No previous studies have examined the physical
characteristics of patients with cauda equina syndrome (CES). We compared
the anthropometric features of patients who developed CES after
a disc prolapse with those who did not but who had symptoms that
required elective surgery. We recorded the age, gender, height,
weight and body mass index (BMI) of 92 consecutive patients who
underwent elective lumbar discectomy and 40 consecutive patients who
underwent discectomy for CES. On univariate analysis, the mean BMI
of the elective discectomy cohort (26.5 kg/m2 (16.6 to
41.7) was very similar to that of the age-matched national mean
(27.6 kg/m2, p = 1.0). However, the mean BMI of the CES
cohort (31.1 kg/m2 (21.0 to 54.9)) was significantly
higher than both that of the elective group (p <
0.001) and the
age-matched national mean (p <
0.001). A similar pattern was
seen with the weight of the groups. Multivariate logistic regression
analysis was performed, adjusted for age, gender, height, weight
and BMI. Increasing BMI and weight were strongly associated with
an increased risk of CES (odds ratio (OR) 1.17, p <
0.001; and
OR 1.06, p <
0.001, respectively). However, increasing height
was linked with a reduced risk of CES (OR 0.9, p <
0.01). The
odds of developing CES were 3.7 times higher (95% confidence interval
(CI) 1.2 to 7.8, p = 0.016) in the overweight and obese (as defined
by the World Health Organization: BMI ≥ 25 kg/m2) than
in those of ideal weight. Those with very large discs (obstructing
>
75% of the spinal canal) had a larger BMI than those with small
discs (obstructing <
25% of the canal; p <
0.01). We therefore
conclude that increasing BMI is associated with CES.
We studied 32 patients with central cord syndrome who were managed conservatively. Six were under 50 years of age (group 1), 16 between 50 and 70 years (group 2) and ten over 70 years (group 3). At the time of discharge all patients in group 1 could walk independently and had good bladder control compared with 11 (69%) and 14 (88%) in group 2 and four (40%) and two (20%) in group 3, respectively. At follow-up after a mean of 8.6 years (4 to 15), ten patients had died leaving 22 in the study. All those in group 1 were alive, could walk independently and had bladder control. In group 2, 13 were alive of whom ten (77%) could walk independently and nine (69%) had bladder control. In group 3 only three were alive of whom only one was independent and none had bladder control. Function at discharge as measured by the ASIA motor scoring system was usually maintained or improved at follow-up, but patients over 70 years of age at injury did poorly.