P.A.T.H.

Stroke or Cerebrovascular Accident Cause: occlusion of cerebral vessels by a thrombus or embolus (mostly ischemic), intracerebral haemorrhage due to ruptured blood vessel, issue external to the CNS Risks: smoking, obesity, hypertension, diabetes, high cholesterol, genetic factors, transient ischaemic attack (mini stroke with quick symptoms that last for several hours, warning sign for major stroke) Symptoms: numbness, weakness or paralysis, sensory deficit, loss of consciousness, severe headache, sudden blurred vision or blindness, slurred speech, unsteadiness, confusion Brain Tumors Gliomas Cause: mostly metastatic and rarely primary tumours Most common type: astrocytoma (cerebrum) Types of astrocytoma: glioblasta multiforme, pilocytic astrocytoma and anaplasic astrocytoma Astrocytoma: glioblasta multiforme Poorly differentiated and fast growing Most common glioma No clearly defined margins Invade locally and spread along white matter pathways Age group: 40...

What is an aneurysm? Aneurysms are an abnormal localised dilation of an artery or vein, most commonly occurring in the aorta. Causes:  congenital weakness in blood vessel, hypertension, atherosclerosis, trauma, syphilis (STI)   1.   Berry Aneurysm Small Spherical dilation of a blood vessel Less than 1.5cm in diameter Common in Circle of Willis   2.   Fusiform Aneurysm Involves entire circumference of the vessel Gradual and progressive dilation of a vessel Up to 20cm in diameter Can occur in entire ascending and transverse portion of the thoracic aorta   3.   Saccular Ranges from 5 to 20cm in diameter Partially or completely filled by thrombi   4.   Dissecting False aneurysm caused by a tear in the intimal layer of the vessel Life-threatening Common in 40-60 years Ascending and descending thoracic aorta What is hypertension? Hypertension is defined as blood pressure that exceeds 140mmHg s...

What is cholesterol? Cholesterol is produced at the liver, but is also consumed when we eat meat and dairy products. In order to test the levels of cholesterol in an individual, a serum lipid test is undergone. The ideal result is less than 5.2mmol/L. When this test is undergone, three types of cholesterol are found in the blood. These are: Triglycerides (0.1-1.9g/L) HDL cholesterol (>0.1mmol/L) LDL cholesterol (<3.2mmol/L) Most of the cholesterol in our system is carried by LDL (low density lipoproteins), with the smaller portion being carried by HDL (high density lipoproteins). HDL is the more favourable transport system, however, as it transports cholesterol to the liver from tissues for catabolism into excretable bile salts. LDL carries cholesterol to cells for the synthesis of cell membranes and steroids, which is not ideal in large quantities. What is atherosclerosis? Atherosclerosis is when there is a build up of plaque in the arteries. Risk increases with ...

Heart Failure Heart failure, unlike coronary artery disease which is a condition in which the blood does receive  enough blood, is characterised by an inability to pump  enough blood to the tissues. It is often referred to as congestive heart failure as fluid begins to accumulate in the tissues, i.e. oedema occurs. It is normally chronic, meaning it develops over a long period of time, and does not have a single cause: Coronary disease High blood pressure Cardiomyopathy Atrial fibrillation Heart valvular problems   1.   Left Heart Failure Causes : mitral stenosis, aortic stenosis, pericarditis, myocardial infarction Characteristics : output of left ventricle becomes less than the amount of blood received from the left side via pulmonary circuit → congested pulmonary circuit ('crackles' when listened to by doctors), systemic blood pressure falls Symptoms : dyspnea, increased respiratory ate, cough, cyanosis (from lack of oxygen), blood tinged...

Angina Angina occurs when the heart muscle does not receive enough blood, i.e. oxygen. It usually means there is a narrowing or partially blocked coronary artery during times of stress or exercise. Characteristics : intense pain, pale, perfuse perspiration, dyspnoea, normal cardiac enzymes, ECG may show some ischemic changes but is not definitive for angina   1.   Stable Angina Most common Chest pain during activity or stress Pain begins slowly and worsens over a few minutes before disappearing Means there is an increased risk of heart attack, but does not guarantee occurrence Requires medical treatment for occlusion within coronary arteries   2.   Unstable Angina Acute chest pain with cardiac hypoxia Warning sign of heart attack Not slow like stable angina, occurs as a severe episode Occurs at any time Myocardial Infarction Myocardial infarction is a result of longterm schema to the myocardium (heart muscle), causing irreversible ce...

Hodgkin's vs Non-Hodgkin's Lymphomas Staging of Hodgkin's and Non-Hodgkin Lymphomas Stage 1: single node or single extra-lymphatic organ Stage 2: 2 or more lymph nodes on same side of diaphragm or limited contiguous (touching at borders) extra-lymphatic organ/tissue Stage 3: both sides of diaphragm, may include extra-lymphatic organ Stage 4: one or more extra-lymphatic organs or tissues with/without lymphatic involvement

Non-Hodgkin Lymphomas Non-hodgkin lymphomas are three times more common than Hodgkin's lymphomas, with increasing incidence. Mostly, they arise in lymphoid tissue, with a small percentage in parenchymal organs. B-lymphocytes are the main cells affected in non-hodgkin lymphomas, with some specific types concerned with T lymphocytes. Non-hodgkin lymphomas have an quick, rapid spread unlike hodgkin's lymphoma and is normally widespread at the time of diagnosis. Characteristics: enlarged non-tender lymph nodes Symptoms: fever, weight loss, malaise, sweating, susceptibility to infection Types of Non-Hodgkin Lymphomas   1.   Diffuse Lymphomas Make up almost half of all non-hodgkin lymphomas Occurs in the elderly Grow in a uniform pattern without any follicles Most form from B cells, but can form from T cells Lymphocytes are large, have large nuclei and have a prominent nucleolus Localised at time of diagnosis Curable with chemotherapy   2.   Foll...