Type I AV fistula of the thoracic spinal cord

Type I AV fistulas of the spinal cord are exceedingly rare. The average age at diagnosis is 50. Clinical presentation is often very non-specific, and sensory deficits and sphincter dysfunction may also occur. Neurological deterioration is generally gradual. Thus, failure to diagnosis frequently results in permanent disability. A 22-year-old female complained of a "muscle spasm" in the midline thoracic area with no history of trauma or prior occurrence. She also experienced bilateral lower extremity weakness/numbness and perianal anesthesia. She is a healthy female with no medical problems. Exam revealed lower extremity motor function of 1/5 as well as diminished sensation. A foley catheter was placed for urinary retention. The remainder of the neurological exam was normal. MRI demonstrated a lesion at the fourth thoracic level with significant cord compression. The patient was taken emergently to the operating room by neurosurgery. This case demonstrates a rare disorder occurring in a 22-year old female, far younger than the typical 50-year old patient. Moreover, the lesion was located in the thoracic rather than the typical lumbar cord. Symptoms may be misinterpreted as a peripheral nerve lesion and delay time to diagnosis. Early diagnosis remains critical to prevent permanent neurologic sequelae. AV fistula should remain high on the differential of patients presenting with back pain and focal neurologic complaints.