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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