When we think of brain diseases, we often fear memory loss. But with Amyotrophic Lateral Sclerosis (ALS), it is movement that slowly slips away, while the mind, in many cases, stays sharp. This week, the disease has returned to headlines after reports that Grey’s Anatomy actor Eric Dane passed away at 53 following a battle with ALS, bringing fresh attention to a condition many still struggle to understand. It is a progressive condition that affects motor neurons — the nerve cells that control voluntary muscles such as those used for walking, speaking, swallowing and even breathing.
Dr Sandeep Nayani, consultant neurologist at Apollo Hospitals, Jubilee Hills, explains, “ALS primarily damages motor neurons, the nerve cells controlling voluntary muscle movement while sparing regions linked to memory and reasoning in many patients. This selective injury highlights the brain’s remarkable specialisation, where distinct circuits govern movement and cognition, functioning independently despite sharing the same intricate neural network.”
When it comes to causes, there are still more questions than answers. Prof Dr Rupam Borgohain, senior consultant neurologist and programme director-PDMDRC at Yashoda Hospitals, points out, “The etiology of ALS is complex; around 90–95 percent of cases are sporadic (no family history), indicating random triggers such as oxidative stress, protein misfolding, or environmental exposures (eg, toxins, smoking, military service). Just 5–10 percent are familial, and they are associated with genes such as SOD1 or C9orf72. Although no one cause predominates, lifestyle variables such as severe physical activity or head trauma may increase risk.”
Dr Mohammed Mahmood Ali, consultant neurologist at Olive Hospital, echoes that uncertainty. “The exact cause of ALS is not fully understood. It is believed to develop due to a combination of genetic and environmental factors. The environmental factors include long term exposure to certain chemicals such as pesticides, heavy metals like lead and Mercury and industrial toxins. Apart from these chemicals physical trauma to the head can also contribute towards damage to the motor neurons. Recent research has also proposed that air pollution not only confers a higher risk of developing ALS but also rapid progression of ALS,” he shares.
A persistent weakness while climbing stairs, visible muscle twitching, slurred speech or frequent stumbling are often brushed aside as stress or aging. As a result, diagnosis can be delayed for months because there is no single test that confirms ALS immediately. Doctors rely on clinical examination, specialised tests and ruling out other conditions.
Even after decades of research, a cure remains elusive. As Dr Sandeep says, “Despite decades of research, it remains one of medicine’s toughest challenges. The disease is complex, with multiple genetic and environmental triggers, and varies widely between patients. Motor neurons deteriorate rapidly, often before diagnosis. Limited understanding of early disease mechanisms and the brain’s intricate biology has slowed drug development and curative breakthroughs.”
Some warning signs that Dr Rupam shares: “Prolonged muscle weakness (such as difficulty ascending stairs or holding objects), fasciculations (visible muscle spasms), cramping, foot drop, slurred speech, or unexplained weight loss due to swallowing issues are important early indicators. Frequent stumbling and fatigue are also prevalent. Due to symptoms that mirror benign conditions, diagnosis delays typically last 12 to 16 months. Since there isn’t a single conclusive test for ALS, mimics must be ruled out by several assessments. This is further worse by subtle onset and awareness gaps; early attention can result in quicker intervention.”
Still, early diagnosis makes a difference. Dr Mohammed underlines its importance: “While there is currently no cure for ALS, early detection remains vital for improving patient outcomes. Certain medications designed to slow disease progression are most effective when initiated in the early stages. Furthermore, a timely diagnosis allows patients and their families to proactively prepare for anticipated complications, such as respiratory or nutritional challenges. Most importantly, early diagnosis grants families the necessary time to understand the condition, make informed care decisions, and explore clinical trials. This proactive approach significantly reduces anxiety and fosters better psychological adjustment for everyone involved.”