HEAD BLEEDS

The brain is covered by the MENINGES of which there are nominally 3 – the PIA MATER, the ARACHNOID MATER and the DURA MATER (‘mater’ means ‘mother’). The pia is practically non existent and we may consider it no more. The brain sits within the skull (as if you didn’t know) but the significance of this is that there is no room for anything else; if ‘something else’ arises within the skull, then the brain has to make room for it. This is why doctors talk about ‘space occupying lesions’ and why they are so important; they squash the brain and that does the brain no good at all.

Bleeds in the skull are one such example of space occupying lesions. They may be associated with skull fractures, which may let in infection, but if there’s a bleed in the skull, it matters.

Such bleeds may be extra-dural (ie outside the dura and just under the skull), sub-dural (ie between the dura and the arachnoid) or subarachnoid. Extra-dural haemorrhages occur in babies when they are abused. Subdural haemorrhages may be ‘acute’ (that is, occurring quickly) or ‘chronic’ (that it occurring over a long time); they are always associated with a head injury but the head injury that leads to a chronic subdural may be so long ago and very slight, so that the afflicted swears blind that it never happened.

An acute subdural is caused by blood accumulating quickly and pressing on the brain. A chronic subdural starts out small and grows over weeks, months even years. It may grow so slowly that the brain is able to compensate, and may present after months or years with headaches. They occur in the elderly.

Subarachnoid haemorrhages are bad news. They may be associated with head trauma but they can occur spontaneously, when a tiny bubble on the wall of a basal artery (a ‘berry’ aneurysm) bursts. Because they are associated with arterial (ie high pressure) bleeds, they do a lot of damage.

Moles and Malignant Melanoma

MELANOCYTES are funny things. They sit in the bottom layer of the EPIDERMIS (which is the outer covering of the skin; the rest of the skin is the DERMIS) and their job is to make melanin, which they pass onto the cells on either side of them. Melanin protects cells from damage to their DNA by UV light. DNA damage can lead to cancer. People with pigmented skin do not have more melanocytes, just more melanin.

They make moles that are benign and evolve from purely intraepidermial (‘junctional’) to mix epidermal and dermal (‘compound’) and eventually purely (‘intradermal’). ie they move downwards. They may be disfiguring, or become inflamed, or be a nuisance, but they are BENIGN, although they may become malignant.

Dysplastic naevi are not entirely benign and may progress to cancer; therefore, they need to be excised completely and with a sufficient margin of normal tissue.

Melonoma (with or without the prefix ‘malignant’) is NEVER benign. Once diagnosed and excised, it is the job of the pathologist to tell the dermatologist all the technical factors which influence how it will behave and therefore what further treatment is required. The most important thing the pathological assesses is how thick the melanoma is: less than 1 millimetre (see how thin that is?) 1-2 millimetres thick, 2-3 millimetres thick, 3-4 millimetres thick or over 4 millimetres thick. The thicker they are, the worse it is.

Further treatment may include a wider local excision (WLE) of up to 3cm around the original melanoma to mop up any satellite deposits. That’s a lot, believe me.

Melanomas can spread, but they may spread in a funny way. The most usual is to the local lymph glands (or nodes). Sentinel node biopsy is a way of determining if the local nodes are involved or not. Melanoma may spread to the liver or lungs or anywhere, though. Also melanoma may occur in funny locations that never see the sun.

All cancers have abnormal genes. Some melanomas have BRAF mutations that may be used as a therapeutic target – ie if the mutation is present, certain drugs may be of help.

Lastly, people can occasionally live a long time with melanoma that has spread. Usually, though it is an aggressive cancer that kills quite quickly.

Heart Failure

Heart failure is a mode of death and not, in itself, a natural disease. As such, it must be followed on a Death Certificate by what disease caused it. It merely means that the heart can no longer fulfill its function as well as it should. If it causes death, the failure is obviously profound.

But what does ‘failure’ mean? It doesn’t usually mean the heart stops, although technically it could. It usually means that its pumping action is no longer efficient and the heart’s output is reduced. People can live with cardiac failure for a long time.

Since the heart is in fact 2 pumps, heart failure can affect just the right side, or just the left side, or most commonly both. Because the ventricle(s) is/are no long pushing out the blood as well as it/they should, it/they dilate(s) (because blood is left in them when the heart beats) and there is a rise in upstream pressure. This is why the lungs fill with water in left or biventricular failure (the atria don’t contribute a great deal to the act of pushing blood out of the heart), because the pressure in the veins of the lungs increases. The blood coming out of the lungs is slightly thicker because water has been pushed out of the blood vessel walls.

This is also why ankles swell in biventricular or right side heart failure. it also affects internal organs such as the liver and can be so severe that the liver scars (‘cardiac cirrhosis’) and may even fail itself.

The water causes breathlessness (aka DYSPNOEA). It’s worse if the patient lies flat, which is why people with cardiac failure sleep with multiple pillows propping them up.

And if the heart is not pushing out blood as it should, arteries constrict to keep up blood pressure, and the heart enlarges because blood is not being ejected but it is still coming in from the veins. The kidneys need blood pressure because they are essentially just high pressure filters; they have their own mechanisms for making sure that the pressure of blood remains reasonable.

But why? Why does it fail?

It might be for one or more of a variety of reasons. Intrinsic problems with the heart muscle (reduced blood supply causing death of myocytes and fibrosis of the heart muscle due to coronary atheroma), myocarditis (where the heart muscle is inflamed, perhaps due to an infection), cardiomyopathy (in which the heart muscle is not normal), etc; or extrinisic problems such as hypertension. If the heart has to push blood out against raised blood pressure, it has to do more work, and eventually that tells.

DEATH CERTIFICATES (UK)

The state likes to know when someone is born, someone dies or a marriage occurs. The registrar of births, deaths and marriages keeps the local records. I am concerned with death certificates, on which is written the particulars of the dead person, including the cause of death.

If a patient has been under medical care for a natural disease and has seen a doctor within 14 days of death, then a doctor CAN write a death certificate. What is put as the cause of death (ie within the central box) need only be to the doctor’s best knowledge (ie it is not necessary for the doctor to have outside proof). Only someone on the medical register (held by the General Medical Council) can fill out the cause of death.

The cause of death is on 4 lines, labelled ‘1a’, ‘1b’, ‘1c’ and ‘2’. 1c must lead to 1b, which must lead to 1c. Somewhere among 1a, 1b and 1c there must be a DISEASE. MODES OF DEATH (such as ventricular fibrillation or heart failure) can figure, but must be qualified by a disease (ie the disease must appear in either 1b or 1c.

For instance, someone may go into ventricular fibrillation, but this is usually caused by coronary atheroma. Therefore, 1a Ventricular Fibrillation 1b Coronary Atheroma is acceptable to the Registrar of Births, Deaths and Marriages, but 1a Ventricular Fibrillation alone is not.

Under 2 are natural diseases that contributed to the death but which are unrelated to anything written under 1a, 1b or 1c.

Things that may not appear are abbreviations and unnatural causes (the latter deaths are referred to the Coroner). Section 2 is often used as a dumping ground for conditions, although I frown on this. ‘Old age’ is regarded as a legitimate disease process only in the very old (the goalposts are moving all the time).

The Medical Examiner acts as the referee, deciding what is reasonable and which cases to refer to the coroner.

THE HEART

The heart is not a pump.

It is TWO pumps.

You do not have a single circulation.

you have TWO (THREE, if you count the portal venous circulation as a separate circulation).

What the heart does is really very simple. The right side pumps blood around the lungs; the left side pumps it around the rest of the body. Those two circulations never mix, but they are linked. They may sit side by side, but essentially the left side of the heart is a pumping station downstream of the right side.

Each pump – the right side and the left side – is two chambers. An atrium (or ‘hallway’) and a ventricle (or ‘stomach’). There is a valve between the atrium and ventricle on either side, and a valve where the ventricle meets its circulation. The work of the valves is the same as all valves, to make sure that the pumped liquid goes in only one direction.

So, two pumps, each with 2 chambers and 2 valves. Simple.

Except that, for some reason, the heart is twisted around in the body, which makes it look more complex than it really is.

The right side of the heart only has to pump blood through the lungs (where it gets oxygenated), this then returns to the heart (the left side) which pumps it around the body where the oxygen is required for the cells to live.

Because the right side of the heart has relatively little work to do compared with the left, it is not as muscular. In fact, the thickness of the myocardium on the right is only a third that of the left in the normal heart.

What of the heart in the unborn baby? What of congenital abnormalities? More of these in later posts.

CHOLESTEROL

Cholesterol is a very, very complicated subject. We make it, but it’s also in foods such as dairy products, red meat and processed meat such as sausages. We NEED it [it’s found in the cell membrane of every cell in your body and its required for digestion (because it’s the basis of bile constituents, and bile is necessary for the absorption of certain foodstuffs including some vitamins), as well as being the basis of steroid hormones and vitamin D (which we DO make)].

There’s lots of talk about high density lipoproteins (HDL – ‘good’ cholesterol), intermediate density low density lipoproteins (IDL – so-so) low density lipoproteins (LDL – not so good) and very low density lipoproteins (VLDL very bad). The names come from the relatively crude method of centrifuging blood plasma, which results in separation of these molecules; those right at the bottom are HDL molecules, etc. etc..

There’s less talk of CHYLOMICRONS, but they’re also involved. Eat fatty cheese, wait a while and then take a blood sample, spin it down and the blood plasma (the liquid in which blood cells float) will be opaque because of chylomicrons containing the fat that’s been absorbed from the cheese.

Essentially, because cholesterol is required all over the body, and because it’s not very soluble in blood, it’s taken hither and thither by lipoproteins. Think of them as Uber cars. HDL is good because of where it takes the cholesterol.

When you go to the doctor and have your cholesterol level measured, it will be a measure of total cholesterol, in all the different lipoprotein types. Too much is associated with atheroma formation in blood vessels (see previous posts), and that’s linked to death by heart disease or stroke (aka CEREBROVASCULAR disease – the clue’s in the name).

Sterols and stanols in foods can lower cholesterol A LITTLE because most of the cholesterol in your body is made by you. They work by competing with cholesterol in the diet. STATINS work by lowering your own cholesterol production and are therefore more effective.

Cervical Cancer

In the UK, there are just over 3,000 cases of cervical cancer diagnosed each year, of which it is estimated that over 99% (that’s not a typo) are preventable, although over 800 people die from it each and every year. The highest incidence is in those aged between 25 and 29 (and that ain’t a typo either) so, in other words, it is a disease of the young. It is associated with smoking and other factors, but it is caused by the Human Papillomavirus (HPV).

Men carry the virus and pass it on to their sexual partners.

HPV is everywhere. There are over a hundred different types and they’re numbered. They cause things as benign as skin warts but they also cause cancers, such as penile cancers (yes, there is such a thing), anal cancer (nasty) and cervical cancer. Some types are troublesome, but benign. Some types, though, cause the cancers. Types 16 and 18 cause cervical cancer.

Cervical screening aims to spot the changes that lead up to cancer, because HPV works slowly, over a course of years, but it isn’t easy. This much is known. The changes that lead to cervical cancer begin in the TRANSFORMATION ZONE (TZ) of the cervix. where the nature of the covering of the cervix abruptly changes from SQUAMOUS (multilayered) to GLANDULAR (single cell layer). They are known as CERVICAL INTRAEPITHELIAL NEOPLASIA, which for the sake of simplicity is known as CIN (pronounced ‘sin’ and I know not if that is a deliberate choice of pronunciation). CIN1 is mild, CIN2 and CIN3 are high grade. Progression to cancer (which is invasive and potentially spreads) is not inevitable, but you don’t want high grade CIN.

The cervical screening test is embarrassing and uncomfortable. The person taking the sample tries to scrape off cells from the TZ. They are then put into a machine that washes the cells and spreads them on a slide. A human being then has to scan that slide and look for cells that mean CIN is present. If they see them, a punch biopsy may be taken to confirm the diagnosis of precancerous changes; the punch biopsy will be looked at by a medically-qualified pathologist.

If high grade CIN is diagnosed, the usual treatment is LOOP EXCISION OF THE TZ (LETZ), which aims to cut out the abnormal area and can be done in out-patients; it is again uncomfortable and embarrassing. In the great majority, that will cure the patient and they won’t develop cancer.

HPV vaccination has been introduced, the aim being to stop HPV 16 and 18 causing the cancer. HPV testing is also undertaken on samples. Soon, everything will change, and it will be for the better. Fewer cases, fewer cervical smears, fewer deaths. But only if that letter calling patients to be tested is not ignored.

Cervical cancer is a horrible way to die.