Main lesions in the central nervous system of dogs due to Leishmania infantum infection.

BACKGROUND: Canine visceral leishmaniasis (CVL) is endemic in São Luís Maranhão/Brazil and it leads a varied clinical picture, including neurological signs. RESULTS: Histopathological evaluation showed that 14 dogs exhibited pathological alterations in at least one of the analyzed areas. Of these, mononuclear inflammatory reaction was the most frequent, although other lesions, such as hemorrhage, chromatolysis and gliosis were also observed. The presence of L. infantum amastigotes was confirmed in eight dogs, identified in four regions: telencephalon, hippocampus, thalamus and caudal colliculus, but only one presented neurological signs. Polymerase chain reaction results detected the DNA of the parasite in 11 samples from seven dogs. The positive areas were the telencephalon, thalamus, hippocampus, cerebellum, caudal and rostral colliculus. CONCLUSION: These results reveal that during canine visceral leishmaniasis, the central nervous system may display some alterations, without necessarily exhibiting clinical neurological manifestations. In addition, the L. infantum parasite has the ability to cross the blood brain barrier and penetrate the central nervous system.

Neurocysticercosis presenting as a vertical one-and-a-half syndrome with associated contralesional horizontal gaze paresis.

We describe a patient presenting with vertical one-and-a-half syndrome and concomitant contralesional horizontal gaze paresis as the result of a solitary neurocysticercosis (NCC) lesion in the right midbrain extending into the thalamomesencephalic junction. The patient received an albendazole-dexamethasone course which resulted in resolution of his symptoms. The neuro-ophthalmological complications of NCC are reviewed and the clinical topography of the neuro-ophthalmological findings of this unusual observation are discussed.

Neurocysticercosis-induced hemiballismus in a child.

Neurocysticercosis lesions can occur in the basal ganglia, but most of these are clinically silent. Neurocysticercosis manifesting as movement disorders is extremely uncommon. The authors report a case of neurocysticercosis in an 11-year-old girl presenting with right hemiballismus (a clinical manifestation not yet reported). Magnetic resonance imaging of the brain confirmed the solitary neurocysticercosis lesion in the left thalamus. The child was symptomatic for 5 years and improved dramatically within 2 days of starting definitive therapy for neurocysticercosis (albendazole and prednisolone).

Unusual cause of dementia in an immunocompetent host: toxoplasmic encephalitis.

A 69-year-old male was presented with a 2-month history of cognitive decline. The most profound deficit was observed in short-term verbal and visual memory and recognition. He was otherwise healthy, apart from atrial fibrillation diagnosed 5 months before. Brain MRI revealed T2 hyperintensities in the left thalamus, right pulvinar thalami, both putamina and right head of caudate nucleus without diffusion restriction on DWI sequences. CSF examination revealed elevated proteins. He was HIV negative. The course of the disease was complicated with gram negative sepsis and the patient died 14 days later. Autopsy revealed the brain lesions to have been caused by toxoplasmic encephalitis. Toxoplasmic encephalitis is an extremely rare cause of rapidly progressive dementia in immunocompetent patients. In patients with multiple lesions, hyperintense on T2 and hypointense on T1 weighted sequences, without diffusion restriction and some expansive effect, infectious causes should be considered, even in the absence of classical signs of infectious diseases and CSF pleocythosis.

Rapidly progressive frontal-type dementia associated with Lyme disease.

The authors report a case of fatal neuropsychiatric Lyme disease (LD) that was expressed clinically by progressive frontal lobe dementia and pathologically by severe subcortical degeneration. Antibiotic treatment resulted in transient improvement, but the patient relapsed after the antibiotics were discontinued. LD must be considered even in cases with purely psychiatric presentation, and prolonged antibiotic therapy may be necessary.

Nasitrema sp.-associated encephalitis in a striped dolphin (Stenella coeruleoalba) stranded in the Gulf of Mexico.

An immature female striped dolphin (Stenella coeruleoalba) found dead on a northwestern Florida beach in 1988 exhibited severe inflammation bilaterally in the dorsal and mid-thalamus in association with adult trematodes (Nasitrema sp.) and trematode eggs. Numerous specimens of Nasitrema sp. also were present in the pterygoid sinuses. Pneumonia in association with a heavy growth of Vibrio damsela was observed also. This report confirms the occurrence of Nasitrema sp.-associated encephalitis in striped dolphins and in small cetaceans from the Gulf of Mexico.