Table 1 Review of the reported clinical cases of paradoxical CNS-IRIS associated to toxoplasmosis^a

Case 1 Female, 30 yo

At diagnosis: HIV infection for 6 months, not on HAART.

Manifestations: Fever, left hemiparesis with the Babinski sign.

Brain MRI: Ring-enhancing mass in the right basal nuclei.

Treatment: ATT with trimethoprim–sulfamethoxazole, corticosteroids, HAART.

Response to treatment: Clinical and radiographic improvement.

Presentation: Approximately 6 weeks after toxoplasmosis diagnosis, patient was readmitted with headaches (for 2 weeks), imbalance, and left hemiparesis (for 48 h).

Brain MRI: Mass persistence, more vasogenic edema and new, bilateral but smaller contrast enhancing lesions. Brain biopsy: Abundant tachyzoites.

Treatment: Reduction of the corticosteroids tapering rate.

Outcome: Clinical improvement without complete resolution (2 months after IRIS diagnosis).

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Case 2 Female, 26 yo

At diagnosis: HIV infection for 8 years, not on HAART. History of cerebral toxoplasmosis 4 years before.

Manifestations: Ataxia, left-sided weakness and hyperreflexia for 1 month.

Brain CT scan: Scattered calcified lesions with no perilesional edema or contrast enhancement. CSF analysis: Negative PCR for T. gondii.

Brain MRI: Multiple areas of high signal intensity on fluid-attenuated inversion recovery (FLAIR) images, some presenting nodular or ring enhancement.

Treatment: ATT and HAART.

Presentation: After a steady clinical period of 1 month, progression of symptoms.

Brain MRI: Enlargement of most of the lesions, mainly with perilesional high signal intensity on FLAIR images, as well as stronger contrast enhancement.

Brain biopsy: Collections of histiocytic giant multinucleated cells. Marked perivascular lymphocytic infiltrates with a predominance of CD8⁺ T cells. Reactive gliosis. No T.gondii cysts or tachyzoites.

Treatment: Maintenance of therapeutic measures. No corticotherapy.

Outcome: Clinical improvement.

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Case 3 Male, 34 yo

At diagnosis: HIV infection, non-compliant with HAART.

Manifestations: Lower extremities weakness for 6 months, sensory level at L4 and constipation. Toxoplasma serum IgG level: Increased. CSF studies: Negative.^b

Brain and spine MRI: No contrast-enhanced brain lesions. Expansive intramedullary enhancing lesion in spine, at T11 through T12.

Treatment: Laminectomy and surgical spinal cord decompression, corticosteroids, ATT, HAART. Pathology of the excised spinal lesion: T. gondii cysts.

Response to treatment: Clinical improvement.

Presentation: Worsening of weakness 3 weeks after treatment initiation. Cachexy, dysarthria, hypotension and areflexia in upper and lower extremities after one month approximately.

Brain and spine MRI: Two new enhancing lesions in brain. No new lesions in spine.

CSF studies: All within normal.

Electromyogram/nerve conduction study: Results consistent with a sensorimotor neuropathy superimposed on a predominantly proximal myopathic process.

Muscle biopsy: Necrosis, lymphocytic and plasma cell infiltrates with abundant T. gondii cysts.^c

Outcome: Multiorgan dysfunction and death 2 weeks after the diagnosis of toxoplasmosis myositis.

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Case 4 Male, 35 yo

At diagnosis: AIDS previously diagnosed, not on HAART or prophylaxis.

Manifestations: Left upper extremity weakness for 3 weeks, associated to fever and respiratory symptoms for 1 week (concomitant respiratory infection).

Brain MRI: Two ring-enhancing lesions in the right precentral and occipital temporal areas.

Treatment: Ceftriaxone and azithromycin, ATT, HAART.

Presentation: Progression of upper extremity weakness during the first 2 weeks on HAART.

CSF studies: 6 WBC/mm³ (96% lymphocytes; 4% monocytes); positive EBV PCR.

Brain MRI: Enlargement of the two prior lesions and development of a third lesion.

Brain biopsy: Rare T. gondii tachyzoites and numerous bradyzoites. CD8⁺ predominant lymphocytic infiltrates.

Treatment: Corticosteroids. Outcome: Clinical improvement without complete resolution.

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Case 5 Male, 51 yo

At diagnosis: AIDS previously diagnosed, not on HAART or prophylaxis.

Manifestations: Unsteady gait, left upper extremity weakness, headaches, weight loss and fever for 2 weeks.

Brain MRI: Multiple ring-enhancing lesions in his fronto parietal region.

Treatment: ATT, HAART.

Presentation: After an initial improvement, there was progression of neurological symptoms around 2 weeks after treatment initiation.

CSF studies: 6 WBC/mm³ (100% lymphocytes); no malignant cells. Brain MRI: No significant change. Brain biopsy: Presence of T. gondii. CD8⁺ predominant lymphocytic infiltrates.

Treatment: Corticosteroids. Outcome: Clinical improvement.

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