| Popis: |
Background & Objectives: Present study was aimed to assess VEP abnormalities in stable COPD patients and correlate the changes with severity of COPD .Methods: Study comprised of 60 healthy adults and 60 stable COPD patients (30-70 years) with no clinical neuropathy or visual impairment. Duration of illness, pack years and spirometric indices (FEV1%, FEV1/FVC, PEFR %) were assessed. Severity of COPD was classified as per WHO GOLD criteria. VEP was recorded using RMS EMG MKII. Latency and amplitude of P100 wave were analysed. Significant abnormality was defined as variations beyond mean ± 3SD from healthy adults. Results: Observations revealed significantly prolonged P100 latency and decreased P100 amplitude bilaterally in COPD patients compared with controls. With increasing severity a trend towards decrease in P100 amplitude was observed in 38% cases, a characteristic feature of axonal loss, in 52% cases axonal loss was associated with demyelination from moderate to very severe grades of COPD. Positive correlation between P100 amplitude and spirometric indices and negative correlation with pack years could be established.Interpretation & conclusion: Observation suggests that hypoxemia of COPD, by inducing changes in arterial blood gases may be implicated for the impairment in visual evoked responses. |
