RESUMEN
This report describes unique presentations of inclusion body myositis (IBM) in two unrelated patients, one male and one female, with genetically and histologically confirmed fragile X-associated tremor/ataxia syndrome (FXTAS). We summarize overlapping symptoms between two disorders, clinical course, and histopathological analyses of the two patients with FXTAS and sporadic IBM, clinically defined per diagnostic criteria of the European Neuromuscular Centre. In case 1, a post-mortem analysis of available brain and muscle tissues is also described. Histopathological features (rimmed vacuoles) consistent with clinically defined IBM were detected in both presented cases. Postmortem testing in case 1 revealed the presence of an FMR1 premutation allele of 60 CGG repeats in both brain and skeletal muscle samples. Case 2 was a premutation carrier with 71 CGG repeats who had a son with FXS. Given that FXTAS is associated with immune-mediated disorders among premutation carriers, it is likely that the pathogeneses of IBM and FXTAS are linked. This is, to our knowledge, the first report of these two conditions presenting together, which expands our understanding of clinical symptoms and unusual presentations in patients with FXTAS. Following detection of a premutation allele of the FMR1 gene, FXTAS patients with severe muscle pain should be assessed for IBM.
Asunto(s)
Ataxia/complicaciones , Síndrome del Cromosoma X Frágil/complicaciones , Miositis por Cuerpos de Inclusión/complicaciones , Temblor/complicaciones , Anciano , Resultado Fatal , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
We prospectively assessed serum lactate and plasma HIV viral load in 20 patients with stavudine-related nucleoside neuropathy, 10 with HIV-related distal sensory polyneuropathy (DSPN), 20 receiving stavudine but without neuropathy and 23 not receiving stavudine and without neuropathy. Raised serum lactate levels discriminated between stavudine nucleoside neuropathy and DSPN with 90% sensitivity and 90% specificity (P = 0.001). DSPN occurred despite an undetectable viral load, making it a poor discriminator.