of the disease;

Evolution refers to the process of developing and changing diseases or medical conditions over time.
synthesis involves the integration of information or components into a coherent whole.
A synthesis of a disease is a summary of a disease, in other words, a brief general description of a disease.

It is difficult to know the meaning of the words without reading the rest of the text; I would have to study the text in order to render a more accurate translation
On the title alone:

Evolución (Development) can mean: how the disease has progressed (stages) in the patient
síntesis (synthesis): different elements that have to converge in o0rder to cause the disease

Evolution" and "synthesis" are terms that can have various meanings depending on the context in which they are used. Here's a brief overview of each term:

Evolution:

Biological Evolution: This refers to the process by which species of living organisms change over generations through the mechanism of natural selection. It involves the passing on of genetic traits that confer advantages in terms of survival and reproduction. This process is the foundation of Charles Darwin's theory of evolution.
Cultural Evolution: This concept refers to the evolution of human cultures and societies over time. It includes changes in language, customs, technology, and social structures.
Technological Evolution: In the context of technology, evolution refers to the gradual development and improvement of tools, systems, and technologies over time.
Evolution in General Terms: In a broader sense, evolution refers to the gradual change and development of something over time.
Synthesis:

Chemical Synthesis: In chemistry, synthesis is the process of combining simpler substances to create a more complex compound. It involves the assembly of molecules or compounds from their individual building blocks.
Philosophical Synthesis: In philosophy, synthesis can refer to the combination or integration of different ideas, concepts, or viewpoints into a unified whole.
Cultural Synthesis: This concept refers to the blending or merging of different cultural elements, often resulting in a new and unique cultural expression.
Synthesis in General Terms: In general, synthesis means the combination or creation of something by bringing different elements together.
In various fields, "evolution" and "synthesis" can describe processes of change, development, and integration. The terms may have more specific meanings based on the discipline they are used in.

I'm feeling a bit more inspired today after a day on the beach, and I think I've come up with a good alternative for "synopsis" -- clinical summary.

It is short, sweet and idiomatic, and will likely appeal to Phil (I should hope so).

As for the first term, it's either course of disease, disease progression or natural history of the disease, but I'd personally go with the last option.