Right Pontine Stroke Symptoms
A right pontine stroke typically presents with left-sided motor and sensory deficits, often accompanied by dysarthria, ataxia, and characteristic eye movement abnormalities including horizontal gaze palsy, internuclear ophthalmoplegia, or one-and-a-half syndrome.
Core Clinical Presentation
The symptoms depend critically on which pontine territory is affected. Based on the anatomical distribution, right pontine strokes manifest in predictable patterns 1:
Motor Deficits (Most Common)
- Left-sided weakness with characteristic faciobrachial (face and arm) predominance
- May present as isolated left arm weakness (brachial monoparesis) in smaller infarcts
- Dysarthria occurs in the majority of cases, particularly with anteromedial pontine involvement 1, 2
Sensory Disturbances
- Left-sided sensory loss affecting pinprick, temperature, vibration, or proprioception
- Pattern varies by lesion location:
- Sensory deficits occur more frequently with anterolateral or tegmental pontine lesions 1
Eye Movement Abnormalities (Highly Localizing)
Right pontine tegmental involvement produces distinctive ocular findings 4, 5:
- Horizontal gaze abnormalities are pathognomonic for pontine stroke
- Left abducens nerve palsy (inability to abduct left eye)
- Internuclear ophthalmoplegia (INO) - impaired left eye adduction with right eye abduction nystagmus
- One-and-a-half syndrome - combination of horizontal gaze palsy and INO 2, 5
- These findings distinguish pontine from hemispheric strokes
Ataxia and Coordination
- Truncal ataxia and limb incoordination
- May occur even with small lesions 6
- Critical pitfall: Bilateral cerebellar signs can occur from pontine lesions alone, without cerebellar involvement 6
Specific Pontine Syndromes by Location
Anteromedial Pontine (Most Common - 58%)
- Left hemiparesis with dysarthria
- Ataxia in one-third of patients
- Mild tegmental signs possible 1
Anterolateral Pontine (17%)
- Combined left motor AND sensory deficits
- Tegmental signs in 56% - more frequent than anteromedial pattern
- Includes eye movement disorders 1
Tegmental Pontine (10%)
- Mild left motor deficits
- Prominent sensory syndromes
- Eye movement disorders (INO, gaze palsies)
- Vertigo, dizziness, ataxia 1
Atypical Presentations Requiring High Clinical Suspicion
Major diagnostic pitfall: Posterior circulation strokes can present with deceptively mild symptoms 4:
- Isolated vertigo, headache, or nausea
- NIHSS score may be 0 despite acute infarction
- Truncal ataxia may be the only neurological sign 4
- These presentations are frequently misdiagnosed as peripheral vestibular disorders 7
Additional Features
- Pathological laughing occurs with basal pontine lesions 2
- Nausea and vomiting common with brainstem involvement 8
- Headache in approximately 25% of cases 8
- Decreased consciousness only with massive bilateral pontine lesions or basilar occlusion 8, 1
Prognostic Indicators
Upper pontine lesions have significantly better outcomes than lower pontine lesions 2. Bilateral pontine involvement carries poor prognosis, while unilateral infarcts generally have excellent recovery except when bilateral 1.