ABSTRACT
Objective:
To study the correlation between the acute-phase characteristics of
motor evoked potential (MEP) and severities of
spinal cord injury in
patients with acute cervical hyperextension
injury and
central cord syndrome (CCS).
Methods:
Retrospectively analyzed were the data of 45
patients with acute cervical hyperextension
injury and CCS (
observation group)
who had been admitted to Department of
Orthopedics, Tongji
Hospital Affiliated to Tongji
University from December 2018 to July 2021 and 20 healthy controls. Examination of
transcranial magnetic stimulation-induced MEP was performed in
patients with CCS and healthy controls using a magpro x100
magnetic stimulator, and recording was conducted in bilateral abductor pollicis brevis (APB). The characteristics of MEP waveform latency, amplitude and motor threshold were described and compared between the healthy control and
observation groups; the correlations were analyzed between the MEP latency and the severity of
spinal cord injury [American
Spinal Injury Association (
ASIA) total score and motor function of
Upper Extremity Motor Subscores (UEMS)] in the
observation group. According to different MEP-induced states, the
patients in the
observation group were divided into a resting group ( n=19), a facilitation group ( n=18), and a no-waveform group ( n=8). The severity of
spinal cord injury (
ASIA total score) and the
functional independence of the
spinal cord (SCIM-Ⅲ score) were compared among the 3 groups to analyze the correlation between the MEP-induced
state and the severity of
spinal cord injury (
ASIA total score).
Results:
The
observation group had a significantly longer MEP latency [(30.16±6.32) ms], a significantly smaller amplitude [(0.54±0.30) mV] and a significantly higher motor threshold [(65%±11%)] than the healthy
control group (all P<0.05). The MEP latency in the
observation group was significantly correlated with
ASIA total score ( r=-0.730, P<0.001) and UEMS ( r=-0.740, P<0.001). The
ASIA total score and SCIM-Ⅲ score were significantly different among the 3 groups ( P<0.05), and the MEP-induced
state was significantly correlated with the severity of
spinal cord injury (
ASIA total score) ( r=0.668, P<0.001).
Conclusions:
In
patients with acute cervical hyperextension
injury and CCS, the MEP latency is prolonged, the amplitude lowered, and the motor threshold enhanced. The MEP latency is strongly correlated with the severity of
spinal cord injury and
upper limb motor function. The MEP-induced
state is also closely related to the severity of
spinal cord injury.