Ms C,35 years old, woke up that morning at 5 am as she did on any other weekday morning. The mornings were always stressed as she was on a strict time schedule – her husband and children had to be fed and sent on their way by 7 am . She herself had to be out of the house by 7-30 am so that she could catch her 7-45 pickup to her office. The mild headache that had been bothering her over the last few days was slightly more intense. As she came out of her bath, the headache suddenly became severe. The intensity was like never before. It was as though she had been hit on her head with a hammer. The room spun around her. As she called to her husband for help, she lost consciousness. Rushed to the hospital casualty, an urgent CT scan was performed which revealed that Ms C had suffered a bleed in her head (Subarachnoid Haemorrhage).

The causes of headaches are multiple and varied. Not all headaches are related to disastrous events in the brain. Actually headache along with fatigue, hunger and thirst represents the most common human discomforts. Medically speaking its significance is wide ranged, as it may stand as a symptom of either minor tension, fatigue, hunger or may represent a symptom of a major illness. Headaches therefore may be caused by pain sensation from a variety of structures in and around the head (speaking in general terms), or more specifically within or outside of the cranial cavity. It must be understood here that the brain itself is not a pain sensitive structure. Structures that can cause pain and therefore headache are (1) scalp, muscles of the head and neck, the periosteum of the skull (2) eye, ear structures, mucous membranes of the nasal cavity and paranasal sinuses (3) blood vessels of the scalp (4) blood vessels of the brain, including the major arteries at the base of the brain, and the venous sinuses (5) the dura mater, which is a tough covering membrane of the brain and spinal cord and (6) pain sensitive nerves of the brain and the upper spinal cord. Thus a headache may be caused by tension, a bad tooth, ear infection, sinusitis, refractory error, viral fever, or may be part of the vascular headache syndrome which includes migraine. These are to be diagnosed and and differentiated from the more serious causes of headache which are caused by (1) irritation of the pain sensitive nerves of the brain or upper spinal cord (2) stretching of the dura mater (3) stretching of the blood vessels of the brain. These serious headaches are symptoms of increase in pressure within the brain and the cranial cavity. These latter serious headaches should be differentiated from the former less serious headaches and the primary cause must be treated. It is therefore best to undertake a medical consultation at the earliest when a headache is worrisome and be under medical supervision and treatment.

One of the serious headaches is that which occurs when there is a bleeding within the brain. The presentation of these headchaes is often classical and the diagnosis can be made from the history itself. The classical description of the headache is that of ‘a bolt out of the blue’. The patient suffers an acute, intense, and severe headache of the type never experienced before. There are generally no prodromal symptoms. The headache may be preceded by an exertion as in lifting a heavy object, sexual intercourse or even by straining at stools due to constipation. The patient may become unconscious for variable periods of time, may have seizures, associated neck pain. More common in persons with high blood pressure, occasionally patients have no symptoms prior to the catastrophic bleeding episode. In some patients there may be a history of episodes of less intense headache occurring within a fortnight of the major episode. These constitute what are called ‘warning headaches’.

Intracranial bleeding which occurs spontaneously (i.e. without any injury) may either occur in the substance of the brain (Intracerebral Hematoma) or in the space immediately surrounding the brain (Subarachnoid space) The subarachnoid space surrounds the brain and contains the cerebro-spinal fluid and carries the blood vessels to the brain substance. Bleeding into the subarachnoid space is called Subarachnoid Hemorrhage (SAH).

Subarachnoid hemorrhage is a potentially dangerous bleeding that occurs in the subarachnoid space. The most common cause of SAH is an Aneurysm of one of the blood vessels of the brain., which accounts for 60 to 70 percent of patients. Other causes of SAH include tumours in the brain, arterio-venous malformations, disorders of blood and anti-coagulation therapy. An aneurysm is a bulge in the wall of the blood vessel due to weakness of the vessel wall. The word ‘aneurysm’ has a Greek derivative meaning dilatation, and is also probably related to the Sanskrit word ‘uru’ meaning wide. They occur most commonly in the large vessels at the base of the brain, and have a predeliction for the points of branching of these vessels. The aneurysms start as small thin-walled blisters at the branching points of vessels. Due the weakness of the vessel wall they gradually enlarge until they burst, causing a bleed in the brain. Aneurysms are most commonly seen between 35 and 60 years of age. They are seen in association with other disorders like polycystic disease of the kidneys or with coarctation of the aorta. Occasionally the aneurysm may be associated with a complex arterio-venous malformation of the blood vessels of the brain. In 20 percent of patients there may be more that one aneurysm. The incidence of aneurysms in India is not clear as some aprts of the country like Kerala and regions around Delhi have a higher incidence than Madras. However it is not known whether this is because of lack of recognition of the SAH.

DIAGNOSIS

SAH is best diagnosed from a CT scan of the brain, where by a non-invasive method blood is seen at the base of the brain. The CT scan, besides giving the physician the diagnosis of SAH, also gives information regarding the amount of bleeding that has taken place, the location of the bleed, and also an insight into the potential problems that can arise in the days to come. False negatives on the CT scan are most commonly because there is too little blood in the subarachnoid space to be picked up by the scan. When the CT scan is normal, and does not reveal any bleeding, and when the physician strongly suspects SAH because of the clinical history, the patient should undergo a Lumbar puncture and analysis of the cerebro-spinal fluid (CSF) that is collected. The pressure of the CSF indicates the pressure in the brain and the nervous system. The fluid should be analysed for the presence of red blood cells, and breakdown products of blood. When there is no obvious discolouration oif the CSF, the laboratory should be asked to centrifuge the fluid and look for crenated red blood cells. The presence of the latter is diagnostic of SAH.