Missed spinal arteriovenous malformation

19 July 2018
By Dr Anna Fox, GP

Mr D was a 33-year-old motor mechanic. He was finding it difficult to work because of pain in his lower back and pains shooting down the backs of both legs; this puzzled him, as he had not done anything to injure his back. Mr D was also constipated, which was very unusual for him, so he made an appointment with his GP, Dr P, who examined his spine and found no localised tenderness. She observed his gait and noted that it was normal. Dr P prescribed tramadol on the basis that Mr D had tried it before to good effect, and she advised him to return if his symptoms did not settle.

Mr D’s back pain improved slightly on tramadol but it did not go away. Seven months later, Mr D started to have problems passing urine. He didn’t feel like he was emptying his bladder properly and he had to keep returning to the bathroom to try again. He went back to see Dr P, complaining of the lower back pain and the urinary issues. Dr P did not examine him, but arranged an MRI scan of his lumbar spine. The MRI report was suggestive of an arteriovenous malformation (AVM) in the lower thoracic and upper lumbar region.

It was almost a month later before Dr P wrote to the neurosurgical team with a copy of the MRI report. There was a further delay of approximately six weeks before Mr D underwent embolisation of the AVM.

Mr D brought a claim against Dr P. It was alleged that Dr P had failed to carry out an adequate neurological examination, failed to refer for a neurosurgical opinion in a timely manner and failed to act promptly on the MRI scan results. It was claimed that these delays had resulted in chronic bladder, bowel and sexual dysfunction. Mr D complained of ongoing neuropathic pain and weakness in his legs, rendering him unable to walk. He claimed that he could no longer work or drive.

Expert opinion
Medical Protection instructed an expert GP to comment on the care provided by Dr P. The GP expert was critical of Dr P, stating that she should have taken a full history and examined Mr D during both consultations, with a view to assessing his neurological status. The expert felt that she should have considered the possibility of a spinal neurological problem at the second consultation, in light of Mr D’s urinary symptoms. In addition, criticism was made of the failure to make inquiries or act on the MRI result in a timely manner. In light of the symptoms, the expert felt that the MRI results should have been discussed with a neurosurgeon the same day, which would have enabled their urgent assessment.

Medical Protection also instructed a consultant neurosurgeon to comment on whether the delays had caused or contributed to Mr D’s injuries. It was felt that causation was not clear cut. The neurosurgeon commented that even if a referral had been made following the second consultation, treatment may not have been provided materially sooner than it was; it followed from this that some of the neurological deficit may have occurred in any event.

Based on the expert advice, a decision was made to explore settlement.
 
Further investigation and outcome
Mr D was claiming a substantial amount of compensation to cover loss of earnings, costs of care and alternative accommodation adapted to his needs. Medical Protection noted that there were certain aspects of Mr D’s claim that did not ring true. The medical evidence served in support of his claim contained a number of inconsistencies in his symptoms, particularly in relation to the loss of power in his legs. He had also declined examination by the spinal rehabilitation expert instructed by Medial Protection to assess his condition.

Medical Protection commissioned surveillance evidence to be gathered on Mr D. This demonstrated that he was fully mobile on both legs and did not need the assistance of crutches or a wheelchair. He was also able to drive. The surveillance evidence was disclosed to Mr D’s solicitors with a request that he undergo electromyography testing to establish the extent of his neurological disability. This offer was not taken up; however, it allowed negotiation and settlement at a fraction of the amount originally claimed.

Learning points
  • Spinal vascular malformations consist of an abnormal connection between the normal arterial and venous pathways. These malformations do not benefit from intervening capillaries. As a result, venous pressure increases and the individual is predisposed to ischemia or haemorrhage and then neurological compromise.1 
  • Diagnosing these lesions early and providing timely treatment is imperative if patients are to achieve optimal neurological outcomes.1

  • When assessing patients with back pain, clinicians should consider red flag symptoms and signs that may suggest a serious underlying cause. If found, urgent admission or referral for specialist assessment should be made. A recent NICE CKS details the red flags that clinicians should be aware of.2

  • Medical Protection rarely carries out surveillance on claimants. Here, however, it was considered appropriate because of the extremely high value claim and discrepancies that cast a doubt on the veracity of the claimant’s case. Such evidence proved highly effective in dramatically reducing the size of Mr D’s claim. This in turn saved Medical Protection – and members – a considerable amount of money, which could be better utilised elsewhere.

References
  1. https://emedicine.medscape.com/article/248456-overview#a7Vascular Malformations of the Spinal Cord
  2. https://cks.nice.org.uk/sciatica-lumbar-radiculopathy#!diagnosis