dermatomere of L2, while anal contraction could be done by himself. Based on the motor nerve and sensory nerve, a neurologic damage part was L1 in paresis and could be classified as C in the American Spinal Injury Association (ASIA) Impairment Scale. From the initial period of hospitalization, a urethral catheter was inserted due to exacerbation of his entire body, so it was difficult to recognize urination symptoms, yet bulbocavernous reflex existed and was under drug treatment due to symptoms of slight constipation. Before the transfer, he was able to urinate by himself after removing the catheter, but exhibited residual urine and intermittent urinary frequency symptoms. After drug treatment, his symptoms improved. Electrodiagnosis was taken 1 week after the transfer (after 3 weeks since the operation); conduction test of the motor and sensory nerves showed normal latency and amplitude in both lower limbs, while the latency of both sides' H-reflexes was delayed. By conducting somatosensory evoked potential of both tibial nerves and motor evoked potential at both abductor hallucis muscles by stimulating the head, we could observe a delay in the transcranial area (). In the needle electromyographic test, we observed a high level of abnormal spontaneous activities in the paravertebral muscles and lower limb muscles of that particular segment, demonstrating complications of conus medullaris syndrome and radiculopathy of the lumbosacral area (). Due to improved symptoms, the patient declined further examination, so tests for pudendal somatosensory evoked potentials and bulbocavernosus reflex latency were not done.\nDuring the hospitalization period in our hospital, the patient continued to exercise to strengthen the muscular power of the lower limbs through stimulating the functional nerve roots, standing up and gait training. Three months after the operation, the results of the manual muscle test showed the hip joint flexor, knee joint extensor and instep flexor muscles as 4/5, while the hip joint extensor, and knee joint flexor and sole flexor muscles as 3/5. The patient was able to walk a short distance on the flatland using a walker (). Before discharge, he scored 113 for FIM, 87 for K-MBI and 86 for SCIM. Currently, he is hospitalized for the second time for continual rehabilitation treatment and is under continual ambulatory observation by our department. He can now walk on the flatland using a quadripod cane.