From the Guidelines
Tremors are fundamentally categorized into resting, postural, and kinetic types, each with distinct characteristics and implications for diagnosis and treatment, particularly in the context of Parkinsonian syndromes and other neurodegenerative diseases 1.
Types of Tremors
- Resting Tremors: These occur when the affected limb is at rest and completely supported against gravity, typically disappearing with voluntary movement. A classic example is the "pill-rolling" tremor seen in Parkinson's disease, characterized by a rhythmic oscillation between the thumb and index finger 1.
- Postural Tremors: These appear when a person maintains a posture, such as holding their arms outstretched. Postural tremors are commonly associated with essential tremor and can also be seen in physiologic tremors, which may be exacerbated by factors like anxiety, caffeine, or certain medications.
- Kinetic Tremors: Occurring during voluntary movement, kinetic tremors can be further subdivided. Simple kinetic tremors happen during any voluntary movement, while intention tremors specifically worsen as the individual approaches their target. Intention tremors are indicative of cerebellar dysfunction and can be observed in conditions such as multiple sclerosis or following a cerebellar stroke.
Clinical Implications
The accurate identification of tremor type is critical for diagnosing the underlying condition and selecting the appropriate treatment strategy. For instance, Parkinsonian tremors, which are typically resting tremors, may respond well to levodopa, whereas essential tremor, often characterized by postural tremors, may be more effectively managed with propranolol or other beta-blockers 1. Understanding the differences between these tremor types, as outlined in the context of Parkinsonian syndromes and other neurodegenerative diseases, is essential for providing optimal patient care.
From the Research
Types of Tremor
- Resting tremor: occurs in a body part that is relaxed and completely supported against gravity 2
- Action tremor: occurs with voluntary contraction of a muscle and can be further subdivided into:
Characteristics of Tremor Types
- Resting tremor is typically asymmetric and becomes less prominent with voluntary movement, often seen in Parkinson's disease 2, 3
- Postural tremor is often symmetric and bilateral, commonly seen in essential tremor 3, 6
- Kinetic tremor is the primary type of tremor in essential tremor, with kinetic tremor being more severe than postural tremor in approximately 95% of cases 6
Diagnosis and Differentiation
- The diagnosis of tremor is based on clinical information obtained from a thorough history and physical examination 2
- The evaluation of tremor should start with a detailed tremor history followed by a focused neurologic examination 5
- Differential diagnosis of essential tremor and Parkinson's disease may be difficult, but the type of tremor and its characteristics can aid in diagnosis 3, 5