The “But For” Test

A 40-year old lady with a long history of migraines presented to the Accident and Emergency Department three hours after the onset of a severe headache.? This was associated with confusion, blurring of her eyesight and a feeling of weakness in her left leg.

She was seen in the Accident and Emergency Department by the junior trainee, who decided this was due to her migraine, gave her pain relief and sent her home.? A full neurological assessment was not carried out.

Several hours later, she was getting worse with nausea and some vomiting, her confusion appeared to be increasing and relatives felt she had great difficulty seeing.? She was taken back to another hospital, where a neurological examination was carried out and found weakness in her left side and she was having difficulty in vision.? An emergency MRI scan was carried out, which showed no specific abnormality, in particular no obvious area of infarct or bleeding within the brain.

She was observed in the hospital for the next 48 hours.? A repeat CT scan showed patchy ischemia at the back of her brain, including the area that deals with vision.

A final diagnosis was made of spasms in the posterior vessels to the brain as part of her migraine.

An action was taken against the initial hospital for not properly examining her, obtaining a scan, and initiating treatment at an early phase.

The management of stroke has changed considerably over the last few years.? It is important, if there is a suggestion of a thrombus (clot) in the vessels that at an early phase, lysis be undertaken to dissolve a clot by giving drugs intravenously.? This has to be undertaken within four hours.?

Therefore, in the present case, this lady should have been fully examined initially and an MRI scan carried out immediately so there is a clear breach of the duty of care, both in terms of the trainee and the trainee’s supervision.? However, this is a very rare syndrome and, with migraine, it is usually transient, rarely giving rise to infarcts of the brain/stroke.?

Initially, scans did not show any abnormalities, so lysis was not required.? The problem was a spasm in the vessels, which was not reasonably diagnosed immediately.? If it had been so, there may have been some help from vasodilators, but unfortunately, by the time the blindness and the weakness were established, before hospitalisation, prolonged problems were already established, and no management at that time would have made a difference.? A Consultant Neurologist gave the same evidence.

It is therefore a case, very similar to Barnett in that there was a clear breach of duty of care but no long-term damage which would not have occurred “but for” the breach.? Therefore, a case in medical negligence could not be substantiated.