Examkin

Question

Difficulty: MediumPhysical Examination Findings

A 68-year-old man is brought to the emergency department by his wife due to a sudden onset of severe, continuous room-spinning dizziness, nausea, and an unsteady gait that began 3 hours ago. He has a history of type 2 diabetes mellitus and hypertension. His blood pressure is 165/95 mmHg, and his heart rate is 82/min. On physical examination, the patient exhibits spontaneous, direction-changing horizontal nystagmus. The physician performs the head impulse test by instructing the patient to fixate his vision on the examiner's nose while the examiner rapidly rotates the patient's head horizontally to each side. During these rapid head movements, the patient's eyes remain smoothly fixated on the examiner's nose, and no corrective saccades are observed. Based on these physical examination findings, which of the following is the most likely diagnosis?

  1. Cerebellar infarctionAnswer
  2. B
    Vestibular neuritis
  3. C
    Benign paroxysmal positional vertigo
  4. D
    Acute labyrinthitis
  5. E
    Meniere disease

Answer

Cerebellar infarction
This patient presents with acute vestibular syndrome (AVS), defined by the rapid onset of continuous vertigo, nausea, and gait instability. In AVS, the bedside HINTS examination (Head Impulse, Nystagmus, Test of Skew) is a critical physical examination tool for distinguishing between a benign peripheral cause (e.g., vestibular neuritis) and a dangerous central cause (e.g., cerebellar infarction). A normal (negative) head impulse test—indicated by the eyes remaining smoothly fixated on the target without requiring a corrective saccade—implies that the peripheral vestibulo-ocular reflex is intact. In the context of continuous, severe vertigo, this intact reflex paradoxically points to a central nervous system lesion. Furthermore, the presence of spontaneous, direction-changing nystagmus is another highly specific indicator for a central etiology. Together, these specific physical examination findings make a cerebellar or posterior circulation stroke the most likely diagnosis.

Step-by-Step Solution

1
Evaluate the symptom presentation and time course.
The patient has an acute vestibular syndrome characterized by continuous severe vertigo, nausea, and gait instability.
Establishing the syndrome type dictates the appropriate physical examination maneuvers (HINTS exam) to differentiate central from peripheral causes.
2
Interpret the nystagmus findings on physical examination.
The patient has spontaneous, direction-changing horizontal nystagmus.
Direction-changing nystagmus is a prominent red flag that strongly suggests a central nervous system etiology.
3
Interpret the result of the head impulse test.
The test is normal, as the patient's eyes remain smoothly fixated without corrective saccades.
In the presence of continuous vertigo, an intact (normal) vestibulo-ocular reflex implies the vestibular nerve is functioning correctly, pointing to a central lesion as the cause of the vertigo.
4
Synthesize the examination findings to reach a diagnosis.
The combination of a normal head impulse test and direction-changing nystagmus points directly to a posterior circulation event.
These findings reliably rule out peripheral vestibulopathies and highly correlate with a cerebellar or brainstem stroke.

Key Concept

In patients with acute vestibular syndrome, the HINTS examination (Head Impulse, Nystagmus, Test of Skew) differentiates central from peripheral vertigo; a normal head impulse test and direction-changing nystagmus strongly suggest a central lesion such as a cerebellar infarction.
Rate this question

Topics

Physical Examination Findings

More questions from this topic