Where Does Herpes Live?

Without our Central Nervous System, we couldn’t do anything. We need it, but not everything it does is helpful. Like letting the herpes virus take up residence.

We have two nervous systems in our bodies: The Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

The CNS contains the brain and spinal cord.

The PNS consists mainly of nerves connecting the CNS to every other part of the body.

So, what makes the Herpes virus so special to our CNS. Unlike most viruses, Herpes infects the nerves in the CNS, most of the time.

For HSV1 (cold sores, facial/ oral herpes) it will take up residence in the Trigeminal (TRI-GEM-IN-AL) Nerve.

The Trigeminal Nerve is the most complex nerve in our face. It is responsible for the sensations we have in our face and motor functions such as biting and chewing.

It gets its name from the fact that each of the two nerves has three major branches.

It has three major branches: the ophthalmic nerve (V₁),  the maxillary nerve (V₂) and the mandibular nerve (V₃).

 The ophthalmic and the maxillary nerves are purely sensory; but the mandibular nerve controls motor functions as well as sensory e.g. taste buds.

The three major branches of the trigeminal nerve converge on the Trigeminal Ganglion. 

Located within an oddly named part called Meckel's Cave which contains the cell bodies of incoming sensory-nerve fibers.

So now that we have that information where does herpes live?

Herpes simplex virus type-1 (HSV-1) typically causes infections of the oral mucosa, so we are talking the mouth, around lips and nose etc.

It will then take up residence in the sensory ganglia neurons.

HSV-2 generally reactivates from the lumbar-sacral ganglia

But that doesn’t mean that it only infects the CNS.

One study conducted by Dr Kate T. Brizzi, MD¹ and  Dr Jennifer L. Lyons, MD found

“HSV-1 is primarily acquired in childhood, and HSV-2 causes most cases of genital herpes, although incidence of HSV-1 causing genital herpes is rising.¹² Peripheral nervous system manifestations of primary HSV infection are rare, but reactivation of the infection can lead to both CNS and PNS diseases.”

So, although rare, it can jump ship to other the nervous systems ganglia. Now isn’t that a lovely thought to end on.