A tremor is an involuntary, rhythmic muscle contraction causing a shaking movement in a body part, such as the hands, arms, head, or legs. Postural tremor specifically manifests when an individual actively maintains a position against gravity.
What Defines Postural Tremor
Postural tremor is characterized by shaking that occurs when a limb or body part is held in a fixed position, such as extending the arms forward. This type of tremor often becomes noticeable when a person attempts to hold a posture, and it may lessen or disappear when the body part is completely at rest. The movements typically appear as rhythmic oscillations, varying in amplitude from fine to coarse. This contrasts with a rest tremor, which occurs when muscles are relaxed and supported, and often diminishes or ceases with voluntary movement.
Postural tremor falls under the broader category of action tremors, which manifest during voluntary muscle contraction. Other action tremor subtypes include kinetic tremor, occurring during any voluntary movement like reaching for an object, and intention tremor, which worsens as the body part approaches its target. These distinctions help differentiate postural tremor from other movement disorders. While everyone experiences a slight, barely noticeable physiological tremor, a postural tremor becomes significant when it interferes with daily activities.
Underlying Causes of Postural Tremor
Postural tremor can arise from various factors, from common physiological responses to underlying medical conditions. One frequent cause is an enhanced physiological tremor, an amplification of the natural, slight tremor present in all individuals. This enhancement can be triggered or worsened by stress, anxiety, fatigue, excessive caffeine, or certain medications. These temporary influences make the tremor more noticeable but are often reversible once the contributing factor is removed.
Essential tremor (ET) is the most common movement disorder and a significant cause of persistent postural tremor. This neurological condition primarily involves tremor in the hands and arms during action, though it can also affect the head, voice, or lower limbs. While its exact cause is not fully understood, ET often has a genetic component, suggesting a hereditary link.
Postural tremor can also be a symptom of other medical conditions. Hyperthyroidism, an overactive thyroid gland, can lead to a more pronounced tremor. Certain neurological conditions, such as Parkinson’s disease, multiple sclerosis, or conditions affecting the cerebellum, may also present with postural components. Additionally, some medications, alcohol withdrawal, or other metabolic imbalances can induce or exacerbate postural tremors.
How Postural Tremor is Diagnosed
Diagnosing postural tremor primarily relies on a thorough clinical evaluation by a healthcare professional. This process begins with a detailed medical history, where the individual describes the tremor’s characteristics, including when it occurs, what makes it better or worse, and any associated symptoms. A physical examination is then performed, focusing on a neurological assessment to observe the tremor directly. The clinician will assess the tremor’s presentation, such as asking the individual to hold their arms outstretched. They will also evaluate other neurological functions, including coordination, gait, and muscle tone, to help distinguish postural tremor from other movement disorders.
While diagnosis is largely clinical, supplementary tests like blood tests may be ordered to rule out underlying medical conditions such as thyroid dysfunction or metabolic imbalances. Imaging studies, such as MRI or CT scans, are generally not required for diagnosing postural tremor itself but might be utilized to exclude other neurological conditions contributing to symptoms.
Approaches to Managing Postural Tremor
Management strategies for postural tremor are tailored to the underlying cause and symptom severity. Lifestyle adjustments can often help alleviate mild tremors. These include reducing caffeine, managing stress through relaxation techniques, and ensuring adequate sleep. Avoiding alcohol, especially if withdrawal is a factor, is also important.
For more pronounced tremors, medication options are available. Beta-blockers, such as propranolol, are frequently prescribed to reduce tremor severity, particularly in essential tremor. Anti-seizure medications and tranquilizers may also be considered to help control symptoms. The specific medication chosen depends on the individual’s overall health and other medical conditions.
In rare and severe instances where tremors significantly impair quality of life and do not respond to conventional treatments, more advanced interventions might be explored. Deep brain stimulation (DBS) is a surgical procedure involving implanting electrodes in specific brain areas to regulate abnormal brain activity. While effective, DBS is generally reserved for individuals with severe, disabling tremors who have exhausted other management approaches. The primary goal of managing postural tremor is to reduce symptoms and improve an individual’s ability to perform daily activities.