Navigation skills-another example of use it or lose it brain theory

A cat’s 200 mile trek home leaves scientists guessing

Recently the above titled article was published in The New York Times dated January 20th 2013. Holly, a domestic cat after getting lost on a family excursion was able to trek back to about a mile away from her family home, a distance of nearly 200 miles. Just how was this domestic animal able to achieve this remarkable feat of navigation ignited some healthy discussion among cat biologists. Wild animals navigate using visual, smell and magnetic cues. Domestic animals such as cats and dogs on the other hand are able to navigate successfully only in the immediate vicinity of their homes. It seems domestication and evolution resulted in loss of navigation qualities which their still wild ancestors (feral cats, big cats and wolves) possess. Take your dog and drop him off in a suburb of Washington DC and it is highly unlikely he shall show up at your apartment door in New York. This got me thinking on how the current generation of homo sapiens navigate. Take any self respecting New Yorker (no self respecting New Yorker will ask another New Yorker for directions) and ask him to find his way to Greenwich Street from say Charles Street and I bet you that only a few shall find their way in a timely fashion. Heck we even use GPS technology to navigate our way in the city we live in. Gone are the days when we navigated using the stars in the sky. We risk losing whatever remaining navigation skills we still possess thanks to the Google maps app on our smart phones. Maybe Holly the cat is a dying breed among cat explorers not just yet willing to let go of the traits of her ancestors.


Nitin K. Sethi, MD

New York-Presbyterian Hospital


525 East, 68th Street

New York, NY10065



Brain diseases blog: it is up and running again

To the readers of my blog and my website ( thank you for your continued support and positive feedback as well as constructive criticism.  I apologize for my delay in replying to your questions. No good excuse apart from that I was really busy the last few months. The blog though is now up and running and I shall be answering all your questions as well writing a few new posts.

Personal Regards,

Nitin Sethi, MD

I had a stroke like episode—what do I do?

I had a stroke like episode—what do I do?


Nitin K Sethi, MD

Assistant Professor of Neurology

New York-Presbyterian Hospital

Weill Cornell Medical Center

New York, NY 10065




I frequently see patients admitted to the hospital for evaluation of a suspected stroke like episode. Most of these patients are “normal” with no neurological signs and symptoms (the presenting symptom has invariably resolved by the time of their admission to an acute care facility).

So what are these stroke like episodes which scare patients and doctors alike leading to admission to a hospital and invariably a battery of tests including but not limited to MRI scans of the brain? Well some may be as vague as an episode of sudden dizziness, difficulty walking or weakness in the arms and legs, others are more restricted-an episode of difficulty speaking (I could speak but my words did not come out right or my speech was slurred as if I was drunk), loss of vision in an eye and so on.

When patients present to the ER or a doctor’s office with a history of such symptoms, they are frequently advised admission to rule out a possible stroke. When people think of stroke, they usually think of someone with weakness of the arm and leg but stroke signs and symptoms can be more subtle. Many patients have what we refer to as transient ischemic attacks (TIAs) prior to the stroke. As the name suggests, TIAs are transient (short lived) episodes of ischemia to the brain. Let me try to explain a TIA with the aid of an example. Let us assume a clot (entangled platelets and cholesterol crystals) breaks from the heart and goes up to the brain via the carotid artery (the carotid artery is one of the main arteries carrying blood to the brain). As it goes up further and further, it may get lodged in the ophthalmic artery (the ophthalmic artery is a branch of the carotid artery and supplies the retina of the eye). Now if the ophthalmic artery gets blocked by the clot there is no blood supply to the retina with resulting loss of vision in that eye (patients frequently complain of a black curtain descending in front of their eye). If the clot breaks by itself and dissolves the vision comes back (we call this transient monocular blindess—transient blindness in one eye). There you have suffered a transient ischemic episode.

There can be other types of TIAs which can involve different blood vessels in the brain and present with a myriad of signs and symptoms such as dizziness, double vision and difficulty speaking. So what is so important about TIAs?

Well put in simple language a TIA may be a warning sign of a future stroke (and by future, I mean in the NEAR future). It is a sign that all is NOT well with the blood vessels of the brain or the heart (either the vessels are slowing getting narrowed or the heart is not functioning well and throwing up small blood clots into the brain). TIAs thus should be aggressively and thoroughly investigated.


What are the stroke risk factors?

How can they be modified?

Does the patient need to be on any blood thinners?


As I frequently explain to my patients and their families









A confused mass of “protoplasm”

The human mind continues to fascinate me. Recently I met a close friend after a long time.  Over dinner and drinks he filled me up on his life. He now had a successful business employing well over 20 people. As we were chatting he said Nitin, I feel I have a problem. I asked what, to which he replied “I think my brain is a confused mass of protoplasm”. Intrigued I asked what did he meant by that.

He answered ” my brain is always working. It never stops thinking. All the time I have thoughts going through my head. What I have to do today, what needs to be done tomorrow. How I wish for just a short while my brain would stop thinking. I am doing one thing but my brain is already thinking about what next has to be done. In the morning I get up to take a shower and as the cold water strikes my face, thoughts race through my mind. Needless and endless thoughts. Do you have any drug which I can take to control my mind?”

I guess the pressures and distractions of modern life has made all our minds (some more than others) confused masses of protoplasm. Our minds are constantly getting bombarded by external images, sense objects, pressures of modern life, all causing a sensory overload which our minds are unable to compensate for. More and more people are burning out at a young age, some willingly and others been forced to opt out of the rat race. Turning to meditation, yoga and solitude to bring this incessant brain chatter under their control. Unfortunately we still do not have any magic drug to switch on and off these thoughts and ramblings of the brain.

Till that happens we continue to suffer the price of modern existence.

Nitin Sethi, MD

The healthy brain


As a neurologist, I see the diseased brain everyday. Patients suffering from acute and chronic debilitating neurological conditions like strokes, uncontrolled seizures, brain tumors, Parkinson disease and ALS. The devastating toll of neurodegenerative conditions like Alzhemiers dementia is enormous. They affect not just the immediate patient but also family and friends.

It seems to me that as doctors we talk a lot about the brain in disease (the diseased brain) but precious little about the brain in health (the healthy brain). Why this fascination with the brain in disease? Why do we not invest more in keeping the brain healthy.

There is so much literature out there about how to keep the heart healthy. Take a low cholesterol diet, exercise regularly, keep your blood pressure under control, eat fish and keep your stress low to keep your heart healthy. What about the brain’s health?  Can we extrapolate data obtained from studies done on the heart and apply it to the brain? Are the heart and brain alike? Is their physiology the same? What is good for the heart, is it also good for the brain?

At the expense of making cardiologists really angry I would like to point out here what was once told to me by my friend. The only function of the heart is to keep the brain alive!!! To pump blood to the brain so that the supercomputer, the masterboard of the human body can work smoothly. The heart and brain are not alike and what is good for the heart need not be good for the brain. The blood vessels of the heart and brain do not work in the same way. The human brain is far more intricate and complex and there is still precious little we know about it.

The decade of the brain came and went. True there has been an explosion of knowledge in the field of neurosciences but we still have miles and miles to go. I think we have reached the stage when we pretty much know everything about the heart, we can open blocked blood vessels, bypass coronary vessels and hey even transplant the heart. A few nicks here and there and out pops the old heart and in goes a new one. But what about the brain? Can we even dream of transplanting a human brain? One can imagine a neurosurgeon trying to connect billions of synaptic connections, so that the new brain works just like th old one. It is the brain which defines us, makes us what we are, the seat of our emotions, memory and intelligence. How would we make sure that the new brain still houses all the old information?

As you can see there are more questions than answers at least with our current degree of understanding of the human brain. So till we learn more, we should as doctors and patient advocates talk more about the brain in health. How do we keep this supercomputer healthy? For every one lecture a neurologist gives about treatment of stroke, he should give ten about stroke prevention. We need good quality research to figure out what foods does our supercomputer like (what are these brain foods, how much is good and how much is bad). How much sleep and down time this supercomputer needs? Does it like complementary therapies like yoga, meditation and tai-chi? Does neurobics help in keeping it hale and hearty.


Emotions that define us as human beings such as love come from the brain. The rush one feels as he sees his beloved, the longing, the pain all come from the brain. Hmm I even propose that instead of having a arrow through the heart to display cupid, we should have an arrow through the brain, after all that is where the love center is.

So lets take a pledge to keep our brains healthy. There is no better gift we can give ourselves than a healthy brain and mind.


Nitin Sethi, MD