An open, non comparative study of cervical myelography in. 68 adult patients using iohexol (Omnipaque) containing. 300 mg I/ml is reported. Satisfactory ...
1984, The British Journal of Radiology, 57, 785-787
SEPTEMBER
1984
Cervical myelography with iohexol By Brian Kendall and John Stevens The National Hospital for Nervous Diseases, London WC1
{Received April 1984)
ABSTRACT
An open, non comparative study of cervical myelography in 68 adult patients using iohexol (Omnipaque) containing 300 mg I/ml is reported. Satisfactory visualisation was achieved in all cases. Minor adverse effects occurred in 13 patients (19%); they were headache (8), neck or back pain (3), vomiting (3), nausea (1), dizziness (1) and nystagmus (1) and were of minor degree in most and moderate in a few, lasting more than 24 hours in only one patient. EEG performed in 39 patients before and 24 h after the myelogram showed no seizure activity or significant change. Iohexol is a very satisfactory drug for all types of myelography.
The merits of iohexol (Omnipaque) for lumbar myelography have been stressed (Eldevik et al, 1983; Kendall et al, 1983). They include absence of convulsive activity and mental changes; decreased incidence and severity of minor adverse effects; stability in solution and great reduction in cost in comparison with metrizamide. Recently trials of iohexol in higher concentration for cervical myelography have been performed and the published results in a small series have been very satisfactory (Nakstad et al, 1984). A larger open non-comparative study of iohexol in cervical myelography was performed with the main objective of further evaluating the safety, tolerance and image quality by monitoring adverse reactions, serial neuropsychological examination, heart rate, blood pressure and EEGs and the results are presented. PATIENTS AND METHODS
Patients between 18 and 70 years of age were admitted to the trial with the following exceptions:— 1. Emergency cases; 2. Epilepsy or pathological EEG, with definite spike activity; 3. Psychiatric disease or difficulty with co-operation; 4. Addiction to drugs or alcohol. After obtaining informed consent a total of 68 adult patients were admitted to the study, 37 men and 31 women, age range 18-74 (median 47 years) referred to the X-ray department for cervical myelography. Ten of the patients suffered from some form of hypersensitivity. The primary clinical diagnosis was cervical spondylosis (48), radiculopathy (15), canal stenosis (1), cervical brachialgia (1), tumour (2), and myelopathy (I)-
intake was encouraged. Concomitant medications were given but premedication was employed in only one patient. The spinal puncture was performed using a 22 gauge needle, and the usual technique for either C1-C2 puncture (49 patients) or lumbar puncture (19 patients) was employed. The former route was preferred unless a high cervical-foramen magnum lesion or a mass causing cervical obstruction was suspected. After the withdrawal of cerebrospinal fluid (0-12 ml, median 7 ml), a dose of 3-12 ml (median 10 ml) of iohexol 300 mg I/ml was injected under TV control; the total procedure time was 15-90 min (median 30 min). For reference, baseline haematology (sedimentation rate, haemoglobin and white blood cell count) and cerebrospinal fluid values (macroscopic description, cell count, protein) were obtained in connection with the myelography.
Observations and measurements 1. Clinical examinations. A detailed neurological examination was performed within 48 h before myelography and repeated at about 24 h following the procedure. A limited number of parameters (general mental condition, brief survey of motor function and sensation) were also assessed about 6 h after the myelography. Blood pressure and heart rate were recorded on the morning of procedure, immediately before and after the investigation, and 6 and 24 h later. 2. EEG was recorded in 40 patients within the 24 h before the examination and was repeated 24 h after the examination in 39 of these patients. 3. Patients were closely observed for any adverse reaction both during the examination and for at least 48 h afterwards; adverse reactions were graded as mild, moderate or severe. 4. The visualisation was recorded as being excellent, good, adequate or poor.
Procedure
To avoid possible dehydration patients were allowed a light meal on the morning of the procedure and fluid 785
Data analysis A Wilcoxon signed rank test was used to decide whether changes in vital signs were significant at a 5% level. For continuous parameters, median and interquartile range values were used as indices of location and dispersion.
VOL.
57, No. 681 Brian Kendall and John Stevens TABLE I BLOOD PRESSURE (mmHg) AND HEART RATE (BEAT/MIN)
Systolic blood pressure Interquartile range Median Diastolic blood pressure Interquartile range Median Heart rate Interquartile range Median
Before
Immediately before Immediately after
120-140 130
120-140 130
77-90 80
80-90 80
70-80 80
70-88* 80
3 h after
24 h after
115-140* 130
112-140* 127
72-90 80
70-80* 80
75-80*
70-84 80
80 74
70-80 72
117-140* 130
*statistically significant changes
showed minor changes considered to be related to drowsiness; in two the changes were in the premyelographic and in three in the post-myelographic record. Minor lateralised abnormalities were present in six cases and were more prominent in three premyelographic and in three post-myelographic records. In the other 13 cases generalised abnormalities occurred, which were minor in 10 and more prominent in three, consisting of irregular theta activity and episodic 2 c/s slow waves, maximal frontally and lasting 2-5 s; the abnormalities were either absent or much less evident in the pre-myelographic record in all but one of
RESULTS
Clinical examination The clinical examinations showed no changes from base values. Blood pressure and heart rate values showed statistically significant changes (Table I), but none of these were of clinical concern. EEG measurements In 26 cases no change due to contrast medium was detectable; this group could be subdivided into three. There was no difference between the recordings before and after giving contrast medium in 15 cases. Five cases
TABLE II ADVERSE REACTIONS
Sex
Age
Puncture
Type of reaction
M F M
57 40 74
C C C
M F M F F F
63 35 57 48 37 64
C C C C
M
36
L
M F M
24 58 49
L L L
Vomiting Headache Nausea Vomiting Headache Pain in neck Headache Pain in neck Headache Dizziness Headache Vomiting Headache Local back pain Headache Headache Nystagmus
cL
Number of patients/total: Number of recorded adverse reactions: Key: Intensity Outcome Cause Puncture
1 ntensity
\> I>
\> \I
\I '.I
Outcome
Time of onset
Duration
Cause
R R R R R R R R R R R R R R R R R
2h 5h 2.5 h
2h 6h 30 min 30 min 6h 30 min 72 h 10 min 3h 6h 6h 5h 5h 1 min 4h 10 min 10 min
C C P P
16 h immediate 12 h immediate 12 h 13.5 h 13.5 h 3h 3h immediate 6h immediate immediate
13/68 (19%) C 8/49 (16.3%) L 5/19 (26.3%) 17 C9 L8
1 = mild 2 = moderate 3 = severe R = recovered without sequelae C = contrast-medium-related P = procedure U = cause uncertain C = cervical injection L = lumbar injection
786
c u c c c c c c c c c c c
SEPTEMBER
1984
Cervical myelography with iohexol these cases, in which minor changes were more pronounced on the first tracing. They were considered to be due to the contrast medium and probably initiated in brain stem disturbances. There was no correlation between EEG changes and adverse clinical reactions. In no case was there any spike or epileptic activity. The EEG findings will be reported separately in more detail, but both the frequency and severity of the changes are much less than those observed with metrizamide. Adverse reactions (Table II) A total of 17 adverse reactions was recorded in a total of 13 patients (19%), seven men (18.9%) and six women (19.4%). The incidence was considerably higher using lumbar injection (26.3%) than cervical puncture (16.3%), the major difference being in the frequency of headache, which occurred in 20% of the lumbar and 8% of the cervical injections. None of the reactions was considered to be severe and all were classified as being either mild or moderate. The duration of reactions was short in all but one case; this patient experienced a moderate headache which began 12 h after the myelogram and persisted for 72 hours. Visualisation The upper level of contrast medium reached to Cl or above in all cases. Visualisation was excellent in 27, good in 40 patients and adequate in one. The radiological diagnoses were: cervical spondylosis (25), disc prolapse (24), canal stenosis (2), syringomyelia (2), tumour (1) and normal (14). DISCUSSION AND CONCLUSION
In this open and non-comparative study in cervical myelography, in which 68 adult patients received doses of between 3 ml and 12 ml of iohexol 300 mg I/ml, the incidence of side-effects compares favourably with that recorded for other non-ionic contrast media (Bassi et al, 1982), and absence of epileptogenic changes on postmyelographic EEG recording, which we believe to be a unique feature of iohexol, combine to make it very satisfactory for cervical myelography at the concentration and dosage levels used in this series. Since this detailed study, about 200 additional cervical myelograms, including many in paediatric patients, have been performed using iohexol in our department. All have been followed with neurological
examinations and questioned directly about possible side-effects. There have been no seizures or mental changes, no deterioration of neurological condition, and the incidence and severity of minor side-effects continues at the levels noted in the trial series. Anticonvulsant cover is unnecessary, even when the medium has been introduced above a spinal obstruction, in which case the danger of a convulsion precipitating paraplegia was an important consideration when epileptogenic contrast media were used. Furthermore, despite the relatively higher incidence of minor reaction, we consider that it is now correct to perform the great majority of cervical myelograms by the lumbar route, since some intracranial spillage of the contrast medium is no longer of great importance and lumbar puncture is a safe and universally available technique. Our personal observations leave us in no doubt that iohexol is the contrast medium of choice for all types of myelography. Encouraged by its safety, in selected cases the volume and concentration have been increased sufficiently to obtain adequate opacification of unusually large subarachnoid spaces including meningoceles, which may be difficult to study with smaller quantities of water-soluble medium; in appropriate patients, we have used as much as 5 g iodine equivalent without significant increase in the proportion or severity of adverse reactions. ACNOWLEDGMENTS .
We are most grateful to Dr H. Townsend for analysing the EEG records, and to Nyegaard Limited, Oslo, for supplying the iohexol and performing the statistical analysis. REFERENCES BASSI, P., CECCHINI, A., DETTORI, P. & SIGNORINI, E.,
1982.
Myelography with iopamidol, a non-ionic water soluble contrast medium; incidence of complications. Neuroradiology, 24, 85-90. ELDEVIK, O. P., NADSTAD, P., KENDALL, B. E. & HINDMARSH,
T., 1983. Iohexol in lumbar myelography. American Journal of Neuroradiology, 4, 299-301. KENDALL, B. E., SCHNEIDAU, A., STEVENS, J. & HARRISON, M.,
1983. Clinical trial of iohexol for lumbar myelography. British Journal of Radiology, 56, 539-542. NAKSTAD, P., AASERUD, O., HELGETVERT, A., NYBERG-HANSEN, R., GANES T. & BACH-GANSMO, T., 1984. Cervical
myelography with iohexol. Neuroradiology, 26, 123-129.
787
