How to Improve Brain Health & Offset Neurodegeneration | Dr. Gary Steinberg

The episode introduces Dr. Gary Steinberg as a medical doctor and PhD who is a professor of neurosurgery, neurosciences and neurology at Stanford University School of Medicine. The introduction describes his field as the cerebrovascular architecture of the brain: how blood flow delivers oxygen and critical nutrients to neurons, and how it also removes waste products so the brain can function normally. The planned topics are how disruptions such as stroke and aneurysm affect brain function, concussion and traumatic brain injury (TBI) and their treatment, his laboratory and clinical findings on using stem cells to recover function in the brain and spinal cord, and protocols for improving brain health.

This section of the transcript covers only the first part of that agenda. It gets as far as definitions of stroke and transient ischemic attack, clotting and bleeding risk factors, the brain's blood demands, modern neurosurgical techniques and spinal cord stroke. Stem cells, concussion and brain-health protocols do not come up within this excerpt.

The discussion begins with a request to sort out the terms stroke, aneurysm and hemorrhage, and to say where they overlap and where they differ. The answer gives a one-line definition and then the proportions.

So a stroke is like a heart attack of the brain.

A stroke is described as a disruption of blood flow to the brain. About 87% of strokes are said to result from a clot. The clot either forms in a brain artery or forms closer to the heart, in the heart or the carotid artery, and then dislodges and blocks flow to the brain. About 13% are attributed to a hemorrhage, meaning a blood vessel bursts. In both cases brain cells stop receiving oxygen and glucose. Tissue dies, and neurologic and bodily functions are disrupted.

Next comes the question of how a person would know whether they have a clot that could travel to the brain. One participant discloses genetic testing showing they are heterozygous for factor V Leiden, a clotting-factor mutation. They explain that this means one mutant copy, that they do not suffer from excessive bleeding or clotting, and that lifestyle factors can make such a mutation worse. They add that homozygous carriers face much greater risk.

The answer is blunt: "In many cases, you don't know, and that's the problem." Genetic predispositions can lead to clots on either the arterial or the venous side of the circulation. Arterial clots are what generally cause ischemic stroke. Venous clots, such as those that can form in the legs during a long flight without much leg movement (the reason some people wear compression socks), can cause deep vein thrombosis. Those clots can travel to the lung as a pulmonary embolus, but on the venous side they generally do not reach the brain.

There is one qualification. Venous problems can arise inside the brain itself and cause a venous-type stroke, though this is much less common. Here the problem is outflow, not supply. A clot in an important vein stops blood from leaving the brain, so it backs up and causes swelling, or edema. Strokes are still discussed mainly as arterial events, caused either by a blocked vessel or by a vessel bursting.

The conversation then lists candidate factors that affect clotting and bleeding: factor V Leiden mutations, blood thinners such as baby aspirin, large amounts of fish oil (a claim the questioner flags as something they would need to check), hemophilia, and certain oral contraceptives. The response focuses on drug therapy and on contraception. It does not address fish oil or hemophilia directly.

Blood-thinning drugs are described as generally safe. In general they do not cause a hemorrhage by themselves, but they can make a bleed much worse if something bursts, or if a fall or other trauma injures the brain or body. Two drug classes are named. Antiplatelet agents such as aspirin are described as very useful for people predisposed to clots. Anticoagulants include Coumadin (warfarin), Eliquis and heparin, along with many newer agents that can be taken orally or given intravenously. Both classes are said to put someone at somewhat increased risk of hemorrhage.

The contraception discussion is historical and comparative. First-generation oral contraceptives from the 1970s were heavily estrogen-dominated rather than progesterone-dominated. Women who took them and also smoked had a "very, very high incidence" of clots and ischemic strokes. Newer generations are described as much safer, but they are still believed to raise risk somewhat. For their own patients, many of whom have had strokes or are at risk of one, the speaker recommends avoiding oral contraceptives in favour of other methods such as an IUD. They describe the IUD as possibly releasing a small amount of progesterone locally without a large systemic rise in estrogen or progesterone. This recommendation is explicitly tied to a high-risk patient group.

Modifiable risk factors named beyond genetics: smoking, described as a very high risk factor for clots leading to strokes, heart attacks and peripheral vascular disease; high LDL (bad) cholesterol, where statins are recommended if diet alone cannot lower it; and hypertension, a risk factor for clots and arterial disease.

Two points on statins go beyond cholesterol. Statins are said to be very effective at lowering LDL and preventing strokes and heart attacks. They have also reportedly been shown to benefit blood vessel integrity even in people without high LDL. On that basis the speaker says they often recommend statins to their own patients even when cholesterol is not high. This comes as an account of practice with their patient population, and no specific studies are named in this excerpt.

Asked whether smoking's stroke risk comes from nicotine itself, such as its vasoconstriction and blood pressure effects, or from other chemicals in cigarettes or vapes, the answer is that it is "not just nicotine." Nicotine is one factor, and other products of smoking also have effects. Vaping is not addressed specifically.

The incidence of stroke is said to be decreasing. The decline is attributed only partly to less smoking. Other contributors named are better treatment of hypertension, more exercise and better self-care, and a lower incidence of obesity in some subgroups. No figures are given for the decline.

The conversation suggests that what is good for the heart is probably good for the brain, because the brain needs so much blood and glucose. The response agrees in general, while noting that the two organs differ and that both depend heavily on blood flow. It then gives the numbers behind the brain's demands.

The brain's unique though because the brain represents only 2% of the body weight, yet it draws 15% of the total blood flow, and remarkably it consumes 20% of the body's oxygen.

The speaker calls the brain the most important organ and openly admits to being biased. The exchange adds that the brain is "what makes us human," and that the brain and the neural retina would be the tissues one would least want to lose even a cubic millimeter of, given the deficits that could follow.

Asked for a moment from neurosurgery that revealed something about how the brain works, the answer is a recent case. A patient had a vascular malformation thought to lie in her speech area. Before surgery, a functional MR scan was used to estimate where the speech area was. The scan relies on the coupling between neuronal activity and blood flow: when the patient talks during the scan, blood flow rises in the language areas, and that increase is visible on the image.

Functional MR gives only an approximate map, so the most accurate approach described is to operate with the patient awake. She was sedated but not given general anesthesia or intubated. The scalp was numbed, a piece of bone was removed, and the dura (the membrane covering the brain) was opened. She was then allowed to wake further. A tiny stimulating probe was applied to regions of her cortex to test whether stimulation disrupted her speech or her understanding of language. Surprisingly, the chosen corridor showed no language activity. When stimulation does reveal eloquent tissue, a different path to the lesion has to be chosen.