Recordings of abnormal activity in patients with deafferentation and central pain.

We have performed a single-unit analysis of the spontaneous activity of cells in 9 patients with central and deafferentation pain and 4 patients without pain. These studies have concentrated on the analysis of cells firing in bursts, which are particularly prevalent in pain patients. These cells were found to fire typically at interspike intervals of 1-2 ms and interburst intervals of 50 ms. Such cells occurred throughout nucleus ventralis caudalis, nucleus ventrocaudalis parvocellularis and possibly nucleus ventralis intermedius and are different in terms of firing characteristics and locations from bursting cells found in non-pain patients.