Neurology Flashcards
What is meningitis?
Inflammation of the arachnoid, pia and CSF.
Is meningitis normally viral or bacterial?
Usually viral
What are the viral/ bacterial causes of meningitis?
Most common is herpes simplex virus
Enteroviruses- coxsackie, echovirus, HIV
Bacterial- HAEMOPHILUS INFLUENZA TYPE B
Streptococcus agalactiae
Group B strep
Childhood- neisseria meningitidis, strep pneumoniae
What is the pathophysiology behind meningitis?
Bacteria and viruses tend to spread to the meninges via. The haemtogenous route, where they cause an inflammatory reaction.
The immune system is activated which causes an increase in cytokines
The increase in cytokines leads to an increased permeability of the blood brain barrier and also causes cerebral vasculature vasodilation (leading to reduced perfusion pressure and ischaemia)
The increased permeability of the blood brain barrier leads to cerebral oedema
The cerebral vasculature vasodilation can lead to a raised ICP.
How does meningitis lead to meningococcal septicaemia?
The bacteria releases an endotoxin that can result in
Increased vascular permeability which may lead to hypovolaemia
Coagulopathy which leads to petechiae and purpura
Myocardial dysfunction
Metabolic disturbance- acidosis, decrease in K+/Ca2+/MG2+
What are the risk factors for meningitis?
Maternal infection Premature rupture of membranes Low birthweight Prematurity Splenectomy Not immunised CSF shunt Immunocompromised
What are the signs and symptoms of meningitis?
Symptoms-
neck stiffness, photophobia (meningeal irritation)
Altered consciousness, N+V (cerebral oedema)
Cytokine release (Rigors, headache)
Signs-
Brudzinski sign, Kernig, seizures (meningeal irritation)
Decrease in GCS, bulging fontanelles, papilloedema
What are the signs and symptoms of meningococcal septicaemia?
Symptoms- hypovolaemia (dehydration) and non blanching rash
Signs- decrease in BP, increase in HR, petechiae and purpura
What investigations would you do in a child your suspecting of having meningitis?
Blood cultures, FBC, CRP, renal profile
LUMBAR PUNCTURE with CSF analysis is GOLD STANDARD (unless there are features of raised ICP!)
When you are doing lumbar puncture with CSF analysis, the glucose in the CSF is compared to glucose in plasma, so take plasma glucose levels at the same time.
What would the CSF analysis for bacterial meningitis likely show?
. The white cells present would be neutrophils
. Appearance would be turbid
. There would be an increased protein content
. There would be a decreased glucose content
What would the CSF sample for viral meningitis likely show?
Clear appearance
White cells would be lymphocytes
Protein content may or may not be increased
Glucose content may or may not be increased
What are the differential diagnoses for meningitis?
Any cause of sepsis Intracranial abscess Encephalitis Intracranial abscess Intracranial tumours Hydrocephalus
What are the differentials for meningitis?
Any cause of sepsis Intracranial abscess Encephalitis Intracranial tumours Hydrocephalus
What is the management of meningitis?
Do NOT delay starting empirical ABx whilst awaiting diagnostic tests
. A to E resuscitation
. IV ABx
. IV corticosteroids (if >3 months of age)
What are the complications of meningitis?
Sepsis, shock, SIADH. Ataxia/abscess DIC (disseminated intravascular coagulopathy) Retardation Epilepsy Paralysis Deafness
What is a febrile convulsion?
A seizure which is associated with fever and unrelated to other pathology.
What history would you expect with febrile convulsions?
Preceding febrile illness
A generalised tonic clinic seizure which lasts 5 minutes and less than 15 minutes
Full recovery within an hour
What are the investigations done for febrile convulsions?
So usually it will be just diagnosed clinically
Can do a lumbar puncture if suspecting something else
MSU and bloods
What are the differentials for convulsions?
If they are febrile- meningitis, encephalitis, sepsis, UTI
Not febrile- epilepsy, breath holding spells, reflex anoxic seizure, electrolyte disturbance, decreased glucose, epilsepsy
How do you manage febrile convulsions?
They can be managed at home
Advice on parental management
Manage fever (doesnt prevent recurrence)
What would the initial management of a seizure be in terms of parent/doctor?
Parents: protect the child, don’t restrain, recovery position after seizure, call 999 if it’s been more than 5 minutes.
Doctors: same as parents, of seizure is more than 5 mins then use IV lorazepam, this can be given 2x every ten mins
If IV lorazepam is unavailable then you can use buccal medazolam, if you cant get IV access then you can try get intraosseous
If lorazepam has been tried twice then you can try phenytoin IO/IV, this is an infusion
What is epilepsy?
Epilepsy is a common condition which affects the brain and causes frequent seizures (which are a burst of electrical activity in the brain, temporarily affecting how it works)
What is the pathophysiology behind epilepsy?
An increased activation of neurones or decreased inhibition can lead to an imbalance of being created, leading to an overall net excitation- paroxysmal discharge. The Brain region affected dictates the symptoms associated with the seizures.
What would the features of epilepsy be if it affected the frontal lobe?
If it affected the motor cortex- movement impairement
If it affected the frontal cortex- emotional/cognitive change
What features would you see if epilepsy affected the temporal lobe?
Auditory cortex- ringing or hissing/ hearing music
Wernickes area- dysphasia
Olfactory area- unusual taste or smell
Superior temporal gyrus- automatisms, lip smacking, chewing
What would the features of epilepsy be if the parietal lobe was affected?
If the sensory cortex was affected causing sensory disturbance
What are the features of epilepsy affecting the occipital lobe?
Flashes, Scotoma, blurring/ formed visual hallucinations
What are the features of epilepsy when the limbic system is affected?
Amygdala, thalamus, hypothalamus will be affected therefore you will get autonomic dysfunction.
What are the causes of epilepsy?
Risk factors…
. Learning disability
. First degree relative affected
Many aetiologies which may cause epilepsy…
. Idiopathic
Genetic syndromes- tuberous sclerosis, Rett syndrome and leader willi metabolic disease
Electrolyte disturbance
What is meant by tonic?
Stiffness in the limbs
What is meant by clinic?
Sustained rhythmical jerking of the limbs
What is meant by tonic clinic?
Initial stiffening which is followed by jerking.
What is atonic?
Sudden loss of muscle tone so the child will fall to the floor
What is meant by myoclonic?
A brief muscle jerk
What is meant by automatises?
Repetitive, purposeless actions (making sounds, picking at clothes, lip smacking, chewing) .
What are the clinical features of focal motor epilepsy?
Symptoms and signs will be up to a few minutes duration . Automatisms . Tonic . Clonic . Tonic clonic . Atonic . Myoclonic Above affects a specific region of the body
What are the clinical features of focal non motor epilepsy?
Altered sensation
An unsustainable smell/taste
Visual disturbance
Autonomic disturbance
What are the clinical features of a motor generalised seizure?
Loss of awareness
Associated with motor symptoms
Most common motor symptom is tonic clonic characterised by an initial rigid phase in which the child may bite their tongue
Followed by rhythmic jerking during which the child may lose control of the bladder and bowels.
Afterwards, there is a post ictal stage which lasts from 5-30 mins in which the child is drowsy and confused 🤷
What are the clinical features of a generalised (absence) non motor epilepsy?
Very brief period (<10s) during which the child
I’ll stops what they are doing, becomes unaware and stares into the distance. It self terminates and the child resumes what they were doing, there is no post ictal phase and it can be confused with day dreaming.
What is the treatment of focal seizure epilepsy?
Carbamazepine or lamotrigine
What is the treatment of generalised tonic clonic seizures?
Sodium valproate or lamotrigine
What is the treatment of generalised non motor (absence) epilepsy?
Ethosuximide or sodium valproate
What is the treatment of myoclonic/tonic/atonic?
Sodium valproate
What are the side effects of sodium valproate?
This can be remembered by VALPROATE V= valproate A= ataxia L= liver failure P= pancreatitis R= reversible hair loss O= oedema A= appetite increased T= teratogenic/thrombocytopenia E= enzyme inhibitor (CYP450)
What are two classifications of headaches?
Headaches can be classified as primary (attributable to a headache disorder) or secondary (due to another underlying disease)
What are examples of primary headaches?
Tension type
Cluster
Migraine
What are the examples of secondary headaches?
Trauma=post concussion headache
Intracranial bleeds
Fracture
MSK= temperomandibular joint, cervical spine
Vascular= subarachnoid (ruptured aneurysm), parenchymal (vascular malformation)
Raised ICP= space occupying lesion, hydrocephalus
Meningeal irritation- meningitis, encephalitis
Sinuses- sinusitis
What are the features of a tension headache?
Bilateral or unilateral
Tight
Unaffected by routine activity
What are the features of migraine?
May be unilateral or bilateral Pulsating Nausea and vomiting Photophobia, photophobia \+/- aura
What are the clinical features of a cluster headache?
Unilateral around the eye, stabbing throbbing and burning
You get a unilateral red eye
Epiphora
Nasal congestion and sweating
What are the features of sinusitis?
Usually frontal, usually there is facial tenderness, nasal congestion, sore ear, cough and fever
What clinical features would suggest encephalitis?
Fever
Altered mental status (Confused/drowsy)
+/- seizures
+/- decreased GCS