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What feature of rabies pathophysiology causes hydrophobia? Why is hydrophobia unique to this one particular type of viral infection?

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Related question – Rory M Apr 22 '14 at 13:29
up vote 3 down vote accepted

Rabies causes hydrophobia in the encephalitic stage which means when it affects the brain and causes swelling and inflammation of multiple areas of the brain. Hence, it affects the complex swallowing areas in the brain. Initially into the course of the disease, the patient has involuntary contractions of neck muscles when he drinks water. At later stages of disease, the patient starts contracting his muscles even at the thought of water. Rabies virus is a neurotropic virus which means that it travels through nerves because of its preference to attach to acetylcholine receptors in the neurons. That is how the virus spreads from the bite site to the brain(via the nerves).

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Why hydrophobia specifically and consistently? Most diseases causing encephalitis or other pathology to the brain has very varied clinical spectra. – AndroidPenguin Apr 22 '14 at 21:34
Yes why specifically – rhill45 Apr 23 '14 at 16:42
This is a good answer above but would like to let this question sit a little longer. What are the swallowing areas of the brain etc... – rhill45 Apr 23 '14 at 16:44
The swallowing areas of the brain are located in temporal cortex, pons and medulla oblongata – Pranay Aryal Apr 23 '14 at 17:57
It starts off with difficulty swallowing water, progressing on to fear of water just on mentioning it. I guess it affects the center of the brain subserving fear. Why fear to water specifically, I do not know the answer. As a clinician, it doesn't bother me much because it has no therapeutic implications. It only serves to me as a marker to suspect rabies. There are many things in medicine which haven't or cannot be explained by reasoning but have shown to be significantly(statistically) associated. But I appreciate your inquisitiveness. – Pranay Aryal Apr 30 '14 at 0:32

Hydrophobia and aerophobia occur as a consequence of involuntary, painful contraction of the diaphram and the accessory respiratory, laryngeal and pharyngeal muscles in response to swallowing liqiud or air.

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It would be great if you added some references to support your response! – Bez Jan 4 '15 at 15:01

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