Parkinson's starts early: Signs that appear before tremors

Parkinson’s disease is often recognised by a visible tremor. But doctors now say the condition may begin much earlier—sometimes decades before any movement-related symptoms appear.

In India, this growing neurological concern is becoming harder to ignore. Nearly 7.5 lakh people are estimated to be living with Parkinson’s, with cases rising by 21% over the past two decades. More strikingly, onset in Indian patients can occur almost 10 years earlier than the global average.

WHAT HAPPENS BEFORE THE TREMOR

The earliest phase of Parkinson’s is known as the prodromal stage a period where the disease quietly develops without the hallmark motor symptoms.

During this time, subtle, non-motor symptoms begin to appear. These can surface 15–20 years before diagnosis, making early detection extremely difficult.

Common early signs include:

• Persistent constipation

• Loss or reduced sense of smell (anosmia)

• Depression and anxiety

• Sleep disturbances

• General gastrointestinal discomfort

Because these symptoms are common and non-specific, they are rarely linked to Parkinson’s in the early stages.

WHAT RESEARCH SHOWS

Emerging research is reinforcing the importance of these early indicators.

A 2025 study from Egypt found that 22% of Parkinson’s patients experienced constipation before motor symptoms began. Meanwhile, a study conducted in Odisha reported widespread non-motor symptoms among patients:

• 100% had gastrointestinal issues

• 70% experienced constipation

• 98% had depression

• 95% reported anxiety

• 78% had sleep disturbances

• 85% experienced loss of smell

• 45% had symptoms years before diagnosis

WHAT’S HAPPENING IN THE BRAIN

Scientists believe these early changes are linked to the gradual accumulation of a protein called alpha-synuclein in the brain.

This buildup initially affects regions responsible for sleep, smell, and gut function. Only later does it impact areas that control movement leading to symptoms like tremors, stiffness, and slowed movement. By then, Parkinson’s can be clinically diagnosed.

WHY EARLY DIAGNOSIS REMAINS A CHALLENGE

Despite growing awareness, diagnosing Parkinson’s in its early stages is complex.

As Dr Praveen Gupta explains, “Parkinson’s is a disease that begins long before it becomes visible. The earliest changes are happening silently in the brain, often years before a patient notices anything unusual.”

He adds, “Symptoms like constipation, anxiety, or sleep disturbances are extremely common and non-specific. That’s what makes early identification of Parkinson’s particularly difficult.”

Highlighting the risk of overdiagnosis, he says, “We have to be cautious. Labelling someone too early can cause significant psychological distress, especially when we are not certain the disease will develop.”

He further notes, “The goal is not just early detection but accurate detection so that we can eventually intervene at the right time without causing unnecessary fear.”

INDIA’S UNIQUE BURDEN

India faces a dual challenge rising prevalence and earlier onset. With patients developing symptoms earlier than the global average, the need for awareness becomes even more critical.

Yet, doctors must strike a careful balance: encouraging attention to persistent, unexplained symptoms without triggering overdiagnosis.

Parkinson’s disease does not begin with a tremor it often starts silently. Recognising early, non-motor symptoms may help prompt timely medical evaluation. But for now, definitive diagnosis still relies on the appearance of movement-related signs.

The key lies in awareness, vigilance, and careful clinical judgment.