Syringomyelia Secondary to Paraplegia due to Fractures of the by mikesanye

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									1406                                          SA     MEDICAL       Jo    R   AL                          2l Augu t 1976


      Syringomyelia Secondary to Paraplegia due to Fractures
                      of the Thoracic Spine
                                                        A. T. SCHER

                           SUMMARY                              with a sensory level at T5. An X-ray film of the thoracic
                                                                spine demonstrated a fracture dislocation at the T5/T6
   The clinical, radiological and operative findings in 3       level.
   patients with paraplegia consequent upon fractures of           Approximately 18 months after the accident the patient
   the thoracic spine are presented. Myelography revealed
                                                                presented with symptoms of decreased sensitivity to tem-
   widening of the cervical spinal cord in all 3 patients and
                                                                perature and pinprick in the right forearm and hand.
   this finding was confirmed at operation. The incidence of
                                                                Clinical examination confirmed the decreased temperature
   this condition in the Spinal Injuries Unit is shown to be
                                                                and pinprick sensitivity in a C6 to C8 distribution and an
   similar to that noted in other large units. The principal
                                                                absent right triceps jerk was also noted.
   theories as to the aetiology of this condition, Le. cavi-
                                                                   A myelogram revealed marked dilatation of the cer-
   tation secondary to haematomyelia or myelomalacia
                                                                vical cord extending from C7 to C3. In addition there
   caused by circulatory disorders, are reviewed.
                                                                appeared to be some dilatation of the thoracic spinal
                                                                cord immediately above the fracture site at T5/T6.
   S. Air. med. J., 50, 1406 (1976).
                                                                   At operation, after removal of the laminae of C5 and
The occurrence of a cervical yringomyelic syndrome in           C6, the dura was opened and a bulging spinal cord with
paraplegic patients some time after trauma to the tho-          a fluctuant centre was found. A midline incision was
racic or lumbar spine, is an unusual but well-recognised        made in the cord and a cavity was entered. After drainage
complication of spinal cord injury.                             a Silastic wick was inserted. The patient made an excel-
  The clinical, radiological and surgical findings in 3         lent neurological recovery and was able to return to his
patients who have developed this complication will be           previous occupation of gem-cutting.
discus ed.
                                                                Case 3
                       CASE REPORTS
CaseI                                                              A 34-year-old woman was involved in a motor vehicle
                                                                accident which resulted in complete motor and sensory
   A 22-year-old man was involved in a motor vehicle            paraplegia with a sensory level at T6. X-ray films of the
 accident which resulted in complete paraplegia with a
                                                                thoracic spine revealed a crush fracture of T6.
sensory level at TIO. X-ray films of the thoracic spine
                                                                   Eleven months after the accident she complained of
 demonstrated an oblique fracture of the body of T9 with
                                                                numbness and lack of appreciation of temperature in the
lateral shift to the left of the lower fracture fragment.
                                                                right arm. On examination she was found to have hypo-
   Approximately 12 months after the accident the patient
                                                                algesia of the hand (except the thumb) and of the medial
complained of altered sensation in the right arm. This
                                                                side of the forearm. There was also decreased apprecia-
alteration was first noticed as decreased perception of
                                                                tion of temperature and vibration over approximately the
temperature.
                                                                same area. Tendon jerks were also absent in the right arm.
   Clinical examination confirmed the decreased perception
                                                                   A myelogram demonstrated some widening of the
of temperature and revealed decreased pinprick sensitivity
                                                                cervical spinal cord A laminectomy was performed at
in the right arm from the C6 to the T2 level. There was
                                                                the C6/C7 level and after the dura had been opened
also wasting of the intrinsic muscles of both hands.
                                                                the cervical cord appeared to be flattened. With respira-
   A myelogram demonstrated welling of the cervical spinal
                                                                tIOn some pulsation was seen as though an intramedullary
cord and measurement revealed a maximal diameter of
                                                                fluctuating mass was present. The cord was incised in
2,6 cm for the cord. Laminectomy of the lower cervical
                                                                the midline posteriorly and a dilated central canal was
spi.ne (C5, C6, and C7) was performed and a cyst-like
                                                                entered at about 3 mm. A Silastic wick was inserted and
leSIOn was found. This was aspirated and approximately
                                                                sutured to the dura. The patient made an excellent neuro-
3 ml fluid was withdrawn. After the operation the patient
                                                                logical recovery after the operation.
showed neurological improvement.

Case 2                                                                                 DISCUSSION
                                                                Clinical Features
  A 33-year-old man was involved in a motor cycle acci-
dent which caused complete sensory and motor paraplegia           All 3 patients were relatively young (between 22
                                                                and 34 years old) and had sustained fractures of the
                                                                thoracic spine in motor vehicle accidents. None of the
Spinal Injuries Unit, Conradie Hospital, Cape Town              patients exhibited any clinical signs of injury to the cer-
A. T. SCHER. M.B. CH.B., D.M.R.D.                               vical spinal cord on admission, nor was there radiological
Dale received: 13 February 1976.                                evidence of any cervical spine fracture or dislocation. All
21 Augustus 1976                            SA      1EDIESE       TYDSKRIF                                             1407

3 had developed complete motor and ensory paraplegia
immediately after injury.
   Treatment was conservative in all 3 cases and no sur-
gery to the pine was performed. The time interval be-
tween injury to the spine and development of symptoms
ranged from 11 to 18 months.
   The clinical presentation of all 3 patients was identical,
i.e. alterations in the perception of sensitivity in the right
arm. and on clinical examination, decreased temperature
and pinprick sensitivity with absent tendon jerks in the in-
volved limb.
   Barnett et af.' noted that in all their 17 cases symptoms
and signs developed unilaterally initially, and subsequently
became bilateral in 11 out of the 17 cases. The onset of
symptoms in their patients varied from 1 to 15 years after
initial injury. They found no relationship between the
latent period and the distance that the new lesion had to
extend from the level of the trauma to produce symptoms
referable to the cervical cord.

Incidence
   Seventy-three patients with this condition have been
recorded in the literature.' Between November 1963 and
December 1973 808 patients with paraplegia due to injury
to the lumbar or thoracic spine were admitted to our
unit. In addition to the 3 cases described above, 3 further
cases of paraplegia with typical syringomyelic symptoms
have been observed, but myelography or surgery were not
performed on these patients. The inclusion of these addi-
tional cases, i.e. a total of 6, would put the incidence
of this complication in our unit at 1.3°~. Barnett et of.'
reported an incidence of 1,8°~ in 864 paraplegic patients.

Radiological Diagnosis                                             Fig. 1. Case 1. Myelogram demonstrating s)'DlIIIetrical
   There was no evidence of any widening of the spinal             widening of the lower cervical spinal cord.
canal on the frontal projection, nor of any flattening of
the pedicles of the cervical vertebrae to suggest an intra-      the spinal cord in all 3 patients showed frontal dimen-
medullary expansive lesion. Conclusive diagnosis is best         sions greater than the upper limit of norma!.'
made by myelography, which demonstrates the typical                 Another technique which has been employed is direct
fusiform expansion of the cord within the theca, usually         intramedullary myelography with injection of contrast
extending over several segments. The cord lies centrally         material directly into the cystic cavity within the spinal
in the Myodil column, the margins of which are in their          cord.' This allows accurate assessment of the extent
normal apposition to the pedicles, arches and vertebral          of cavitation within the dilated cervical spinal cord.
bodies. Fig. 1 demonstrates this typical appearance.                Myelographic evidence of arachnoiditis at the original
   Di Chiro and Fisher' have pointed out that measure-           site of spinal fracture has been described: This was also
ment of the cervical spinal cord on the frontal view is          present in 1 of our patients. This arachnoiditis does not
liable to error, owing to the magnification factor which         extend more than 3 segments above the level of the
changes with variations in the size and the anatomical           original trauma, having been found both in patients who
features of the patient. Measurement of the myelographic         have been treated by laminectomy, and in those who have
ratio of the spinal cord width to the subarachnoid width         been given no surgical treatment.
would appear to be a more accurate a sessment of enlarge-           All these observations apply to myelography performed
ment of the cervical spinal cord.' Thi ratio is unaffected       using iophendylate (Myodil), but recently the use of ga
by differences in tube-film and object-film distances and        myelography for the investigation of yringomyelia ha
i less influenced by individual variations in the patient"       been advocated. The advantage of thi technique are
size than are absolute measurement of the cord.                  that there is good visualisation of the cord in the lateral
   A value greater than 0,80 for the ratio of cord width         view and that the neces ity for the introduction of iophen-
to subarachnoid space should be considered pathological.'        dylate into the subarachnoid pace, with the pas ibility
Assessment of the ratio in our 3 patients did, however,          of producing an arachnoiditi , i obviated. It has been
not produce a figure greater than 0,80 in any case, where-       demon trated' that a mobile column of fluid exists within
as conventional measurement of the frontal diameter of            ome yringomyelic cavitie. Thi column of fluid will
 1408                                         SA     MEDICAL           JOUR        AL                                   21 August 1976

 expand a cord in the 5° head-down tilt of the radiogra-           traumatic necrosis and cavitation.
 phic table and the size of the cord shadow will diminish             The capillary circulation in the grey matter of the
 vi ibly in the 15° feet-down position. Gas myelography           spinal cord is known to be much richer than that in
 with lateral tomography has been used to make these               white matter.s The dorsal horn area is even more richly
 observations. Facilitie for such techniques are not avail-         upplied than the rest of the grey matter. Blows to the
 able in our unit.                                                 cord lead to early haemorrhage in this area of abundant
    Gas myelography is, however. technically more difficult        blood supply.
 and ince the faint ga shadow is obscured on the frontal             Autopsy findings in 95 cases of traumatic paraplegia
 view by superimposed tracheal and bowel shadows, pecial           revealed the frequent occurrence of haemorrhage, usual-
 techniques such as tomography or subtraction are neces-           ly involving the grey matter of the cord most extensively.'
  ary. The examination i more uncomfortable for the                  Venous infarction may be an additional factor which
 patient than conventional myelography and general                 determines the site as well as the nature of the early lesion.
 anaesthesia is recommended.'                                     The central posterior horns and ventral part of the dorsal
                                                                  columns have been identified as the major sites of haemor-
                                                                  rhage and haemorrhagic infarction in cases of thrombosis
 Aetiology
                                                                  of spinal veins. s
     The aetiology of post-traumatic syringomyelia has been          Once cavitation of the spinal cord has begun, it may
  a matter of some discussion. One theory is that cavitation       be enlarged by the transudation of fluid into it under
  i caused by haemorrhage into the cervical spinal cord            pressure. This expansion is more likely to occur in grey
  at the time of injury. Wolman: in postmortem investiga-         matter than in the firmer columns of white matter and,
  tions, found 3 types of intramedullary haemorrhage cavi-        owing to restricting investment of the pia mater, must take
  ties which extended over several segments, and which occur-     place chiefly upwards and downwards. Du Boulay' has
  red 4 - 6 weeks after injury to the spinal cord. The cavities   observed that with coughing or by other Valsalva-like
  were often multiple, being separated by strands of glial        manoeuvres the epidural veins become greatly distended,
 fibres. They were almost always associated with a frac-          and that 2 - 3 ml of spinal fluid is forced out of the spinal
  ture dislocation of the vertebrae.                              cord into the cerebral subarachnoid space under great
     It WOUld, however, be expected that haematomyelia in         pressure. This head of venous pressure leads to marked
 the cervical spinal cord would manifest with immediate           narrowing of the spinal subarachnoid space and to maxi-
 neurological deficit. None of our patients showed such           mal 'squeezing' of the cord in the cervical region. It is
 deficit on initial admission despite thorough neurological       evident that paraplegic patients confined to wheel-chairs
 examination.                                                     are forced to move the upper halves of their bodies more
     Holmes' reported cavities in spinal cord segments in         frequently and also through a greater range of movement
 more than half of his patients with gunshot injuries to the      to compensate for the lack of use of their lower limbs.
 spinal cord. These cavities adjoined the area of injury          These movements produce repeated Valsalva manoeuvres
 - above or below - and often extended as much as 4               which raise the spinal fluid pressure. This rise in pressure
 or 5 segments, and occurred just as frequently with con-         in the CSF around the cord would be transmitted to the
 tusion or compression of the cord as with direct injury.         side walls of the cysts and cause it to extend. The absence
     Holmes' postulated that they originated from an accu-        of valves in the veins draining the spinal cord probably
 mulation of fluid degeneration products under pressure,          contributes to the prolongation of the effect of a Valsalva
 in a small projection of the primary lesion, and extended        manoeuvre.
 along the lines of least resistance, increasing in size with
                                                                                            CONCLUSION
 time. Klawans,' on J9ostmortem examination of a patient
 with traumatic paraplegia who had developed progressive          Secondary syringomyelia should be suspected in patients
 myelopathy, described the presence of a syrinx (cleft) in        with paraplegia consequent upon previous fractures of the
 direct relationship to the previously injured area of the        thoracic and lumbar vertebrae, who develop a progressive
spinal cord. Histological examination demonstrated that           ascending syndrome which deprives them of some motor
 the syrinx was lined not by the ependyma. but by col-            and/ or sensory function in one or both of their upper
 lagenous tis ue.                                                 limbs. Complaints of alteration in pain and temperature
     All 3 of our patients exhibited a gap between the            sensitivity in the upper limbs some time after initial injury,
 upper level of the original sensory loss and the lower           should be carefully investigated by thorough neurological
level of the secondary sensory loss, following on develop-        examination and, if necessary, by myelography. The con-
ment of the cervical syringomyelia. In several of Barnett         dition is unusual, but recognition is important. particularly
et al.'s' patients similar findings were noted, and it is         since it is amenable to surgical treatment.
postulated that cavities of the type described by Holmes'
                                                                                                REFERE CES
extend up into the cervical region, but that expansion is
maximal in the cervical enlargement of the cord and is            1. Barnell, H. J. M., Foster, J. B. and Hudgson. P. (1973): Major
                                                                     Problems in Neurology. val. 1. p_ 129. London: \V. B. Saunders.
only radiographically demonstrable in this region.                2. Di Chiro, G. and Fisher, R. L. (1964): Arch.     eurol. (Chic.). 11, 125.
                                                                  3. Khilnani, M. and Wolf, B. S. (1963): J. Neurosurg .. 20. 660.
    Another theory of causation of this condition is mye-         4. Westberg, G. (1966): Acta radiol., suppl. 252. p. 5.
lomalacia through local changes in circulation. This would        5. Wolman. L. (1964): Paraplegia, 2. 213.
                                                                  6. Holmes. G. (1915): Brit. med. J .. 11. 769.
al 0 explain the predilection of the dorsal horns and the         7. Klawans. H. (1968): Dis. nerv. Syst., 29. 525.
                                                                     Hughes. J. T. (1971): Neurology (Minneap.), 21, 794.
anterior dorsal columns of the spinal cord for post-              9. Du Boulay, G. H. (19£6): Brit. J. Radiol., 39, 255.

								
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