Toxoplasmosis Myopathy as a Possible Manifestation of Immune Reconstitution Inflammatory Syndrome

A 34 year-old man with a history of HIV/AIDS noncompliant with highly active anti-retroviral therapy (HAART) presented to the hospital with a six month history of bilateral lower extremity weakness and a sensory level at L4. His CD4+ T-lymphocyte count was 67 cells/mm3 and human immunodeficiency virus (HIV) RNA level was 41,000 copies/ml. Cerebrospinal fluid (CSF) studies were unrevealing. An enhanced MRI of the spine, demonstrated an expansive intramedullary enhancing lesion at T11 through T12. The patient underwent laminectomy and spinal cord decompression, and pathological studies of the excised lesion revealed T. gondii cysts. His Toxoplasma IgG levels was 1.4 IU/ml (normal range <6.4). He was treated with sulfadiazine and pyrimethamine and continued on HAART. He gradually improved and was transferred to an inpatient rehabilitation facility. Twenty-seven days later, the patient became hypotensive and was transferred back to the acute care hospital. He was now dysarthric and diffusely weak in all of his extremities. His serum creatinine kinase level (CK) was 788 IU/L. Repeat CSF studies were all within normal limits. His CD4+ count had increased to 277 cells/mm3 and the HIV RNA level was 531 copies/ml. Both serum and CSF T. gondii IgG and IgM were negative. There were no new lesions on an MRI of the spine but an enhanced MRI of the brain showed two enhancing lesions that were compatible with T. gondii infection. An EMG/NCS showed a sensorimotor neuropathy superimposed upon a predominantly proximal myopathic process. A muscle biopsy revealed areas of necrotic muscle demonstrating lymphocytic and plasma cell infiltrates with abundant T. gondii cysts. Discussion