The brain is a complex organ that is enclosed within the skull. It is covered by the membranes called meninges . These are the dura mater. The pia (the delicate innermost membrane enveloping the brain and spinal cord) and arachnoid mater.
The various parts of the brain include:
- Cerebrum: This is commonly referred to as the big brain. It has a deep groove at the top which divides it into halves and the surface is folded. It’s the part of the brain that controls all your deliberate and voluntary actions such as reasoning and memory.
In fact, there is a relationship between the size and complexity of the cerebrum to the size of the mammal and its levels of intelligence.
What are the functions of the cerebrum?
- It is the reason why you are conscious, intelligent, and sensible, and helps you to learn, interpret, judge, and imagine things.
- It’s the messenger that collects information for later use.
- It helps you to carry out voluntary actions such as walking, running, reading, dancing, swimming, talking, walking, etc.
- Cerebellum: This is referred to as the small brain and its surface is folded too. It maintains the coordination between the various movements of the body.
What are the functions of the Cerebellum?
- It helps your body to maintain posture
- It also helps your body muscles in voluntary responses.
- Medula Oblongata: This part of the brain serves as a passage of impulses between the brain and spinal cord.
What are the functions of Medula Oblongata?
- It’s what controls your breathing, heartbeat, movement, supply of blood to different parts of the body, secretion of saliva, laughter, coughing, and blinking of your eyes. They are termed Involuntary actions.
Some of the brain diseases we battle in the world today include:
This is the inflammation of the coverings of the brain specifically the pia and arachnoid mater. The infection is always cerebrospinal.
Causes of Meningitis
• Bacterial organisms: It can be from infection from bacteria which results to Pneumococcal pneumonia , Neisseria Meningitidis, Haemophilus influenza, and Staphylococcus.
- Viruses such as mumps, echo virus and polio virus
- Fungus in very rare cases
Non-Infective: causes include chemicals, cancer, and subarachnoid hemorrhage.
The disease is epidemic in Western Africa during dry season. It is due to exposure to the dust and the organism that causes it is meningococcus, and in some part, it is caused by pneumococcus.
Haemophilus influenza affect children of three to twelve years. It occurs sporadically and the onset is insidious.
Clinical Features of Meningitis
In children as already stated above, the onset is insidious. At first, there is loss of interest in toy and play, and unwillingness to talk.
In adult, its clinical features include:
- Drowsy and unaware
For neck stiffness, the person cannot touch the chest with the chin (jaw bone).
For Kerning sign, flex the knee, flex the hip, and the knee becomes difficult to extend.
For Brudzinsky’s sign; hold the chest down, attempt to lift the neck, and make the knee move up.
In all these demonstrations, the person should lie on the back, and will be done by the health care provider.
Laboratory Investigation of Meningitis
- Lumber puncture and analysis of the cerebrospinal fluid
- Chest X-ray to rule out tuberculosis
- Skull X-ray
Complications Of Meningitis
- Mental subnormality: is defined by the World Health Organization as the incomplete or insufficient general development of mental capacities. It has two components: mental deficiency and mental retardation.
- Hydrocephalus: is characterized by head enlargement in infants. While adults and older children experience headaches, impaired vision, cognitive difficulties, loss of coordination, and incontinence.
- Meningoencephalitis is an ailment that is usually caused by a virus, bacterium, parasite, or another microorganism. Examples include West Nile virus, mumps or tuberculosis.
- Cerebral palsy is due to abnormal brain development, often before birth.
- Cranial nerve palsy is a lack of function of a nerve. A cranial nerve palsy may cause a partial weakness or complete paralysis of the areas served by the affected nerve.
Is there any way you can manage Meningitis?
Prevention of meningitis can be achieved by immunizing the population with the vaccine against meningitis.
Cerebrovascular Accident (CVA)
CVA, commonly called stroke is a sudden loss of blood supply to part or all the brain due to sudden vascular problem.
The problem may be either occlusion of the vascular supply or hemorrhage as a result of rupture of the vascular system.
It’s one of the major problems in the world and has no racial or sexual dominance. It is common in older people aged after forty years and the peak is fifty to sixty years.
What are the causes of Cerebrovascular accidents (CVA)?
- Heart problem
- Atherosclerosis (the thickening of big vessels)
- Bleeding disorders
- Drugs such as contraceptive pills
- Hemoglobinopathies such as SS in children.
What are the clinical features of Cerebrovascular accident/stroke?
There is a sudden onset of cerebral dysfunction which may or may not be associated with loss of consciousness.
If the problem is due to occlusion of the vessels, the stroke usually occurs when the person is at rest or sleeping.
However, in the case of hemorrhagic stroke, the incidence occurs usually during activity and it is often preceded by severe headache and vomiting. Varying degrees of the loss of consciousness may occur.
Whatever the type of problem, the end result is usually the same and depends on the blood vessel that is involved.
The major arterial supply to the brain are the internal carotid arteries and the vertebral arteries. Both arteries divide giving rise to:
- Anterior cerebral arteries
- Middle cerebral arteries
- Posterior cerebral arteries
- Vertebro-basilarl artery
- Posterior inferior cerebellum arteries
The affection of the anterior cerebral artery results to:
- Weakness in the lower limb on the contralateral side: This means that if the right cerebral artery is affected, there will be a weakness of the lower limb on the left.
- There may or may not be a weakness of the upper limb.
The affection of the middle cerebral artery result to:
- Hemiplegia (a condition caused by brain damage or spinal cord injury that leads to paralysis on one side of the body. It causes weakness, problems with muscle control, and muscle stiffness) of both upper and lower limbs on the contralateral side.
- There is speech disturbance
- There is also an eye problem
The affection of the vertebrobasilar artery result to:
- Vertigo: a sudden internal or external spinning sensation, often triggered by moving your head too quickly.
- Ataxia: an impaired balance or coordination that can be due to damage to the brain, nerves, or muscles and cause clumsy voluntary movements.
- Diplopia (seeing double)
Laboratory Investigation of Cerebrovascular Accidents
- Lumbar puncture
- Brain Scan
- Blood hemogram to rule out the bleeding disorder.
Treatment of Stroke
Contact your health care provider who will administer these drugs if it’s due to occlusion:
- Disprin tablet
- Persantin tablet
- Oral anticoagulant (Warfarin) where necessary
- Treat hypertension if it is the cause
If it is due to a Hemorrhage
- Bed rest
- Sedative using diazepam
- Treat hypertension
- If unconscious, IV fluid is set up
- The catheter is placed in situ and the input and output charts kept
- Turn the patient from side to side to avoid pressure sores
- Oral defecation is indicated
- When a patient can take it by mouth, the intravenous fluid is discontinued
- Complamin retard tablet one daily is added to the regimen
- Later, the patient is sent to the physiotherapy department.
Dr. Anthony A. Ufere