Seizures, Encephalitis, Migraine, Raised ICP Flashcards
What is status Epilepticus?
a medical emergency characterized by prolonged or recurrent seizures that occur without full recovery between episodes or seizures lasting longer than 5 minutes.
How is Status Epilepticus Treated?
benzodiazepines (e.g., lorazepam, diazepam)
- Lorazepam given IV
- Diazepam given Rectally
- Midazolam is give Buccal
(Midazolam - Mouth)
In Status Epilepticus if two boluses of IV lorazepam have been given (with 5 minute intervals after each dose), second-line options for terminating the seizure would be IV….
phenytoin, levetiracetam or sodium valproate.
What is Encephalitis an inflammation of?
The brain parenchyma.
What is the most common cause of Encephalitis?
Herpes Simplex Virus type 1
Others:
- VZV
- Enteroviruses
What Clinical features does a patient with Encephalitis show?
Personality and behavioural changes, which progresses to reduced level of conciousness and even coma.
- Fever
- Meningism
- Seizures (focal and generalised)
What investigations are done in Encephalitis?
- Blood cultures and Viral PCR.
- Lumbar Puncture (CSF analysis with Viral PCR)
(viral - elevated lymphocytes) - MRI
Which areas of the brain are involved in Encephalitis?
(seen on MRI)
Bilateral Medial TEMPORAL LOBE involvement
What is given in suspected HSV and VZV encephalitis?
IV Acyclovir, even before investigation results are available.
- Significantly improves outcomes.
What is Limbic Encephalitis?
A form of antibody-mediated encephalitis.
- May be assoc. w underlying malignancy or autoimmune.
What is the management of Limbic Encephalitis?
Depends on cause
e.g. Treat tumour for malignancy.
or
Immunosuppression in Autoimmune.
What kind of Electrolyte abnormality is commonly associated with HSV encephalitis?
Hyponatraemia
What is the most common cause of Episodic Headache?
Migraine
What is the most common type of Migraine?
Migraine without Aura (80%)
Migraine with Aura (20%)
Are migraines typically unilateral or bilateral?
Unilateral throbbing headache.
What is a typical timeframe for Migraines?
4-72 hrs
What sensations can make headaches worse in migraine?
Photophobia or Phonophobia.
What can be done to try and Identify triggers in Migraines?
Headache diary
What are the Acute medical treatments offered in Migraine?
- NSAID / Paracetamol + Triptan (5HT agonist) e.g. Sumatriptan, Rizatriptan.
If Gastoparesis consider antiemetic.
When should prophylaxis be considered in Migraines?
When a patient is experiencing more than 3 attacks per month or has very severe attacks.
What is the First, second and Third line Tx in Migraine Prophylaxis?
1st : Amitriptyline or Propranalol (CI: Asthma)
2nd : Topiromate/Valproate
3rd : Pizotifen.
What are some causes of a raised ICP?
- Mass effect e.g. tumour
- Brain swelling due to e.g. ischaemia or liver failure.
- Increased central venous pressure e.g. venous sinus thrombosis.
- Problems with CSF flow: Hydrocephalus, Increased production (choroid plexus papilloma)
What is the normal range for ICP?
Constantly fluctuating between 7 and 15mmHg
What is the compensatory mechanism for expanding masses called?
Monroe-Kellie Doctrine.
What is the Immediate compensatory mechanism used for an Increased ICP?
Decrease in CSF volume by moving it out of Foramen Magnum.
+
Decrease in Blood volume by squeezing sinuses.
Later: Decrease in ECF
What is the Cerebral Perfusion Pressure calculated using?
CCP = MAP - ICP
What are some early signs of a raised ICP?
- Decreased Level of Consciousness.
- Headache
- Pupilliary dysfunction +/- Papilloedema.
- Changes to vision
- N&V
What are some later signs of Raised ICP?
- Coma
- Fixed, Dilated pupils
- Hemiplegia
- Hyperthermia
- Increase UO
- Bradycardia > Cushings triad
What is Cushings reflex in response to a raised ICP and how does it affect the HR, BP and RR?
Cushings reflex begins when an event causes a raised ICP.
- During the raised ICP both sympathetic and Parasympathetic systems are activated.
Causes an Increased BP, Decreased HR and Irregular Breathing.
What are some medical management options for raised ICP?
Diuretics - hypertonic Saline
Barbiturate coma (Medically induced coma)
Antiepileptics
What is Normal Pressure Hydrocephalus?
Idiopathic disease of the elderly, possibly due to decreased brain elastance.
What is The Typical triad in Normal Pressure Hydrocephalus?
Wet, Wobbly and Weird
Hakim’s Triad:
- Dementia: Often manifests as global cognitive impairment, with memory and Attention disturbance.
- Magnetic Gait: Characterised by difficulty lifting feet off the floor, appearing as if they are stuck.
- Incontinence: Primarily urinary.
What is the Investigation usually done in Normal Pressure Hydrocephalus?
CT/ MRI : typically show dilated lateral ventricles and absent sulci.
LP: Measurement of walking ability and Cognative assessment pre- and Post LP can help ascertain whether patients could benefit from further surgical management.
What is the the management of Normal Pressure Hydrocephalus?
Therapeutic LP: Removing CSF to alleviate symptoms.
Ventriculoperitoneal shunt: In px responsive to LP, neurosurgery may insert shunt to permanently redirect the excess CSF from the brain to the abdomen.
When should Sumatriptan be taken when a patient is having a Migraine with aura?
only once the headache itself starts, but not during the Aura Phase.
What is a possible side effect of Lamotrigine?
Steven-Johnstone syndrome
Drugs which cause SJS:
SCALP
Sulfonamides
Carbamazepine
Allopurinol
Lamotrigine
Penicillins
What visual changes occur in IIH?
Enlarged blind spot and constriction of the Visual Fields
What can be used in Bacterial Meningitis, especially Pneumococcal meningitis, to reduce the risk of long term neurological symptoms?
IV Dexamethasone
- should be started within 4 hrs of IV Abx
What is a Cluster Headache?
- Recurrent unilateral periorbital pain of sudden onset
- Associated symptoms: watery and bloodshot eye, lacrimation, rhinorrhoea, miosis, ptosis, lid swelling, and facial flushing
- Headache duration of 15 minutes to 3 hours, occurring once or twice daily over 4-12 weeks, followed by a pain-free period of several months
Who are most Likely to get Cluster Headaches?
Men > Women
Aged 20 - 40 yrs.
What is the management of Cluster Headaches?
- Avoiding triggers,
- Prophylaxis with Verapamil,
- Treat acute attacks with 100% oxygen via a non-rebreathable mask (contraindicated in COPD) and a subcutaneous or nasal Triptan (contraindicated in ischaemic heart disease).
What area do Jacksonian Seizures affect in the brain?
The Frontal Lobe
