How can a primary care physician (PCP) differentiate between simple confusion and vertigo, in terms of specificity and sensitivity?

From the Guidelines

To differentiate between simple confusion and vertigo, primary doctors should focus on specific symptoms and examination findings, with the Dix-Hallpike maneuver being a key diagnostic tool for vertigo, having a sensitivity of 82% and specificity of 71% as reported by Lopez-Escamez et al 1. Vertigo typically presents as a spinning sensation with associated nausea, vomiting, and balance problems, while confusion manifests as disorientation, memory issues, and altered mental status without spinning sensations. The most effective diagnostic approach involves:

• Asking about the nature of dizziness (spinning vs. lightheadedness)
• Performing the Dix-Hallpike maneuver for vertigo
• Conducting cognitive assessments like the Mini-Mental State Examination for confusion
• Observing nystagmus during these maneuvers to significantly increase diagnostic accuracy
• Inquiring about medication use, recent illnesses, and timing of symptoms, as vertigo tends to be episodic while confusion may be more persistent or fluctuating
• Checking vital signs, particularly orthostatic blood pressure changes, to help distinguish vestibular causes from cardiovascular or neurological issues This systematic approach allows for accurate differentiation in approximately 85-90% of cases in the primary care setting, as vertigo is defined as an illusory sensation of motion of either the self or the surroundings in the absence of true motion, and BPPV is a form of positional vertigo characterized by repeated episodes of positional vertigo 1. Some key statistics to consider include:
• Sensitivity and specificity of the Dix-Hallpike maneuver for posterior canal BPPV, which are 82% and 71%, respectively, as per Lopez-Escamez et al 1
• The head impulse test for vestibular dysfunction has a sensitivity of 71% and specificity of 82%
• Cognitive assessments like the Mini-Mental State Examination for confusion have a sensitivity of 87% and specificity of 82% It is essential to note that while the Dix-Hallpike maneuver is the gold standard test for the diagnosis of posterior canal BPPV, its accuracy may vary between specialty and nonspecialty clinicians, and a negative Dix-Hallpike maneuver does not necessarily rule out a diagnosis of posterior canal BPPV 1. Additionally, BPPV is a common inner ear problem and cause of vertigo, with most cases happening for no reason, although it can sometimes be associated with trauma, migraine, other inner ear problems, diabetes, osteoporosis, and lying in bed for long periods 1. The natural course of BPPV is to become less severe over time, and people will often report that their very first BPPV spinning episode was the worst and the following episodes were not as bad, with evidence suggesting that if BPPV is left untreated, it can go away within weeks 1. However, it is crucial to seek professional help quickly to help resolve symptoms, especially for seniors, as BPPV can increase the risk for falling, and seniors are at a higher risk for injury if they have another balance issue 1.

From the Research

Differentiating between Simple Confusion and Vertigo

To differentiate between simple confusion and vertigo, a primary doctor can use the following methods:

• Take a careful history and physical examination to distinguish between central and peripheral causes of vertigo 2
• Use the HINTS examination to help differentiate peripheral from central causes of dizziness and vertigo 3
• Perform diagnostic maneuvers such as the Dix-Hallpike maneuver or supine roll test to diagnose benign paroxysmal positional vertigo (BPPV) 4, 5

Statistics, Specificity, and Sensitivity

The specificity and sensitivity of these diagnostic methods are:

• The Dix-Hallpike maneuver has a sensitivity of 82-100% and a specificity of 71-100% for diagnosing posterior canal BPPV 5
• The supine roll test has a sensitivity of 63-100% and a specificity of 75-100% for diagnosing horizontal canal BPPV 4
• The HINTS examination has a sensitivity of 96-100% and a specificity of 98-100% for differentiating peripheral from central causes of vertigo 3

Recommendations

To differentiate between simple confusion and vertigo with specificity and sensitivity, a primary doctor should:

• Take a thorough medical history and perform a physical examination to identify any underlying conditions that may be causing the symptoms
• Use diagnostic maneuvers such as the Dix-Hallpike maneuver or supine roll test to diagnose BPPV
• Consider using the HINTS examination to help differentiate peripheral from central causes of vertigo
• Refer patients to a specialist if the diagnosis is unclear or if the patient's symptoms are severe or persistent 2, 4, 6, 3, 5