The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform

Shannon Roe - One of the best experts on this subject based on the ideXlab platform.

  • effect of intravenous Sodium Amytal on cutaneous sensory abnormalities spontaneous pain and algometric pain pressure thresholds in neuropathic pain patients a placebo controlled study ii
    Pain, 1997
    Co-Authors: Angela Mailis, Neda Amani, Margarita Umana, Roshan Basur, Shannon Roe
    Abstract:

    This study investigated the behaviour exhibited by 17 neuropathic pain patients (almost half of whom had documented neurological injury) with diffuse pain and extraterritorial sensory, sudomotor and vasomotor abnormalities, under the influence of intravenous administration of saline-controlled Sodium Amytal (SA), a medium action barbiturate. After SA (but not after normal saline) infusion, there was a dramatic and selective reduction of allodynia (touch-evoked pain) in all patients displaying this phenomenon, while pin prick and cold hypo- or hyperalgesia, as well as algometric pressure thresholds of the symptomatic limb (as a measurement of deep pain) were minimally changed in most patients. Spontaneous subjective pain was reduced substantially but not totally. The patients were able (once allodynia was eliminated) to recognize a deep-seated pain of which they were unaware before, evoked by firm but gentle palpation of the limb. Sympathetic blocks and A-fibre ischemic blocks in several patients and spinal stimulation in one patient produced effects identical to those observed during SA administration. The deep pain component was maintained despite elimination of allodynia even under stages of sleep induced by SA, at which time the patients would withdraw only the symptomatic limb upon firm but gentle palpation. We argue that neuropathic pain patients have two separate pain components, a cutaneous one (touch-evoked pain or allodynia) mediated by large fibres as a product of central sensitization, and a deep pain component mediated via nociceptors, which can be easily discriminated during systemic administration of SA.

  • effect of intravenous Sodium Amytal on cutaneous limb temperatures and sympathetic skin responses in normal subjects and pain patients with and without complex regional pain syndromes type i and ii i
    Pain, 1997
    Co-Authors: Angela Mailis, Perola Plapler, P Ashby, Roy Shoichet, Shannon Roe
    Abstract:

    This study examined the effects of intravenous administration of Sodium Amytal (SA), a medium action barbiturate, on cutaneous limb temperatures and sympathetic skin responses (SSR) to electrical stimulation. Eight normal volunteers and 13 patients with musculoskeletal pain, somatoform pain disorders or nerve/root injury (with findings strictly limited to the distribution of the involved nerve) were compared to 15 patients with Complex Regional Pain Syndromes (one of whom had documented nerve injury). The Complex Regional Pain Syndromes (CRPS) patients were characterized by the presence of severe diffuse limb pain and extraterritorial sensory, sudomotor and vasomotor abnormalities (i.e., not confined to the site of injury or the distribution of the injured nerve). The CRPS patients were different from the normal controls and the non-CRPS patients in their tendency to warm significantly many of their limbs (not just the symptomatic ones). SSR were reduced or lost in a few limbs only in all three groups, irrespective of the increase or decrease of limb temperature and the side of symptoms. We argue that the enhanced thermogenic effect of SA in CRPS patients is due to generalized central changes of thermoregulatory control specifically in this group.

Todd A. Abruzzo - One of the best experts on this subject based on the ideXlab platform.

  • Diagnostic Cerebral Angiography and the Wada Test in Pediatric Patients
    Techniques in Vascular and Interventional Radiology, 2011
    Co-Authors: Manraj K.s. Heran, Todd A. Abruzzo
    Abstract:

    Pediatric cerebral angiography is a commonly performed procedure and its performance has many similarities to the technique used in adults. However, some notable differences exist, especially in the nuances of arterial access, catheter manipulation, patient sedation, and fluid/radiocontrast load. A thorough understanding of cerebral angiography and its application to pediatric patients is imperative to ensure appropriate selection of patients requiring cerebral angiography and to minimize risk while obtaining the desired information. The intracarotid Sodium Amytal injection (Wada) test is a specialized procedure performed in the workup of patients with seizure disorders who are being considered for surgical resective therapy. However, Wada testing in children poses unique challenges, as will be discussed in this paper. Specific aspects of performing the Wada test in the pediatric setting, anatomic considerations and contraindications, and the relevance of the Wada test in comparison with noninvasive tools, such as functional magnetic resonance imaging, will be discussed.

Angela Mailis - One of the best experts on this subject based on the ideXlab platform.

  • effect of intravenous Sodium Amytal on cutaneous sensory abnormalities spontaneous pain and algometric pain pressure thresholds in neuropathic pain patients a placebo controlled study ii
    Pain, 1997
    Co-Authors: Angela Mailis, Neda Amani, Margarita Umana, Roshan Basur, Shannon Roe
    Abstract:

    This study investigated the behaviour exhibited by 17 neuropathic pain patients (almost half of whom had documented neurological injury) with diffuse pain and extraterritorial sensory, sudomotor and vasomotor abnormalities, under the influence of intravenous administration of saline-controlled Sodium Amytal (SA), a medium action barbiturate. After SA (but not after normal saline) infusion, there was a dramatic and selective reduction of allodynia (touch-evoked pain) in all patients displaying this phenomenon, while pin prick and cold hypo- or hyperalgesia, as well as algometric pressure thresholds of the symptomatic limb (as a measurement of deep pain) were minimally changed in most patients. Spontaneous subjective pain was reduced substantially but not totally. The patients were able (once allodynia was eliminated) to recognize a deep-seated pain of which they were unaware before, evoked by firm but gentle palpation of the limb. Sympathetic blocks and A-fibre ischemic blocks in several patients and spinal stimulation in one patient produced effects identical to those observed during SA administration. The deep pain component was maintained despite elimination of allodynia even under stages of sleep induced by SA, at which time the patients would withdraw only the symptomatic limb upon firm but gentle palpation. We argue that neuropathic pain patients have two separate pain components, a cutaneous one (touch-evoked pain or allodynia) mediated by large fibres as a product of central sensitization, and a deep pain component mediated via nociceptors, which can be easily discriminated during systemic administration of SA.

  • effect of intravenous Sodium Amytal on cutaneous limb temperatures and sympathetic skin responses in normal subjects and pain patients with and without complex regional pain syndromes type i and ii i
    Pain, 1997
    Co-Authors: Angela Mailis, Perola Plapler, P Ashby, Roy Shoichet, Shannon Roe
    Abstract:

    This study examined the effects of intravenous administration of Sodium Amytal (SA), a medium action barbiturate, on cutaneous limb temperatures and sympathetic skin responses (SSR) to electrical stimulation. Eight normal volunteers and 13 patients with musculoskeletal pain, somatoform pain disorders or nerve/root injury (with findings strictly limited to the distribution of the involved nerve) were compared to 15 patients with Complex Regional Pain Syndromes (one of whom had documented nerve injury). The Complex Regional Pain Syndromes (CRPS) patients were characterized by the presence of severe diffuse limb pain and extraterritorial sensory, sudomotor and vasomotor abnormalities (i.e., not confined to the site of injury or the distribution of the injured nerve). The CRPS patients were different from the normal controls and the non-CRPS patients in their tendency to warm significantly many of their limbs (not just the symptomatic ones). SSR were reduced or lost in a few limbs only in all three groups, irrespective of the increase or decrease of limb temperature and the side of symptoms. We argue that the enhanced thermogenic effect of SA in CRPS patients is due to generalized central changes of thermoregulatory control specifically in this group.

Robin G Morris - One of the best experts on this subject based on the ideXlab platform.

  • episodic memory dysfunction during Sodium Amytal testing of epileptic patients in relation to posterior cerebral artery perfusion
    Journal of Clinical and Experimental Neuropsychology, 1996
    Co-Authors: Nick Morton, C E Polkey, T C S Cox, Robin G Morris
    Abstract:

    The effect of filling of the posterior cerebral artery (PCA) on memory performance during the intracarotid Sodium Amytal test (IAP) was investigated in 57 patients with unilateral temporal epileptic seizure foci under consideration for surgical therapy. Memory functioning was tested following injection of the internal carotid artery contralateral and ipsilateral to the side of seizure focus. In both cases, patients with PCA filling observed using conventional angiography showed a greater memory deficit, although this effect was more robust with contralateral injections. In a subsample of patients with left hemisphere dominance for language, the effect of PCA filling on memory performance was only significant when the right hemisphere was injected. The implications of these findings are discussed in terms of the validity of the IAP test and the different factors that need to be taken into account when interpreting IAP memory performance.

C E Polkey - One of the best experts on this subject based on the ideXlab platform.

  • independent recovery of memory and language functioning during the intracarotid Sodium Amytal test
    Journal of Clinical and Experimental Neuropsychology, 1998
    Co-Authors: R G Morris, C E Polkey, Timothy T Cox
    Abstract:

    Memory and language recovery during the Intracarotid Sodium Amytal Test (IAP) was investigated in 49 left-hemisphere-dominant patients with unilateral temporal epileptic seizure foci. Memory was assessed by presenting items (words, objects, and faces) immediately after injection, and testing for recognition memory 10 min after motoric recovery. To assess language the patients responded verbally to the same items during memory presentation. Memory for the individual items was found to be independent of their presentation order and language functioning was impaired only with the dominant-hemisphere injection, recovering during the presentation of the memory items. These results suggest that the encoding of material remains at a constant level throughout the initial active phase of the IAP, whereas language functioning recovers independently.

  • episodic memory dysfunction during Sodium Amytal testing of epileptic patients in relation to posterior cerebral artery perfusion
    Journal of Clinical and Experimental Neuropsychology, 1996
    Co-Authors: Nick Morton, C E Polkey, T C S Cox, Robin G Morris
    Abstract:

    The effect of filling of the posterior cerebral artery (PCA) on memory performance during the intracarotid Sodium Amytal test (IAP) was investigated in 57 patients with unilateral temporal epileptic seizure foci under consideration for surgical therapy. Memory functioning was tested following injection of the internal carotid artery contralateral and ipsilateral to the side of seizure focus. In both cases, patients with PCA filling observed using conventional angiography showed a greater memory deficit, although this effect was more robust with contralateral injections. In a subsample of patients with left hemisphere dominance for language, the effect of PCA filling on memory performance was only significant when the right hemisphere was injected. The implications of these findings are discussed in terms of the validity of the IAP test and the different factors that need to be taken into account when interpreting IAP memory performance.