What condition causes vertigo and nystagmus when sitting up?

Benign Paroxysmal Positional Vertigo (BPPV)

The condition that causes vertigo and nystagmus when sitting up from a lying position is Benign Paroxysmal Positional Vertigo (BPPV), specifically posterior canal BPPV, which is diagnosed by the Dix-Hallpike maneuver where nystagmus appears when moving from sitting to supine and may reverse when returning to sitting. 1

Understanding the Clinical Presentation

BPPV is characterized by brief episodes of rotational vertigo triggered by changes in head position relative to gravity, most commonly when:

• Rolling over in bed 1
• Tilting the head upward 1
• Bending forward 1
• Moving from lying to sitting position 1

The vertigo episodes last less than 60 seconds from onset of nystagmus, which distinguishes BPPV from central causes that may have longer duration symptoms. 1

Diagnostic Criteria for Posterior Canal BPPV

History Requirements

• Patient reports repeated episodes of vertigo with changes in head position relative to gravity 1
• Episodes are brief (less than 1 minute) 1
• Patients often modify movements to avoid triggering symptoms 1

Physical Examination Findings

The Dix-Hallpike maneuver is the gold standard diagnostic test and must demonstrate: 1

• Torsional (rotatory) upbeating nystagmus toward the forehead 1
• Latency period of 5-20 seconds (rarely up to 1 minute) between completing the maneuver and onset of symptoms 1
• Crescendo-decrescendo pattern where nystagmus increases then resolves within 60 seconds 1
• Reversal of nystagmus direction when returning to upright sitting position 1

Critical Diagnostic Distinction

A common pitfall is misdiagnosing central positional nystagmus as BPPV. 2, 3 Red flags indicating central pathology rather than benign BPPV include:

• Downbeating nystagmus without torsional component suggests cervicomedullary junction pathology 2
• Direction-changing nystagmus that doesn't follow typical BPPV patterns 2
• Nystagmus lasting longer than 60 seconds 1
• Absence of latency period 1
• Associated cerebellar signs (ataxia, dysmetria) 2
• Persistent nystagmus in primary gaze position 2

In 12-20% of cases, positional vertigo may be caused by CNS pathology including cerebellar tumors, where positional nystagmus may be the only presenting feature. 3 Urgent neuroimaging with MRI (not CT, which inadequately visualizes posterior fossa) is warranted when central features are present. 2

Pathophysiology

Posterior canal BPPV accounts for 85-95% of all BPPV cases and results from canalithiasis, where fragmented otolith particles (otoconia) enter the posterior semicircular canal and cause abnormal cupular displacement with head movement. 1 Lateral canal BPPV accounts for 5-15% of cases. 1

Complete Diagnostic Approach

Both Dix-Hallpike and supine roll testing must be performed to avoid missing lateral canal involvement, as posterior canal BPPV can convert to horizontal canal BPPV during positioning maneuvers. 2, 4

The Dix-Hallpike maneuver has 82% sensitivity and 71% specificity among specialty clinicians, with a positive predictive value of 83% in primary care settings. 1 However, a negative test does not rule out BPPV, as up to one-third of patients with atypical histories will still show positional nystagmus on testing. 1

Treatment Implications for Morbidity and Quality of Life

Treatment of BPPV significantly improves quality of life, and the condition causes substantial morbidity when chronic. 1 Canalith repositioning procedures (CRPs) are the definitive treatment:

• Epley maneuver for posterior canal BPPV 4
• Gufoni maneuver for lateral canal BPPV 4

Vestibular suppressant medications like meclizine are indicated for symptomatic treatment of vertigo but do not address the underlying pathology. 5 The primary treatment should be mechanical repositioning maneuvers, not medication. 1