EXPERIMENTAL
NEUROLOGY
48,
NO.
Epidemiology
3,
2, 163-236 (1975)
PART
of Spinal
Cord
Injury
JOHN F. KURTZKE~ Departmerct
of Neurology,
Georgetown Washington,
University D.C.
Sclaoolof Medicine,
INTRODUCTION Damage to the spinal cord generally results in loss of motor and sensory function of body parts below the level of the lesion, a state which is often irreversible. Strictly speaking, paraplegia refers to complete paralysis of both lower extremities, and quadriplegia or tetraplegia to a similar involvement of all four extremities. These terms though are often used much more loosely to include weakness as well as paralysis. In this work they will be so employed unless otherwise specified; in general “paraplegia” will refer to all such weakness, modified as to “complete” for true paraplegia and “incomplete” for paraparesis. There is in fact a tendency to use “paraplegia” for all motor weakness consequent to cord lesions regardless of level (or etymology), and some indeed include paralysis consequent to states such as poliomyelitis or the Guillain-Barre 1 Without the aid of many people, this paper would not have been possible. I would like to thank all who provided data (or ascertained their nonavailability) including: M. Askeland of the National Central Bureau of Statistics, Sweden; E. R. Black and M. H. Wilder of the U.S. National Center for Health Statistics; N. 0. Borhani and staff of the University of California, Davis; G. Dean and J. O’Gorman of the Medico-Social Research Board of Ireland; R. Gjone and H. Natvig of the State Institute of Rehabilitation, Norway ; I. D. Goldberg of the U.S. National Institute of Mental Health; K. Gudmundsson of the University Hospital, Reykjavik, Iceland; H. Hamtoft of the National Health Service of Denmark ; I. W. Kemp, J. A. Clarke, and Dr. Heasman of the Scottish Health Service; Y. Kuroiwa of Kyushu University, Fukuoka, Japan; L. Mesard and W. V. Huber of the U.S. VA Central Office; anonymous members of the Mortality Branch, U.S. National Center for Health Statistics; F. Seitelberger of the University of Vienna; S. C. Stracey of the Office of Population Censuses and Surveys, England; S. Tusji and H. Fujishima of Kyushu Rosai Hospital, Fukuoka, Japan; K. Westlund of Troms$ University, Norway; and G. Zrubecky of the Rehabilitation Center, Tobelbad, Austria. My special thanks though to J. F. Kraus of the University of California, Davis, who not only provided me with a prepublication copy of his outstanding study, but also sent all other data and information he had available from this work. 163 Copyright 1975 by Academic Press,IllC. All rights 93 reproduction in any form reserved.
164
JOHN
F.
KURTZKE
syndrome. Depending on the nature and location of the lesion, spinal cord damage can also produce hemiplegia or monoplegia. In most instances except physiologic or anatomic transection, the sensory loss is less than the motor deficit. When motor impairment is marked, loss of bowel and bladder function is common. When the damage is at vertebral levels of the thoracic or cervical region, the cord lesion produces spastic paraplegia or quadriplegia ; when at the lumbar spine level, the injury of conus medullaris or cauda equina results in flaccid paralysis. The clinical characteristics of cord damage and its management are not under consideration here. To these points there are a number of recent text books and monographs of which the best, I believe, is that of Guttmann (20). Not all instances of trauma to the spine result in damage to the spinal cord, and conversely, not all paraplegia is the result of physical trauma. While the emphasis here will be on the traumatic plegias, brief discussions of trauma in general and of other causes of paralysis are needed to put the problem in context, All Accidents Death Rates. In the United States for 1959-1961, the average annual crude death rate due to accidents was 52/100,000 population and that due to homicide was 5/100,000 (24). For either cause the rate for males exceeded that for females, and those for nonwhites were considerably in excess of those for whites (Table 1). Some 90% of nonwhites are blacks, and thus differences from whites are mostly the result of the findings among blacks. Age-specific death rates by sex and color for accidental deaths are drawn in Fig. 1. The peaks at either end of the age-spectrum, and especially that for the elderly, are largely attributable to deaths from accidental falls. The principal causes of accidental deaths are listed in Table 2. Note that motor vehicle accidents and falls are by far the most common, together accounting for almost 2/3 the deaths. The causes TABLE
1
AVERAGE ANNUAL AGE-ADJUSTED DEATH RATES PER 100,000 POPULATION FOR ACCIDENTS AND HOMICIDE BY SEX AND COLOR: UNITED STATES, 1959-1961 (FROM ISKRANT AND JOLIET, 1968) Cause of death Accidents Homicide
T
49.4 5.2
Total M
73.3 7.8
White M (rates/100,000)
F
T
26.4 2.6
47.3 2.7
70.2 3.9
F
T
25.1 1.5
65.5 25.2
INonwhite M
98.6 41.3
F
34.9 10.7
165 700 600 E
_J
100
FIG. 1. Average annual death rates per 100,000 population revision ISC codes E8OO-E%2) by age, sex, and color, United from Iskrant & Joliet (1968).
due to accidents States, 1959-l%l ;
(7th data
in Table 2 constitute S6.27, of accidental deaths: motor vehicle 41.1%, falls 20.3%, fire 7.7%, drowning S.6%, firearm and inhalation 2.5% each, machinery 2.1 ‘j%, water and air transport 1.6% each, and rail transport 1.2%. TABLE AVERAGE
ANNUAL CRUDE DEATH RATES PER 100,000 POPULATION DUE TO ACCIDENTS ACCORDING TO THE MAJOR CAUSES,‘” UNITED STATES, 1959-1961 (FROM ISKRANT AYD JOLIET, 1968) Major
cause’c
All (E800-E962) Motor vehicle (E810-835) Traffic (E810-825) \Yater transport (E850-858) Aircraft (E860-866) Railway (E800-802) Falls (E900-904) Fire & explosion (E916) Drowning (E929) Firearm (E919) Inhalation/obstruction (E921, Machinery (E912) a Rates
2
Death
922)
in excess of l.O/lOO.OOO.
rate
Total
Male Female (rates/lOO,OOO)
51.7 21.2 20.7 0.8 0.8 0.6 10.5 4.0 2.9 1.3 1.3 1.1
72.3 31.8 30.9 1.6 1.4 1.0 10.5 4.6 4.9 2.2 1.6 2.1
31.8 11.0 10.7 0.1 0.2 0.1 10.5 3.4 0.9 0.3 1.0 0.1
‘/& Total
100.0 41.1 40.0 1.6 1.6 1.2 20.3 7.7 5.6 2.5 2.5 2.1
166
JOHN
F.
KURTZKE
In 1971 in the United States, 62/1OQO persons interviewed in the Health Interview Survey stated they were currently physically impaired because of accidents (55). This survey, conducted by the National Center for Health Statistics, is an ongoing structured interview of a specified sample of the civilian noninstitutionalized population of the United States. The predominant types of impairment were those of back and extremities (excluding paralysis or amputation). Paralysis, complete or partial, due to injury, was recorded for O.S/lOOO population (Table 3), or 1.3% of all impairments from injury. The major causes of such impairments due to injury are listed in Table 4. Vehicular accidents, falls, and machinery in operation were the three principal types, accounting for nearly 3/5 the impairments. Incidence. From the same Health Interview Survey, the annual incidence rate for impairments due to injury was 6.5/1000 population in 1971. Rates for only several types of impairment could be calculated: visual (0.26/1000), back or spine ( 1.94), upper limb or shoulder ( 1.13), lower limb or hip (1.71)) other or multiple limb or trunk impairments (0.46)-the four last categories excluding paralysis or loss of the part. Prezdence.
All Paralysis Prevalence. Unpublished data on frequency and other characteristics of paralysis from the Health Interview Survey for 1971 have been kindly provided by E. R. Black (3). The prevalence rate per 1000 population for paralysis was 6.9/1000 and 11% of the cases were complete paraplegia (0.5/1000) or quadriplegia (0.3) (Table 5). According to the respondents, their paralysis was most often the result of cerebrovascular disease or poliomyelitis, with only 11% attributed to injury (Table 6). Rates for males exceeded those for females regardless of age, and the increase with age was striking-doubtless a reflection of the stroke category. For all ages combined, white rates exceed those of nonwhites (now categorized as “all other”), though they were lower in the elderly, the only two age-groups with a sufficiency of casesto provide reasonably stable rates for the nonwhites (Table 7). An interesting relationship was seen with socioeconomic status, as measured by the educational level of the head of the family (Table 8). With but one exception there was a steady decrease in the rates at each agegroup with increasing educational levels. The rates for residents of nonmetropolitan areas exceeded those of metropolitan: 7.6 vs 6.5, and rates in the South were notably higher than the other three regions of the U.S., the excess there being in the two higher age-groups only.
167
IZI’IDEMIOLOGY
PR~VALXNCB
RATES
PER
1000
F'OPITLATION
IWR
IWPAIK~~~~
I)ub
m
INJURY;
PROPORTION OF AIL SKH IMPAIRMENTS DIJIX TO INJURY; AND PROPORTION OF ALL INJURIES CAUSING SUCH IMPAIRMENTS; HEALTH INTERVIEW SURVEY, 1971, UNITED STATES (WILDER AND PEARSON, 1973) Type
of impairment
All impairments Visual impairment Hearing impairment Paralysis Absence fingers/toes Absence major extremity Impairment-back/spine” Impairment-UE/shoulder” Impairment-LE/hipa Other/multiple, limb/trunks All other impairment+
Prevalence rate per 1000 due to injury (%)
Proportion of this impairment due to injury
Proportion of injuries with this impairment
62.0 (100.0) 4.6 (7.4) 4.7 (7.5) 0.8 (1.3) 3.7 (6.0) 0.9 (1.4) 15.4 (24.8) 8.4 (13.5) 13.6 (21.9) 3.8 (6.2) 6.2 (10.0)
0.246 0.097 0.065 0.113 0.872 0.653 0.389 0.696 0.371 0.749 0.224
0.105 0.056 b b
0.126 0.135 0.126 0.121 0.080
a Excluding paralysis, absence. b Rate unstable due to small numbers
TABLE
4
PERCENTAGES OF IMPAIRMENTS DUE TO INJURY ACCORDING TO MAJOR CAUSES” OF ACCIDENTS; HEALTH INTERVIEW SURVEY 1971 AND 1957-1961, UNITED STATES (WILDER AND PEARSON, 1973)
a >47e
Major causes” of accidents
1971
Total Moving motor vehicle Nonmotor vehicle in motion Fall downstairs/from height Other falls Machinery in operation Struck by moving object Lifting Bumping into object/person
100.0 17.8 2.0 8.7 11.3 9.2 5.3 5.6 5.1
of accidents.
Year 1957-1961 (percentages) 100.0 15.4 2.9 14.1 13.2 11.6 7.3 5.7 4.3
168
JOHN
F.
KURTZKE
TABLE PREVALENCE
RATES HEALTH Type
PER 1000 POPULATIOU INTERVIEW SURVEY, of paralysis
toe(s)
only,
finger(s)
TO TYPE;
Rate/1000
Total (X40-69) Complete, upper limb(s), except fingers only (X40, Complete, lower limb(s), except toes only (X43) Paraplegia (X44, 46) Hemiplegia (X47) Quadriplegia (X48) Other sites, complete (X49) Cerebral palsy (X50) Partial paral. upper limb(s) Partial paral. lower limb(s) Hemiparesis (X.53) Partial paral.-other (X54) Paralysis face All other” and unspecified a Includes
5 FOR PARALYSIS ACCORDING U. S. 1971 (BLACK, 1974)
% 100.0
6.9 41)
only,
(X51) (X52)
bowel
0.5
7.9
0.9 0.5 1.0 0.3 0.4 0.9 0.3 0.5 0.7 0.4 0.3 0.3
12.7 7.3 14.3 3.7 5.3 13.0 4.7 7.3 9.6 6.0 4.0 4.2
or bladder.
Spinal Paralysis Causes. As mentioned, there are causes of paraplegia and quadriplegia other than trauma, Some representative hospital series are presented in Table 9. Probably the most useful is that of Guttmann (20), wherein 2/3 of 3000 admissions to a spinal cord injury center were the result of trauma, But note the absence of tumor cases. The 5% resulting from TABLE
6
PREVALENCE RATES PER 1000 POPULATION FOR ALL PARALYSIS ACCORDING TO CAUSE : HEALTH INTERVIEW SURVEY, U. S. 1971 (BLACK, 1974) Cause Total Poliomyelitis Cerebrovascular disease Injury Congenital/birth Other & ill-defined Unknown to respondent
Rate/1000 6.9 1.6 2.3 0.8 0.8 0.7 0.8
% 100.2 23.0 33.0 11.3 11.4 10.1 11.4
169
EPIDEMIOLOGY
~‘RI’V:ALl
17.8
30.2 17.2 24.3 54.9
18.8
>
18.7 19.2
Cauda Equina/Other All Complete-A Complete-A + B Incomplete
69.6 55.6 66.7 72.7
29.7 -
Total All Complete-A Complete-A Incomplete
35.6 23.4 30.8 51.4
19.9
(612)
(356)c
+ B
(W a A is complete motor and sensory loss, B complete loss. * Includes “other paralysis.” c Excludes 28 with no persistent neurologic deficit.
motor
16.4 21.9b
but
not
complete
sensory
198
JOHN
F.
KURTZKE
the nature of the lesion (severity and level) by the age at onset and by the cause of injury and death, as well as perhaps by sex. As a first approximation though, we can look at two large series with at least some cases followed for lengthy periods, and wherein most the cases were probably ascertained soon after injury (Table 35). Breithaupt, Jousse and Wynn-Jones (5) reported on life expectancy for a series of 599 cases of traumatic spinal cord injury out of 643 “treated at Lyndhurst Lodge, Sunnybrook Veterans Hospital and the Toronto General Hospital between January 1, 1945 and December 31, 1958.” (p. 74). TABLE
35
LATE SURVIVAL IN TRAUMATIC SC1 EXPRESSED AS CASE-FATALITY RATIOS, ACCORDING TO LEVEL AND SEVERITY OF LESION AND SEX ; OBSERVATION PERIODS TO 21 yr IN (A) TORONTO (JOUSSE ET AL., 1967) AND TO 20 yr IN (B) ENGLAND (GUTTMANN 1973) Level
& severity by series
Case-Fatality Total Male (percentages)
Total series (4 (B) Quadriplegia All (A) (B) Complete Incomplete
(A) (B) (A) (B)
Paraplegia All (A) (W Complete Incomplete
(A) @I (A) WV
All
complete (A) W
All incomplete (A) w Other lesions cauda equina
(B)
ratio Female
Total
Deaths/cases Male
Female
21.0 16.9
21.5 -
1.5.S -
203/965 331/1963
184/842 -
19/123 -
23.0 15.2 29.0 20.7 19.0 13.0
25.9 -
12.7 -
66/255 -
9/71 -
26.7 -
46.7 -
31/116 -
7115 -
25.2 -
3.4 -
75/326 71/466 381131 28/135 37/195 43/331
35/139 -
2156 -
20.0 18.1 22.7 20.2 16.6 12.5
20.1 -
19.2 -
118/587 -
10/52 -
21.5 -
38.5 0 -
72/335 46/252 -
lo/26 -
18.3 -
128/639 188/1036 82/361 154/763 46/278 34/273
24.4 20.3
22.8 -
415 -
120/492 182/898
103/451 -
17/41 -
17.6 12.8
20.7
2.4 -
831473 77/604
81/.?91 -
2/82 -
15.6
-
-
72/461
-
-
0 -
EPIDEMIOLOGY
199
This study was expanded (25) to include 965 patients, but excluding 99 partial paraplegics with good urinary function who “were found to have a life expectation equal to the nonparaplegic group. . . . The period of ubservation thus covers 21 years from January 1, 1945, to December 31, 1966.” (p. 199). It also includes 366 first treated after January 1, 1959. Guttmann’s (20) series from the Stoke Mandeville Spinal Cord Injury Center at Aylesbury, England, where he has been the director since its origin in February 1944, has been referred to repeatedly. It was unfortunate that the data from such a vast experience were not, in this portion, differentiated by sex. The results presented deal with the situation of the patients as of 1963, Table 35 summarizes the case fatality ratios according to level and severity of lesion, and sex, from these two surveys. Percentages dead are uniformly a bit lower in the English series than the Canadian. In both, complete lesions-particularly quadriplegia-are once again of worse prognosis than incomplete, and incomplete paraplegics seem to fare best of all. Recall that these series would include at least some early deaths in hospital, as in Table 33. The sex differentiation in Toronto suggests a more benign course for females-but numbers are quite small, since in all we are dealing with only 19 deaths in 123 injuries among females. It is for this reason too that the apparent excess of females in complete lesion deaths, especially cervical, and their deficit in incomplete, should be regarded cautiouslyespecially when there were no incomplete paraplegia cases recorded for women. Causes of Lute Death. Guttmann (20) made the valid point that not all deaths following spinal cord injury are in fact the result of such trauma, a point which is obvious upon reflection, since individuals are still subject to the other ills of man. In his own series of 331 deaths among 1963 patients with traumatic SCI, 242 he attributed to the injury; 89 or 27% of the total were “causes of death quite independent of those as a direct result of paraplegia, such as tuberculosis of the lung, cancer, other diseases, cerebral hemorrhage and new accidents.” (p. 631). In Table 36 is a comparison of deaths in a spinal cord injury center versus those found upon follow-up of the group in Toronto, for most of whom death occurred after discharge from hospital. The former is a summation of a series of 55 autopsies for 1946-1955 (13) and of 35 for 19551963 (43) from the same VA Hospital Center in Richmond, Virginia. Differences between the two reflect the youth of the VA series, and the ageing over time for the Toronto group-thus the higher proportions of vascular disease in the latter. The most common cause of death in either series is renal disease. Nyquist and Bors (39) also reported renal failure as the underlying cause in 32% of cord injury deaths in another VA
200
JOHN
F.
KURTZKE
TABLE CAUSES Cause
OF LATE
of death
36
DEATHS
IN TRAUMATIC
VA Hospital5 percentages
Renal disease Cardiovascular disease Cerebrovascular accident Pulmonary disease Gastrointestinal disease Liver disease
30.0 7.8 0 13.3 8.9 8.9J
Decubiti Suicide Other Unknown W
6.7e 0 18.9
a Dietrick 1957 and Pearce 1964, b Jousse 1967. c 1965 population of Canada. d Includes 5 (5.6%) hepatitis. e Generalized infection/septicemia.
(!g Richmond,
SC1
Toronto Percentages
36.5 16.3 5.9 7.4 5.9 1% 2.0 3.4 14.3
follow-up* Cases observed/ expectedc 74/l 33/31 12/6 15/l 12/4 3/4/-
7/2 29135 14/(203/80)
Virginia.
Hospital center. This is most often renal failure from ascending pyelonephritis or from amyloidosis-the latter the resultant of chronic recurrent infections of skin (decubiti) or bladder. The observed/expected ratios for renal deaths from the Canadian series point out the massive excess therein. And this is far from the entirety of the renal disease problem in the cord-injured. In the series of Dietrick and Russi (13), although renal disease was the underlying cause in 20%, pyelonephritis was present in 65%, cystitis in 75%, and either one of these in 90% of these autopsied cases. The excess for pulmonary disease is predominately for bronchopneumonia and-less so-for pulmonary emboli. The excess for the gastrointestinal tract is largely for peritonitis (with or without perforation) from bowel obstruction-and from urinary tract instrumentation and decubiti. Amyloidosis plays a role here too, as in the liver-diseased. In one sense it may be surprising that so few suicides are reported-but 7/%5 cases in Toronto. Even the excess for stroke may be a sequel of the cord damage-either directly through the hypertensive crises such patients suffer, or indirectly through renal hypertension. In essence though, most of the excess of deaths in the cord-injured
201
EPIDEMIOLOGY
would likely disappear if one could find an answer long-term management of the neurogenic bladder. Survival
from Life-Table
to the problems
of
Allalysis
It is clear that the case fatality ratios from the prior sections do not adequately reflect a true picture of the course of traumatic SCI, even in terms of survival, since the observation periods would have ranged from but a few months up to some 20 yr, patients would have been added over the interval in question-and would have been at varying intervals after injury when first ascertained. The proper method for handling such data is life-table analysis. In simplified fashion, an annual survivorship table is built by taking the number at risk at the start of a given year, finding the proportion who die and who survive during that year, and beginning the next year with the survivors in order to repeat the process. Each year’s survival proportion is multiplied by the fraction surviving up to that year. The point at which the percent survival is 50% will be close to the average life expectancy for the group in question. In order to calculate this properly, a subject is included as “at risk” only for the interval he is under observation. If then, a patient is first seen 10 years after injury, he should be added to the series for calculation only for the 11th year of illness and thereafter. Conversely, if he is no longer observed after five years of illness, he is a loss or withdrawal in that year, and is deleted from the survivors at risk for year 6, just the same as the deaths. This method permits then valid estimations of survivorship when one is not able to take a single cohort in time and follow them all to death. One can also compare the survival experience of the group under study with that for the population from which the group is drawn, and provide estimates as to the excess (or deficit) of observed mortality to that expected. Breithaupt et al. (5) reported just such a procedure, and concluded that the death rate for traumatic quadriplegia (all severity) was 12 times that of the normal population, and for traumatic paraplegia nearly five times the normal. Of the 94 deaths-which must have occurred within the maximum observation period of 16 yr-56 had occurred within 5.5 yr of the onset of paralysis. Data were not published to permit calculation of the life tables, which were drawn to show survival from 100% to 0%. The “50% survival duration” was given as 36 years for those age 20, 25 years for age 35, and 17 years for those age 50 at injury. It would appear that the curves as drawn-if based on observation and not on projectionwere calculated from very small numbers.
202
JOHN
F.
KURTZKE
The later experience of these Toronto patients is noted in Table 37. Again, the data on which this table was based are not available, and the prior comments may be just as valid. But though one might question the quantitation of the foreshortened life expectancy, the qualitative aspects are likely : complete quadriplegia is especially ominous, while incomplete paraplegia apparently gives little if any foreshortening of normal life expectancy. Complete paraplegia seems more threatening than incomplete quadriplegia-a finding in accord with all series insofar as early results go, except for that of California (see above). The effects of age are not striking. For complete paraplegia, for example, the ratio for observed/ expected years of life ranges from 0.68 at age 20 to but 0.54 at age 50. An actuarial analysis of traumatic SC1 clearly limited to the period of observation in terms of entry into and withdrawal from the series was presented by Burke et al. (7), based upon the nationwide series of U.S. veterans who had been patients in VA hospitals at some time during the 11 years from onset of injury. Even though only “a small percentage” of the patients were so hospitalized immediately after injury, this point is taken into account in the analysis. (Whether this was so in the Canadian series cannot be ascertained.) There is though no guarantee the included early cases reflect all early cases. The survival experience for this veteran series is presented in Table 38. Both age and level of lesion are seen to be additive in their adverse effects, as prior data indicate. A similar study has been undertaken by Mesard et al. (34) covering new admissions to VA hospitals during the next decade, October 1955September 1965, with survival to September 1967 (Table 39). Method-
TABLE
37
ESTIMATED YEARS OF LIFE EXPECTANCY AFTER TRAUMATIC SC1 ACCORDING TO AGE AND TYPE OF LESION ; TORONTO 1945-66 (APPROXIMATED FROM FIGURE 2 “PREDICTED SURVIVAL TIME,” IN JOUSSE ET AL., 1967) Age at injury
Normal life expectancy*
Type Complete Quadriplegia
20 30 40 50 n Based
50 40 32 24 on 1965 Canadian
21 1.5 10 5 mortality
tables.
of lesion
Complete Incomplete paraplegia quadriplegia (years life expectancy) 34 26 19 13
40 32 24 17
Incomplete paraplegia
48 38 30 22
203
EPIDEMIOLOGY
TABLE PERCENTAGE LEVEL
Age
81 Level
Suw1v.4~
38
IN TRAUMATIC
SC1 ACCWIXNG
OF LESION, U. S. VA HOSPITAL SERIES, ADMISSIONS (BURKE ET AL., 1960)
(Original
N) 1 mo
Totalh
(5575)
15-24 yr Paraplegic Quadriplegic
(2452) (1845)
TO .\GE
Time after injury 1 yr 5 yr (percentage survival)
10 yr
89
85
77
(607)
94 89
92 87
88 83
81 77
25-34 yr Paraplegic Quadriplegic
(2212) (1705) (507)
95 70
92 68
86 64
79 5.5
35-44 yr Paraplegic Quadriplegic
(606) 92 64
83 57
69
U-56)
94 73
45-59 yr Paraplegic Quadriplegic
(305) (198) (107)
91 76
82 66
69 54
41
(450)
~\XI)
1946-1955
Normal 10 yr Survival”
c.70 98
97
94 c 83 c
a Normal survival for U. S. men based on death rates 1949-1951. * Calculated weighted average based on data presented. c Numbers too few for authors’ calculations.
ology was the same as for the prior study. It is unfortunate the prior work was not updated as well. Weighted averages based on proportions alive at each age and level and the proportions so represented in the original series by age and level have been calculated for both the veteran series. Looking first at these figures, one could conclude there has been a dramatic improvement in survival over the few years between these series: 97% of the recent series survive one month instead of 89% ; at five years 88% are alive instead of 77% ; and so on. In each age-lesion category there has been a striking gain (there had been no patients 60 or older reported in the early series). The marked effects of age on survival (as well as the level) are seen in Fig. 5. Note however that only 55% of normal individuals in the eldest age group would be likely to have survived ten years, while the cord-damaged ratios were 29% for paraplegics and 24% for quadriplegics. It is then not clear that the proportional fatality ratio by age differs very greatly. For the paraplegics, the observed/expected ratio at each successively older age group is 0.98, 0.93, 0.97, 0.87, and 0.51. The decline then is really only in the oldest group, which is quite small.
204
JOI-IN
F.
KURTZKE
TABLE PERCENTAGE LEVEL
SUKVIVAL
Age and level
U. S. VA
OF LESION,
ADMISSIONS
(FROM
Original
MESARD
N 1 mo
Totalb Paraplegia Quadriplegia
2823 1559 1264
NEUROLOGY
48,
NO.
Epidemiology
3,
2, 163-236 (1975)
PART
of Spinal
Cord
Injury
JOHN F. KURTZKE~ Departmerct
of Neurology,
Georgetown Washington,
University D.C.
Sclaoolof Medicine,
INTRODUCTION Damage to the spinal cord generally results in loss of motor and sensory function of body parts below the level of the lesion, a state which is often irreversible. Strictly speaking, paraplegia refers to complete paralysis of both lower extremities, and quadriplegia or tetraplegia to a similar involvement of all four extremities. These terms though are often used much more loosely to include weakness as well as paralysis. In this work they will be so employed unless otherwise specified; in general “paraplegia” will refer to all such weakness, modified as to “complete” for true paraplegia and “incomplete” for paraparesis. There is in fact a tendency to use “paraplegia” for all motor weakness consequent to cord lesions regardless of level (or etymology), and some indeed include paralysis consequent to states such as poliomyelitis or the Guillain-Barre 1 Without the aid of many people, this paper would not have been possible. I would like to thank all who provided data (or ascertained their nonavailability) including: M. Askeland of the National Central Bureau of Statistics, Sweden; E. R. Black and M. H. Wilder of the U.S. National Center for Health Statistics; N. 0. Borhani and staff of the University of California, Davis; G. Dean and J. O’Gorman of the Medico-Social Research Board of Ireland; R. Gjone and H. Natvig of the State Institute of Rehabilitation, Norway ; I. D. Goldberg of the U.S. National Institute of Mental Health; K. Gudmundsson of the University Hospital, Reykjavik, Iceland; H. Hamtoft of the National Health Service of Denmark ; I. W. Kemp, J. A. Clarke, and Dr. Heasman of the Scottish Health Service; Y. Kuroiwa of Kyushu University, Fukuoka, Japan; L. Mesard and W. V. Huber of the U.S. VA Central Office; anonymous members of the Mortality Branch, U.S. National Center for Health Statistics; F. Seitelberger of the University of Vienna; S. C. Stracey of the Office of Population Censuses and Surveys, England; S. Tusji and H. Fujishima of Kyushu Rosai Hospital, Fukuoka, Japan; K. Westlund of Troms$ University, Norway; and G. Zrubecky of the Rehabilitation Center, Tobelbad, Austria. My special thanks though to J. F. Kraus of the University of California, Davis, who not only provided me with a prepublication copy of his outstanding study, but also sent all other data and information he had available from this work. 163 Copyright 1975 by Academic Press,IllC. All rights 93 reproduction in any form reserved.
164
JOHN
F.
KURTZKE
syndrome. Depending on the nature and location of the lesion, spinal cord damage can also produce hemiplegia or monoplegia. In most instances except physiologic or anatomic transection, the sensory loss is less than the motor deficit. When motor impairment is marked, loss of bowel and bladder function is common. When the damage is at vertebral levels of the thoracic or cervical region, the cord lesion produces spastic paraplegia or quadriplegia ; when at the lumbar spine level, the injury of conus medullaris or cauda equina results in flaccid paralysis. The clinical characteristics of cord damage and its management are not under consideration here. To these points there are a number of recent text books and monographs of which the best, I believe, is that of Guttmann (20). Not all instances of trauma to the spine result in damage to the spinal cord, and conversely, not all paraplegia is the result of physical trauma. While the emphasis here will be on the traumatic plegias, brief discussions of trauma in general and of other causes of paralysis are needed to put the problem in context, All Accidents Death Rates. In the United States for 1959-1961, the average annual crude death rate due to accidents was 52/100,000 population and that due to homicide was 5/100,000 (24). For either cause the rate for males exceeded that for females, and those for nonwhites were considerably in excess of those for whites (Table 1). Some 90% of nonwhites are blacks, and thus differences from whites are mostly the result of the findings among blacks. Age-specific death rates by sex and color for accidental deaths are drawn in Fig. 1. The peaks at either end of the age-spectrum, and especially that for the elderly, are largely attributable to deaths from accidental falls. The principal causes of accidental deaths are listed in Table 2. Note that motor vehicle accidents and falls are by far the most common, together accounting for almost 2/3 the deaths. The causes TABLE
1
AVERAGE ANNUAL AGE-ADJUSTED DEATH RATES PER 100,000 POPULATION FOR ACCIDENTS AND HOMICIDE BY SEX AND COLOR: UNITED STATES, 1959-1961 (FROM ISKRANT AND JOLIET, 1968) Cause of death Accidents Homicide
T
49.4 5.2
Total M
73.3 7.8
White M (rates/100,000)
F
T
26.4 2.6
47.3 2.7
70.2 3.9
F
T
25.1 1.5
65.5 25.2
INonwhite M
98.6 41.3
F
34.9 10.7
165 700 600 E
_J
100
FIG. 1. Average annual death rates per 100,000 population revision ISC codes E8OO-E%2) by age, sex, and color, United from Iskrant & Joliet (1968).
due to accidents States, 1959-l%l ;
(7th data
in Table 2 constitute S6.27, of accidental deaths: motor vehicle 41.1%, falls 20.3%, fire 7.7%, drowning S.6%, firearm and inhalation 2.5% each, machinery 2.1 ‘j%, water and air transport 1.6% each, and rail transport 1.2%. TABLE AVERAGE
ANNUAL CRUDE DEATH RATES PER 100,000 POPULATION DUE TO ACCIDENTS ACCORDING TO THE MAJOR CAUSES,‘” UNITED STATES, 1959-1961 (FROM ISKRANT AYD JOLIET, 1968) Major
cause’c
All (E800-E962) Motor vehicle (E810-835) Traffic (E810-825) \Yater transport (E850-858) Aircraft (E860-866) Railway (E800-802) Falls (E900-904) Fire & explosion (E916) Drowning (E929) Firearm (E919) Inhalation/obstruction (E921, Machinery (E912) a Rates
2
Death
922)
in excess of l.O/lOO.OOO.
rate
Total
Male Female (rates/lOO,OOO)
51.7 21.2 20.7 0.8 0.8 0.6 10.5 4.0 2.9 1.3 1.3 1.1
72.3 31.8 30.9 1.6 1.4 1.0 10.5 4.6 4.9 2.2 1.6 2.1
31.8 11.0 10.7 0.1 0.2 0.1 10.5 3.4 0.9 0.3 1.0 0.1
‘/& Total
100.0 41.1 40.0 1.6 1.6 1.2 20.3 7.7 5.6 2.5 2.5 2.1
166
JOHN
F.
KURTZKE
In 1971 in the United States, 62/1OQO persons interviewed in the Health Interview Survey stated they were currently physically impaired because of accidents (55). This survey, conducted by the National Center for Health Statistics, is an ongoing structured interview of a specified sample of the civilian noninstitutionalized population of the United States. The predominant types of impairment were those of back and extremities (excluding paralysis or amputation). Paralysis, complete or partial, due to injury, was recorded for O.S/lOOO population (Table 3), or 1.3% of all impairments from injury. The major causes of such impairments due to injury are listed in Table 4. Vehicular accidents, falls, and machinery in operation were the three principal types, accounting for nearly 3/5 the impairments. Incidence. From the same Health Interview Survey, the annual incidence rate for impairments due to injury was 6.5/1000 population in 1971. Rates for only several types of impairment could be calculated: visual (0.26/1000), back or spine ( 1.94), upper limb or shoulder ( 1.13), lower limb or hip (1.71)) other or multiple limb or trunk impairments (0.46)-the four last categories excluding paralysis or loss of the part. Prezdence.
All Paralysis Prevalence. Unpublished data on frequency and other characteristics of paralysis from the Health Interview Survey for 1971 have been kindly provided by E. R. Black (3). The prevalence rate per 1000 population for paralysis was 6.9/1000 and 11% of the cases were complete paraplegia (0.5/1000) or quadriplegia (0.3) (Table 5). According to the respondents, their paralysis was most often the result of cerebrovascular disease or poliomyelitis, with only 11% attributed to injury (Table 6). Rates for males exceeded those for females regardless of age, and the increase with age was striking-doubtless a reflection of the stroke category. For all ages combined, white rates exceed those of nonwhites (now categorized as “all other”), though they were lower in the elderly, the only two age-groups with a sufficiency of casesto provide reasonably stable rates for the nonwhites (Table 7). An interesting relationship was seen with socioeconomic status, as measured by the educational level of the head of the family (Table 8). With but one exception there was a steady decrease in the rates at each agegroup with increasing educational levels. The rates for residents of nonmetropolitan areas exceeded those of metropolitan: 7.6 vs 6.5, and rates in the South were notably higher than the other three regions of the U.S., the excess there being in the two higher age-groups only.
167
IZI’IDEMIOLOGY
PR~VALXNCB
RATES
PER
1000
F'OPITLATION
IWR
IWPAIK~~~~
I)ub
m
INJURY;
PROPORTION OF AIL SKH IMPAIRMENTS DIJIX TO INJURY; AND PROPORTION OF ALL INJURIES CAUSING SUCH IMPAIRMENTS; HEALTH INTERVIEW SURVEY, 1971, UNITED STATES (WILDER AND PEARSON, 1973) Type
of impairment
All impairments Visual impairment Hearing impairment Paralysis Absence fingers/toes Absence major extremity Impairment-back/spine” Impairment-UE/shoulder” Impairment-LE/hipa Other/multiple, limb/trunks All other impairment+
Prevalence rate per 1000 due to injury (%)
Proportion of this impairment due to injury
Proportion of injuries with this impairment
62.0 (100.0) 4.6 (7.4) 4.7 (7.5) 0.8 (1.3) 3.7 (6.0) 0.9 (1.4) 15.4 (24.8) 8.4 (13.5) 13.6 (21.9) 3.8 (6.2) 6.2 (10.0)
0.246 0.097 0.065 0.113 0.872 0.653 0.389 0.696 0.371 0.749 0.224
0.105 0.056 b b
0.126 0.135 0.126 0.121 0.080
a Excluding paralysis, absence. b Rate unstable due to small numbers
TABLE
4
PERCENTAGES OF IMPAIRMENTS DUE TO INJURY ACCORDING TO MAJOR CAUSES” OF ACCIDENTS; HEALTH INTERVIEW SURVEY 1971 AND 1957-1961, UNITED STATES (WILDER AND PEARSON, 1973)
a >47e
Major causes” of accidents
1971
Total Moving motor vehicle Nonmotor vehicle in motion Fall downstairs/from height Other falls Machinery in operation Struck by moving object Lifting Bumping into object/person
100.0 17.8 2.0 8.7 11.3 9.2 5.3 5.6 5.1
of accidents.
Year 1957-1961 (percentages) 100.0 15.4 2.9 14.1 13.2 11.6 7.3 5.7 4.3
168
JOHN
F.
KURTZKE
TABLE PREVALENCE
RATES HEALTH Type
PER 1000 POPULATIOU INTERVIEW SURVEY, of paralysis
toe(s)
only,
finger(s)
TO TYPE;
Rate/1000
Total (X40-69) Complete, upper limb(s), except fingers only (X40, Complete, lower limb(s), except toes only (X43) Paraplegia (X44, 46) Hemiplegia (X47) Quadriplegia (X48) Other sites, complete (X49) Cerebral palsy (X50) Partial paral. upper limb(s) Partial paral. lower limb(s) Hemiparesis (X.53) Partial paral.-other (X54) Paralysis face All other” and unspecified a Includes
5 FOR PARALYSIS ACCORDING U. S. 1971 (BLACK, 1974)
% 100.0
6.9 41)
only,
(X51) (X52)
bowel
0.5
7.9
0.9 0.5 1.0 0.3 0.4 0.9 0.3 0.5 0.7 0.4 0.3 0.3
12.7 7.3 14.3 3.7 5.3 13.0 4.7 7.3 9.6 6.0 4.0 4.2
or bladder.
Spinal Paralysis Causes. As mentioned, there are causes of paraplegia and quadriplegia other than trauma, Some representative hospital series are presented in Table 9. Probably the most useful is that of Guttmann (20), wherein 2/3 of 3000 admissions to a spinal cord injury center were the result of trauma, But note the absence of tumor cases. The 5% resulting from TABLE
6
PREVALENCE RATES PER 1000 POPULATION FOR ALL PARALYSIS ACCORDING TO CAUSE : HEALTH INTERVIEW SURVEY, U. S. 1971 (BLACK, 1974) Cause Total Poliomyelitis Cerebrovascular disease Injury Congenital/birth Other & ill-defined Unknown to respondent
Rate/1000 6.9 1.6 2.3 0.8 0.8 0.7 0.8
% 100.2 23.0 33.0 11.3 11.4 10.1 11.4
169
EPIDEMIOLOGY
~‘RI’V:ALl
17.8
30.2 17.2 24.3 54.9
18.8
>
18.7 19.2
Cauda Equina/Other All Complete-A Complete-A + B Incomplete
69.6 55.6 66.7 72.7
29.7 -
Total All Complete-A Complete-A Incomplete
35.6 23.4 30.8 51.4
19.9
(612)
(356)c
+ B
(W a A is complete motor and sensory loss, B complete loss. * Includes “other paralysis.” c Excludes 28 with no persistent neurologic deficit.
motor
16.4 21.9b
but
not
complete
sensory
198
JOHN
F.
KURTZKE
the nature of the lesion (severity and level) by the age at onset and by the cause of injury and death, as well as perhaps by sex. As a first approximation though, we can look at two large series with at least some cases followed for lengthy periods, and wherein most the cases were probably ascertained soon after injury (Table 35). Breithaupt, Jousse and Wynn-Jones (5) reported on life expectancy for a series of 599 cases of traumatic spinal cord injury out of 643 “treated at Lyndhurst Lodge, Sunnybrook Veterans Hospital and the Toronto General Hospital between January 1, 1945 and December 31, 1958.” (p. 74). TABLE
35
LATE SURVIVAL IN TRAUMATIC SC1 EXPRESSED AS CASE-FATALITY RATIOS, ACCORDING TO LEVEL AND SEVERITY OF LESION AND SEX ; OBSERVATION PERIODS TO 21 yr IN (A) TORONTO (JOUSSE ET AL., 1967) AND TO 20 yr IN (B) ENGLAND (GUTTMANN 1973) Level
& severity by series
Case-Fatality Total Male (percentages)
Total series (4 (B) Quadriplegia All (A) (B) Complete Incomplete
(A) (B) (A) (B)
Paraplegia All (A) (W Complete Incomplete
(A) @I (A) WV
All
complete (A) W
All incomplete (A) w Other lesions cauda equina
(B)
ratio Female
Total
Deaths/cases Male
Female
21.0 16.9
21.5 -
1.5.S -
203/965 331/1963
184/842 -
19/123 -
23.0 15.2 29.0 20.7 19.0 13.0
25.9 -
12.7 -
66/255 -
9/71 -
26.7 -
46.7 -
31/116 -
7115 -
25.2 -
3.4 -
75/326 71/466 381131 28/135 37/195 43/331
35/139 -
2156 -
20.0 18.1 22.7 20.2 16.6 12.5
20.1 -
19.2 -
118/587 -
10/52 -
21.5 -
38.5 0 -
72/335 46/252 -
lo/26 -
18.3 -
128/639 188/1036 82/361 154/763 46/278 34/273
24.4 20.3
22.8 -
415 -
120/492 182/898
103/451 -
17/41 -
17.6 12.8
20.7
2.4 -
831473 77/604
81/.?91 -
2/82 -
15.6
-
-
72/461
-
-
0 -
EPIDEMIOLOGY
199
This study was expanded (25) to include 965 patients, but excluding 99 partial paraplegics with good urinary function who “were found to have a life expectation equal to the nonparaplegic group. . . . The period of ubservation thus covers 21 years from January 1, 1945, to December 31, 1966.” (p. 199). It also includes 366 first treated after January 1, 1959. Guttmann’s (20) series from the Stoke Mandeville Spinal Cord Injury Center at Aylesbury, England, where he has been the director since its origin in February 1944, has been referred to repeatedly. It was unfortunate that the data from such a vast experience were not, in this portion, differentiated by sex. The results presented deal with the situation of the patients as of 1963, Table 35 summarizes the case fatality ratios according to level and severity of lesion, and sex, from these two surveys. Percentages dead are uniformly a bit lower in the English series than the Canadian. In both, complete lesions-particularly quadriplegia-are once again of worse prognosis than incomplete, and incomplete paraplegics seem to fare best of all. Recall that these series would include at least some early deaths in hospital, as in Table 33. The sex differentiation in Toronto suggests a more benign course for females-but numbers are quite small, since in all we are dealing with only 19 deaths in 123 injuries among females. It is for this reason too that the apparent excess of females in complete lesion deaths, especially cervical, and their deficit in incomplete, should be regarded cautiouslyespecially when there were no incomplete paraplegia cases recorded for women. Causes of Lute Death. Guttmann (20) made the valid point that not all deaths following spinal cord injury are in fact the result of such trauma, a point which is obvious upon reflection, since individuals are still subject to the other ills of man. In his own series of 331 deaths among 1963 patients with traumatic SCI, 242 he attributed to the injury; 89 or 27% of the total were “causes of death quite independent of those as a direct result of paraplegia, such as tuberculosis of the lung, cancer, other diseases, cerebral hemorrhage and new accidents.” (p. 631). In Table 36 is a comparison of deaths in a spinal cord injury center versus those found upon follow-up of the group in Toronto, for most of whom death occurred after discharge from hospital. The former is a summation of a series of 55 autopsies for 1946-1955 (13) and of 35 for 19551963 (43) from the same VA Hospital Center in Richmond, Virginia. Differences between the two reflect the youth of the VA series, and the ageing over time for the Toronto group-thus the higher proportions of vascular disease in the latter. The most common cause of death in either series is renal disease. Nyquist and Bors (39) also reported renal failure as the underlying cause in 32% of cord injury deaths in another VA
200
JOHN
F.
KURTZKE
TABLE CAUSES Cause
OF LATE
of death
36
DEATHS
IN TRAUMATIC
VA Hospital5 percentages
Renal disease Cardiovascular disease Cerebrovascular accident Pulmonary disease Gastrointestinal disease Liver disease
30.0 7.8 0 13.3 8.9 8.9J
Decubiti Suicide Other Unknown W
6.7e 0 18.9
a Dietrick 1957 and Pearce 1964, b Jousse 1967. c 1965 population of Canada. d Includes 5 (5.6%) hepatitis. e Generalized infection/septicemia.
(!g Richmond,
SC1
Toronto Percentages
36.5 16.3 5.9 7.4 5.9 1% 2.0 3.4 14.3
follow-up* Cases observed/ expectedc 74/l 33/31 12/6 15/l 12/4 3/4/-
7/2 29135 14/(203/80)
Virginia.
Hospital center. This is most often renal failure from ascending pyelonephritis or from amyloidosis-the latter the resultant of chronic recurrent infections of skin (decubiti) or bladder. The observed/expected ratios for renal deaths from the Canadian series point out the massive excess therein. And this is far from the entirety of the renal disease problem in the cord-injured. In the series of Dietrick and Russi (13), although renal disease was the underlying cause in 20%, pyelonephritis was present in 65%, cystitis in 75%, and either one of these in 90% of these autopsied cases. The excess for pulmonary disease is predominately for bronchopneumonia and-less so-for pulmonary emboli. The excess for the gastrointestinal tract is largely for peritonitis (with or without perforation) from bowel obstruction-and from urinary tract instrumentation and decubiti. Amyloidosis plays a role here too, as in the liver-diseased. In one sense it may be surprising that so few suicides are reported-but 7/%5 cases in Toronto. Even the excess for stroke may be a sequel of the cord damage-either directly through the hypertensive crises such patients suffer, or indirectly through renal hypertension. In essence though, most of the excess of deaths in the cord-injured
201
EPIDEMIOLOGY
would likely disappear if one could find an answer long-term management of the neurogenic bladder. Survival
from Life-Table
to the problems
of
Allalysis
It is clear that the case fatality ratios from the prior sections do not adequately reflect a true picture of the course of traumatic SCI, even in terms of survival, since the observation periods would have ranged from but a few months up to some 20 yr, patients would have been added over the interval in question-and would have been at varying intervals after injury when first ascertained. The proper method for handling such data is life-table analysis. In simplified fashion, an annual survivorship table is built by taking the number at risk at the start of a given year, finding the proportion who die and who survive during that year, and beginning the next year with the survivors in order to repeat the process. Each year’s survival proportion is multiplied by the fraction surviving up to that year. The point at which the percent survival is 50% will be close to the average life expectancy for the group in question. In order to calculate this properly, a subject is included as “at risk” only for the interval he is under observation. If then, a patient is first seen 10 years after injury, he should be added to the series for calculation only for the 11th year of illness and thereafter. Conversely, if he is no longer observed after five years of illness, he is a loss or withdrawal in that year, and is deleted from the survivors at risk for year 6, just the same as the deaths. This method permits then valid estimations of survivorship when one is not able to take a single cohort in time and follow them all to death. One can also compare the survival experience of the group under study with that for the population from which the group is drawn, and provide estimates as to the excess (or deficit) of observed mortality to that expected. Breithaupt et al. (5) reported just such a procedure, and concluded that the death rate for traumatic quadriplegia (all severity) was 12 times that of the normal population, and for traumatic paraplegia nearly five times the normal. Of the 94 deaths-which must have occurred within the maximum observation period of 16 yr-56 had occurred within 5.5 yr of the onset of paralysis. Data were not published to permit calculation of the life tables, which were drawn to show survival from 100% to 0%. The “50% survival duration” was given as 36 years for those age 20, 25 years for age 35, and 17 years for those age 50 at injury. It would appear that the curves as drawn-if based on observation and not on projectionwere calculated from very small numbers.
202
JOHN
F.
KURTZKE
The later experience of these Toronto patients is noted in Table 37. Again, the data on which this table was based are not available, and the prior comments may be just as valid. But though one might question the quantitation of the foreshortened life expectancy, the qualitative aspects are likely : complete quadriplegia is especially ominous, while incomplete paraplegia apparently gives little if any foreshortening of normal life expectancy. Complete paraplegia seems more threatening than incomplete quadriplegia-a finding in accord with all series insofar as early results go, except for that of California (see above). The effects of age are not striking. For complete paraplegia, for example, the ratio for observed/ expected years of life ranges from 0.68 at age 20 to but 0.54 at age 50. An actuarial analysis of traumatic SC1 clearly limited to the period of observation in terms of entry into and withdrawal from the series was presented by Burke et al. (7), based upon the nationwide series of U.S. veterans who had been patients in VA hospitals at some time during the 11 years from onset of injury. Even though only “a small percentage” of the patients were so hospitalized immediately after injury, this point is taken into account in the analysis. (Whether this was so in the Canadian series cannot be ascertained.) There is though no guarantee the included early cases reflect all early cases. The survival experience for this veteran series is presented in Table 38. Both age and level of lesion are seen to be additive in their adverse effects, as prior data indicate. A similar study has been undertaken by Mesard et al. (34) covering new admissions to VA hospitals during the next decade, October 1955September 1965, with survival to September 1967 (Table 39). Method-
TABLE
37
ESTIMATED YEARS OF LIFE EXPECTANCY AFTER TRAUMATIC SC1 ACCORDING TO AGE AND TYPE OF LESION ; TORONTO 1945-66 (APPROXIMATED FROM FIGURE 2 “PREDICTED SURVIVAL TIME,” IN JOUSSE ET AL., 1967) Age at injury
Normal life expectancy*
Type Complete Quadriplegia
20 30 40 50 n Based
50 40 32 24 on 1965 Canadian
21 1.5 10 5 mortality
tables.
of lesion
Complete Incomplete paraplegia quadriplegia (years life expectancy) 34 26 19 13
40 32 24 17
Incomplete paraplegia
48 38 30 22
203
EPIDEMIOLOGY
TABLE PERCENTAGE LEVEL
Age
81 Level
Suw1v.4~
38
IN TRAUMATIC
SC1 ACCWIXNG
OF LESION, U. S. VA HOSPITAL SERIES, ADMISSIONS (BURKE ET AL., 1960)
(Original
N) 1 mo
Totalh
(5575)
15-24 yr Paraplegic Quadriplegic
(2452) (1845)
TO .\GE
Time after injury 1 yr 5 yr (percentage survival)
10 yr
89
85
77
(607)
94 89
92 87
88 83
81 77
25-34 yr Paraplegic Quadriplegic
(2212) (1705) (507)
95 70
92 68
86 64
79 5.5
35-44 yr Paraplegic Quadriplegic
(606) 92 64
83 57
69
U-56)
94 73
45-59 yr Paraplegic Quadriplegic
(305) (198) (107)
91 76
82 66
69 54
41
(450)
~\XI)
1946-1955
Normal 10 yr Survival”
c.70 98
97
94 c 83 c
a Normal survival for U. S. men based on death rates 1949-1951. * Calculated weighted average based on data presented. c Numbers too few for authors’ calculations.
ology was the same as for the prior study. It is unfortunate the prior work was not updated as well. Weighted averages based on proportions alive at each age and level and the proportions so represented in the original series by age and level have been calculated for both the veteran series. Looking first at these figures, one could conclude there has been a dramatic improvement in survival over the few years between these series: 97% of the recent series survive one month instead of 89% ; at five years 88% are alive instead of 77% ; and so on. In each age-lesion category there has been a striking gain (there had been no patients 60 or older reported in the early series). The marked effects of age on survival (as well as the level) are seen in Fig. 5. Note however that only 55% of normal individuals in the eldest age group would be likely to have survived ten years, while the cord-damaged ratios were 29% for paraplegics and 24% for quadriplegics. It is then not clear that the proportional fatality ratio by age differs very greatly. For the paraplegics, the observed/expected ratio at each successively older age group is 0.98, 0.93, 0.97, 0.87, and 0.51. The decline then is really only in the oldest group, which is quite small.
204
JOI-IN
F.
KURTZKE
TABLE PERCENTAGE LEVEL
SUKVIVAL
Age and level
U. S. VA
OF LESION,
ADMISSIONS
(FROM
Original
MESARD
N 1 mo
Totalb Paraplegia Quadriplegia
2823 1559 1264
