Infections of the nervous systemCharlie Grant

Harvey Davies

A worried mother brings her 4 year old son into A&E. When you speak to her she says her son has ‘not been himself’ all morning. He seems exhausted and very irritable, preferring to lie still with the bed sheets over his head. She says that he’s usually out all day playing with the other kids in the traveller’s site where they live. He was sick on the way to the hospital.

MeningitisWhich features of this patients presenting symptoms may point to a diagnosis of bacterial meningitis?Age: <5Behaviour: malaise, lying still, photophobiaVomitingRapid onsetSocial factors: overcrowding, non-immunisation, low socioeconomic status

MeningitisName the three cardinal features of the meningitic syndrome Neck stiffnessHeadacheFever

MeningitisName three of the most common causes of meningitis in this age group (bacterial or viral)Neisseria meningitidesStreptococcus pneumoniaStaph aureusHaemophilus influenza

MeningitisYou examine the patient and notice that he has a purpuric rash and very cold hands and feet. What condition are you concerned about and why are you so worried about it?Meningococcal septicaemia – because it’s a medical emergency! Even with optimal care, mortality is 15%

MeningitisWhat is the definition of septic shock?SepsisHypotension despite adequate fluid resusPerfusion abnormalities

MeningitisWhat are you going to do IMMEDIATELY?IV antibioticsBlood cultures

MeningitisIn general, how does viral meningitis differ from bacterial meningitis?More commonLess severe (not always!)Normally complete recovery (not always!)

A 19 year old student has recently returned from holiday. She presented to her GP with a two week history of headache, fever, malaise and drowsiness. She doesn’t think it’s related but she has noticed a number of painful ulcers on her genitals and reports having unprotected sex while abroad.

Encephalitis What is encephalitis?‘A pathological state of brain parenchymal dysfunction demonstrated by an altered state of consciousness and/or signs of neurological dysfunction’

EncephalitisWhat is the likely pathogen in this case?HSV-1/2

EncephalitisCan you identify any diagnostic factors in the stem? Age: <20FeverVesicular rash: suggestive of HSVAltered mental state: in this case the patient is withdrawn

EncephalitisHow would you manage this case?IV Aciclovir

An itchy rash…

A 30 year old tree surgeon presents to the GP with a vesicular-bullous, itchy rash that developed a 2-3 days ago. He describes the rash as a strip across his back and right shoulder.

What is your main DDx?

Shingles

Caused by Herpes-Zoster Virus (Varicella-Zoster Virus)

Following a bout of Chickenpox, the Herpes Zoster Virus can remain within neurons / ganglia of the body, awaiting their resurrection.

Shingles

How Shingles presents:

General malaise, tiredness, and headaches A vesicular-bullous rash forms over a few days,

and is painful to touch (although can be maculopapular), that follows a dermatomal region

Corneal ulceration can occur if the trigeminal nerve is affected

Shingles

How is Shingles treated?

Pain relief (WHO pain ladder) Antivirals (e.g. Aciclovir) can reduce symptomatic time Calamine lotion – zinc oxide cream (anti-itch)

Is Shingles contagious?

Yes! Well, kind of. Shingles can pass and cause Chickenpox in someone who

has not previously suffered from Chickenpox, but Shingles can not spread Shingles.

Some years later…

A 45 year old presents with progressive loss of light touch sensation, vibration, and an altered gait. He has little past medical history or social history of note, but on questioning says he frequently undertook unprotected sex in his youth.

What is your main DDx?

(progressive loss of fine touch, vibration, and conscious proprioception)

Neurosyphilis – Tabes dorsalis

Tabes dorsalis is a slowly progressing demyelination of the dorsal columns of the spinal cord.

It is a form of Tertiary Syphilis, that occurs many years after an initial syphilis infection.

Neurosyphilis

Neurosyphilis is an infection of the CNS, caused by Treponema pallidum (double-membrane bacteria that causes syphilis)

Syphilis has 3 main stages: Primary chancre (painless ulcers)

Secondary eruptions Tertiary disease

Neurosyphilis

Tertiary Neurosyphilis can have 4 different forms:

Asymptomatic Meningio-Vascular Syphilis Tabes dorsalis Generalised Paresis of the Insane

Questions?