A physical therapist reviews the medical record of a patient who was recently diagnosed with multiple sclerosis. Which of the following clinical findings is MOST likely to be documented during the initial physical therapy examination?

Option 1- Asymmetrical resting tremor that decreases with voluntary movement
Option 2- Bilateral visual disturbances accompanied by a delayed pupillary light reflex
Option 3- Progressive symmetrical distal muscle weakness and diminished deep tendon reflexes
Option 4- Significant cogwheel rigidity during passive upper extremity range of motion

Transcript

Welcome back to the Scorebuilders' Question and Answer Podcast! This podcast provides members of the Scorebuilders' team with the opportunity to explore challenging multiple-choice examination questions with students actively preparing for the licensing examination.

Ready? Let's go!

Multiple sclerosis is a chronic, demyelinating disease of the central nervous system that primarily affects young to middle-aged adults. The disease process targets the myelin sheath of axons in the brain and spinal cord, leading to scattered plaque formation and a wide array of neurological deficits.

Before we look at the options, let's establish the core pathological mechanism of multiple sclerosis - because every answer in this question flows directly from understanding what M.S. does and does not do. Multiple sclerosis is a demyelinating disease of the central nervous system. Because myelin is essential for rapid, efficient nerve conduction, demyelination slows or blocks signal transmission - and the clinical deficits that result depend entirely on where those plaques form. Two critical points anchor this question: M.S. is a central nervous system disease - it affects upper motor neurons, not peripheral nerves.

Let's explore each of the options:

Option 1 - Asymmetrical resting tremor that decreases with voluntary movement

An asymmetrical resting tremor that decreases with voluntary movement is a classic hallmark finding of Parkinson's disease, which involves degeneration of dopamine-producing neurons in the substantia nigra. In contrast, patients with multiple sclerosis typically present with an intention tremor, which is absent at rest and appears or intensifies during voluntary, targeted movement.

This option describes the wrong disease entirely. M.S. does not affect the substantia nigra or the dopaminergic pathways. When tremor does occur in MS, it is an intention tremor - a cerebellar sign that is absent at rest and emerges or worsens as the patient reaches toward a target. The asymmetry described in this option is also more characteristic of Parkinson's disease, which classically begins unilaterally.

Option 2 - Bilateral visual disturbances accompanied by a delayed pupillary light reflex

Bilateral visual disturbances and a delayed pupillary light reflex are highly characteristic of multiple sclerosis due to demyelination of the optic nerve, often referred to as optic neuritis. Visual changes such as blurred vision, diplopia, or transient vision loss are frequently among the earliest clinical manifestations of the disease and directly impact the patient's balance and safety.

The optic nerve is C.N.S. tissue - it is myelinated by oligodendrocytes, the same cells targeted by the M.S. disease process. Visual disturbances are not only diagnostically significant in M.S. - they are functionally significant for physical therapy, as impaired vision directly affects balance, spatial orientation, and safety during mobility training.

Option 3 - Progressive symmetrical distal muscle weakness and diminished deep tendon reflexes

Progressive symmetrical distal muscle weakness and diminished deep tendon reflexes describe a lower motor neuron presentation characteristic of peripheral neuropathies or Guillain-Barré syndrome. Multiple sclerosis is strictly an upper motor neuron disorder affecting the central nervous system. Upper motor neuron lesions produce the opposite reflex findings - hyperreflexia, not hyporeflexia - along with spasticity, clonus, and a positive Babinski sign

This option describes the wrong level of the nervous system. If a question describes diminished reflexes and distal weakness, think peripheral nervous system, not M.S.

Option 4 - Significant cogwheel rigidity during passive upper extremity range of motion

Significant cogwheel rigidity during passive upper extremity range of motion is a component of the extrapyramidal symptoms associated with basal ganglia dysfunction, most notably seen in Parkinson's disease. Multiple sclerosis affects the corticospinal tracts and cerebellum rather than the basal ganglia pathways, resulting in velocity-dependent spasticity rather than uniform, non-velocity-dependent cogwheel rigidity.

The increased tone seen in MS is spasticity - a velocity-dependent increase in resistance to passive stretch that is mediated by corticospinal tract damage. Spasticity and cogwheel rigidity are both forms of increased tone, but they have different mechanisms, different characteristics on examination, and different disease associations. That distinction is clinically and examination-critical.

When we apply the C.N.S. demyelinating disease framework across all four options, three of them describe findings associated with Parkinson's disease or peripheral nervous system disorders - none of which are consistent with the pathophysiology of M.S. Only Option 2 describes a finding that is directly explained by demyelination of C.N.S. tissue - specifically the optic nerve - and is consistent with the known clinical presentation of multiple sclerosis.

The correct answer is Option 2.

Let's explore the all student data:

50% of students selected Option 2 - Bilateral visual disturbances accompanied by a delayed pupillary light reflex - the correct response
41% of students selected Option 3 - Progressive symmetrical distal muscle weakness and diminished deep tendon reflexes
5% of students selected Option 4 - Significant cogwheel rigidity during passive upper extremity range of motion
4% of students selected Option 1 - Asymmetrical resting tremor that decreases with voluntary movement

System Classification
This question is a Neuromuscular and Nervous Systems question which represents approximately 24% of all exam items.

Content Outline Classification
This question is a Foundations for Evaluation, Differential Diagnosis, and Prognosis question which represents approximately 10% of all exam items.

Level Classification
This question is a Level 2 question since the question requires students to integrate numerous pieces of information or to apply knowledge in a given clinical scenario. Remediation of Level 2 questions occurs by increasing flexibility with academic content and by carefully analyzing decision making processes when answering applied examination questions.

Academic Focus Area

Looking to review related academic content? Check out pages 288 and 352-353 in PTEXAM: The Complete Study Guide.