What is the most likely diagnosis and urgent management for a patient who feels a left‑ward tilt while walking, has normal limb strength, and an isolated stiff left pinky due to ulnar‑nerve dysfunction?

Posterior Fossa Pathology with Urgent Neuroimaging Required

This patient requires urgent brain MRI with and without contrast to evaluate for posterior fossa pathology—specifically stroke, demyelination, or mass lesion—as the combination of leftward tilt sensation (suggesting vestibular pathway dysfunction) and isolated ulnar nerve findings points toward a central nervous system process rather than a benign peripheral cause. 1

Most Likely Diagnosis: Skew Deviation with Ocular Tilt Reaction

The sensation of tilting leftward while walking with preserved strength is highly characteristic of skew deviation, a vertical strabismus caused by disruption of vestibular pathways in the posterior fossa (brainstem or cerebellum) or peripheral vestibular apparatus. 1

Key Diagnostic Features Present:

• Leftward tilt sensation represents the subjective visual vertical tilt component of the ocular tilt reaction 1
• Normal limb strength excludes motor pathway lesions and helps localize to vestibular/sensory pathways 1
• The stiff left pinky from ulnar nerve dysfunction may represent either:
  • A separate peripheral nerve issue (most common—compression at elbow) 2, 3
  • Part of a broader neurological process if other cranial nerve or brainstem signs emerge 1

Why This Demands Urgent Recognition:

Skew deviation requires immediate differentiation from benign fourth nerve palsy because the underlying causes—acute vestibular neuronitis, demyelination, ischemic stroke, or posterior fossa mass—demand urgent treatment and imaging. 1

Urgent Management Algorithm

Step 1: Immediate Neuroimaging

• Order MRI brain and brainstem with and without contrast to evaluate for:
  • Ischemic or hemorrhagic stroke in posterior circulation 1
  • Demyelinating lesions (multiple sclerosis) 1
  • Mass lesions compressing vestibular pathways 1
  • Acute vestibular neuronitis (though often a clinical diagnosis) 1

Step 2: Concurrent Neurological Examination

While awaiting imaging, perform focused assessment for:

• Vertical diplopia (suggests skew deviation) 1
• Head tilt toward the shoulder of the hypotropic eye 1
• Other brainstem signs: facial weakness, dysarthria, dysphagia, ataxia, nystagmus 1
• Cardiovascular risk factors: hypertension, diabetes, hyperlipidemia, smoking (increase stroke risk) 1

Step 3: Urgent Neurology Referral

• Refer immediately to neurology or neuro-ophthalmology for patients with:
  • Confirmed skew deviation on examination 1
  • Any additional neurological signs beyond the tilt sensation 1
  • Acute onset symptoms (within days to weeks) 1

Addressing the Ulnar Nerve Component

The stiff left pinky represents ulnar nerve dysfunction, most commonly from compression at the cubital tunnel (elbow). 2, 3

Evaluation of Ulnar Neuropathy:

• Physical examination: Check for point tenderness at elbow, digital numbness in 4th-5th digits, weakness of hand intrinsics, positive Tinel's sign at cubital tunnel 2
• Elbow flexion test: Sustained elbow flexion for 3-5 minutes may reproduce symptoms 2
• Electrodiagnostic studies (if diagnosis unclear): Ulnar motor nerve conduction velocity <50 m/sec across elbow segment is most reliable finding 3

Management of Isolated Ulnar Neuropathy:

• Conservative approach initially: Rest, avoid prolonged elbow flexion, nighttime elbow extension splinting, NSAIDs 2
• Dynamic splinting that allows movement while protecting the nerve (avoid static immobilization which worsens outcomes) 4
• Functional task training with normal movement patterns to prevent learned non-use 4
• Surgical decompression reserved for progressive weakness or failed conservative management after 3-6 months 2

Critical Pitfalls to Avoid

Do Not Dismiss as Benign Peripheral Vertigo

• Peripheral vestibular disorders (BPPV, vestibular neuronitis) typically cause rotational vertigo, not a sensation of body tilt 1
• The specific complaint of leftward tilt while walking suggests disruption of graviceptive pathways in the posterior fossa 1

Do Not Delay Imaging for Tilt-Table Testing

• Tilt-table testing is used for syncope evaluation, not for vestibular pathway dysfunction 1
• This patient has disequilibrium (imbalance), not syncope (loss of consciousness) 1

Do Not Assume the Ulnar Nerve Finding is Unrelated

• While most likely a separate peripheral compression issue, document carefully whether ulnar symptoms preceded or followed the balance symptoms 2, 3
• If ulnar dysfunction is acute and concurrent with tilt sensation, consider broader neurological process 1

Do Not Use Static Immobilization for the Hand

• Prolonged static splinting of the affected hand worsens muscle deconditioning, promotes learned non-use, and can trigger complex regional pain syndrome 4
• Use dynamic splinting that provides support while allowing functional movement 4

Expected Timeline and Prognosis

For Skew Deviation:

• Vestibular neuronitis: May be self-limiting and respond to medical intervention over weeks 1
• Transient ischemia: May cause transient skew that resolves as perfusion improves 1
• Stroke or mass lesions: Often result in long-lasting symptoms requiring ongoing management 1

For Ulnar Neuropathy:

• Conservative management successful in majority of mild-to-moderate cases with 3-6 months of treatment 2
• Electrodiagnostic studies help establish prognosis and guide surgical decision-making if needed 3

The priority is urgent MRI to rule out life-threatening posterior fossa pathology before attributing symptoms to benign causes.