Male, 30 years old, with flaccid paraplegia, HIV positive, evaluate for lesions in the brain or cord. Brain:Scattered irregular T2 hyperintense lesions are evident in the cerebral hemispheres, predominantly in the subcortical white matter with some preference for the frontal lobes. These lesions range in size from punctate to 1 or 2 cm in size, but they exert no significant mass effect. The largest lesion, in the left superior frontal gyrus, appears to demonstrate associated volume loss. None of these lesions demonstrates evidence of enhancement. None is associated with evidence of blood product.Morphology of the brain is otherwise unremarkable. No abnormal extra-axial fluid collections are seen. No pathologic parenchymal or extra-axial enhancement is detected. The ventricles are normal in size and morphology.Spine:The distal spinal cord and conus are edematous. Beginning at the T11 and T12 level, the emerging cauda equina nerve roots show diffuse enhancement and thickening. Beginning at the L2 level, the thecal sac is filled with solidly enhancing tissue which may represent compacted thickened nerve roots or nerve roots intermixed with some other pathologic tissue. Extensive enhancement and nerve root clumping persists into the sacral region where CSF becomes evident again.In the cervical and thoracic region, minimal if any nerve root enhancement is detected and the spinal cord itself shows normal morphology and signal intensity.Reversal of the cervical lordosis is seen. There is a moderate loss of vertebral body height at C4 with evidence of marrow edema at this level. A moderate to severe loss of vertebral body height is seen at T10 and at L5, both of which show edematous marrow signal. Right-sided pedicle screws are in place at L5 and S1.Multiple enlarged left periaortic lymph nodes are seen in the lumbar region. In addition, the iliopsoas muscle complex shows evidence of ill-defined enhancement suggesting inflammation.
1.Extensive enhancement is seen along the distal spinal cord and within the thecal sac of the lumbar spine. This is favored to represent either thickened and enhancing nerve roots or nerve roots mixed with some other pathologic enhancing soft tissue process. There may be at most minimal nerve root enhancement in the cervical and thoracic spine, but those regions of the spinal cord are otherwise unremarkable. The differential diagnosis for this finding includes infection, particularly opportunistic and atypical agents as well as tuberculosis. The possibility of a malignant process should also be considered including lymphoma. The possibility that this represents a postinfectious or autoimmune phenomenon such as Guillain-Barre syndrome is considered less likely given the severity of the soft tissue thickening.2.Multiple mild to moderate compression deformities are also seen with evidence of marrow edema suggesting a relatively recent onset. The etiology for these compressions is uncertain. These could simply represent compressions related to osteopenia, though superimposed infection or some other marrow infiltrating process can also be considered. Tuberculous osteomyelitis could be considered, though in most cases, there is evidence of adjacent soft tissue thickening which is not seen in this case.3.Left periaortic lymphadenopathy is noted along with inflammation of the left iliopsoas muscle complex.4.Intracranially, scattered foci of white matter signal abnormality are seen, predominantly in the subcortical white matter and with some preference for the frontal lobes. These lesions appear to be chronic as they do not enhance and exert no mass effect. The differential would include sequelae of demyelinating or infectious processes including the direct action of HIV on the CNS. Vasculitis or a small vessel vascular process can also be considered.