The central nervous system is the largest and the most complex part of the nervous system. It works to align the activities of all the body parts and is vulnerable to different disorders and diseases. The article throws light on the various disorders of the central nervous system.
The central nervous system (CNS) plays an important role in controlling the human behavior. It comprises two main components: the brain and the spinal cord. This system is held within the dorsal cavity, with the brain in the cranial cavity and the spinal cord in the spinal cavity. The nervous system is made up of nerve cells, called neurons, which allow the various parts of the body to coordinate with each other through the brain and the spinal cord.
A person affected by any type of disorder of the CNS may be identified due to the symptoms such as delay in developmental milestones, changes in activity, reflexes or movements, abnormal head growth, variations in level of consciousness or mood, muscle rigidity, tremors or seizures, severe headaches, visual changes, and lack of coordination.
Disorders of the CNS
Transverse Myelitis (TM)
It is an inflammatory attack on the spinal cord, with no brain or optic nerve involvement. It is mainly a monophasic condition where the attack occurs only once. In rare cases, the patient may experience more than one inflammatory attack on their spinal cord, and this condition is called recurrent TM. Some patients may also experience an inflammatory attack in the spinal cord along with an underlying rheumatic disorder like Lupus or Sjogren’s syndrome. Since the underlying cause is unknown, it is also referred to as idiopathic TM. The symptoms of TM develop quickly within a few hours to a few weeks. The spinal cord is responsible for carrying motor nerve fibers to the limbs, trunk, and sensory fibers from the body back to the brain. Inflammation within the spinal cord disrupts these pathways and causes symptoms like limb weakness, sensory disturbance, bowel and bladder malfunction, back pain, and radicular pain.
Neuromyelitis Optica or Devic’s Disease
It involves inflammatory attacks in the spinal cord and optic nerve. A person affected by this condition is at a higher risk for multiple attacks of spinal cord inflammation or optic neuritis, or both. The main symptoms of NMO are loss of vision and spinal cord dysfunction. The visual impairment is manifested by visual field defects, loss of color vision, decreased visual activity, etc. The spinal cord dysfunction causes muscle weakness, reduced sensation, and loss of bladder and bowel control. Patients may also experience an acute and severe spastic weakness of the legs (paraparesis) or all four limbs (tetraparesis).
It involves an inflammatory attack that may occur anywhere within the CNS, i.e. brain, spinal cord, or optic nerves. The disease usually occurs in young adults, and is more common in females. Most of the patients have brain lesions during the onset of the disease. A person affected by multiple sclerosis may observe symptoms like muscle spasms, dysarthria, lack of coordination and balance (ataxia), hypoesthesia and paraesthesia, visual problems, and loss of bladder and bowel control. Its relapses are quite unpredictable and happen without any warning or obvious inciting factors.
It is a progressive, neurodegenerative disease that affects the brain and is a common form of dementia. It reduces the generation of certain brain chemicals which are essential for communication between the nerve cells like norepinephrine, soamtostatin, acetylcholine, and serotonin. The causes for the disease are not completely known but abnormal protein deposits in the brain, environmental or genetic factors are some suspected causes. Alzheimer’s disease leads to impaired memory or judgment, language deterioration, emotional apathy, and impaired visiospatial skills.
Some other disorders are Parkinson’s disease, epilepsy, amyotrophic lateral sclerosis (ALS), Huntington’s chorea, etc. Presently there’s no cure for these disorders but treatments like medication, rehabilitation activities, clinical trials, and assistive technology may be beneficial for the patients.