Neurophysiological evaluation of patients with degenerative diseases of the cervical spine

Abstract

Bacground/Aim. Diagnostic protocol for patients with degenerative diseases of the cervical spine demands, in parallel with neuroimaging methods, functional evaluation through neurophysiological methods (somatosensitive and motor evoked potentials and electromyoneurography) aiming to evaluate possible subclinical affection of spinal medula resulting in neurological signs of long tract abnormalities. Considering diversities of clinical outcomes for these patients, complex diagnostic evaluation provides a prognosis of the disease progression. Methods. The study included 21 patients (48.24 ? 11.01 years of age) with clinical presentation of cervical spondylarthropathy, without neuroradiological signs of myelopathy. For each patient, in addition to conventional neurophysiological tests (somatisensory evoked potentials - SSEP, motor evoked potentials - MEP, electromyoneurography - EMG, nerve conduction studies), we calculated central motor conduction time (CMCTF), as well the same parameter in relation to a different position of the head (maximal anteflexion and retroflexion), so-called dynamic tests. Results. Abnormalities of the peripheral motor neurone by conventional EMNeG was established in 2/3 of the patients, correponding to the findings of root condution time. Prolonged conventional CVMPF were found in 29% of the patients, comparing to 43% CVMPF abnormalities found with the dynamic tests. In addition, the SSEP findings were abnormal in 38% of the patients with degenerative diseases of the cervical spine. Conclusion. An extended neurophysiological protocol of testing corticospinal functions, including dynamic tests of central and periheral motor neurons are relevant for detection of subclinical forms of cervical spondylothic myelopathy, even at early stages. In addition to the conventional neurophysiological tests, we found usefull to include the dynamic motor tests and root conduction time measurement in diagnostic evaluation.Uvod/Cilj. Dijagnosticki protokol bolesnika sa degenerativnim oboljenjima cervikalne kicme zahteva, pored neuroradioloskih metoda morfoloske vizuelizacije (magnetna rezonancija cervikalnog mijelona), dodatnu funkcionalnu procenu nizom neurofizioloskih metoda (somatosenzitivni, motorni evocirani potencijali i elektromioneurografija) u cilju evaluacije mogucnosti supklinickog zahvatanja dugih puteva spinalne medule. Imajuci u vidu raznovrsnost klinickih ishoda ovakva slozena evaluacija obezbedjuje prognozu napredovanja bolesti. Metode. Ispitan je ukupno 21 bolesnik (48,24 ? 11,01 god) sa klinickom prezentacijom cervikalne spondilatropatije, bez pouzdanih neuroradioloskih znakova mijelopatije. Pored konvencionalnih neurofizioloskih testova (somatosenzorni evocirani potencijal - SSEP, motorni evocirani potencijal - MEP, elektromioneurografija - EMNeG) kod svakog bolesnika vrsena je evaluacija centralnog vremena motornog provodjenja (CVMP) u zavisnosti od polozaja glave (dinamicki testovi). Rezultati. Abnromalnosti perifernog motornog neurona kod ovih bolesnika utvrdjene su primenom konvencionalne EMNeG kod 2/3 bolesnika, sto je slicano analizi korenskog vremena provodjenja. Medjutim, u cilju detekcije supklinickih oblika cervikalnih spondilotskih mijelopatija, produzenje CVMP konvencionalnom metodom utvrdjeno je kod 29% bolesnika, dok je primenom dinamickih testova ucestalost ovih abnormalnosti povecana na 43%. Abnormanosti pokazatelja SSEP sa n. medianus za istu grupu ispitanike ispoljila su se kod 38% bolesnika sa cervikalnom spondilozom. Zakljucak. Primena prosirenog protokola neurofizioloskih testova funkcije centralnih i perifernih motornih neurona, ukljucujuci dinamicka testiranja zavisna od polozaja, neposredno uticu na utvrdjivanje supklinickih oblika bolesti vec u najranijim stadijumima. Pored konvencionalnih neurofizioloskih testova u protokol ispitivanja supklinicke cervikalne spondilotske mijelopatije, optimalno je uvrstiti i dinamicke testove transkranijumske magnetne stimulacije, kao i merenje provodljivosti u proksimalnim (korenskim) segmentima perifernih motoneurona.