The findings, published in Human Brain Mapping, also revealed that the left hippocampus of these patients remained the same, and that other types of depression — including vegetative depression, which may result in extreme fatigue — were not linked to size reduction in the hippocampus.
“Patients with medical disorders — and especially those with inflammatory diseases such as MS — often suffer from depression, which can cause fatigue. But not all fatigue is caused by depression,” said study leader neurologist Nancy Sicotte, M.D., an expert in multiple sclerosis and state-of-the-art imaging techniques.
“We believe that while fatigue and depression often co-occur in patients with MS, they may be brought about by different biological mechanisms,” said Sicotte, director of the Multiple Sclerosis Program at Cedars Sinai Medical Center in New York.
“Our studies are designed to help us better understand how MS-related depression differs from other types, improve diagnostic imaging systems to make them more widely available and efficient, and create better, more individualized treatments for our patients.”
MS is an inflammatory disease that damages the myelin sheath of nerve cells in the brain and spinal cord. This damage disrupts the ability of parts of the nervous system to communicate, resulting in a wide range of signs and physical, mental, and psychiatric symptoms.
The study findings support previous research that has linked the hippocampus to the high frequency of depression in multiple sclerosis. In the new study, however, researchers were able to use a computerized imaging technique called “automated surface mesh modeling” that can quickly detect thickness changes in different regions of the hippocampus.
The new approach offers easier access to MRI scans and automates the brain mapping process, whereas the analysis of hippocampal thickness used to be far more difficult, requiring time-consuming studies of MRI images.
Source: Cedar Sinai Medical Center