Do No Harm by Dr. Henry Marsh

Dr. Henry Marsh is a neurosurgeon who mostly practiced in London, and sometimes in Ukraine. He talks very candidly about his accounts as a neurosurgery resident and eventually as a neurosurgeon himself. This summary will focus more on the diagnosis and type of surgery rather than the other aspects of the book. 

Chapter 1: Pineocytoma (noun)

Pineocytoma is a benign tumor found in the pineal gland, which is located in the middle of the brain, right below the choroid plexus, which is right bethe corpus callosum, pictured below. It is an uncommon small growing tumor of the pineal gland. 

He uses computer navigation to help him determine where he is in the brain. These cameras use infrared technology, that can decipher between medical instruments, which have reflexive bulbs attached to them, and tissue. Dr. Henry Marsh performs this surgery while the patient is under local anesthetic, keeping the him awake during the surgery. This is possible because the brain does not feel pain since all of the pain receptors originate from the.

Aside: If the brain could feel pain, then you would need another brain that could handle/ perceive those pain receptors. 

During the surgery, the anesthetist gives the patient certain tasks to do so that he can see if he is causing any damage to the brain while he is performing his surgery. If he were doing surgery on the spinal cord, he would use a method of electrical stimulation, evoked potentials, to warn him if he is about to cause paralysis.   

Pineal tumors are rare. The benign tumors can be left alone. The malignant pineal tumors are treated with radiotherapy, chemotherapy, and can be life threatening. This is challenging surgery since the pineal gland is in the middle of the brain.

The patient that Dr. Marsh wrote about in this chapter suffered from a pineal tumor which caused his acute hydrocephalus and caused him to have terrible headaches. The kind that woke him up at night. The tumor was obstructing the flow of cerebrospinal fluid, CSF, causing the acute hydrocephalus. This is dangerous as it causes increased pressure within the brain. Without treatment, as Dr. Marsh says, he could go blind. In this patient, the tumor turned out the be benign. 

Terms:

• CSF: Cerebrospinal Fluid

• Obstructive Hydrocephalus: Occurs when the flow of CSF is blocked 

• Pineoblastoma: relatively benign tumors, part of the parenchymal tumors

• Pineocytoma: primitive neuroectodermal tumors (PNET), located in the pineal gland, and resembles medulloblastoma, retinoblastoma, supratentorial. They are amongst the most aggressive parenchymal tumors [http://radiopaedia.org/articles/pineoblastoma]

• Diathermy forceps:

• Evoked Potentials: Electrical potential that is recorded from the nervous system

• Local Anesthetic: Anesthesia given to a specific region/ part/ are of the body

• Hydrocephalus: An abnormal amount of CSF accumulates in the brain

• Descartes: Dualist Psychologist

Chapter 2: Aneurysm (noun)

Aneurysms involve the dilatation of the wall of a blood vessel, usually an artery. Dr. Henry’s first view of neurosurgery was on a woman with a ruptured cerebral aneurysm.The surgery was done with an operating microscope, through a small incision. Aneurysms usually cause catastrophic hemorrhages in the brain, if they burst. This is a delicate surgery, as they neurosurgeon as to try not to rupture the aneurysm. Aneurysms as a balloon like dilatation. They often have very thin walls, but an immense amount of pressure of arterial blood within them. If the aneurysm ruptures, it can cause the patient to have a stroke, which is the death of brain cells in that region. Aneurysm surgery is an extremely delicate surgery as the surgeon has to try not to rupture the aneurysm. Few patients survive premature rupture. 

At the end of the surgery, the neurosurgeon who he was shadowing, clips the aneurysm and destroys it with, by clipping on a titanium clip. After witnessing this, Dr. Marsh figured out that he wanted to become a neurosurgeon. 

Unruptured right middle cerebral artery aneurysm. When presented with this type of aneurysm, Dr. Marsh did not know whether or not to operate on this 32 year old patient. Either it would rupture later on in life, or maybe it wouldn’t, or maybe she it would rupture during surgery, or maybe she may suffer some other complication during surgery, or maybe the surgery would be a success. He could cause a stroke and risk her, but the chances of that happening was between 4 and 5%, which, as he says, is the same probability of her living with the aneurysm. As he mentions, the only difference is she would know it was there. Unfortunately, this surgery did not go as planned, leaving the patient severely disabled. 

The large aneurysms are the dangerous ones, and the ones that need to be treated. You clip the aneurysm so that blood no longer gets into it. The clip is usually left in the patient's brain for the rest of their lives. 

Terms: 

• Dark Brown Antiseptic: an antimicrobial substance applied to living tissue to reduce the possibility for infection during surgery

• CTA: Computed Tomography Angiography

• Angiography: an X- ray photograph of blood vessels and lymph vessels

Brain Retractor: [video: https://www.youtube.com/watch?v=GtBIQdvsfxM]