Dr. Lisa H Johnston M.D.

What are cold sores?Cold sores or fever blisters are a very common perioral condition caused by the herpes simplex virus (HSV). There are two types of herpes simplex virus. Type 1 usually causes cold sores, although in some cases, the cold sores can also be caused by type 2. It is usually...

A new study by Australian researchers shows that childhood head injuries, which affect the development of children, can improve over time. The poorest recovery was seen with severe brain injury, while children with less severe injuries did not have many serious problems later. According to the...

Alzheimer’s is one of the primary causes of age-related dementia, and it's typically characterized by the progressive loss of connectivity between brain cells and their death, leading not only to the loss of memory and cognition, but also difficulties in social interaction.As the disease...

High blood sugar, blood flow problems, and diabetic ketoacidosis are just a few issues that diabetic patients need to keep in mind when managing their illness. But, this list continues to grow as we learn more about the disease.It was recently discovered that those who are struggling with this...

During one weekend in the summer of 2005, when Tammy “Mimi” Duchesne and her husband JP went camping, Mimi noticed double vision in her left eye. A few years later, her vision become blurry. Being a nurse, she realized that she needed to see a doctor right away to discuss her symptoms. A year...

Where is the hypothalamus located?The hypothalamus is a small, almond-sized, cone-shaped structure that projects downwards, ending in the infundibular stalk of the brain. This is a tubular connection to the pituitary gland, with which it has a direct relationship. The two are connected by nervous...