Somatosensory evoked potentials, electroencephalography and CT scans in the assessment of the neurological sequelae of decompression sickness.

Decompression sickness can lead to neurological complications. Recovery may be studied by somatosensory evoked potentials (SEPs), which are more sensitive than normal methods of neurological examination, and by electroencephalography (EEG). The combination of EEG and SEP may be useful in differentiating among spinal, brainstem and cortical pathology.

The relevance of contralateral recordings and patient disability to assessment of brain-stem auditory evoked potential abnormalities in multiple sclerosis.

Brain-stem auditory evoked responses (BAER) were recorded in a group of 83 patients with a diagnosis of clinically definite or probable multiple sclerosis to assess the relevance of recording contralateral responses simultaneously with ipsilateral responses and to correlate patients disability with the detection of abnormalities. The contralateral responses generally mirrored the ipsilateral responses, but in seven patients the responses differed, mainly involving the presence or absence of wave V. However, contralateral recordings did not contribute significantly to the sensitivity of lesion detection, and their main value was to aid in the recognition of waves when they were not clearly seen in the ipsilateral recordings. The BAER abnormality rates were found to be significantly correlated with disability, and it is suggested that this is an important variable to consider when undertaking or comparing results of BAER studies in patients with multiple sclerosis.

Short-latency somatosensory-evoked potentials from radial, median, ulnar, and peroneal nerve stimulation in the assessment of cervical spondylosis. Comparison with conventional electromyography.

A study of data on 30 patients with cervical spondylosis was carried out to determine whether short-latency somatosensory-evoked responses (SEPs) to median, ulnar, radial, and peroneal nerve stimulation provided additional information to that obtained by electromyography (EMG), late responses, and peripheral conduction studies. Peripheral studies, EMG results and SEPs were within normal limits in ten patients with pain, but without objective neurological deficit. By contrast, of ten patients who had objective signs of root compression, conventional EMG results were normal in nine, but abnormalities of the SEPs from radial nerve stimulation were obtained in only five patients, and were normal from ulnar and median nerve stimulation. In ten patients with clinical features of myelopathy, seven had abnormal median SEPs and all had abnormal peroneal SEPs, whereas EMG results were abnormal in only five patients. It is suggested that SEPs and EMG are both of limited use in patients with only symptoms of root compression. In patients with signs of root compression, EMG is the most sensitive procedure; however, some additional information can be obtained from superficial radial SEPs. In patients with cervical myelopathy, SEP was the most useful procedure, especially when upper and lower limbs were studied.