Decompression of idiopathic lumbar epidural lipomatosis: diagnostic magnetic resonance imaging evaluation and review of the literature.
OBJECTIVE
Idiopathic symptomatic spinal epidural lipomatosis (SEL) is a rare condition, and few reports have discussed diagnostic imaging criteria. To evaluate factors relating to its clinical symptoms, correlations between clinical features and the presence of spinal epidural fat were investigated, and the literature concerning idiopathic SEL was reviewed.


METHODS
Morphological gradings of epidural fat were evaluated in seven patients with idiopathic SEL by using magnetic resonance (MR) imaging. In addition, body mass index (BMI), the number of involved vertebral levels, grade, and preoperative Japanese Orthopaedic Association (JOA) score were analyzed. Surgery resulted in symptomatic relief, with a mean JOA score recovery rate of 67.4%. Grading of epidural fat tended to display a slight negative correlation with preoperative JOA score, whereas a strong significant positive correlation was found between the number of involved vertebral levels and BMI.


CONCLUSIONS
The number of involved vertebral levels and obesity are strongly correlated, whereas severity of dural compression is not always significantly associated with neurological complications. These results indicate that epidural fat of the lumbar spine contributes to neurological deficits. In addition, weight-reduction therapy appears to decrease the number of vertebral levels involved. Magnetic resonance imaging-based grading is helpful for the diagnosis and evaluation of idiopathic lumbar SEL. Moreover, symptoms and neurological findings are important for determining the surgical approach.
Ishikawa
Yoshinori
Y
Department of Orthopedic Surgery, Akita University School of Medicine, Japan. mitsuki@rio.odn.ne.jp
Shimada
Yoichi
Y
Miyakoshi
Naohisa
N
Suzuki
Tetsuya
T
Hongo
Michio
M
Kasukawa
Yuji
Y
Okada
Kyoji
K
Itoi
Eiji
E
D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D003937:Diagnosis, Differential; D004824:Epidural Space / Q000473:pathology; D005260:Female; D006801:Humans; D008068:Lipomatosis / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D012189:Retrospective Studies; D013118:Spinal Cord Diseases / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome