What is the Clinical Examination of the Nervous System?

The clinical examination of the nervous system is essential for identifying neurological disorders. In this blog, “What is the Clinical Examination of the Nervous System?” we will explore how it is performed and what it evaluates. Don’t miss it!

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How is the Clinical Examination of the Nervous System Conducted?

The clinical examination of the nervous system involves the following steps:

1. Detailed patient history
2. Mental status examination
3. Cranial nerve assessment
4. Motor function tests
5. Coordination and balance evaluation
6. Sensory testing
7. Reflex testing

These allow the physician to evaluate different functions. Below are the key aspects of this examination.

Patient History and Symptoms

The exam begins by gathering detailed information about the patient’s symptoms. This helps guide the physical evaluation.

Key aspects of the patient history include:

• Symptom duration: How long has the patient experienced pain or weakness?
• Symptom nature: Are the symptoms constant or fluctuating?
• Triggers: What activities or situations worsen or relieve the symptoms?
• Family history: Knowing about possible hereditary neurological conditions, like neuropathies, is important.

This information helps tailor the physical exam and determine which tests are most relevant.

Neurological Assessment Techniques

This part of the exam includes a systematic evaluation of key neurological functions. Common techniques include:

• Gait assessment: Observing how the patient walks to detect motor or balance issues.
• Coordination tests: Such as the finger-to-nose test, which assesses cerebellar function.

These techniques help effectively evaluate balance, coordination, and muscle strength.

Mental Status Examination

Evaluating the patient’s mental status helps detect any cognitive impairments or altered consciousness.

• Orientation: Asking the patient about their location, the current date, and personal details.
• Memory: Testing short-term and long-term memory with simple tasks.
• Language: Assessing the patient’s ability to understand and follow instructions.

This exam helps identify brain dysfunctions affecting cognitive abilities.

Cranial Nerve Examination

The cranial nerve exam helps detect focal lesions in the brain and brainstem. It assesses the 12 cranial nerves, each with specific functions:

• Olfactory nerve (I): Responsible for the sense of smell.
• Optic nerve (II): Responsible for vision.
• Oculomotor nerve (III): Controls most eye movements, upper eyelid elevation, and pupil constriction.
• Trochlear nerve (IV): Controls the superior oblique muscle of the eye, allowing downward and inward movement.
• Trigeminal nerve (V): Responsible for facial sensation and controlling the muscles of mastication.
• Abducens nerve (VI): Controls the lateral rectus muscle, allowing side-to-side eye movement.
• Facial nerve (VII): Controls facial expression muscles and transmits taste sensation from the anterior two-thirds of the tongue.
• Vestibulocochlear nerve (VIII): Responsible for hearing and balance.
• Glossopharyngeal nerve (IX): Controls swallowing and taste sensation in the posterior third of the tongue.
• Vagus nerve (X): Innervates many visceral organs and helps control the muscles of the pharynx and larynx.
• Accessory nerve (XI): Controls the sternocleidomastoid and trapezius muscles, enabling head and shoulder movements.
• Hypoglossal nerve (XII): Controls tongue movements.

Assessing these nerves provides a detailed view of sensory and motor functions in the face and head.

Motor System Evaluation

This evaluation measures muscle strength, tone, and motor reflexes while observing for abnormal movements.

• Muscle strength: Testing the patient’s ability to move different body parts against resistance.
• Muscle tone: Checking if the muscles are stiff or floppy.
• Involuntary movements: Looking for tremors, spasms, or muscle jerks.

Motor system problems can indicate damage in the motor cortex, spinal cord, or peripheral nerves.

Sensory System Assessment

This part evaluates the patient’s ability to perceive various stimuli.

Common tests:

• Light touch: Using cotton to assess sensitivity.
• Pain: Using a pin to check pain perception.
• Vibration: Using a tuning fork to detect peripheral neuropathies.

These tests help locate lesions in the spinal cord or peripheral nerves.

Reflexes Testing

Reflexes provide information about the central and peripheral nervous system’s function.

Reflexes evaluated:

• Patellar reflex: Tapping the tendon below the kneecap to observe the quadriceps response.
• Achilles reflex: Testing the Achilles tendon to check the calf muscle response.
• Plantar reflex: Helps assess motor nerve function.

An abnormal reflex may indicate damage to the spinal cord or peripheral nerves.

Common Findings and Interpretations

During the neurological exam, some common signs can guide the diagnosis:

• Unilateral weakness: A possible sign of a stroke.
• Sensory loss in a glove or sock pattern: Suggests peripheral neuropathy, often seen in diabetes.
• Absent reflexes: May indicate damage to the peripheral nerves or spinal cord.

When to Refer for Further Evaluation?

In certain cases, the doctor should refer the patient to a specialist for more advanced evaluations:

• Worsening symptoms: Such as vision loss, muscle weakness, or severe walking difficulties.
• Difficulty managing pain: If treatment is ineffective, additional tests like MRIs or nerve conduction studies may be needed.
• Unclear diagnosis: A neurologist may be required for a more detailed diagnosis.

Important Neurological Health Knowledge 

Maintaining neurological health is essential for preventing and detecting problems early. Here are some key points:

• Exercise: Helps maintain good circulation and prevent peripheral nerve degeneration.
• Managing chronic conditions: Keeping conditions like diabetes under control can prevent neurological damage.
• Regular check-ups: Especially for individuals with a family history of neurological disorders.

Sources:

• Lee, J. S., Cramer, S. D., & Butt, M. T. (n.d.). Pathology of the nervous system. In M. T. Butt (Ed.), Fundamental Neuropathology for Pathologists and Toxicologists (Chapter 7). Springer Link. https://doi.org/10.1007/978-1-4939-9777-0_7
• Zengeya, S. T., & Serane, T. V. (2011). Chapter 8: Examination of the central nervous system. In MRCPCH Clinical: A Guide for the Examination (pp. 79). Oxford Academic. https://doi.org/10.1093/med/9780199592287.003.0008
• Abraham, A., Alabdali, M., Alsulaiman, A., Albulaihe, H., Breiner, A., Katzberg, H. D., et al. (2017). The sensitivity and specificity of the neurological examination in polyneuropathy patients with clinical and electrophysiological correlations. PLOS ONE, 12(3), e0171597. https://doi.org/10.1371/journal.pone.0171597