Ulm, Univ., Diss., 2008.

Thesis (doctoral)--Uppsala University, 1983. / Includes bibliographical references (p. 19-21).

<p>It is known that there is an intraindividual amplitude variation in motor electroneurography when the same person is examined at different times. This variation affects the evaluation the status of the patient. The aim of this study was to investigate if the intraindividual amplitude variation decreased by photographing the electrode position, that later is used in the follow-up study. Twenty test persons were examined by four laboratory scientists. The nerves that were examined were median, ulnar, peroneal and tibial nerve. At the first examination the laboratory scientists used method guidelines and took photographs of the electrode position. The photographs were then used in the follow-up. The results showed that there was an indication of decreased of the intraindividual amplitude variation when photographic documentation was used instead of method guidelines.</p>

It is known that there is an intraindividual amplitude variation in motor electroneurography when the same person is examined at different times. This variation affects the evaluation the status of the patient. The aim of this study was to investigate if the intraindividual amplitude variation decreased by photographing the electrode position, that later is used in the follow-up study. Twenty test persons were examined by four laboratory scientists. The nerves that were examined were median, ulnar, peroneal and tibial nerve. At the first examination the laboratory scientists used method guidelines and took photographs of the electrode position. The photographs were then used in the follow-up. The results showed that there was an indication of decreased of the intraindividual amplitude variation when photographic documentation was used instead of method guidelines.

Elektroneurografi är en undersökningsmetod som används för att undersöka nervledingskapaciteten i perifera nerver. Det är en metod som ofta används på sjukhuskliniker vid diagnostisering av perifera nervsjukdomar. Syftet med studien är att undersöka om det finns en signifikant skillnad i motorisk och sensorisk nervledningshastighet, amplitud och F-respons mellan dominant och icke-dominant hand. I studien undersöktes det även om en korrelation finns mellan handgreppsstyrka och svarsamplitud från motorisk elektroneurografi.  I studien deltog 26 testpersoner från biomedicinska analytikerprogrammet i termin 6. Testpersonernas genomsnittsålder är 24 år (range 21-32 år), och testpersonernas kroppslängd är i genomsnitt 169 cm (range 155- 185). Elektroneurografi utfördes motoriskt och sensoriskt på nervus medianus bilateralt. Handgreppsstyrka undersöktes bilateralt med Jamar Hydraulic Hand dynamometer. För samtliga mätvariabler bestämdes signifikantnivån till α=0,05.  Resultatet visar att det finns en signifikant skillnad i sensorisk nervledningshastighet, motorisk amplitud och sensorisk amplitud mellan dominant och icke-dominant hand. Sensorisk nervledningshastighet är högre i icke-dominant hand, medan motorisk och sensorisk amplitud är högre i dominant hand. Däremot kan inte en signifikant skillnad påvisas i motorisk nervledningshastighet, FM-latens samt antalet F-svar mellan dominant och icke-dominant hand. Resultatet visar att det inte finns någon korrelation mellan handgreppsstyrka och amplitud i motorisk elektroneurografi. I dag används samma referensvärden för dominant och icke-dominant hand. Den här studien visar att det kan finnas ett värde i att utforma referensintervall som baseras på handdominans. / Electroneurography is an examination method used for examining the nerve conduction capacity of the peripheral nerve. The method is often used in hospitals in the diagnosis of peripheral nerve injuries. The aim of this study is to examine if there is a significant difference in motor and sensory nerve conduction velocity, amplitude, and F-response between dominant and non-dominant hands. The correlation between hand grip strength and the amplitude in motor electroneurography was also examined in this study.  The study involved 26 students from Biomedical Scientist Programme term 6. The average age of the participants is 24 years (range 21-32 years), and the participants body length is on average 169 cm (range 155-185 cm). Electroneurography was performed on the median nerve bilaterally. Hand grip strength was examined bilaterally with Jamar Hydraulic Hand dynamometer. For all measurement variables, the significant level was determined to α=0,05.  The result shows that there is a significant difference in sensory nerve conduction velocity, motor amplitude, and sensory amplitude between dominant and non-dominant hands. Sensory nerve conduction velocity is higher in non-dominant hand, while motor and sensory amplitude is higher in dominant hand. However, a significant difference cannot be detected in motor nerve conduction velocity, FM-latency, and the number of F-responses between dominant and non-dominant hands. The result shows no correlation between hand grip strength and the amplitude in motor electroneurography.  Today, the same reference values are used for dominant and non-dominant hands. This study shows that there may be a value in creating reference intervals based on hand dominance.

Median Nerve Ultrasonography Examination Correlates for the Diagnosis of Moderate to Severe Carpal Tunnel Syndrome Objective: The aim of the study was to investigate the associations of cross-sectional area (CSA) of the median nerve measured by ultrasonography (US), the median to ulnar nerve ratio (MUR), the median to ulnar nerve difference (MUD) and the ratio of CSA of the median nerve to height squared (MHS) in relation to electrodiagnostic classification of moderate and severe carpal tunnel syndrome (CTS) and thus to identify patients suitable for surgical treatment. Materials and Methods: A prospective study was conducted in patients aged ≥ 18 years who underwent both median and ulnar nerve US and electrodiagnostic studies (EDS). 124 wrists of 62 patients were examined. The patients' characteristics were acquired through a questionnaire. CTS was diagnosed using EDS and classified according to the guidelines of the Czech Republic Association of Electrodiagnostic Medicine. The CSA of the median nerve and of the ulnar nerve were measured at the carpal tunnel inlet, i.e. at the level of the pisiform bone. Results: The median nerve swells at the wrist in CTS. Median nerve CSA at the tunnel inlet ≥ 12mm2 correlates with electrodiagnostic classification of moderate to severe carpal tunnel syndrome. At...

Introduktion: Vid perifera nervundersökningar med elektroneurografi spelar temperaturen i vävnaden som undersöks stor roll. Kall vävnad leder till försämrad funktion i nervernas jonkanaler, vilket leder till att aktionspotentialer utlöses långsammare och nervledningshastigheten minskar vilket därmed kan ge falskt patologiska undersökningsresultat. För att minska den risken mäts och korrigeras alltid hudtemperaturen. Vid registrering från övre extremiteter mäts hudtemperaturen standardmässigt på handryggen. Trots att stimulering sker från handflatan och från fingrar så mäts inte temperaturen där. Syftet med studien är därför att undersöka om kalla fingrar på en i övrigt varm hand påverkar conduction velocity och peaklatenstiden, jämfört med när hand och fingrar har samma varma temperatur. Metod: 30 unga, friska personer deltog i studien. Ortodrom elektroneurografiundersökning utfördes på nervus medianus sensoriska del. Handryggstemperaturen var konstant 32° Celsius (C) och fingertoppstemperaturerna var 32° C, 27° C respektive 22° C. Vid varje fingertoppstemperatur registrerades conduction velocity och peaklatenstiden vid stimuleringar från handflatan, fingerbasen och fingertoppen på digitorum III. Resultat: En statistiskt signifikant skillnad fanns i både nervledningshastigheten och peaklatenstiden vid registrering från fingerbasen vid fingertoppstemperaturen 32° C jämfört med såväl 27° C som 22° C. Slutsats: Kalla fingrar på en varm hand ger en statistiskt signifikant påverkan på både nervledningshastigheten och peaklatenstiden. / Background: In peripheral nerve examinations with electroneurography, temperatures in the tissue that is being examined is important. Cold tissue leads to impaired function of the ion channels of the nerves, which causes action potentials to be triggered more slowly and the nerve conduction velocity to decrease, which can cause false pathological examination results. To reduce this risk, the skin temperature is always measured and corrected. When registering from the upper extremities, the skin temperature is measured by default on the back of the hand. Despite stimulating in the palm and on the fingers, the temperature is not measured there. The purpose of the study is to investigate whether cold fingers on a warm hand affects the conduction velocity and peak latency time, compared with the hand and the fingers having the same warm temperature. Methods: 30 young, healthy persons participated in the study. An orthodrome electroneurography examination was performed on the sensory part of the median nerve. The backhand temperature was constant 32° Celsius (C) and the fingertip temperatures were 32 ° C, 27 ° C and 22 ° C. Results: A statistically significant difference was found in both nerve conduction velocity and peak latency time when registering from the finger base with fingertip temperature 32 ° C compared with both 27 ° C and 22 ° C Conclusions: Cold fingers on a warm hand give a statistically significant effect on both the nerve conduction velocity and the peak latency time.

Bakgrund: Det perifera nervsystemets axon utgår från cellkroppar i ryggmärg eller hjärna och går ut till kroppens perifera delar. Det perifera nervsystemet undersöks med hjälp av elektroneurografi. Elektroneurografi kan utföras antingen antidromt, där mätningen sker i motsatt riktning till nervimpulsens naturliga, eller ortodromt, där nervimpulsmätningen sker i nervens naturliga riktning. Vid elektroneurografi används den nervledningshastighet, amplitud och kurvformation som undersökningen resulterar i för att sätta en diagnos. Studien syftade till att undersöka om det förelåg signifikant sensorisk amplitudskillnad beroende på om antidrom eller ortodrom elektroneurografi användes genom att undersöka nervus medianus och nervus ulnaris, detta för att bedöma om den metod som använts vid framtagandet av referensvärdena har betydelse.  Material &amp; Metod: 33 neurologiskt friska testindivider i åldrarna 18–80 år deltog i studien. Nerverna stimulerades i handledsnivå och registrering gjordes i fingrarna vid ortodrom elektroneurografi, det omvända gjordes vid antidrom elektroneurografi. Parat t- test användes. Signifikansnivån (α) sattes till 0,05 och normalfördelning ansågs föreligga då median och medelvärde hade en differens på ≤5. Resultat: Det fanns en signifikant amplitudskillnad mellan de båda metoderna vid samtliga mätningar.  Diskussion: Referensvärdena bör baseras på samma metod som kliniken använder för att undvika felaktiga positiva eller negativa diagnoser. / Background: The peripheral nervous system (PNS) goes from the soma in the spinal cord or brain out to the peripheral body parts. The PNS is studied using electroneurography. Electroneurography can be performed either by an antidrome method, which measures against the nerve impulses natural direction, or with an ortodromic method, in which the nerve impulses are measured in its natural direction. In electroneurography the nerve conduction velocity, amplitude and formation are used to make a diagnosis. The aim of the study was to examine if there was a significant difference in sensory amplitude when using an antidrome method compared to an ortodrome method by examining the median nerve and the ulnar nerve, this to be able to determine if the method used to achieve the reference values matters. Materials &amp; Method: 33 neurologically healthy test subjects in the ages 18–80 participated in the study. The nerves were stimulated at the wrist and the registrating electrode was positioned on the fingers by the orthodromic method and the other way around by the antidromic method. Paired t- test was used. The level of significance (α) was placed at 0,05. The data was considered to be normally distributed when the median and mean had a difference of ≤5. Results: There were a significant difference in amplitudes in all of the measurements.  Discussion: The reference values should be produced using the same method that is used in the clinic to avoid misdiagnosis.

Elektroneurografi är en grundläggande icke invasiv metod som används dagligen inom kliniska verksamheter för att diagnostisera olika perifera nervsjukdomar. Metoden speglar den funktionella statusen av de myeliniserade motoriska och sensoriska axonen. Vid sensorisk neurografi mäts sensory nerve actionpotential (SNAP) som är summan av alla aktionspotentialer som är genererade av enskilda myeliniserade axon. Vid undersökningen erhålls olika variabler som är viktiga för diagnostik såsom amplitud, duration, latenstid och ledningshastighet.   Syftet med studien var att undersöka om det finns skillnad i amplitud och duration på sensory nerve actionpotential vid antidrom sensorisk stimulering av nervus medianus vid två olika stimuleringspunkter.   Nervus medianus stimulerades elektriskt distalt och proximalt hos 18 friska testpersoner med en hudtemperatur på minst 32°C. Antidrom sensorisk stimulering av nervus medianus vid två olika stimuleringspunkter visade att det förelåg en signifikant skillnad i amplitud och duration mellan distal och proximal stimuleringspunkt. Reproducerbarheten för metoden visades vara hög. / Electroneurography is a basic non-invasive method that is used daily in clinical practice to diagnose various peripheral nerve diseases. The method reflects the functional status of the myelinated motor and sensory axons. In sensory neurography, sensory nerve action potential (SNAP) is measured, which is the sum of all action potentials generated by individual myelinated axons. During the examination, various variables are obtained that are important for diagnostics, such as amplitude, duration, latency time and conduction velocity.    The aim of this study was to investigate whether there is a difference in amplitude and duration of sensory nerve action potential in antidrome sensory stimulation of the median nerve at two different stimulation sites.   The median nerve was stimulated electrically distally and proximally in 18 healthy subjects with a skin temperature of at least 32 ° C. Antidrome sensory stimulation of the median nerve at two different stimulation sites showed that there was a significant difference in amplitude and duration between distal and proximal stimulation sites. The reproducibility of the method was shown to be high.