A Case of Idiopathic Thoracic Spinal Subdural Hematoma With Bilateral Lower Limb Paralysis

Subdural hemorrhage is rare and is mostly triggered non-traumatically due to intracranial surgery, lumbar puncture, anticoagulant therapy, blood diseases, vascular malformations, and tumors. We experienced a case of idiopathic subdural hematoma with acute bilateral lower limb paralysis on postoperative day 4 after laparoscopic hysteromyomectomy. The patient was a 40-year-old woman with uterine myoma who took no medication nor had history of trauma or abnormalities such as vascular malformations. Four days after laparoscopic surgery, sudden chest and back pain and bilateral lower limb paralysis appeared. Muscle weakness was found predominantly on the left side. In manual muscle test (MMT), the quadriceps femoris was 5/5 on both sides, but the tibialis anterior, extensor pollicis longus and flexor pollicis longus were 5/5 only on the right, and 2/5 on the left side. Warm pain sensation was decreased below Th4 (Fourth thoracic vertebra), and the right side showed a greater decrease of deep sensation than the left. Excretion was difficult and dysuria was also apparent. There were no abnormalities in blood biochemical tests or in the blood coagulation system. Using the results of diagnostic imaging, as preoperative diagnosis of the patient, spinal subdural hematoma was suspected. Conservative treatment was initially conducted but the emergency surgery for hematoma removal was performed at 14 hours after the onset because of progression of paralysis. This resulted in improvement of neurological symptoms including lower limb paralysis, bladder-rectal disorder and hypoesthesia. If subdural hematoma is suspected regardless of the cause, it is important to observe neurological findings over time and make a quick decision to treat with surgery.