Dementia is a decline in cognitive functions like memory, thinking, and reasoning, severe enough to interfere with daily life. It stems from abnormal brain changes affecting nerve cells. Tremors are involuntary, rhythmic shaking movements of body parts such as hands, arms, or head, typically caused by problems in brain regions controlling movement. This article explores the relationship between dementia and tremors, and why these motor symptoms might appear alongside cognitive decline.
The Relationship Between Dementia and Tremors
Dementia involves cognitive decline, while tremors are motor symptoms characterized by involuntary muscle movements. While dementia itself doesn’t typically cause tremors, their co-occurrence suggests a more complex underlying neurological condition. When tremors are observed with dementia, it often indicates a specific disease process affecting both cognitive and motor pathways.
Not all forms of dementia include tremors. Their presence points toward certain neurodegenerative conditions impacting both cognitive and motor systems, or they might stem from a separate medical issue coexisting with dementia. Understanding this distinction is important for identifying the cause of tremors in someone experiencing cognitive decline.
Dementia Conditions Linked to Tremors
Certain types of dementia or related neurodegenerative conditions are strongly associated with tremors. Lewy Body Dementia (LBD) is a common type where tremors, alongside other Parkinson’s-like motor symptoms, are frequently observed. In LBD, Lewy bodies, which are protein deposits, develop in brain nerve cells, affecting areas responsible for thinking, memory, and movement. These motor symptoms, including tremors, muscle rigidity, and slow movement, can appear early, sometimes even before significant cognitive decline.
Parkinson’s Disease Dementia (PDD) is another condition with prominent tremors. PDD typically begins as Parkinson’s disease, with motor symptoms like tremors appearing first, followed by cognitive decline usually more than a year later. Lewy bodies are also a feature of Parkinson’s disease, explaining shared motor symptoms with LBD. While both LBD and PDD involve Lewy bodies and tremors, symptom onset timing helps differentiate them. Vascular dementia, caused by reduced blood flow affecting brain regions controlling movement, can also sometimes lead to tremors.
Recognizing Different Tremor Types
Tremors are classified by when they occur, providing clues to their origin. A resting tremor happens when the affected body part is at rest, not actively moving and supported against gravity. This type often subsides with voluntary movement and is commonly associated with Parkinson’s disease, sometimes described as a “pill-rolling” motion.
Action tremors occur during voluntary muscle movement. A postural tremor is evident when a person holds a position against gravity, such as extending their arms outwards. Kinetic tremor appears during any voluntary movement, like moving the wrist up and down. An intention tremor is a specific type of kinetic tremor that worsens as a person’s hand or limb approaches a target during a purposeful movement, such as reaching for a cup.
Other Reasons for Tremors
Tremors can arise from causes unrelated to dementia. Essential tremor is a common movement disorder characterized by rhythmic shaking, often affecting both hands and arms during action. This type can also involve the head, voice, or legs and often has a genetic component. While distinct from Parkinson’s disease, essential tremor can coexist with dementia.
Certain medications can induce tremors as a side effect, including antidepressants, antipsychotics, anti-seizure drugs, asthma medications, and thyroid hormones. If tremors begin after starting a new medication or increasing a dosage, consider this a possible cause. Factors like anxiety, stress, excessive caffeine intake, and thyroid problems can also lead to tremors.
Guidance for Tremors and Dementia
Observing new or worsening tremors in someone with dementia warrants a medical evaluation. A healthcare professional, particularly a neurologist, can assess the tremor type and its potential underlying causes. An accurate diagnosis is fundamental for determining if tremors relate to the specific type of dementia, an unrelated condition, or medication side effects.
Professional medical advice ensures appropriate steps can be taken. This might involve adjusting current medications, exploring therapies to manage symptoms, or investigating other health conditions contributing to the tremors. Early evaluation provides clarity and can lead to improved management and comfort for the individual experiencing both cognitive and motor symptoms.