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Specialty Diagnostic Testing

The Neurological Clinical Evaluation is part of all the comprehensive assessment and management protocols performed by board-certified specialists at the NIA. Patients and their caregivers have a discussion with their clinician and provide an extensive history on current and past health symptoms and therapies. To allow more time for discussing diagnoses and future planning, several questions can be answered in advance through structured questionnaires. After all necessary information is obtained, the clinician examines patients and reviews past laboratory work to establish a diagnosis and, if indicated, to recommend additional testing or therapies.​​

Neuropsychological testing refers to performing one or more standardized tests using paper and pencil or electronic devices that examine people’s cognitive abilities, such as memory, executive function, visuospatial skills, and language. It is used in diagnosing neurocognitive disorders, comparing current to previous cognitive testing results, and evaluating effectiveness and side-effects of therapies. It is recommended by international guidelines on evaluating cognitive complaints through comprehensive assessment protocols.

Polysomnography is a diagnostic study performed either in the lab or at home while people are asleep that examines several measures of bodily function through different types of sensors and is critical in the diagnosis of several sleep disorders. PSG captures quality of sleep as reflected in brain function through electroencephalography, breathing through air flow and temperature sensors under the nose as well as belts over the chest and abdomen, blood oxygen through an oximeter, muscle activity through electromyography, and heart rate through electrocardiography. When performed in the lab, video is available to also review possible abnormal behaviors. Common reasons for people having a sleep study is to diagnose possible sleep apnea or parasomnias. Recent studies suggest it carries additional value in examining sleep architecture and its relation to neurocognitive disorders when combined with neuropsychological testing.

The MSLT is a study performed in the lab where people are given four or five 20-minute napping opportunities the day after an overnight polysomnography study. It examines whether people are excessively sleepy in the daytime, allowing the diagnosis of hypersomnia syndromes, such as narcolepsy, after more common causes of excessive daytime somnolence are ruled out, such as sleep apnea or medication side-effects.

The MWT is a study performed in the lab where people are given four 40-minute trials of trying to stay awake during the day, after other causes of excessive daytime somnolence have been ruled out. It helps establish if people who are in charge of vehicles or heavy machinery are at high likelihood of falling asleep at work, in which case work-related accidents can put them or others at bodily risk. In certain circumstances it can also help establish if therapies given for excessive daytime somnolence are effective.

EEG is a diagnostic study performed in the lab or at home that examines whether the brain’s electrical activity is abnormal that would otherwise support a diagnosis of seizures or epilepsy . Brain activity is captured through electrodes placed on the scalp using a conductive paste. The specialist clinician ordering the test will decide if an EEG should be performed during resting wakefulness or sleep, or with the patient moving freely in the lab or at home. An EEG can last as little as 30 minutes or up to several days. Prolonged recordings can be performed at home or in the lab, and are usually accompanied by video monitoring (video-EEG). To provoke abnormal activity in susceptible brains, patients may be asked to look at flashing lights or take deep breaths during portions of an EEG. During the test, it is possible that people who have seizures will experience an event. There are no side-effects from EEG, other than having to clean the scalp from the conductive paste.

Actigraphy is a diagnostic tool that examines the amount of activity of people over several days, usually over one to two weeks. It relies on special motion-recording devices called actigraphs that are placed on the wrist like a watch and record movement acceleration. Actigraphy results provide a distribution of sleep and wakefulness in real-life settings.

An EMG-NCV is a diagnostic protocol performed in the lab that examines the functional integrity of nerves and muscles, and used to diagnose and follow the progression of neuromuscular and motor neuron disorders. During NCV testing, small electrodes may are placed over or into the skin and convey a small electrical current in order to test whether nerves work properly. During EMG, very thin needle-like electrodes are passed though the skin into the muscles and test muscle function by recording its own electrical activity. There can be some discomfort during needle insertion into muscles, or a jolt-like feeling when a current is passed through the electrodes to test whether the nerves work properly. An EMG-NCV lasts approximately 30 minutes in most cases, although detailed testing may require longer testing when more areas of the body are examined. ​

In most circumstances blood tests are part of routine diagnostic evaluations. During a blood test people have blood drawn with a needle from a vein or an artery, which is then sent to specialized laboratories for chemical analyses. The specific chemical analyses performed depend on the neurological clinical examination and available laboratory tests.

In certain situations, there is need to examine the fluid that surrounds the brain and spinal cord, called cerebrospinal fluid (CSF). This is commonly done if CSF biomarkers can support the presence of a specific brain disease, such as inflammatory (e.g., multiple sclerosis), infectious, certain types of cancer, and neurodegenerative diseases, or when the CSF pressure could be contributing to symptoms. The CSF is acquired through a lumbar puncture, colloquially called a spinal tap, during which patients are either sitting hunched or lying down on their side and a needle is passed through the lower back after a local anesthetic is applied in the area. The usual side effect from the procedure in a third of people is a headache that is worse upon standing and that usually does not last more than a couple of hours.  Rare side effects include an infection or a local hematoma. Clinicians performing the procedure provide specific instructions for how to address side effects that present after a lumbar puncture.