July 1, 2022

Between life and death

Many doctors misdiagnose the so-called vegetative state.

The controversial case of Terri SchiavoFew end-of-life decisions can be more heart-wrenching for relatives than assenting to a doctor’s recommendation that life support be removed from a patient in a vegetative state because they show no signs of awareness at all.

However, a Belgian study in the journal BioMed Central Neurology suggests that about 40% of doctors’ diagnoses of "vegetative state" (VS) are wrong. These patients are actually in a minimally conscious state (MCS) in which they drift in and out of consciousness. And they could even emerge from that state.

The implications of this research are disturbing, according to The Economist: "many people may be at risk of early termination even when they show flickering signs that their consciousness has not departed entirely".

"Differentiating the vegetative from the minimally conscious state is often one of the most challenging tasks facing clinicians involved in the care of patients with disorders of consciousness. Misdiagnosis can lead to grave consequences, especially in end-of-life decision-making," says Dr Steven Laureys, of the University of Liege.

The problem seems to be that MCS is a relatively recent diagnostic category – and doctors still are not familiar with it. Furthermore, they trust their intuition rather than a more precise diagnostic scale. As a result, the error rate of 40% does not appear to have changed since a similar study 13 years ago.

The Belgian team studied how doctors diagnosed 103 patients with disorders of consciousness. They compared diagnoses based on doctors’ observations with those based on a well-established standardized neurobehavioral rating scale, the JFK Coma Recovery Scale-Revised (CRS-R).

They found that of the 44 patients diagnosed with VS based on the clinical consensus of the medical team, 18 (41%) were found to be in MCS following standardized assessment with the CRS-R. In the words of Dr Laureys, "It is likely that the examiners’ reliance on unstructured bedside observations contributed to the high rate of misdiagnosis of VS patients."

As The Economist points out, this puts vulnerable patients at risk: "Insurance companies, for example, prefer a diagnosis of vegetative to one of minimally conscious, Dr Laureys says, because no expensive rehabilitation is required for those in a vegetative state." ~ BMC Neurology, July 21