Caroline Schnakers, who carried out the research with Laureys, told CNN that one probable reason for the high rate of misdiagnosis is that doctors often base their diagnosis on observations of a patient's behavior, rather than assessing patients using standardized tests.

CNN: Trapped 'coma' man: How was he misdiagnosed?

Seventy percent of patients remained with standardized physical therapy.

FORBES: Physical Therapy: A Reasonable Alternative to Surgery for Patients with Meniscal Tears and Arthritis

In a clinical trial conducted in Russia, dimebon improved the ability of patients with Alzheimer's disease on a standardized test used to measure disease severity.

FORBES: Magazine Article

Patients were randomly assigned to groups who received either surgery and postoperative physical therapy or standardized physical therapy.

FORBES: Physical Therapy: A Reasonable Alternative to Surgery for Patients with Meniscal Tears and Arthritis