Is there a pathway in the posterior funiculus that signals visceral pain?

Abstract

The present report provides evidence that axons in the medial part of the posterior column at T10 convey ascending nociceptive signals from pelvic visceral organs. This evidence was obtained from human surgical case studies and histological verification of the lesion in one of these cases, along with neuroanatomical and neurophysiological findings in animal experiments. A restricted lesion in this area can virtually eliminate pelvic pain due to cancer. The results remain excellent even in cases in which somatic structures of the pelvic body wall are involved. Following this procedure, neurological testing reveals no additional neurological deficit. There is no analgesia to pinprick stimuli applied to the body surface, despite the relief of the visceral pain. Since it is reasonable to attribute the favorable results of limited midline myelotomies to the interruption of axons of visceral nociceptive projection neurons in the posterior column, we have performed experiments in rats to test this hypothesis. The results in rats indicate that the dorsal column does indeed include a nociceptive component that signals pelvic visceral pain. The pathway includes neurons of the postsynaptic dorsal column pathway at the L6-S1 segmental level, axons of these neurons in the fasciculus gracilis, and neurons of the nucleus gracilis and the ventral posterolateral nucleus of the thalamus.

Analysis of the Perception of and Reactivity to Pain and Heat in Patients With Wallenberg Syndrome and Severe Spinothalamic Tract Dysfunction

“…Bilateral projections of these systems exist in animals. 28 -30 The lemniscal system may also be involved, because it may take part in visceral nociceptive perception 2,31 ; however, there is no evidence that this pathway plays a role in cutaneous pain. The information processing to the cortex is slow and multisynaptic, as indicated by the delay between the stimulation application and the occurrence of painful sensation.…”

Spinal Cord Stimulation: An Update

“…This was also demonstrated in animal studies, in which dorsal column activity was observed in pelvic visceral nociception. 86 Initially, there was lack of evidence for the application of spinal cord stimulation for visceral and somatic pain, secondary to the belief that nociceptive pain could not be modulated via stimulation. Several initial studies have since demonstrated the benefit of SCS in abdominal visceral disease.…”

Nerve injury-induced tactile allodynia is present in the absence of FOS labeling in retrogradely labeled post-synaptic dorsal column neurons

“…The dorsal column pathway consists of direct afferent projections from large-diameter Aβ fibers and projections from post-synaptic dorsal column (PSDC) neurons Hendry et al 1999;Palecek, 2004;Willis and Coggeshall, 2004). It is well established that the PSDC neurons mediate visceral pain (Al-Chaer et al 1996a,b;Hirshberg et al 1996;Houghton et al 1997;Nauta et al 1997;Houghton et al 2001). For example, the physiologic responses of PSDC neurons to colorectal distension are opioid-sensitive and behavioral responses to noxious visceral stimuli are blocked by lesions of the dorsal columns (Al-Chaer et al 1996a;Houghton et al 2001;Palecek et al 2002).…”