Somatosensory evoked potential (SEP) studies were performed in 14 patients with peripheral vascular disease who received epidural spinal cord stimulation (SCS) for chronic pain relief of the lower limbs. Signals were amplified and filtered between 20-2000 Hz and 200-2000 Hz to better identify activities in the high frequency range. In 7 patients bit-colour maps were also computed. In all the patients a homogeneous short-latency scalp evoked potential with a prevalent diphasic shape (P1-N1) was recorded. In all our scalp records, even with the wide bandpass, small short-latency positive deflections were observed on the descending front of the first major positive wave and they were better defined as a series of up to 6 wavelets, preceding the major negative scalp wave in the tracings filtered through the narrow bandpass. They appeared in an interval ranging from 5.5 to 15.6 msec. Bit-colour maps showed consistent positive fields, with a maximum at the vertex, starting mainly at about 5.5 msec; in 3 patients, a prominent positivity between 8.5 and 10.5 msec was recorded followed by smaller components preceding the major positive-negative (P1-N1) complex. More synchronous volleys during direct SCS produced clear short-latency SEPs. Although they were of larger amplitude, we regarded them as corresponding to those described by previous authors obtained by stimulation of nerves of the lower limbs, and probably arising from subcortical structures.

Peripheral arterial disease (PAD) patients are commonly classified on the basis of subjective evaluations of pain and fatigue. Surface electromyography (EMG) is an objective method for studying peripheral muscle fatigue. Fifteen patients with PAD and 15 healthy volunteers matched for age and sex were studied. Surface EMG was recorded over the medial gastrocnemius during 100 seconds at 60% of maximal effort. EMG traces were analyzed off-line to obtain the power spectrum. The median frequency was calculated in the first 30 seconds (T0) and between 70 and 100 seconds (T1). Significantly lower T1 values, compared with T0, were found in both the PAD and the control groups (p < .005; p < .05). T0 values were not different between group, whereas T1 values were significantly lower in PAD patients (p < .01). EMG frequency analysis can be considered an easy, painless method providing objective information on muscular performance and fatigue in PAD patients.

Clinical evaluation of patients with peripheral arterial disease (PAD) is mainly based on Fontaine's classification, in which pain is the most important element. The use of objective techniques can allow a more precise evaluation, since pain is always subjective. In PAD patients, pain is frequently associated with early fatigue. Peripheral muscle fatigue can be easily assessed by a particular electromyographical method, based on the frequency analysis of the signal. In PAD patients, this method can provide objective information on muscular performance, with possible uses in medicine, surgery, rehabilitation and occupational medicine.

On the base of a study performed on 34 patients who underwent an amputation since 1981 to 1987, we evaluated the incidence of postamputation syndromes such as phantom limb, phantom pain, stump pain analyzing their variations during 6 years. The patients were divided in 6 groups according to the time gone by from the date of operation. The results reveals a not significant decrease of incidence of postamputation syndromes even though their frequency and intensity show a relative improvement.