title: Proposal of a new criterion for electrodiagnosis of meralgia paresthetica by evoked potentials.
abstract: We examined 19 subjects with meralgia paresthetica (bilateral in three cases), recording bilateral somatosensory-evoked potentials (SSEPs) after stimulation of the tibial posterior nerve (TPN) and cutaneous stimulation in the region of the lateral femoral cutaneous nerve (LFCN). We calculated the difference between TPN SSEPs and LFCN SSEPs cortical potentials, identifying a temporal parameter that we termed D(SEP). We defined D(SEP) normal values in a control group. D(SEP) evaluation showed good sensitivity and specificity (85.7% and 82.4%, respectively; accuracy, 83.3%) in discriminating affected limbs from unaffected. The main advantage of this method is to disengage from the necessity of contralateral comparison of LFCN recordings, joined with a reduction of interindividual variability of LFCN SSEPs amplitude and latency that often causes a lower sensitivity of other methods. As an interesting consideration, D(SEP) evaluation appears to mark out a possible subclinical involvement of LFCN in the asymptomatic side of patients with meralgia paresthetica.
authors.affiliation: Neurophysiology Unit, Department of Neurology and Psychiatry, Azienda Ospedaliera Careggi, Florence, Italy. caramellir@ao-careggi.toscana.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Caramelli
authors.forename: Francesca
authors.initials: F
authors.lastname: Del Corso
authors.forename: Vincenza
authors.initials: V
authors.lastname: Schiavone
authors.forename: Selvaggia
authors.initials: S
authors.lastname: Fossi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Cassardo
authors.forename: Francesco
authors.initials: F
authors.lastname: Pinto
authors.forename: Giuseppe
authors.initials: G
authors.lastname: de Scisciolo
mesh_terms: D000328:Adult; D000368:Aged; D004558:Electric Stimulation / Q000379:methods; D004568:Electrodiagnosis / Q000379:methods* / Q000592:standards*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D020428:Femoral Neuropathy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis*; D010292:Paresthesia / Q000175:diagnosis*; D011930:Reaction Time / Q000502:physiology; D012680:Sensitivity and Specificity; D013979:Tibial Nerve / Q000503:physiopathology / Q000528:radiation effects