From the Research
Postural tremors are distinct from intention tremors in their clinical presentation, with postural tremors occurring during maintained posture and intention tremors appearing or worsening during purposeful movement toward a target. The key differences between postural and intention tremors lie in their characteristics and the conditions they are associated with. Postural tremors are typically seen in conditions like essential tremor or physiologic tremor, presenting as rhythmic oscillations of 4-12 Hz that remain relatively constant in amplitude throughout sustained postures 1. In contrast, intention tremors are characteristic of cerebellar dysfunction, presenting as slower (2-5 Hz), more irregular movements that intensify as the person approaches their target, such as when performing the finger-to-nose test 2.
Clinical Presentation
Some key points to consider when differentiating between postural and intention tremors include:
- Postural tremors are more common in essential tremor, with a frequency between 4 and 8 Hz, and involve mainly the upper extremities and head 3.
- Intention tremors are more characteristic of cerebellar dysfunction and may be seen in conditions such as cerebellar ataxia or lesions of the cerebellum 2.
- The neuroanatomical basis for this difference lies in their origins: postural tremors generally involve enhanced physiologic tremor circuits or basal ganglia dysfunction, while intention tremors result from damage to the cerebellum or its connections, disrupting the coordination of movement sequences 4.
Treatment Approaches
Treatment approaches differ accordingly, with postural tremors often responding to beta-blockers like propranolol (40-320 mg daily) or primidone (50-250 mg daily), while intention tremors may require medications like isoniazid, carbamazepine, or physical therapy interventions focused on weighted devices to increase proprioceptive feedback during movement 1. Some of the recent studies have proposed a new classification system for tremors, which may help in better understanding and management of these conditions 4.
Management
In clinical practice, it is essential to accurately diagnose and manage tremors, considering the marked etiological and phenomenological heterogeneity of these conditions. A detailed clinical evaluation, including history, physical examination, and laboratory tests, is necessary to determine the underlying cause of the tremor and to develop an effective treatment plan 2, 1.