Scan with Purpose: Mastering the Neurological Scanning Exam in Physical Therapy

What is a Scanning Exam?

A scanning exam is a focused neurological screen that helps physical therapists quickly assess for signs of nerve root or central nervous system involvement. It’s not something you’ll use with every patient, but it’s a critical tool when red flags are present either during the subjective interview, early objective testing, or when the mechanism of injury (MOI) raises concern.

This exam allows us to identify or rule out concerning neural involvement before we dive deeper into musculoskeletal testing. When done well, it can uncover serious pathology early and guide appropriate referral or intervention.

When Should You Use a Scanning Exam?

You should consider performing a scanning exam if:

1. Subjective or Early Objective Exam Reveals Red Flags

   1. Radiating symptoms along a dermatomal pattern

   2. Bilateral or diffuse numbness/tingling

   3. Limb weakness not explained by pain alone

   4. Reports of gait disturbances, balance issues, or bladder/bowel dysfunction

2. Objective Signs Warrant Further Investigation

   1. Decreased or asymmetrical sensation

   2. Spasticity or abnormal tone

   3. Muscle weakness consistent with a specific spinal level

   4. Exaggerated reflexes or presence of clonus

3. Mechanism of Injury Being Dangerous

   1. Motor vehicle accidents (MVAs)

   2. Falls from significant heights

   3. High-impact blunt trauma (e.g., sports collision, assault)
      These situations increase the risk of spinal cord or nerve root compromise, even if initial pain seems musculoskeletal.

The Three Components of the Scanning Exam

Once you determine a scanning exam is appropriate, it should include the following:

1. Dermatomes – Sensory screen

2. Myotomes – Motor strength testing

3. Reflexes – Deep tendon reflex evaluation

Let’s break each one down with tips, rationale, and common patterns.

Dermatome: Sensory Screening

Dermatomes are skin regions supplied by specific spinal nerve roots. Testing helps determine if a nerve root may be compromised.

What to Do:

• Lightly tap or touch the skin using fingers or cotton.

• Have the patient close their eyes to avoid cueing.

• Ask them if it feels the same on both sides. Diminished or hyper sensitivity on either side is an abnormal finding.

Tips for Effective Testing:

• Don’t drag your fingers across the skin, you might cross into multiple dermatomes.

• Keep the interaction professional. Use clear instructions and minimize awkwardness.

• Always compare side to side. Ask: “Does this feel the same on both sides?”

Common Dermatomal Landmarks:

Myotomes: Motor Testing

Myotomes represent muscle groups innervated by specific spinal nerve roots. Weakness in a myotomal pattern can help localize nerve root pathology.

How to Test:

• Use strong, sustained resistance (hold for at least 5 seconds).

• Compare right vs. left for strength and fatigue.

• Watch for compensation or co-contraction.

Key Tips:

• Push with real force, don’t "baby" the test. You need a true isometric contraction to test nerve integrity.

• Don’t test both sides at once if it doesn’t make sense. Example: Testing C6 (elbow flexion) bilaterally may pull a patient off the table and create anxiety or false weakness.

• Be patient and observe quality of contraction.

Common Myotomal Actions:

Reflexes: Deep Tendon Reflex Testing

Reflexes offer insight into nervous system integrity. Abnormal responses help differentiate between central and peripheral issues.

How to Test:

• Use a reflex hammer and strike the tendon quickly.

• Observe the response and symmetry.

What You're Looking For:

• Hyporeflexia → Suggests peripheral nerve or root involvement (lower motor neuron).

• Hyperreflexia → Suggests central nervous system involvement (upper motor neuron).

If You See Hyperreflexia:

• Consider testing for clonus, especially at the ankles.

• Document carefully—this could influence referral or imaging decisions.

Pro Tips:

• Use common sense. You don’t have to test reflexes exactly as you were taught in lab.

• Modify position to avoid painful provocation. Example: Testing the triceps (C7) in shoulder impingement position may hurt, just have the patient put their hand on their hip.

Case Study: Scanning Exam in Real Practice

A 44-year-old male was referred to PT with a diagnosis of left shoulder impingement syndrome following six weeks of persistent arm pain. The pain extended from the scapula to the forearm, with occasional hand involvement, described as burning and throbbing. Conservative interventions including a steroid pack, cortisone injection, and a normal shoulder X-ray only offered only minimal relief.

However, the therapist noticed red flags: the pain had an insidious onset, radiated below the shoulder, and was aggravated by coughing. This led to suspicion of a cervical source, prompting a neurological scanning exam.

Key Exam Findings

• Negative shoulder special tests (Neer, Hawkins-Kennedy, lift-off, ER lag)

• Pain reproduced with cervical extension and left rotation

• Positive Spurling’s, cervical distraction, and upper limb tension test

• Myotomal weakness in wrist flexors/extensors, biceps, and triceps

• Reflexes and sensation remained symmetrical

Based on these findings, cervical radiculopathy, specifically C6–C7 involvement, was suspected. Imaging confirmed a large disc herniation at C6–C7 along with degenerative changes.

Outcome

With the correct diagnosis, the treatment plan shifted to address cervical radiculopathy. Over 12 visits, the patient experienced:

• Full return of cervical AROM

• Improved strength (left triceps to 4+/5)

• Pain reduction (3/10 → 1/10)

• QuickDASH score dropped from 50 to 5

This case shows how a well-timed scanning exam can redirect care, reveal underlying pathology, and lead to successful, targeted treatment. Without it, the true source of symptoms might have been missed.

Parting Words

The scanning exam is one of those tools you may not use every day, but when you need it, you’ll be glad you practiced. Learn it now, drill it during your rotations, and get fast at recognizing when it's needed. It’s not about memorizing the dermatome chart. It’s about noticing patterns, staying alert to red flags, and ruling big things in or out before they become emergencies.

Whether you’re in ortho, neuro, or acute care, this exam can be the difference between a missed diagnosis and a patient getting the care they truly need.

References

1. Slaven EJ, Mathers J. Differential diagnosis of shoulder and cervical pain: a case report. J Man Manip Ther. 2010;18(4):191-196. doi:10.1179/106698110X12804993426884

Disclaimer

I am a current Doctor of Physical Therapy (DPT) student sharing information based on my formal education and independent studies. The content presented in this newsletter is intended for informational and educational purposes only and should not be considered professional medical advice. While I strive to provide accurate and up-to-date information, my knowledge is based on my current academic and clinical rotations and ongoing learning, not extensive clinical practice.