Visual and somotosensory evoked potentials in asymptomatic patients with vitamin B12 deficiency.

OBJECTIVE: Vitamin B12 deficiency may be asymptomatic or present with a wide range of neurological and hematological disorders. Our aim in this study is to evaluate visual (VEP) and somatosensory evoked potential (SEP) parameters in patients with vitamin B12 deficiency who had no clinical evidence of visual impairment or neurological syndrome findings and compare the findings with healthy controls to determine whether there is a correlation between VEP and SEP parameters and serum vitamin B12 levels. PATIENTS AND METHODS: 30 patients (6 females [20%], 24 males [80%]; mean age, 52 years [range 17-80 years]), and 15 healthy subjects with vitamin B12 deficiency (3 females [20%], 12 [80%] male; mean age, 49 years [range 17-78 years]) were included in the study. P100 wave latencies and amplitudes were recorded as VEP parameters, and P40 wave latencies and amplitudes were recorded as tibial SEP parameters. RESULTS: Comparison of VEP and SEP parameters in the patient and control groups revealed significantly prolonged SEP latencies and lower SEP amplitudes in the patient group. VEP latencies did not significantly differ between the patient and the control groups while VEP amplitudes were found to be lower in the patient group than in controls. A significant correlation was obtained between serum vitamin B12 levels and tibial SEP latencies (r > 0.5). CONCLUSIONS: These findings suggest that asymptomatic patients with vitamin B12 deficiency may have SEP and VEP abnormalities indicating the subclinical optic nerve and spinal cord involvement.

Is there a relationship between Parkinson's disease and Chlamydia pneumoniae?

OBJECTIVES: The aim was to investigate a possible relationship between Chlamydia pneumoniae and Parkinson's disease (PD). STUDY DESIGN: Serum samples obtained from a cohort of 51 patients with PD and from 37 age- and sex-matched controls were assessed for the presence of antibodies. The control group was selected from healthy people. In both groups, 5 mL of blood was taken and after centrifugation frozen at -80°C. Presence and concentration for C. pneumoniae IgM and IgG were determined by the enzyme linked immunosorbent assay (ELISA) and immunofluorescence (IFA), using C. pneumoniae IgG and IgM kit (Euroimmun, Germany). RESULTS: Chlamydia pneumoniae IgG was positive in 50 (98%) patients in ELISA study. C. pneumoniae IgG was positive in 34 (92%) control subjects in ELISA study. C. pneumoniae IgG positivity in patients was slightly higher, but the difference did not reach statistical significance (P = 0.17). No statistically significant difference was found between the patient and the control groups in IFA study (P ≥ 0.5). C. pneumoniae IgM results (both ELISA and IFA study) was negative in the both PD group and control group.