Bacteria invade the CNS following direct inoculation of the brain parenchyma or by spread from a focus of infection outside the CNS. Hematogenous spread is the most common route, and the upper respiratory tract is the most common source of entry of microorganisms.
How do pathogens affect the nervous system?
If a pathogen manages to get inside neurons somewhere else in the body, it can make its way back along the nerves up to the spinal cord and brain . This is called retrograde transport and allows the virus to bypass the blood-brain barrier completely (used by rabies, poliovirus, and herpes viruses including chickenpox).
How the central nervous system CNS can be breached by pathogens?
Microbial pathogens may access the CNS (i) by penetrating the BBB or the BCSFB or (ii) via the olfactory and/or trigeminal nerves (101). Peripheral nerves other than the olfactory and trigeminal cranial nerves have also been implicated as routes of entry for some viruses, but these are not reviewed here.
Which pathogenic bacteria can affect the nervous system?
| Table 1. Bacterial Infections of the Nervous System | Disease Pathogen Vaccine | Hansen’s disease (leprosy) Mycobacterium leprae None | Haemophilus influenzae type b meningitis Haemophilus influenza Hib vaccine | Listeriosis Listeria monocytogenes None |
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What bacteria attacks the central nervous system?
Great strides have been made in understanding the mechanisms by which bacterial pathogens with a predominantly extracellular life cycle, such as Streptococcus pneumoniae, Neisseria meningitidis , and Haemophilus influenzae, invade the CNS from the bloodstream (for recent reviews, see references 172, 196, 206, 274, and ...
How does bacteria get in the brain?
Bacteria and other infectious organisms can reach the brain and meninges in several ways: By being carried by the blood . By entering the brain directly from the outside (for example, through a skull fracture or during surgery on the brain) By spreading from nearby infected structures, such as the sinuses or middle ear.
Do protists have a nervous system?
Since protists have no nervous system , a comparison of their behaviours to the same behaviours in animals could reveal the advantages of using neurons.
What are 5 diseases of the nervous system?
- Alzheimer’s disease. Alzheimer’s disease affects brain function, memory and behaviour. ...
- Bell’s palsy. ...
- Cerebral palsy. ...
- Epilepsy. ...
- Motor neurone disease (MND) ...
- Multiple sclerosis (MS) ...
- Neurofibromatosis. ...
- Parkinson’s disease.
What infections affect the nervous system?
Infections that cause significant nervous system morbidity globally include viral (for example, HIV, rabies, Japanese encephalitis virus, herpes simplex virus, varicella zoster virus , cytomegalovirus, dengue virus and chikungunya virus), bacterial (for example, tuberculosis, syphilis, bacterial meningitis and sepsis), ...
What role does the nervous system play in the human body?
The nervous system helps all the parts of the body to communicate with each other . It also reacts to changes both outside and inside the body. The nervous system uses both electrical and chemical means to send and receive messages.
What bacteria causes nerve pain?
When flesh-eating bacteria called S. pyogenes , pictured here, slip under the skin via a small cut or bug bite, they eat away at the tissue underneath. It turns out these infections are incredibly painful because the bacteria hijack the body’s pain-sensing neurons.
Do bacteria have a nervous system?
Bacteria may not have a central or sensory nervous system as we know it, but they can still physically “feel” the world around them, according to a new study. It turns out the tiny microorganisms don’t just respond to chemical signals – they also have a sense of touch, and can recognise surfaces and respond to them.
Can the nervous system become infected?
Infection of the central nervous system can occur when a pathogen, such as a virus or bacteria, enters the brain . Pathogens can get to the brain via the blood, the nerves, or through a skull fracture.
What is the symptoms of nerve problem?
Common symptoms of nerve conditions
Confusion or cognitive changes . Loss of balance . Loss of consciousness . Loss of muscle coordination .
What causes damage to the central nervous system?
Some serious conditions, diseases, and injuries that can cause nervous system problems include: Blood supply problems (vascular disorders) . Injuries (trauma), especially injuries to the head and spinal cord. Problems that are present at birth (congenital).
What viruses affect the brain?
- enteroviruses – such as coxsackievirus, poliovirus and echovirus.
- herpes simplex virus.
- varicella zoster virus.
- Epstein-Barr virus.
- cytomegalovirus.
- adenovirus.
- rubella.
- measles.
