Neuro Flashcards
Causes of bitemporal hemianopia?
caused by a lesion of optic chiasm
- upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
- lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
what is GBS?
Guillain-Barré syndrome is an “acute paralytic polyneuropathy” that affects the peripheral nervous system. It causes acute, symmetrical, ascending weakness and can also cause sensory symptoms. It is usually triggered by an infection and is particularly associated with to campylobacter jejuni, cytomegalovirus and Epstein-Barr virus.
it is an acute inflammatory demyelinating polyneuropathy
pathophys of guillain barre syndrome
Guillain-Barré is thought to occur due to a process called molecular mimicry. The B cells of the immune system create antibodies against the antigens on the pathogen that causes the preceding infection. These antibodies also match proteins on the nerve cells. They may target proteins on the myelin sheath of the motor nerve cell or the nerve axon
presentation of GBS
Symmetrical ascending weakness (starting at the feet and moving up the body)
Reduced reflexes
There may be peripheral loss of sensation or neuropathic pain
It may progress to the cranial nerves and cause facial nerve weakness
there may also be autonomic dysfunction: sweating, raised pulse, BP changes, arrhythmias
proximal muscles are more affected (trunk, respiratory and cranial nerves - eps VII)
clinical course of GBS
Symptoms usually start within 4 weeks of the preceding infection. The symptoms typically start in the feet and progresses upward. Symptoms peak within 2-4 weeks, then there is a recovery period that can last months to years.
how is GBS diagnosed
A diagnosis of Guillain-Barré syndrome is made clinically. The Brighton criteria can be used for diagnosis.
Diagnosis can be supported by investigations:
Nerve conduction studies (reduced signal through the nerves)
Lumbar puncture for CSF (raised protein with a normal cell count and glucose)
management of GBS
IV immunoglobulins
Plasma exchange (alternative to IV IG)
Supportive care
VTE prophylaxis (pulmonary embolism is a leading cause of death)
4 hrly FVC measurement
In severe cases with impending respiratory failure, patients may need intubation, ventilation and admission to the intensive care unit.
prognosis for GBS
80% will fully recover
15% will be left with some neurological disability
5% will die
ddx for headaches
Tension headaches
Migraines
Cluster headaches
Secondary headaches
Sinusitis
Giant cell arteritis
Glaucoma
Intracranial haemorrhage
Subarachnoid haemorrhage
Analgesic headache
Hormonal headache
Cervical spondylosis
Trigeminal neuralgia
Raised intracranial pressure (brain tumours)
Meningitis
Encephalitis
red flags in someone with a headache
Fever, photophobia or neck stiffness (meningitis or encephalitis)
New neurological symptoms (haemorrhage, malignancy or stroke)
Dizziness (stroke)
unilateral, eye pain and Visual disturbance (temporal arteritis or glaucoma)
Sudden onset worst headache, thunderclap (subarachnoid haemorrhage)
Worse on coughing or straining (raised intracranial pressure)
Postural, worse on standing, lying, in the morning or bending over (raised intracranial pressure)
Severe enough to wake the patient from sleep
Vomiting (raised intracranial pressure or carbon monoxide poisoning)
History of trauma (intracranial haemorrhage)
Pregnancy (pre-eclampsia)
persisting headache_/- scalp tenderness in over 50s - GCA
change in pattern of usual headaches
reduced lvl of consciousness
recent travel (malaria)
what examination is an important part of assessing a headache?
Fundoscopy examination to look for papilloedema is an important part of an assessment of a headache. Papilloedema indicates raised intracranial pressure, which may be due to a brain tumour, benign intracranial hypertension or an intracranial bleed.
tension headaches are associated with
Stress
Depression
Alcohol
Skipping meals
Dehydration
mx of tension type headaches
Reassurance
Basic analgesia
Relaxation techniques
Hot towels to local area
secondary headaches causes
Secondary headaches give a similar presentation to a tension headache but with a clear cause. They produce a non-specific headache secondary to:
Underlying medical conditions such as infection, obstructive sleep apnoea or pre-eclampsia
Alcohol
Head injury
Carbon monoxide poisoning
sinusitis headahces?
Sinusitis causes a headache associated with inflammation in the ethmoidal, maxillary, frontal or sphenoidal sinuses. This usually produces facial pain behind the nose, forehead and eyes. There is often tenderness over the affected sinus, which helps to establish the diagnosis.
Sinusitis usually resolves within 2-3 weeks. Most sinusitis is viral. Nasal irrigation with saline can be helpful. Prolonged symptoms can be treated with steroid nasal spray. Antibiotics are occasionally required.
Analgesic Headache
An analgesic headache is a headache caused by long term analgesia use. It gives similar non-specific features to a tension headache. They are secondary to continuous or excessive use of analgesia. Withdrawal of analgesia important in treating the headache, although this can be challenging in patients with long term pain and those that believe the analgesia is necessary to treat the headache.
Hormonal Headache
Hormonal headaches are related to oestrogen. The produce a generic, non-specific, tension-like headache. They tend to be related to low oestrogen:
Two days before and first three days of the menstrual period
Around the menopause
Pregnancy. It is worse in the first few weeks and improves in the last 6 months. Headaches in the second half of pregnancy should prompt investigation for pre-eclampsia.
The oral contraceptive pill can improve hormonal headaches.
Cervical Spondylosis headache?
Cervical spondylosis is a common condition caused by degenerative changes in the cervical spine. It causes neck pain, usually made worse by movement. However, if often presents with headache.
it is important to exclude other causes of neck pain such as inflammation, malignancy and infection. It is also important to exclude spinal cord or nerve root lesions.
trigeminal neuralgia?
Trigeminal neuralgia can affect any combination of the branches of the trigeminal (V) nerve. 90% of cases are unilateral, 10% are bilateral. Around 5-10% of people with multiple sclerosis have trigeminal neuralgia.
It presents with intense facial pain that comes on spontaneously and last anywhere between a few seconds to hours. It is often described as an electricity-like shooting pain. attacks can be triggered by washing affected area, shaving, eating, talking, dental prostheses. Attacks often worsen over time.
secondary causes: compression of trigeminal root by anomalous or aneurysmal intracranial vessels or tumor, chronic meningeal inflammation, MS, zoster, skull base malformation. MRI is req to exclude 2ndary causes.
Tx - carbamazepine usually 1st line
other options - lamotrigine, phenytoin, gabapentin and surgery
Mx of trigeminal neuralgia
NICE recommend carbamazepine as first-line for trigeminal neuralgia. Surgery to decompress or intentionally damage the trigeminal nerve is an option.
diff types of migraines
Migraine without aura
Migraine with aura
Silent migraine (migraine with aura but without a headache)
Hemiplegic migraine
typical migraine headahce presentation
more common in females
associated with obesity and fhx
Headaches last between 4 and 72 hours. Typical features are:
Moderate to severe intensity
Pounding or throbbing in nature
Usually unilateral but can be bilateral
photophobia
phonophobia
With or without aura (lasting 15-30 mins followed by headache within 1 hr)
Nausea and vomiting
Aura -
Aura is the term used to describe the sensorymotor changes associated with migraines. There can be multiple different types of aura:
visual -
Sparks in vision
Blurring vision
Lines across vision
Loss of different visual fields
somatosensory - paraesthesia
motor - dysarthria and ataxia. hemiparesis, ophthalmoplegia
speech - dysphasia or paraphasia
symptoms of hemiplegic migraine and initial management of someone presenting with symptoms of a hemiplegic migraine
Symptoms of a hemiplegic migraine can vary significantly. They can be of sudden or gradual onset and can include:
Typical migraine symptoms
Hemiplegia (unilateral weakness of the limbs)
Ataxia
Changes in consciousness
Hemiplegic migraines can mimic stroke. It is essential to act fast and exclude a stroke in patients presenting with symptoms of hemiplegic migraine.
triggers for migraine
- Stress
- Bright lights
- Strong smells
- Certain foods (e.g. chocolate, cheese and caffeine)
- Dehydration
- Menstruation
- oral contraceptives
- Abnormal sleep patterns
- Trauma
- alcohol
- travel
- exercise
5 stages of a migraine
These stages are not typical of everyone and they will vary between patients. Some patients may only experience one or two of the stages. The prodromal stage can involve several days of subtle symptoms such as yawning, fatigue or mood changes prior to the onset of the migraine.
- Premonitory or prodromal stage (can begin 3 days before the headache)
- Aura (lasting up to 60 minutes)
- Headache stage (lasts 4-72 hours)
-
Resolution stage (the headache can fade away or be relieved completely by vomiting or sleeping)
- Postdromal or recovery phase
acute mx of migraine
Often patients will go to a dark quiet room and sleep. Options for medical management are:
- Paracetamol
- oral Triptans (e.g. sumatriptan 50mg as the migraine starts)
-
NSAIDs (e.g ibuprofen or naproxen)
- Antiemetics if vomiting occurs (e.g. metoclopramide)
triptans? and CIs
They are 5HT receptors agonists (serotonin receptor agonists)
Triptans are used to abort migraines when they start to develop
They act on:
- Smooth muscle in arteries to cause vasoconstriction
- Peripheral pain receptors to inhibit activation of pain receptors
- Reduce neuronal activity in the central nervous system
CI - IHD, coronary spasm, uncontrolled hypertension, recent lithium, SSRIs, ergot use
Migraine Prophylaxis
headache diary - identify and then avoid the triggers, also useful in demonstrating the response to treatment.
- Propranolol
- Topiramate (this is teratogenic and can cause a cleft lip/palate so patients should not get pregnant)
- Amitriptyline
Acupuncture is an option recommended by NICE recommend for the treatment of migraines. It is reported to be as effective as prophylactic medications.
Supplementation with vitamin B2 (riboflavin) may reduce frequency and severity.
In migraine specifically triggered around menstruation, prophylaxis with NSAIDs (e.g. mefanamic acid) or triptans (frovatriptan or zolmitriptan) can be used as a preventative measure.
botulinum injections are a last resort
Migraines tend to get better over time and people often go into remission from their symptoms.
cluster headaches presentation
they come in clusters of attacks and then disappear for a while. For example, a patient may suffer 3 – 4 attacks a day for 4-12 weeks followed by a pain-free period lasting months to 1-2 years. Attacks last between 15 minutes and 3 hours. it can be chronic as well rather than episodic.
more common in males and smokers.
Attacks can be triggered by things like alcohol, strong smells and exercise.
Cluster headaches are often described as one of the most severe and intolerable pains in the world. They are sometimes referred to as “suicide headaches” due to the severity of the pain.
Symptoms are typically all unilateral:
- Red, swollen and watering eye (lacrimation)
- Pupil constriction (miosis)
- Eyelid drooping (ptosis)
- Nasal discharge (rhinorrhoea)
- Facial sweating (flushing)
treatment options for cluster headahces
Acute management:
- Triptans (e.g. sumatriptan injected subcutaneously)
- High flow 100% oxygen for 15-20 minutes via non-rebreathable maks(can be given at home)
Prophylaxis options:
- avoid triggers eg alcohol
- Verapamil
- Lithium
- corticosteroids such as prednisolone (a short course ONLY for 2-3 weeks to break the cycle during clusters)
RFs for intracranial bleeds
- Head injury
- Hypertension
- Aneurysms
- Ischaemic stroke can progress to haemorrhage
- Brain tumours
- Anticoagulants such as warfarin
presentation of intracranial haemorrhage
Sudden onset headache is a key feature. They can also present with:
- Seizures
- Weakness
- Vomiting
- Reduced consciousness
- Other sudden onset neurological symptoms
presentation of intracranial bleeding
Sudden onset headache is a key feature. They can also present with:
- Seizures
- Weakness
- Vomiting
- Reduced consciousness
- Other sudden onset neurological symptoms
below which GCS score do u need to consider securing someone’s airway
When someone has a score of 8 or below then you need to consider securing their airway as there is a risk they are not able to maintaining it on their own.
bacterial vs viral LP results
It makes sense that bacteria swimming in the CSF will release proteins and use up the glucose. Viruses don’t use glucose but may release a small amount of protein. The immune system releases neutrophils in response to bacteria and lymphocytes in response to viruses.
from C5 to T1 - nerve root affected, muscle weakness, reflex changes and sensory changes table
