Somatosensory evoked potential studies can be used as a supplementary test for the diagnosis of lumbosacral stenosis, with the dermatomal studies being more valuable expressing multiple root abnormalities. S1 dermatomal wave latency has the highest diagnostic value, followed by L5, N25, and then L4 latencies.

Background: Schizophrenia is a psychiatric disorder characterized by multiple symptoms such as positive symptoms, negative symptoms, and cognitive symptoms. Cognitive deficit can be detected with specific neurophysiological tests. Among these tests are the measurements of auditory P300 event-related potential which is a neurophysiological method that allows the examination of cognitive functioning of the human brain. Objective: The aim of this article is to assess cognitive deficits in chronic schizophrenia patients by studying the amplitude and latency of P300 potential and to compare findings with those from control subjects. Materials and Methods: The present study was a case–control study extended from January 2020 to May 2020. Forty subjects were enrolled in this study: 20 patients aged 20–50 years comprising 11 males and 9 females diagnosed with schizophrenia and 20 apparently healthy volunteers comprising 11 males and 9 females were analyzed. Results: The results of the current study revealed that a highly significant difference was found in the years of education between patients and controls (P-value <0.001) with no significant difference to be noticed regarding age or gender. When analyzing the P300 component with an unpaired t-test, the patient group showed delayed latency and smaller P300 amplitude than the control group (P<0.001). Conclusion: The present study concludes that P300 indices could be valuable biomarkers to assess changes in cognitive functioning of patients with schizophrenia.