Practically, AD is usually diagnosed clinically. Concussion remains a significant cause of AD so a high index of suspicion is called for in all concussion patients. Intimate knowledge of the way it presents, its treatment and appreciation of features it shares with other diagnoses is required.
These patients will usually complain of one or many of the symptoms
that could be caused by AD (see above). Some of these symptoms may not be typical symptoms of concussion – abdominal cramps, clamminess, feeling either warm or cold, etc.
2. Physical exam
Changes in blood pressure and heart rate (compared to pre-injury levels or even post-injury postural differences, i.e., sitting vs. standing); changes in measures of the eyes ability to accommodate
for near targets; etc.
3. Functional exams
•Bruce Treadmill Protocol
can identify those with AD that present with exercise intolerance.
•Functional tests of the visual, neck and vestibular systems are often carried out on concussion patients. If symptoms persist despite the patient performing well on these specific challenges, it is a clue that AD is claiming part of the clinical picture.
a. Specific investigations targeting the complaint (i.e., the effect) are often employed:
•Palpitations – Holter monitor
•Blood pressure changes – Ambulatory Blood Pressure Monitoring
•Urinary difficulty – laboratory investigations, cystoscopy, urodynamic studies, post-void residual ultrasound
•Abdominal issues – laboratory investigations, Imaging, Endoscopy
•Weight gain – laboratory investigations including a hormonal panel
•Sleep Disturbances – Sleep Diary
b. Biofeedback equipment can detect abnormalities of many of the systems directly impacted by changes in the ANS:
•Skin conductance – measure of the sweat gland responsiveness to stress and relaxation protocols
•Skin temperature – caused by your blood vessels ability to dilate (warm up) and constrict (cool down) to stress and relaxation protocols
•Blood pressure monitoring in response to postural changes, stress/relaxation protocols and breathing maneuvers.
•Heart rate variability (HRV)
is a big topic and one that receives a lot of attention recently with respect to AD and specifically concussion patients.
c. Traditional methods of looking for Autonomic dysfunction
have variable success rates in different clinical contexts and are often impractical. These include methods like tilt-table testing and quantitative sudomotor axon reflex test (QSART).