Chronic neuropathic pain in spinal cord injury patients: What relevant additional clinical exams should be performed?

AbstractObjectiveStudy the indications and level of evidence of clinical exams that might be relevant in exploring the causes of neuropathic pain in spinal cord injury patients.MethodLiterature review from three databases: PubMed, Embase, Pascal.ResultsDisparity and heterogeneity of the answers given by the attendees to the experts conference of the French Society of Physical Medicine and Rehabilitation (SOFMER) and the physicians surveyed via the SOFMER website. These results corroborate the shortage of available data on this topic in the literature. From this analysis, we can however validate spinal MRI imaging as a mandatory exam for the diagnosis of post-traumatic syringomyelia (cystic myelopathy) – this exam can even be considered a Gold Standard. Furthermore, we can also recommend using electrodiagnostic studies for compressive neuropathies. However, it is not possible to validate the relevance of additional clinical exams for radicular pain, segmental deafferentation pain, central deafferentation pain as well as Complex Regional Pain Syndrome (CRPS) type 1; for these types of pain we can only formulate experts recommendations in light of the dearth of available data on the subject.ConclusionFor the neuropathic pain of spinal cord injury patients’ additional clinical exams should be used in the framework of an etiological diagnosis

How the vestibular system modulates tactile perception in normal subjects: a behavioural and physiological study

Caloric vestibular stimulation (CVS) is a physiological technique demonstrated to transiently improve hemianaesthesia in right brain-damaged patients (Bottini et al. in Exp Brain Res 99(1):164–169, 1994, Nature 376:778–781, 1995, Neurology 65(8):1278–1283, 2005). Recent studies suggest that these effects are based on the anatomical overlapping between vestibular and tactile projections (Bottini et al. in Nature 376:778–781, 1995) in the human brain. However, much less is known about behavioural effects of this manipulation on normal subjects. We aimed to explore tactile perception during left ear CVS in normal subjects. We administered seventeen right-handed normal subjects with different types of tactile stimuli (above and below threshold) during left ear CVS. To further ensure standardized procedure, tactile stimulation was delivered through a tool-developed ad hoc for the experiment. The experiment was divided in 3 conditions: (1) Baseline, (2) PostCVS and (3) Delayed CVS. We found a main effect of stimulus type (F (2,32) = 907.712; P = 0.000) and condition (F (2,32) = 55.505; P = 0.000). Moreover, post hoc comparisons revealed that below threshold stimuli are most affected by CVS (t (16) = −11.213; P = 0.000). Left ear CVS modulates tactile perception also in normal subjects. Moreover, this modulation seems to be selective for below threshold stimuli and not caused by attentive processes. A multisensory phenomenon is possibly the best explanation for this interaction between touch and vestibular systems, corroborated also by the anatomical evidence and by the previous knowledge about interaction with the environment