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A 59-year-old woman with a background of HIV living with an uncontrollable movement disorder presented to Eoghan Donlon, MB, BCh BAO, MRCPI, of the Mater Misericordiae University Hospital in Dublin, Ireland, and colleagues.

Of note, the symptoms occurring on the left side of her body were very different than those on her right side, the team reported in .

They learned that the patient had been diagnosed with cerebral toxoplasmosis 18 months previously, shortly after the movement disorder first developed. At that time, she received antimicrobial treatment, but that had been largely ineffective.

On examination, Donlon and team observed cogwheel rigidity affecting her right upper limb, which moved very slowly, with tremor at rest. When clinicians assessed her gait, they noted reduced swing of her right arm. "In contrast, there were prominent hyperkinetic movements of the left side of her body with dystonic posturing of the left upper and lower limb and choreiform movements," they wrote.

The patient underwent a brain MRI with contrast that revealed several ring-enhancing lesions located in the right thalamus, left lentiform nucleus, right frontal lobe, and right posterior-temporal lobe.

Cerebrospinal fluid (CSF) analysis returned normal findings, with no evidence of HIV-1 and HIV-2. On blood tests, HIV viral load was undetectable; she had a CD4 count of 174. Neither serum nor CSF tests detected Toxoplasma DNA.

Donlon and colleagues performed a CT scan of the patient's brain and compared the findings to a scan from 18 months before. Evidence of increased calcification of all lesions suggested the diagnosis of chronic toxoplasmosis. The team considered that the hemiparkinsonism affecting the patient's right side was due to the lesion in the left lentiform nucleus, and the hemidystonia of her left limbs was caused by the lesion in the right thalamus.

They recommended a short trial of risperidone 0.5 mg daily; however, the patient experienced adverse effects of flattened mood and orobuccal dyskinesia, and declined to continue with treatment.

Discussion

Opportunistic infection with cerebral toxoplasmosis is not uncommon in patients with HIV, and as this case demonstrates, may be associated with movement disorders.

During the HIV epidemic, suggested that 2% to 3% of patients with HIV were affected by movement disorders, particularly parkinsonism and tremor, Donlon and team said. However, they cautioned that use of neuroleptic medications to manage neuropsychiatric complications may have a confounding effect.

Of hyperkinetic movement disorders that may be associated with HIV infection, hemiballismus and hemichorea are reported most commonly, especially in the setting of toxoplasmosis, since it frequently involves the basal ganglia structures, the group noted.

"The presence of hemichorea-hemiballism in patients with AIDS is felt to be pathognomonic of cerebral toxoplasmosis," they wrote.

A found that the rates of the various manifestations of movement disorders associated with toxoplasmosis were:

• Chorea: 44%
• Ataxia: 20%
• Parkinsonism: 16%
• Tremor: 14%
• Dystonia: 14%
• Myoclonus: 2%
• Akathisia: 2%

There is scarce evidence regarding response to treatment of toxoplasmosis, Donlon and team said. As in this patient's case, treatment may improve symptoms but not necessarily resolve them.

In three of the 64 cases that reported treatment outcomes, "response to levodopa was mild to absent." And while treating the infection tends to improve chorea, "there are few reports of response to symptomatic treatment (apart from 1 report of partial response to tetrabenazine)," the authors wrote.

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