Cerebral toxoplasmosis

Case contributed by Ian Bickle


Fever and URTI for the past 2 weeks. Frequent infections prior 2 months. Right LMN facial palsy. Tandem gait. Newly diagnosed immunosupressive disease

Patient Data

Age: 30 years
Gender: Male

Ill defined non-enhancing low attenuation in the left lentiform nucleus and internal capsule.

Similar ill defined area of low attenuation in the left posterior parietal lobe, including the post central gyrus.

No abnormal enhancement.


Multiple lesions of variable size measuring from 9 to 25 mm with surrounding edema throughout the brain including, cerebral hemispheres, cerebellum and brain stem. The lesions are hyperintense on T2 and involving the subcortical regions, white matter and basal ganglia. The largest one is in the left basal ganglia. Several have low T2 signal rims.

Focal areas of restricted diffusion in a few lesions in the parietal lobe. No intralesional calcification.

Variable enhancement with faint ring enhancement of a minority of the lesions.

Normal paranasal sinuses.

Mastoids are normal and the calvarium demonstrates no abnormality.

A follow up MRI was performed 9 weeks after treatment


Comparison was made with the previous MRI brain from 9 weeks prior.

The multiple supratentorial and infratentorial T2W and TIRM hyperinetnse lesions have markedly decreased in number and size. The largest residual lesion in the left lentiform nucleus is 5 mm.  Minor residual rim enhancement.

No new lesions.

Case Discussion

This is a case of proven cerebral toxoplasmosis with clinical and radiological follow up. This was the patient's presentation with previously unknown HIV.

The serum titers for Toxoplasma gondii were elevated at 650 IU/mL.

The CD4 count on admission was 4 cells/mm3. HIV serology came back as positive.

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