What is the differential diagnosis for abnormal gait?

Differential Diagnosis for Abnormal Gait

The differential diagnosis for abnormal gait is broad and requires systematic categorization based on the underlying pathophysiology: neurological causes (cerebellar, sensory, motor, extrapyramidal, frontal), musculoskeletal causes, vascular causes, and functional disorders. 1, 2, 3

Neurological Causes

Cerebellar Ataxia

• Wide-based, unsteady gait with dysmetria, nystagmus, and intention tremor 4, 5
• Does not worsen significantly with eye closure (negative Romberg test) 6
• Truncal ataxia suggests cerebellar vermian pathology 4
• MRI brain is the preferred imaging modality to identify cerebellar lesions, congenital malformations, or neurodegenerative processes 4, 5

Sensory (Proprioceptive) Ataxia

• Wide-based gait that worsens dramatically when visual input is removed (positive Romberg test) 6, 2
• Results from dorsal column dysfunction, dorsal root ganglia pathology, or peripheral sensory nerve damage 6
• Associated with sensory loss, hyporeflexia, and absence of cerebellar signs (no nystagmus, dysmetria, or intention tremor) 6
• MRI of cervical and thoracic spine is recommended to evaluate for spinal cord pathology 6

Spastic Gait

• Characterized by stiffness, scissoring pattern, and circumduction of legs 2, 3
• May indicate upper motor neuron lesions from stroke, multiple sclerosis, or cervical myelopathy 3
• Urgent MRI of the spinal cord without contrast is indicated if spinal cord compression is suspected, particularly with progressive neurologic deficits, sensory level, or urinary incontinence 7

Parkinsonian Gait

• Shuffling, festinating gait with reduced arm swing, stooped posture, and difficulty initiating movement 2, 3
• Freezing of gait and turning en bloc are characteristic features 2

Steppage Gait

• Foot drop with high-stepping pattern to clear the toes 2, 3
• Indicates peripheral neuropathy, peroneal nerve palsy, or L5 radiculopathy 3

Frontal Gait Disorder

• Magnetic gait with difficulty initiating steps, shuffling, and wide base 3
• Associated with normal pressure hydrocephalus, vascular dementia, or frontal lobe pathology 3

Vestibular Dysfunction

• Lurching gait triggered by head rotation 4
• Associated with vertigo, nystagmus, and imbalance 1

Musculoskeletal Causes

Antalgic Gait

• Shortened stance phase on affected limb due to pain 3
• Common with hip arthritis, knee arthritis, or foot/ankle pathology 4

Trendelenburg Gait (Waddling Gait)

• Hip drop on contralateral side during stance phase 2, 3
• Indicates hip abductor weakness or hip joint pathology 3

Knee Hyperextension Gait

• Excessive knee extension during stance phase to compensate for quadriceps weakness 3

Joint Contractures

• Limited range of motion causing altered gait mechanics 3

Vascular Causes

Peripheral Artery Disease (PAD)

• Claudication: reproducible leg discomfort with exertion that is relieved by rest within 10 minutes 4
• Resting ankle-brachial index (ABI) ≤0.90 confirms PAD diagnosis 4
• In patients with exertional leg symptoms and normal or borderline resting ABI (>0.90 and ≤1.40), exercise treadmill ABI testing should be performed 4
• Differential includes hip arthritis (aching discomfort, variable with exercise, history of degenerative arthritis), spinal stenosis (bilateral buttocks/posterior leg pain, worse with standing/extending spine, relief with lumbar flexion), and venous claudication (tight bursting pain, subsides slowly, history of deep vein thrombosis) 4

Spinal Stenosis

• Neurogenic claudication with bilateral leg pain, worse with standing and lumbar extension, relieved by sitting or lumbar flexion 4, 3

Functional Gait Disorders

Primary Functional Gait Disorder

• Slow-hesitant gait, astasia-abasia, bouncing with knee buckling, excessive slowness, and inconsistent patterns 8
• Bouncing gait with knee buckling is particularly characteristic of isolated functional gait disorder 8
• May present with wheelchair dependency despite inconsistent neurological findings 8
• Diagnosis requires positive functional signs and absence of organic pathology 8

Metabolic and Toxic Causes

Drug-Induced Ataxia

• Occult medication toxicity from anticonvulsants, benzodiazepines, or alcohol 1, 3

Vitamin B12 Deficiency

• Sensory ataxia with posterior column dysfunction 3

Red Flags Requiring Urgent Evaluation

• Progressive neurologic deficit over days (neurologic emergency requiring immediate MRI) 7
• Lower limb weakness with urinary incontinence and sensory level (spinal cord compression or cauda equina syndrome) 7
• Acute onset ataxia in children (infectious, inflammatory, toxic, ischemic, or traumatic etiology) 4
• Pupillary abnormalities, torticollis, or resistance to neck motion (posterior fossa tumor, craniocervical junction pathology) 4

Diagnostic Approach Algorithm

1. Determine temporal pattern: acute (hours-days), subacute (weeks), chronic progressive, or episodic 4, 1
2. Perform Romberg test: positive suggests sensory ataxia; negative suggests cerebellar or other cause 6, 2
3. Assess for pain: antalgic gait suggests musculoskeletal cause; claudication suggests vascular cause 4, 3
4. Evaluate for upper motor neuron signs: spasticity, hyperreflexia, Babinski sign suggest myelopathy or stroke 3
5. Check for extrapyramidal signs: bradykinesia, rigidity, tremor suggest parkinsonism 2, 3
6. Measure resting ABI if vascular claudication suspected: ABI ≤0.90 confirms PAD 4
7. Order MRI brain for cerebellar signs or MRI spine for sensory ataxia or myelopathy 4, 7, 6