Brain conditions - not PD or Dementia Flashcards
What is Cortical Dysplasia?
Occura before birth
0 During brain cell/ neuron development b- they fail to reach the parts of the brain which they are destined for————————–> those areas lack function & the right neuronal connections. ———————————-> loss of proper function—————————-> causes epilepsy & seizures.
- Most common type of epilepsy in children - seizures difficult to control with medications.
2/3rd most common cause of medically intractable / refractory (not easily managed by medicines ) seizures.
Type 1a - usually confined to Temporal lobes
Type 1b - found outside temporal lobes.
Type 2 - found in frontal lobes - less commonly in temporal
Type 3 - architectural distortion of cortical layer.
a:in temporal lobe with hippocampal atrophy
b: adjacent to glial or glioneuronal tumour
c: adjacent to vascular malformation
d: adjacent to other lesions acquired in early childhood
Features on MRI
- Cortical thickening (Gyri , sulcuses are thickened - can displace midline structures in severe cases.
- Blurring of white /grey matter junction with abnormal architecture of subcortical layer.
What is Gray matter / Periventricular Heterotopia ?
Malformation of cortical development.
Heterotopia - (out of place)
Nodules of neurones - located in the wrong location in the brain.
Neurones form in periventricular region (next to ventricles ) ————————–> then move towards the cortex ————————–> In condition fail to move and form clumps around ventricles.
Symptoms
Common - Seizures (often appear in teenage years)
May have :
0 Mild intellectual disability.
0 Dyslexia
0 Movement problems
Less common :
- Severe brain maliformations
- developmental delays
- BV abnormalities
- Stomach problems
- Lung disease.
- can occur in association with elhlers - Danlos syndrome.
Imaging - MRI
CAUSES
- mutation in gene that codes for protein filamin A - builds cytoskeleton that gives structure to cells and allows them to change shape & structure.——————————> disrupts migration patterns.
What is polymicrogyria ?
Abnormal brain development before birth
Poly - many
Micro - small
Gyria - gyri
on the surface of the brain.
Brain develops too many folds which are very small (instead of the normal sized gyri.
Usually unilateral.
Unilateral focal polymicrogyria - happen is small area - mild symptoms
0 Mild seizures - easily controlled by medication.
0 some are asymptomatic
Bilateral form - more severe 0 recurrent seizures 0 Delayed development 0 Crossed eyes 0 Problems with speech & swallowing 0 muscle weakness , paralysis
Bilateral generalized polymicrogyria - most severe - affects whole brain.
0 Severe seizures
0 Severe intellectual disability.
Imaging -MRI
gyri look fused - can be unilateral or bilateral.
Treatments
1st line
0 Antiseizure medications
0 If small area affected - resection surgery
0 Unilateral presentation - hemispherectomy
0 Bilateral - not good candidates for surgery -
Options
- Deep brain stimulation (DBS)
- Vagus nerve stimulation (VNS)
0 Occupational health
0 Physical therpay
0 Speech therapy
What is Tuberous Sclerosis ?
Multi- system disorder
Formation of Hamartomas (non - cancerous tumour - made out of abnormal mixture of tissues and cells )
Found in ;
o Brain - not cancer but can lead to seizures - commonly in childhood but can happen in adulthood
Childhood - Focal seizures & infantile spasms
- Subependymall Giant cell Astrocytoma - Benign tunours - devlop in 10 -15 % of patients (almost only occurs in TB patients (usually young ) near formina of monroe (connects both lateral ventricles )—————————————————-> can cause Obstructive Hydrocephalus ( mass around ventricular system )
Subependymal bodies - small nodules/ lesions in lining of ventricles (do not cause hydrocephalus) - can calcify
o Skin o Kidneys o eyes o Heart o Lungs
What is Mesial Temporal sclerosis (Hippocampal sclerosis )
Scarring of a deep part of the temporal lobe. Affects Hippocampus (involved in memory) & amygdala - emotional processing.
SYMPTOMS
- Temporal Lobe epilepsy (Seizures )
- Changes in behaviour / emotions
- Strange sensations (auras , euphoria , deja vu etc. )
- Muscle spasms
Imaging MRI
- Scarring in temporal lobe
Most common form of structural epilepsy and focal seizures in temporal lobe.
- Associated with temporal lobe epilepsy - most patients present with this.
- Also associated with febrile seizures - some patients who develop temporal lobe epilepsy have history of seizures when the develop a fever.
(prolonged seizures while feverous - risk factor for MTS)
Temporal lobe contains :
o Hippocampus
o Amygdala etc.
What are cavernomas ?
Cluster of abnormal BV (look like a raspberry )———————> flow through BV slowly —————————–> thin walled so prone to leaking blood ————————–> can bleed (often small amounts , but can be severe in some cases ) or press on areas of the brain producing symptoms
Severe Haemorrhages - life threatening and can lead to life long problems.
Causes
- Can be Genetic or random.
- Can occur in Brain or Spinal cord.
SYMPTOMS
0 Bleeding (hemorrhage) - the more you have the higher the risk.
0 Seizures
0 Headaches
0 Neurological problems - dizziness , dysarthria , double vision ,balance problems , difficulty concentrating
0 Hemorrhagic stroke
Treatment
Treat symptoms ie. seizure medication or headaches etc.
Surgery - removal of Cavernoma.
- Neurosurgery - preferred
- Stereotatic surgery - single dose of radiation aimed at Cavernoma causing it be thickened and scarred.
(prevent further hemorrhages - if at risk of recurrent ones )
HAVE TO TELL DVLA IF HAVE CAVERNOMA
What is a DNET brain tumor ?
Dysembryoplastic neuroepithelial tumour.
(Glioneuronal tumour)
(surgically curable - important )low-grade brain tumor, neuronal and mixed neuronal-glial tumor (it is benign)
0 Usually seen in children / young adults
(1.2 % of all neuroepthelial tumours in under 20s) - Rare
0 prone to developing epilepsy/seizures (mostly refractory to medication) - usually starts around 10- then has recurrent episodes.
0 peripheral tumour (mostly) - found in cortex
Treatment
Surgery
(Anti seizure mediction)
What is Herpes Encephalitis ?
Encephalitis - inflammation of the brain parenchyma associated with neurological dysfunction - infectious or non -infectious course - direct inflammation of brain tissue not meninges
CAUSES
Herpes simplex -most common cause of encephalitis
0 altered state of consciousnes 0 seizures 0 personality changes 0 cranial nerve palsies 0 speech problems, and motor and sensory deficits
Symptoms
- Fever
- rash -
1. vesicular eruption (any vesicles outside primary dermatome , herpes simpex )
2. Maculopapular eruption - flat red area (macule - discoloured flat skin lesions) + small raised bumps (papule)
Viral
Encephalitis - can also be caused by the
-varicella zoster virus (chickenpox and shingles)
- measles , mumps , rubella
- viruses spread by animals, such as tick-borne encephalitis, Japanese encephalitis, rabies (and possibly Zika virus)
bacteria , fungi & parasites rarely cause tjis.
RISK FACTORS - Postinfection - animal /insect bites - organ transplants - infected donors - body fluid / blood exposure - immunodeificency - age - below 1 (high risk) , above 65 years. travel abroad - to certain areas - tropical disease
Investigtion
FBC - elevated WBC
- peripheral lood smear - sign of infection
- Blood cultures
- throat swab - dection of viruses
- Sputum
- CT brain -ordered in all patients with altered mental state - usually normal , but later there can be chnages.
- MRI - if encephalitis suspected - very important for diagnosis.
- CSF analysis (lumbar puncture)/ serlogy
- culture
=
What is epilepsy ?
Clinical diagnosis - e.g not a (single) test can diagnose it , realise on careful history , typical signs an features etc.
EEG telemetry - normal
What is epilespy ?
WHAT
CAUSE
TYPES OF SEIZURES
seizure disorder - recurrent and unpredictable episodes.
Disease of the brain with the following features :
0 miminum - 2 unprovoked seizures occurring more than 24 hours apart.
0 One unprovoked seizure and a probability of further seizures similar to the general recurrence risk after two unprovoked seizures, occurring over the next 10 years.
Diagnosis of an epilepsy syndrome (when seizures occur with other signs ans symptoms / patterns e.g age which it began , types , genderetc - classified as syndrome e.g.
- Childhood absence epilesy , Epilepsy with myoclonic absences , juvinile myoclonic epilespy , childhood epilespy with Centro-temporal spikes etc)
CAUSE
Neurons are firing at the same time - abnormal
(can be a specific area in the brain where neurones are being excited to o much or not being inhibited enough.)
SYMPTOMS - depends on which neurones is affected.
- Outwards signs - jerking , moving , loss of conciousness
-Only experienced by person - smells , fears ,
- Can experince symptoms after seizure e.g
- Postictal confusion
- Todd’s Paralysis (Paresis)
o usually affects one side of body ,
arms & legs
0 can last for on average 15 hours ,
usally goes away after 2 days. - caused be severe suppression of area affected by seizure)
TYPES OF SEIZURES
PARTIAL / FOCAL SEIZURE - limited to one hemisphere or lobe.
- Simple partial seizure (can still drive)- remains concious
0 strange sensations
0Jerking movements
(Jacksonian march - if jerking activity starts in specific muscle group then spreads to thers)
*remembers seizure after & will know what is happening - known as auras - sign / warning of another seizure.
- Complex - impaired conciousness/ loss of conciousness/ self awareness - do not remember
0 Random body movements
- smacking your lips
- rubbing your hands
- making random noises
- moving your arms around
- picking at clothes or fiddling with objects
- chewing or swallowing
GENERALISED SEIZURE - affect both hemispheres / lose conciousness
(sometimes starts with partial seizure then progresses to generalised (in this case called - secondary generalised seizure))
0 Tonic seizure - body becomes stiff / flexed - fall to the floor (often backwards)
0 Atonic seizure - Muscles suddenly relax , become floppy , fall to the floor (often forwards)
(Sudden onset of loss of muscle tone - NICE)
*0 Tonic - Clonic - MOST COMMON - 2 stages
tonic stage – you lose consciousness, your body goes stiff, and you may fall to the floor
clonic stage – your limbs jerk about, you may lose control of your bladder or bowel, you may bite your tongue or the inside of your cheek, and you might have difficulty breathing (muscles rapidly contract and relax)
0 Myoclonic- body / some of body twitch / jerk (like electric shock) - only last a fraction of a sec , but several can happen in short space of time
- awake during episode
- happens usually just after waking up.
(Brief, ‘shock-like’ involuntary single or multiple jerks - NICE)
0 absence - is where you lose awareness of your surroundings for a short time.
*Effects children mainly - but not always the case.
stare blankly into space
look like they’re “daydreaming”
flutter their eyes
make slight jerking movements of their body or limbs
(last about 15 secs - not able to remeber episode)
- Dont respond to stumli e.g. brisk sternal rub ,
- During the seizures the eyes may be open & fainting (compared to non -seizure related causes of loss of conciousness)
STATUS EPILEPITICUS - seizure longer than 5 mins or multiple sizures where person has not gained conciousness in between.
(Medical emergency)
other classification
- Motor onset
- Non motor onset.
- unclassified.
Non epiletic attack disorder (NEAD)
Thought to be triggered by stress - overwhelming stress causes brain to shut down.
Dissociative seizure - happen for pyscholocial reasons rather than physical reasons e.g EEG (electroencephologram will be normal vs abnormal in epilepsy. )
other names -
0 Psychogenic non-epileptic seizures
0 Psychogenic seizures
0 Functional seizures
*reason why you need to distingiush btw epilespy and other cause of seizures , e.g infection (Febrile seizure) , haemorrage , stroke (approx 10% will have seizures) , structural e.g Temporal DNET (tumor) etc. - epilespy medication will not work for these causes)
When do you begin treatment?
0 Start with offer of drugs after 2 seizures or 1 and significantly abnormal EEG or underlying cause, or patient choice
WAIT AND SEE
Single seizure – tests normal 50% risk of further seizure in 2 years
Treatment of seizures ?
To abort seizure (emergency) - Benzodiazpein
For people having a tonic-clonic seizure lasting more than 5 mins , more than 3 seizures in an hour.
0 Buccal midazolam as first-line treatment in the community.
Rectal diazepam if preferred, or if buccal midazolam is not available.
0 Intravenous lorazepam if intravenous access is already established and resuscitation facilities are available.
If has after this they are diagnosed with epilespy - given anti - epileptic medication (Taken daily):
0 Focal seizure only - 1st line:
- Carbamazepine
- lamotrigine
0 Generalised - 1st line:
- Tonic- Clonic - Sodium
Valoporate
- lamotrigine - if SV not
(other prtions e.g. topiramate , carbamazepine, levetiracetam, oxcarbazepine , SECONDARY: phenytoin, brivaracetam, lacosamide , zonisamide ) TERTIARY ; Pregabalin , gabapentin)
suitable (e.g young women -premenapausal)
- Absence - SV ,
Ethosumide.
- lamotrigine if other 2 not suitable.
- Myoclonic - SV ,if
unsuitable
( topiramate (unfavorable
side effects) and
levetiracetam )
- Atonic & Tonic - SV ,lamotrigine (adjunctive - if benefical)
If monotherpay does not work , change to another drug - if fails ——————————–> dual therapy.
SURGICAL RESECTION(if it is focal - one area) DRUG resistan epilepsy - failure of two appropriate and tolerated anticonvulsant medications at optimal doses
IF ALL THIS FAILS : Neurostimulation :deep brain stimulation, vagus nerve stimulation, and responsive neurostimulation can be used.
THIS FOR UNDER 65
Lamotrigine, gabapentin, and levetiracetam - fewer side effects - more suitable for over 65s.
ketogenic diet have been shown to be useful.
SODIUM VALPORATE - not suitable during pregnancy - before starting women of childbearing age must be enrolled in pregnancy prevention programme.
all anti- epileptic drugs (monotherapy) can be used for breast feeding when normal doses used but caution is needed & monitoring unless against specialist advice
Diagnosis of Epilespy ?
0 EEG - Electroencephologram
(Can have EEG LTM (LONG TERM MONITORING WITH VIDEO - capturing seizure activity simultaneously on video recording and EEG)
Ruling out provoked seizures - tonic - clonic but applies to all - in absence sizures - EEG is the main one
0 Blood glucose - Extreme 0 Hypoglycemia or hyper can cause seizures.
0 FBC - elevated WBC - infection can cause seizures.
0 Electrolyte panel - hyponatraemia, hypernatraemia, or uraemia , electrolyte imbalalnce - especiallt those 3 can cause seizures)
0 Toxicology screen - drugs can cause seizures
0 Head CT - looking for structural cause.
CONSIDER
0 Lumbar puncture - if suspected Central nervous system infection (elevated protein , low glucose)
0 Brain MRI - should be done within 1 month of unprovoked sizure event - detect brain abnormalities e.g cortical dysplasia , tumors etc.
0 serum Creatine kinase - help differiate btw syncope or another non-epileptic event. elebated in some seizures.
Febrile - clinical diagnosis e.g fever linked with seizures - Lumbur puncture , Blood culture ,etc.
