Patients with AIDS are highly susceptible to toxoplasma infection, especially recurrence of latent infection. In such cases with acquired toxoplasmosis, lymphadenopathy may be less evident but acute fetal infections with extensive dissemination may occur. The clinical manifestations include high fever, pneumonia, skin rash, hepatosplenomegaly and myocarditis. Sometimes, spinal toxoplasmosis occurs as a complication of HIV/AIDS.

Patients with AIDS can develop myelitic lesions induced by multiple viruses, such as cytomegalovirus (CMV), varicella zoster virus (VZV) and herpes simplex virus (HSV). It is commonly believed that the lesion is resulted from demyelination secondary to infection and is related to the autoimmunity. The foci can be found at any part of spinal white matter, with characteristic demonstrations of concurrent lesions around the veins and under the soft pia mater in the diseased white matter area. The lesion may involve the gray matter, with a diffusive distribution.

Viral myelitis has an acute onset, with initial clinical manifestations of fever, headache, nausea and vomiting 1–2 weeks prior to the onset. The following manifestations are anxiety, deliration, lethargy, stiffness and coma. The imaging demonstrations are not characteristic, making it difficult to be differentiated from acute multiple sclerosis. CT scanning demonstrates diffusive low-density area in the spinal white matter. MR imaging demonstrates swollen spinal cord, with equal or low signal of T1WI and high signal of T2WI. The focus is prone to be complicated by hemorrhage and swollen and enlarged spinal cords show no enhancement by enhanced imaging. In the chronic stage, the spinal cord may be shrunk and thin, with dilated central duct. However, the manifestations are not specific, making it difficult to be differentiated from lymphoma.

HIV/AIDS complicated by spinal tuberculosis [4] and syphilis [12] have been reported. Tuberculosis mycobacterium can cause meningoradiculitis or intramedullary tuberculoma. Syphilis may cause syphiloma within the spinal canal. In patients with frequent intravenous drug abusers, bacteremia commonly occurs, with possible occurrence of epidural abscess that may extend to paravertebral. The most common pathogen of epidural abscess is staphylococcus; tuberculosis mycobacterium, Nocardia and Aspergillus [13] are also reported to cause high fever with progression to paralysis within 24–72 h. The lesion may be sub-acute, with nerve symptoms in 1 week or several months. Intramedullary infection is resulted from venous occlusion by bacteria colonies, leading to spinal venous occlusion. CT and MRI scanning can definitively demonstrate the location and range of the abscesses. Plain CT scanning demonstrates local spinal thickening, irregular morphology, and clearly defined boundary of intraspinal foci. The enhanced scanning shows ring shaped enhancement of the capsule. MRI demonstrates low signal of T1WI and T2WI of the capsule, low signal of T1WI and high signal of T2WI of the abscess fluid. The enhanced MR imaging demonstrates ring shaped enhancement of abscess wall by T1WI. Both CT and MRI demonstrate flaky or nodular enhancement before the formation of large abscess cavity at the inflammation phase.

Due to dependence on the immune response, patients with AIDS rarely have myeloma. The rarely found reports also include cases of spinal lymphoma and plasmocytoma. Lytic enzyme in the extraspinal Kaposi’s tumor (KS) can also impair the spinal cord. In HIV/AIDS related neoplasms, the accompanying spinal metastasis tumor may occur.

HIV/AIDS related multiple sclerosis is related to HIV-induced immunodeficiency, with acute or sub-acute onset. Its initial symptoms include bilateral or unilateral visual impairment. Spinal cord lesions commonly occur in the dorsal horn, with clinical manifestations of limbs pain, paresthesia, weakness and paralysis of limbs or hemiplegia. Some patients may develop sensory disturbance, specifically sensing the plane as incomplete. Plain CT scanning demonstrations are negative; uneven ring shaped enhancement of the spinal cord in the acute phase can be found by enhanced scanning, with low sensitivity. Sagittal MR imaging demonstrates clearly the range of the lesions by T1WI and T2WI. In the acute phase, T1WI only demonstrates thickened spinal cord, with normal intraspinal signal; T2WI demonstrates intraspinal singular or multiple high signal foci, with space occupying effects of different degrees. By enhanced imaging, some foci are in ring shaped enhancement. Increased dosage of the contrast reagent can increase the detection rate of the foci.

Diagnostic examinations for HIV/AIDS related myelopathy include: For patients with spastic paralysis or paraplegia of the lower extremities, CSF test should be firstly performed to find the common pathogenic microorganisms and PCR can be performed to detect myelitis related viruses. For patients with large epidural abscess, lumbar puncture is of tremendous risk. CT scanning can effectively detect epidural lesions, but with poor demonstration of intraspinal lesions. MR imaging is ideal for clinical diagnosis of HIV/AIDS related myelopathy to distinguish epidural and subdural structures, demonstrate spinal degeneration, extensive necrosis and hemorrhage. When MR imaging is not available or feasible, enhanced CT scanning can facilitate the preliminary diagnosis.