Gait Imbalance in a 72-Year-Old Male — Possible Causes

Key Distinction First

🔴 Top Causes to Consider

1. Normal Pressure Hydrocephalus (NPH) — Must rule out first

• Gait: slow, widened base, short shuffling steps, feet appear "glued to the floor", difficulty turning
• Patients complain of imbalance or vague dizziness but find it hard to articulate
• Can look like Parkinson's superficially but lacks the stooped posture and festination
• Treatable — VP shunt can dramatically improve gait
• Diagnosed with MRI (enlarged ventricles out of proportion to sulci) ± large-volume LP

2. Parkinson's Disease / Parkinsonism

• Shuffling gait, reduced arm swing, start hesitation, freezing of gait when turning
• Rigidity ("stiffness/heaviness in legs") and bradykinesia
• Falls: typically forward, late feature in classic PD; backward early falls suggest MSA or PSP
• Progressive Supranuclear Palsy (PSP) — backward falls early, vertical gaze palsy, more rapid progression

3. Cerebellar Ataxia

• Wide-based, staggering, veer to one side, inability to walk in a straight line
• Worsened on uneven ground
• Causes at this age: cerebellar stroke, alcoholic cerebellar degeneration, paraneoplastic syndrome, medication toxicity (phenytoin, amiodarone), hypothyroidism
• Check: heel-shin test, tandem walking, finger-nose test

4. Sensory Ataxia (Proprioceptive Loss)

• Unsteadiness worse in the dark or eyes closed (positive Romberg)
• Sensation of walking on "cotton wool" or spongy surface
• Causes: B12 deficiency (subacute combined degeneration), peripheral neuropathy (diabetic), tabes dorsalis (rare), posterior column lesion
• Very common and treatable — check B12, glucose, HbA1c

5. Cervical Spondylotic Myelopathy

• Spastic gait with leg stiffness, "legs that don't do what they're told"
• May drag toes, trip on flat surfaces, give-way falls
• Often no neck pain — the gait problem can be the first symptom
• Associated sensory level, hyperreflexia, upgoing plantar responses
• MRI cervical spine is diagnostic; surgical decompression can be curative

6. Cerebrovascular Disease (Small Vessel / White Matter Disease)

• Diffuse subcortical ischemia → frontal-subcortical disconnection
• Imbalance prominent when turning, stepping backward, or dual-tasking
• MRI: periventricular white matter hyperintensities (leukoaraiosis)
• Often coexists with NPH and Parkinson's clinically

7. Lumbar Spinal Stenosis / Neurogenic Claudication

• Gait worsened after walking a distance (claudication), relieved by sitting or leaning forward (flexing the spine)
• Leg pain/weakness, not just imbalance
• MRI lumbar spine confirms

8. Vestibular Dysfunction (Chronic)

• Chronic unilateral or bilateral vestibulopathy causes veering and imbalance without active vertigo
• Worse in visually busy environments (shopping malls), darkness
• Can be post-labyrinthitis, ototoxicity (gentamicin, furosemide), or bilateral vestibulopathy from aging

9. Drug-Induced / Iatrogenic

• Extremely common and missed: benzodiazepines, antiepileptics, antihypertensives (orthostatic hypotension), metformin (B12 depletion), antipsychotics, antihistamines
• Always take a full drug history in a 72-year-old

10. Orthostatic Hypotension

• Imbalance and near-syncope on standing and walking — measure lying/standing BP

🟡 Less Common but Serious Causes Not to Miss

🔍 Recommended Evaluation

• Romberg test (proprioceptive vs. cerebellar)
• Tandem gait (cerebellar)
• Heel-shin test
• Power, tone, reflexes, plantar response
• Cranial nerves (especially eye movements for PSP)
• Mini-cognitive assessment (MMSE/MoCA)

• MRI brain + spine (cervical) — single most useful investigation
• B12, folate, TFTs, FBC, HbA1c, LFTs, RFTs
• Lying & standing BP

Summary Probability Ranking (for this age/presentation)

Referral: Neurology evaluation is appropriate. An MRI brain and spine should be the priority investigation alongside routine blood work.

Vestibular Screening Interpretation — 72-Year-Old Male with Drunken Gait

Your Clinical Findings Summary

🔴 The Pivotal Finding: Normal HIT + Gaze-Evoked Nystagmus = Central Pattern

"In the setting of acute vestibular syndrome, a normal horizontal head impulse test result strongly suggests a central origin (e.g., brainstem or cerebellar stroke)." — Roberts and Hedges' Clinical Procedures in Emergency Medicine

"Gaze-evoked nystagmus has approximately equal amplitude in all directions and results from either medication toxicity or cerebellar dysfunction. In patients with a partially compensated peripheral vestibular lesion, nystagmus in one direction may be present." — Bradley and Daroff's Neurology in Clinical Practice

• ✅ Normal HIT (intact VOR reflex arc — i.e., peripheral end-organ is working)
• ✅ Gaze-evoked nystagmus (neural integrator failure — cerebellar/central)
• ✅ Bilateral Romberg failure (not just one side)
• ✅ Fukuda deviation to right (vestibular asymmetry)
• ✅ Drunken/truncal ataxic gait (no vertigo)

Differential Diagnosis — In Order of Probability

1. 🔴 Cerebellar Degeneration / Vestibulocerebellar Lesion — Most Likely

• Gaze-evoked nystagmus is the hallmark of cerebellar (especially vestibulocerebellum — flocculonodular lobe) dysfunction
• Drunken gait = classic cerebellar truncal ataxia
• Bilateral Romberg failure
• Normal HIT (peripheral VOR arc intact; the problem is central processing)
• Causes at age 72:
  • Idiopathic cerebellar atrophy (age-related)
  • Chronic alcohol — cerebellar vermis predominant
  • Paraneoplastic cerebellar degeneration (anti-Yo, anti-Hu)
  • Hypothyroidism — reversible cerebellar syndrome
  • Drug toxicity — phenytoin, carbamazepine, lithium, amiodarone
  • Vitamin E or B1 deficiency

2. 🟡 CABV — Cerebellar Ataxia with Bilateral Vestibulopathy

• Progressive gait ataxia + bilateral vestibular loss + cerebellar atrophy (vestibulocerebellum)
• Signs: Gaze-evoked nystagmus + downbeat nystagmus, impaired pursuit, bilateral Romberg failure, ataxic gait
• If peripheral neuropathy is also present → CANVAS syndrome (Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome)
• Fukuda asymmetry here could reflect asymmetric bilateral vestibular loss
• This fits your patient's profile very well

3. 🟡 Chronic Bilateral Vestibulopathy (not presbyvestibulopathy)

• Romberg bilaterally affected, gait imbalance, Fukuda deviation
• BUT — GEN is not a feature of pure peripheral bilateral vestibulopathy
• GEN here argues against a purely peripheral bilateral etiology

4. Can This Be Presbyvestibulopathy?

• Age ≥60 years
• Mild bilateral peripheral vestibular hypofunction
• Chronic, slowly progressive unsteadiness/imbalance
• Reduced vestibular function on formal testing (reduced VOR gain on vHIT, caloric, VEMP)
• No gaze-evoked nystagmus — that finding is NOT consistent with presbyvestibulopathy

• Only 4.5% of elderly patients with chronic vestibulo-dizziness met presbyvestibulopathy criteria
• Isolated presbyvestibulopathy was found in only 0.14% of 707 patients — it almost always coexists with other sensorimotor disorders
• The majority had another vestibular, neurological, cardiac, or psychiatric diagnosis explaining their symptoms

Most Likely Working Diagnosis

Vestibulocerebellar dysfunction / early cerebellar degeneration with possible bilateral vestibular involvement (CABV spectrum), with a right-sided vestibular asymmetry on Fukuda.

🔍 Recommended Next Steps

Urgent

Vestibular Lab

Blood Work

Summary

Referral: Neurology + Neuro-otology/Audiology for complete vestibular battery. An MRI posterior fossa is urgent given the central signs.

Could This Be Acute Central Vestibular Hypofunction?

Why This Is a Central Vestibular Syndrome

"Absence of a head impulse sign in a patient with acute prolonged vertigo should suggest a central cause... Nystagmus that changes direction with gaze is due to a central lesion." — Harrison's Principles of Internal Medicine, 22nd Ed.

"Gaze-evoked nystagmus has approximately equal amplitude in all directions and results from either medication toxicity or cerebellar dysfunction." — Bradley and Daroff's Neurology in Clinical Practice

The Correct Terminology

1. Acute Central Vestibular Syndrome (ACVS)

• Acute/subacute onset of sustained imbalance/dizziness
• Central signs on bedside exam (normal HIT, GEN, skew deviation)
• Duration >24–72 hours (distinguishes from TIA)
• Must urgently exclude posterior fossa stroke (cerebellar or brainstem infarct)

2. Why Not "Acute Central Vestibular Hypofunction"?

Most Important Acute Central Cause to Exclude First

🔴 Posterior Fossa Stroke / TIA

Why Normal HIT Is the Game-Changer Here

Labyrinth → Vestibular nerve → Vestibular nucleus → Abducens nucleus → Eye

Putting It Together — This Patient's Most Likely Diagnosis

Immediate Action Required

Priority 1: MRI Brain (Posterior Fossa Protocol)

• DWI sequence — exclude acute infarct
• FLAIR — cerebellar atrophy, white matter lesions
• T1 with gadolinium — demyelination, tumor, paraneoplastic
• MRA of posterior circulation (PICA/AICA/basilar) — vascular disease

Priority 2: Complete Vestibular Battery

• vHIT (all 6 canals) — if peripheral VOR gain is truly normal, confirms central-only dysfunction
• Caloric testing — bilateral canal function
• VEMP — otolith function

Priority 3: Blood Work

• Drug levels (phenytoin, carbamazepine, lithium)
• Alcohol markers (GGT, MCV)
• B1, B12, vitamin E
• Paraneoplastic antibodies (anti-Yo, anti-Hu, anti-CASPR2)
• TFTs

Summary

"Acute central vestibular hypofunction" is not standard terminology, but this patient does have an acute/subacute central vestibular syndrome (ACVS). The GEN + normal HIT combination is the HINTS exam equivalent of a central stroke signal. Do not discharge or manage as a peripheral vestibular disorder. MRI posterior fossa is urgent.