The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. It is essentially the body’s electrical wiring.
The Nervous System
It has two components:
- central nervous system (made up of the brain, spinal cord and nerves) and
- peripheral nervous system (consisting of nerves that connect to one another and to the central nervous system).
The brain controls what we think and feel, how we learn and remember, and the way we move and talk. But it also controls things we’re less aware of — like breathing, the beating of our heart and the digestion of our food.
So, a “neurologic disorder” applies to any condition that is caused by a dysfunction in any part of the brain or nervous system, leading to physical and/or psychological symptoms.
Many neurologic disorders emerge during the early years of development and may be diagnosed at birth.
However some are diagnosed later because symptoms only appear when:
- developmental difficulties become evident
- A damaging infection occurs (e.g. meningitis).
- An accident causes brain injury (stroke, trauma, hypoxia).
Examination and history is always the starting point.
There are a number of tests and procedures to diagnose conditions involving the nervous system.
- Laboratory investigations
- Traditional X-ray,
- MRI (magnetic resonance imaging),
- CT scan
- electroencephalogram (EEG).
- Regression of previously attained milestones
- Abnormal muscle tone at birth
- Floppy baby
- Subtle staring/unresponsive episodes
- Slow language and/or motor skills
Who & Why (causes):
A. Congenital Causes (present at birth)
- Inherited from parents (genes and chromosomes.)
- Metabolic disorders: many are detected at birth on a blood sample sent for ‘newborn screening’ (optional at birth)
- Congenital malformation or ‘defects’
B. Pre/perinatal Causes
- Toxins and environmental factors:
- Nutritional deficiencies: (eg folic acid deficiency could lead to a neural tube defect – spina bifida (open spine).
- Infections: can cause developmental abnormalities in the unborn child. Chorioamnionitis can be a cause of cerebral palsy.
- Hypoxia/asphyxia: a condition resulting from a lack of oxygen
- Complications during childbirth
- Prematurity/low birth weight
C. Acquired Causes (developed after birth)- less common than congenital causes:
- Immune disorders, (eg autoimmune encephalitis)
- Postnatal infections
- Traumatic brain injury
- Spinal cord injuries
Examples of neurological disordes:
- Infections such as meningitis & encephalitis.