Neurodiagnostic Tests and Procedures

Abstract

Remember the following general rules when you are ordering a diagnostic test or procedure on your patient:

• 1. Diagnostic procedures are a supplement or an extension of your history and physical examination, and are ordered to support your clinical impression or exclude other possibilities.

• 2. Diagnostic procedures should be considered on an individual basis and not routinely; not all patients with dementia need to have an electroencephalogram (EEG) or spinal tap. Each patient should be analyzed individually.

• 3. The clinician should be familiar with the test, knowing how it is done (explaining it to the patient), and the risks, limitations, contraindications and indications, sensitivity, and specificity.

• 4. Consider the potential risk(s) (invasiveness) and cost of the test. Explain these facts to the patient when necessary. For practical purposes, consider ordering the test that gives you the most information and is noninvasive. Consider ordering an invasive test when it has a high sensitivity, specificity, and is beneficial to the patient by influencing the treatment and/or outcome.

• 5. At times, it is necessary and justified to repeat a test. Some disease processes require time to establish their full clinical expression; repeating a test will increase its diagnostic yield, for example, repeating an EEG in the evaluation of a seizure disorder.

• 6. When ordering a test, provide adequate and pertinent information regarding the history and physical findings to the consultant. Be as specific as possible regarding what you are looking for.