What type of workup should be done for a patient presenting with intention tremor?

Workup for Intention Tremor

The workup for intention tremor should focus on identifying cerebellar pathology through targeted neuroimaging with MRI brain, followed by assessment for underlying causes including multiple sclerosis, stroke, structural lesions, and metabolic/toxic etiologies.

Initial Clinical Assessment

Key Historical Features to Elicit

• Tremor characteristics: Intention tremor worsens during goal-directed movements, particularly during the deceleration and target phase of reaching tasks 1
• Associated cerebellar signs: Ask about gait instability, dysarthria, truncal ataxia, and coordination difficulties 2
• Temporal progression: Document whether this represents new-onset symptoms or progression from pre-existing postural tremor, as intention tremor can develop at variable intervals after postural tremor onset in essential tremor 1
• Medication and substance history: Identify potential toxic causes and assess alcohol sensitivity 1
• Family history: Essential tremor with intentional component may have familial patterns 1

Physical Examination Priorities

• Finger-nose-finger testing: Quantify tremor amplitude increase during target approach 1
• Assess for hypermetria: Patients with intention tremor demonstrate overshooting of targets 1
• Evaluate movement velocity: Intention tremor causes slowed movement during deceleration and target phases 1
• Check for additional tremor types: Document presence of postural, kinetic, or rest tremor components 1, 3
• Examine for head involvement: Intention tremor can affect the head (neck or chin) in 9% of cases 3
• Look for parkinsonian features: Fine tremor unaffected by intention, rigidity, staccato speech, and shuffling gait suggest alternative diagnoses 2
• Assess for asterixis: Flapping tremor indicates hepatic encephalopathy rather than cerebellar pathology 2

Neuroimaging Workup

Primary Imaging Modality

• MRI brain without and with IV contrast is the first-line imaging study for evaluating intention tremor to identify cerebellar lesions, demyelinating disease, stroke, or structural abnormalities 2
• High-resolution T2-weighted sequences provide excellent visualization of cerebellar structures and can detect subtle lesions 2
• Contrast administration facilitates detection of inflammatory changes, demyelinating plaques, and neoplasms 2

When CT May Be Considered

• CT head has insufficient sensitivity for detecting cerebellar pathology compared to MRI and should not be the primary imaging modality 2
• CT temporal bone is not indicated unless there are specific auditory or vestibular symptoms suggesting peripheral causes 2

Laboratory and Additional Testing

Essential Laboratory Studies

• Thyroid function tests: Thyrotoxicosis causes tremor through increased sympathetic activity 4
• Metabolic panel: Assess for hyperparathyroidism, particularly in patients with uremia 4
• Liver function tests: Rule out hepatic encephalopathy if asterixis is present 2
• Vitamin B12 and folate levels: Nutritional deficiencies can cause cerebellar dysfunction 2

Specialized Testing When Indicated

• Cerebrospinal fluid analysis: Consider if inflammatory or infectious etiology suspected, particularly for rapidly progressive symptoms 2
• Genetic testing: May be appropriate if family history suggests hereditary ataxia syndromes 1

Differential Diagnosis Considerations

Distinguishing Intention Tremor from Other Tremor Types

• Essential tremor with intentional component: 25% of essential tremor patients develop moderate-to-severe intention tremor, with another 33% showing mild intentional features 1
• Multiple sclerosis: Intention tremor is a common manifestation of cerebellar involvement 5, 6
• Functional/conversion disorder tremor: Shows variable frequency, amplitude, and direction; worsens with attention and improves with distraction; entrainable with voluntary movements 7
• Enhanced physiologic tremor: Triggered by anxiety, exercise, or caffeine; lacks true intentional component 8

Red Flags Requiring Urgent Evaluation

• Rapidly progressive symptoms: Suggests prion disease, inflammatory conditions, or neoplastic processes 2
• Focal neurological deficits: Indicates structural lesion requiring immediate imaging 2
• Altered mental status: May indicate metabolic encephalopathy or increased intracranial pressure 2

Common Pitfalls to Avoid

• Assuming all action tremors are essential tremor: 25% of essential tremor patients develop true intention tremor with cerebellar features, requiring different management considerations 1
• Ordering CT instead of MRI: CT has inadequate sensitivity for cerebellar pathology and should not be the initial imaging study 2
• Missing functional tremor: Functional tremors can mimic intention tremor but respond to entrainment techniques and distraction rather than pharmacotherapy 7
• Overlooking medication-induced causes: Many drugs can exacerbate or cause tremor through various mechanisms 8
• Failing to assess functional impact: Document effects on activities of daily living, as this guides treatment decisions 2, 7