Læknablaðið - 15.11.1996, Síða 36

784
LÆKNABLAÐIÐ 1996; 82
Miðtaugarþvingun í úlnliðsgöngum
Niðurstööur vöðvarafrits og taugaleiðingarannsókna
Marinó Pétur Hafstein1,2’, Brjánn Á. Bjamason3), Kristinn Tómasson3’
Carpal tunncl syndrome. Rcsults of electrodiagnostic
studies
Hafstcin MP, Bjarnason BÁ, Tómasson K
Læknablaðið 1996; 82: 784-94
The results of electrodiagnostic studies on 557 hands
of 383 patients with the clinical diagnosis of carpal
tunnel syndrome (CTS) are described. History tak-
ing, examination and electrodiagnostic studies were
performed by the same neurologist (MPH). The
diagnostic sensitivity for the distal motor latency
(DML) was 68%, while the sensitivity for the distal
sensory latency (DSL) was 77% and the combined
sensitivity for these parameters was 83%. With vari-
ous "unconventional” studies 91% of hands were
diagnosed with CTS.
From our results the cause for slowing of median
motor nerve conduction velocity (m-MNCV) in the
forearm seems to be both demyelination at the wrist
and axonal degeneration. However, hands with de-
nervation had more slowing of m-MNCV in the
forearm than hands without denervation. Hands
with clumsiness, subjective weakness, objective
weakness and thenar atrophy, compared to hands
without these symptoms and signs, had a higher
estimate of the relative risk of abnormal DML,
DSL, compound motor action potential (CMAP),
compound sensory nerve action potential
Frá 'Læknastofunni Bárugötu 15, 2)taugalækningadeild
Landspítalans, 3)geðdeild Landspítalans. Fyrirspurnir,
bréfaskipti: Marinó P. Hafstein, Domus Medica, Egilsgötu 3,
101 Reykjavík.
Lykilorð: Median nerve, carpal tunnel syndrome, nerve
conduction studies, clinical and electropathophysiologic as-
sessment.
(CSNAP), m-MNCV in the forearm and electro-
myography (EMG) on abductor pollicis brevis
(APB) and from less severe to more severe motor
symptoms and signs the odds ratio steadily increased
for all tested parameters. Hands with Phalen’s sign
had more prolonged DML and abnormal EMG on
APB compared to hands without Phalen’s sign but
other test parameters showed no difference. No dif-
ference could be found for any test parameters be-
tween hands with or without Tinel’s sign, neither
between hands without pain or with pain, whether in
the hand or more proximally in the upper extremity,
nor between hands of 150 patients with bilateral CTS
who claimed one hand worse than the other. In
hands with decreased pin prick, decreased touch or
hyperesthesia, compared to hands with a normal
sensory examination, the DML, CMAP, and EMG
on APB were significantly more often abnormal but
no difference was found for any of the sensory con-
duction test parameters. With increasing duration of
symptoms there were significantly more abnormal
results for all tested parameters except CMAP, es-
pecially when the symptoms had lasted for more
than 10 years.
Ágrip
Lýst er niðurstöðum taugaleiðinga- og
vöðvarafritsrannsókna á 557 höndum 383
sjúklinga með miðtaugarþvingun í úlnliðs-
göngum (carpal tunnel syndrome, CTS).
Næmi til þess að greina taugarfergið var 68%
fyrir hreyfitaugafjærtöf (distal motor latency,
DML), 77% fyrir skyntaugatöf (distal sensory
latency, DSL) og samanlagt næmi þessara
tveggja rannsóknarþátta var 83%, en með
„óhefðbundnum" rannsóknaraðferðum
greindust 91% handa með taugarfergið.
Rannsóknarniðurstöður voru metnar með
tilliti til ýmissa einkenna miðtaugarþvingunar í