A case of spinal epidural lipomatosis associated with phenytoin induced hypothyroidism and obesity

ABSTRACT

Spinal epidural lipomatosis(SEL) is characteristic by abnormal accumulation of unencapsulated fat in the epidural space, which usually occurred as a complication of longterm steroid therapy or Cushing's syndrome and occasionally in obese patients with no other known etiology. This condition, which may result in devastating neurologic complications has also been reported without exogenous steroid intake. Magnetic resonance imaging is the meet helpful diagnostic means and should be used initially. We describe a case of nonsteroid induced symptomatic SEL associated with phenytoin-induced hypothyroidism and obesity. A 27-year-old woman was hospitalized with inability to walk for 2 months ago. She has back pain in her legs associated with radiating pain. She had a history of myoclonic seizure and treated with phenytoin 300 mg for 8 years. On admission, she shows mild hypothyroidism on thyroid function test. Serum phenytoin level was elevated as to 22.1 ug/ml. On cross sectional MRI, the thecal sac has a striking stellate appearance with three rays emanating from a central core. It produces a trifid shape resembling the letter "Y". Correction of underlying endocrine abnormality with weight reduction instead of decompressive laminectomy can reverse the process. In a obese patient with radicular pain or progressive paralysis, SEL may be the etiologic factor involved.