Pseudobulbar syndrome in two patients with human immunodeficiency virus infection

Different forms of motor neuron disease occurring in association with HIV infection have been described. We present two patients with pseudobulbar syndrome and HIV infection, with no clinical or electromyographic signs of lower motor neuron loss. In patient 1, on follow-up, focal seizures led to additional investigations that identified unsuspected HIV infection and progressive multifocal leucoencephalopathy (PML). In patient 2, all investigations excluded an active HIV infection or central nervous system involvement, and the disease progression made primary lateral sclerosis (PLS) with pseudobulbar onset the most likely diagnosis. ALS-like syndrome can occur in association with HIV infection; however, the causal relationship remains uncertain. Patient 1 shows that PML is a possible cause for pseudobulbar syndrome, and our second patient demonstrates that ALS may also occur by chance in patients with HIV infection.