Neuro Exam

The Neurological Examination

Introduction

• Rola Mahmoud, MD, Associate Professor of Neurology

• Associate Program Director, Neurology Residency

• University of Missouri-Kansas City School of Medicine

• Lectures for the Class of 2025 Medical Students

Objectives

• Recognize the importance of neurological exams in patient care

• Learn to perform the neurological exam

• Accurately identify and interpret normal or abnormal findings through clinical reasoning

• Integrate basic neuroanatomy to localize lesions based on exam findings

Purpose of the Neurological Examination

• Key Questions:

  • Where is the lesion?

  • What is the lesion?

• The objective is to localize the lesion based on physical findings and to plan next steps in treatment.

• Historical Context: In the pre-CT/MRI era, skilled clinicians could accurately diagnose lesions based solely on neurological history and examination findings.

Importance of Lesion Localization

• Lesion localization is fundamental to generating a differential diagnosis.

• Following lesion localization, a hypothesis must be formed regarding the potential disease processes.

• Certain conditions cannot be diagnosed with imaging, necessitating keen clinical examination skills.

• The urgency and choice of imaging modality are influenced by the disease categories being considered.

• Neurologists use a systematic analysis of history and examination to develop a hypothesis concerning the underlying pathophysiological process.

• The neurological exam must be considered in the context of general assessment, which includes history, general examination, blood work, and radiologic studies.

Observation in Neurological Exam

• Most of the neurological exam relies heavily on observation.

• The neurological exam is a component of the general physical exam.

• Important Observational Indicators:

  • Patient's speech, thinking, walking, movement, interaction with the environment (indicators of mental status and motor system).

  • Vital signs and their implications on orthostatic responses, autonomic dysfunction, and potential brainstem injuries.

  • Bruits, murmurs, and irregular heartbeats provide clues in stroke patients.

Tools for Examining Vision

J. G. Rosenbaum Pocket Vision Screener

• Standard distances and card readings are described to test visual acuity.

Components of the Neurological Exam

• Seven Key Components:

  1. Mental Status and Language

  2. Cranial Nerves

  3. Motor System

  4. Reflexes

  5. Sensory System

  6. Coordination

  7. Gait

• Emphasize the order of these components during examination.

Detailed vs. Focused Neurological Exam

• In practice, the neurological exam is seldom performed in its entirety due to practical constraints.

• Screen key elements based on the presenting complaint; pursue a detailed examination if uncertain, which may take longer.

• Tailor the exam based on the patient's specific complaints (e.g. visual complaints necessitate a complete visual exam).

• Resource: Neuroexam.com for guidance on conducting a focused 4-minute neurological exam.

Core Elements of a Screening Exam

• Motor Examination:

  • Checks for drift, rapid hand and foot tapping, upper and lower extremity tone, and strength in proximal and distal muscle groups in the upper and lower extremities.

• Sensory Examination:

  • Tests for light touch, pinprick or temperature sensation, vibration, and joint position sense.

• Reflexes:

  • Evaluates bilateral biceps, brachioradialis, patellar, Achilles tendon, and plantar reflexes.

• Coordination:

  • Includes finger-to-nose bilaterally and heel-to-shin bilaterally.

Mental Status Examination

• Components to Assess:

  1. Level of consciousness

  2. Orientation

  3. Memory

  4. Language

  5. Calculations (including assessments of right-left confusion, finger agnosia, and agraphia)

  6. Apraxia

  7. Neglect and constructions

  8. Sequencing tasks and frontal release signs

  9. Logic and abstraction

  10. Mood, affect, delusions, and hallucinations

Consciousness

• Defined as the state of full awareness of self and the environment, typically assessed through responses to stimuli.

• Patients can be conscious but unresponsive (e.g., locked-in syndrome or psychological conditions).

Level of Consciousness (LOC)

• Mediation of LOC occurs through brainstem and diencephalic centers that manage global cortical function and arousal.

• LOC continuum: alert -> mild sleepiness -> unarousable unresponsiveness (coma).

• Assessment parameters: eye opening, interaction, movement (responses observed), and the intensity of stimuli necessary for response.

• Avoid using confusing terms such as obtunded, lethargic, and somnolent.

Examples of Documentation for LOC

• Documentation must be precise:

  • Example 1: "Mrs. A is lying quietly with her eyes closed, no eye opening to verbal stimuli. She briefly opens her eyes with light tactile stimulus and requires nearly continuous tactile stimulus to maintain eye opening."

  • Example 2: "Mr. C does not open his eyes or respond to verbal or light tactile stimuli. With a deep sternal rub he transiently opens his eyes, grimacing, and exhibits non-purposeful movements of his extremities."

Attention

• Defined as the ability to focus on particular tasks or stimuli, notably tested through digit repetition and simple reversals of words.

• Attention closely relates to cognitive function, depending on the integrity of the RAS, brainstem, thalamus, and cerebral hemispheres.

Content of Consciousness

Cognition

• Cognitive functions are assessed based on thinking processes, mediated by cerebral cortical levels.

• Note: A detailed examination of content demands nearly normal LOC and an understanding of the patient's language capabilities.

Neuroanatomical Correlation

• A lesion can disrupt networks of cortical neurons responsible for cognitive functions.

  • Example: Left frontotemporal stroke leading to aphasia; right parietal tumor leading to neglect.

• Systems governing content (localized cortical regions) differ from those governing level (global cortical and arousal systems).

Examining Content of Consciousness

• Core Components: Attention, Orientation, Memory, Language, Calculations, Praxis, Neglect and Constructions, Sequencing, Logic, and Abstraction.

Orientation

• Multidimensional: self, time, place, and person.

• Disorientation to personal identity frequently indicates psychiatric disease (e.g. psychologically-induced amnesia).

• Clinical Pearl: Document orientation status with specifics, avoiding vague terms like A&O x3.

Memory

• Mediated through the limbic system and global cortical networks.

• Functions measured include Immediate recall (registration), Recent memory (storage), and Remote memory (retrieval).

• The assessment includes asking patients to recite three items after a short delay and querying significant past events.

Language Assessment

• Mandatory explicit testing, inquire about fluency and comprehension, including naming, repetition, comprehension, reading, and writing.

• Neurologically, likely lesions correlate with dysfunction in the left hemisphere, affecting multiple language areas (Broca's and Wernicke's).

• Differentiation between dysarthria and language issues is crucial: Dysarthria reflects motor control issues, while language problems stem from aphasia.

Language Testing - Methodology

1. Observe spontaneous speech for fluency and errors.

2. Confirm understanding through simple and complex verbal commands.

3. Perform formal tests for naming, repetition, comprehension, reading, and writing.

Additional Cognitive Assessments

• Calculations: Serial 7 subtractions or monetary calculations test attention alongside cognition.

  • Note on Localization: Acalculia without other deficits can indicate a right-left confusion or finger agnosia leading to Gerstmann’s syndrome.

• Praxis: Assessment of complex motor task ability, testing apraxia through functional task requests.

Neglect Assessment

1. Hemi-neglect: Indicates abnormal attention to one side, tested through double simultaneous stimulation.

   • Neuroanatomical correlation: Right parietal lesions often result in left neglect.

2. Motor Neglect: Despite intact strength, the patient may only move a limb upon directive attention.

3. Anosognosia: Lack of awareness regarding neurological deficits, needing assessment of subjective patient insights.

Other Testing Modalities

• Go/No Go tasks, Construction tasks (e.g., clock drawing), Sequencing, and Abstraction.

Formal Mental Status Tests

• Common tests include:

  • MOCA (Montreal Cognitive Assessment)

  • SLUMS (Saint Louis University Mental Status) exam

  • Mini-Mental Status Exam

  • Neuropsychological testing

Cranial Nerves Overview

Testing Specific Cranial Nerves

I. Olfactory Nerve

• Rarely tested unless obstructed; use nonirritating scents while occluding nostrils.

II. Optic Nerve

• Assess visual acuity, confrontational visual fields, fundus inspection, pupillary responses, and color vision.

III, IV, VI - Oculomotor, Trochlear, Abducens

• Examination includes tracking movement, checking for strabismus, and observing for nystagmus.

V. Trigeminal Nerve

• Testing includes sensory and motor evaluation across three facial divisions, checking the corneal reflex, and assessing muscle contractions.

VII. Facial Nerve

• Check for asymmetry in facial movements at rest and during action, as well as sensory testing for taste.

VIII. Vestibulocochlear Nerve

• Evaluate hearing through finger rub and nystagmus observation; management of vertigo includes tests like the Dix-Hallpike maneuver.

IX & X. Glossopharyngeal and Vagus Nerves

• Test through palate elevation and gag reflex.

XI. Spinal Accessory Nerve

• Evaluate through shoulder shrug and head rotation against resistance.

XII. Hypoglossal Nerve

• Observe tongue movement and assess for fasciculations or atrophy.

Motor Examination

1. Observation

   • Assess for involuntary movements, tremors, and twitches.

2. Inspection

   • Evaluate for muscle bulk changes and signs of atrophy or hypertrophy.

3. Palpation

   • Check for tenderness or fasciculations.

4. Tone

   • Measure muscle tension when relaxed; differentiate between spasticity and rigidity.

5. Functional Testing

   • Examine drift and fine movements.

6. Power/Strength Testing

   • Compare and evaluate for symmetry and strength:

   • Grade Scale:

     • 0/5: No movement

     • 1/5: Visible contraction but no movement

     • 2/5: Movement eliminated against gravity

     • 3/5: Movement against gravity only

     • 4/5: Movement with some resistance

     • 5/5: Movement against full resistance.

7. Common Movements Tested in UE/LE:

   • Upper Extremity (UE): Shoulder abduction, elbow flexion/extension, wrist flexion/extension.

   • Lower Extremity (LE): Hip flexion, knee extension, ankle movements.

Reflex Examination

• Testing of deep tendon reflexes (DTRs) in relaxed positions, adjusted similarly across limbs.

• Hyporeflexia: Associated with LMN lesions.

• Hyperreflexia: Indicates upper motor neuron damage.

• DTR scale:

  • 0: Absent

  • 1+: Trace

  • 2+: Normal

  • 3+: Brisk

  • 4+: Non-sustained clonus

  • 5+: Sustained clonus.

Plantar Response and Pathologic Reflexes

• Plantar Response Testing: Must differentiate normal toe flexion from the abnormal Babinski sign (indicative of UMNL).

• Pathological reflex response indicates loss of cortical inhibition:

  • Primitive reflexes (e.g., snout, grasp) suggest cerebral dysfunction.

Common Pathological Gait Abnormalities

• Antalgic Gait: Often due to pain on one side.

• Ataxic Gait: Characteristic of cerebellar dysfunction

• Shuffling Gait: A sign in patients with parkinsonism.

• Tilted Gait: Could indicate underlying inner ear pathology.

• High-Stepping Gait: Seen with foot drop conditions, warning of potential muscular issues.

Conclusion

• Importance of thorough practice and refinement in performing the neurological exam.

• Reconfirming knowledge of neurological conditions and their examinations regularly enhances clinical acumen.