Age / Sex : 63 / M

Age / Sex :
male/63

Chief complaint :

Weakness in lower extremities, low back pain and left leg paralysis after drinking

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD (lis@pusan.ac.kr)

Courtesy : Hyun-joo Kim,  Soonchunhyang University Seoul Hospital

Compartment syndrome

Discussion

Findings:

 On initial MRI, there is a 6.3x3.5x3.0 cm sized T1 iso to slight high and T2 heterogenous high signal intensity changes in the right multifidus muscle from L3 to L5 level. There is also swelling of the muscles. After contrast injection, the involved segment show heterogenous enhancement.

Ten days after, he underwent follow up MRI.  The volume of involved segment is increased and the T1 and T2 SI of the lesion is also increased compared with that of previous MRI. The enhancement pattern of the lesions has changed. The central T2 bright high SI portion showes persistent low SI and the peripheral portion of the lesion shows thick irregular enhancement.

Differential Diagnosis:

 Muscle strain

 Hematoma with secondary infection.

Diagnosis:  

 Paraspinal muscle compartment syndrome.

Discussion:

A 63-year-old man came to the emergency unit for increasing low back pain; the pain had persisted for 3 days. He had slept in a squatting position on a side walk after drinking.

Laboratory findings were normal with the exception of BUN/Creatinine 60.6/4.7 mg/dL  (normal, 8-20 and 0.6-1.4 mg/dL) creatinine phosphokinase 1006 IU/L (normal, 43-272 IU/L), myoglobin 128ng/mL (normal, 27-75 ng/mL) and LDH 840  IU/L (normal, 100-450 IU/L).

Renal function test showed slightly decreased bilateral kidney functions and the bilateral kidneys showed findings of medical renal disease. The patient was treated with fluids intravenously (2 L/day) for acute renal failure. The patient improved and was discharged 12 days after admission.

For the evaluation of paraspinal lesion, US guided biopsy was done. The pathology result was consistent with compartment syndrome. The specimen section showed a central area of ischemic necrosis or loss of muscle cells with edema, intermuscular granulation tissue and regenerating muscle cells in the surrounding tissues.

Acute compartment syndrome is defined as the pathologic elevation of the hydrostatic tissue pressure within a closed compartment inducing ischemia and myonecrosis. The common sites of acute compartment syndrome are volar compartment of forearm and anterior and deep posterior compartment of lower leg. Acute paraspinal compartment syndrome, although rare, has been well described in a few case reports.

The diagnosis of compartment syndrome is based on clinical criteria. However, imaging studies points out the involved muscle compartments and enables the surgeon to selectively split the fascias of affected compartments.

CT shows diffuse enlargement of the involved muscles due to muscle edema and the density of the involved muscles is decreased. In chronic case of compartment syndromes, the muscles show atrophic changes, fatty infiltration, sheet-like calcification or ossificiations.

Edema of the affected muscular compartment is easily observed on T1-weighted and T2-weighted MR images. After Gd-DTPA administration, the affected compartments strongly enhanced, which reflected disturbances of cell membrane permeability. Within the enhancing compartments, areas of liquefaction (necrosis) and normal muscle could be identified. The presence and extent of necrosis presented valuable preoperative information that helped to plan muscle resection.

References:

1.     Stock, K. W.; Helwig, A. Clinical Image. MRI of Acute Exertional Rhabdomyolysis in the Paraspinal Compartment. Journal of Computer Assisted Tomography 1996;20(5):834-836.

2.     M. B. Rominger, C. J. Lukosch, G. F. Bachmann. MR imaging of compartment syndrome of the lower leg: a case control study. European Radiology 2004;14:1432–1439.

3.     Izuru Kitajima, Shintaro Tachibana, Yutaka Hirota, et al, Acute Paraspinal Muscle Compartment Syndrome Treated with Surgical Decompression. The American Journal of Sports Medicine 2002 30: 283-285.