Stroke Symptoms, Types & the Critical 4.5-Hour Window — Dr. Anand Karnam, Hyderabad

Stroke is India's second leading cause of death and the leading cause of adult disability. In Hyderabad alone, hundreds of stroke cases arrive at hospitals every week — and tragically, many arrive too late to receive the treatment that could have reversed their paralysis. The reason is almost always the same: the family did not recognise the symptoms in time, or they waited to "see if it gets better."

Dr. Anand Karnam, Neurologist at Sri Anand Child and Neuro Center, explains what a stroke is, the different types, how to recognise it instantly, and why the first 4.5 hours are so critical.

What Happens in a Stroke?

A stroke happens when blood supply to a part of the brain is suddenly cut off. Brain cells begin dying within minutes of losing blood supply — at a rate of approximately 1.9 million neurons per minute. There is no such thing as a "mild stroke" — the extent of damage depends entirely on which artery is blocked and how quickly blood flow is restored.

Two Main Types of Stroke

Ischaemic Stroke (80–85% of cases)

A blood clot blocks an artery supplying the brain. The clot either forms in the brain artery itself (thrombotic) or travels from elsewhere — often from the heart or a carotid artery plaque — and lodges in a brain vessel (embolic). Treatment: clot-dissolving injection (tPA) within 4.5 hours, or mechanical clot removal (thrombectomy) within 24 hours of the last known normal time.

Haemorrhagic Stroke (15–20% of cases)

A blood vessel in the brain bursts, causing bleeding into the brain tissue (intracerebral haemorrhage) or around the brain (subarachnoid haemorrhage). Most often caused by uncontrolled high blood pressure. Treatment is different — blood thinners make this worse. Surgery may be needed for large bleeds.

Recognise a Stroke — The FAST Test

Every person in India should know the FAST test by heart. Show it to your family today:

• F — Face: Ask the person to smile. Does one side of the face droop? Is the smile uneven?
• A — Arms: Ask the person to raise both arms. Does one arm drift downward? Can they hold both up?
• S — Speech: Ask them to repeat a simple sentence. Is the speech slurred? Garbled? Unable to speak? Can they not understand what you are saying?
• T — Time: If ANY of the above — call 108 immediately and note the exact time symptoms started. Do not wait. Do not drive yourself — call an ambulance.

Other Stroke Symptoms That Are Missed

Beyond the classic FAST symptoms, these also indicate stroke and are commonly ignored:

• Sudden severe headache — described as the worst headache of your life, coming on like a thunderclap (subarachnoid haemorrhage until proven otherwise)
• Sudden loss of vision in one eye, or loss of half the visual field in both eyes
• Sudden double vision
• Sudden dizziness with difficulty walking and falling to one side
• Sudden confusion — person does not know where they are or what day it is
• Sudden numbness of face, arm, or leg — typically on one side only

The 4.5-Hour Window — Why It Matters So Much

For ischaemic stroke, intravenous tPA (tissue plasminogen activator) can dissolve the clot and restore blood flow — but only within 4.5 hours of symptom onset. After this window closes, the drug cannot be given safely. Studies show that tPA given within the first 90 minutes saves an average of 30 brain cells for every second earlier it is administered.

Mechanical thrombectomy — a procedure where a catheter is passed into the brain artery to physically remove the clot — has a wider window of up to 24 hours for some patients, but outcomes are significantly better the earlier it is done.

The message is brutal in its simplicity: time is brain. Every minute of delay is more disability.

What Families Do Wrong

These are the most common mistakes Dr. Anand Karnam sees families make:

1. Waiting to see if it improves: "Maybe it'll go away." Stroke symptoms do not improve on their own in the early hours — if anything, they worsen
2. Assuming it is fatigue or low BP: Sudden arm weakness or speech difficulty is never just tiredness
3. Going to a nearby clinic first: Go directly to a hospital with a CT scanner and neurology team — not a small clinic
4. Not noting the time: The doctor's most important question is: what time did symptoms start? Always note the exact time
5. Giving medication at home: Do not give aspirin or any tablet before reaching hospital — in a haemorrhagic stroke, aspirin could be fatal

Mini-Stroke (TIA) — The Warning You Must Not Ignore

A Transient Ischaemic Attack (TIA) is a stroke where the clot dissolves on its own before causing permanent damage — symptoms last minutes to hours and then resolve completely. This is not reassuring. A TIA is a medical emergency because 10–15% of TIA patients have a full stroke within 90 days, with the highest risk in the first 48 hours. If you have TIA symptoms that resolve — go to hospital that day.

For stroke prevention assessment, carotid artery evaluation, and BP management in Hyderabad: Sri Anand CNC, Chanda Nagar. Call +91 90633 66983.