Neuro & Metabolic Flashcards
Herpes simplex virus? Types? (HSV)
- type 1 & 2
Herpes simplex virus type 2 ? Common on what age group?
In Young children
Herpes simplex virus type (1)? Common in which age group?
Older adults
signs & symptoms of HSV infection?
Fever
Malaise
Headache
Confusion
Seizures
Investigation for HSV?
- CT not sensitive for temporal lobe changes
- CSF - Lymphocytosis & Elevated proteins
- HSV PCR highly specific
Treatment of HSV?
Acyclovir
Prognosis for HSV encephalitis ?
- Untreated mortality > 70%
- Treated mortality < 20%
Complications post-SAH endovascular intervention?
- Re-bleeding (unlikely after successful procedure)
- Hydrocephalus
- Delayed cerebral ischaemia (common: Day 4-21)
- Seizures
- Neurogenic pulmonary oedema
Types of hydrocephalus ?
- Acute
- Chronic / delayed onset
Mechanism of acute hydrocephalus?
Blockage in the flow of CSF within the ventricles due to intraventricular blood
Mechanism of chronic / delayed onset hydrocephalus?
Reduced absorption of CSF by the arachnoid villi due to fibrosis or inflammation
Mechanism of delayed cerebral ischaemia?
Note: May cause new neurological deficit or reduced GCS
- Due to breakdown of blood products causing vasoconstriction
- High risk day 7-10 post-bleed
Management of delayed cerebral ischaemia?
- Nimodipine
- Endovascular intervention
- Hypertension
Management of Hydrocephalus?
- Extra-ventricular drain
- Shunt (chronically)
Indication for intubation in myasthenia gravis?
- Decline in spirometry
- Hypercapnia
- Respiratory failure
- Inability to clear secretions
- Bulbar dysfunction
Whats is myasthenia gravis?
Disorder of the nuro-muscular junction (AchR antibodies) where autoantibodies block the nicotinic acetylcholine receptor and respiratory failure occurs.
Treatment of Myasthenia gravis?
- Steriods
- Plasma exchange (vs) IVIg
Neuro-protectibve measures in traumatic brain inury ?
- ICU admission
- Intubation
- Serial examination of neuro & pupil
- Head elevation 30-45 degrees
- Analgesia & Sedation
- Temperature management
- Anti-seizure medication
- CPP > 60mmHg
What is central diabetes insipidus?
Deficiency of vasopressin (ADH) due to dysfunction of posterior pituitary or hypothalamus. Inability to absorb water in the collecting duct
Signs & symptoms of Central Diabetes Insipidus?
- Inability to concentrate urine
- Hypernatraemia
- High serum osmolality / Low urinary osmolality
Pathophysiology of DKA?
- Insulin deficiency
- Hyperglycaemia
- Osmotic diuresis
- Hypovolaemia
- Inability to utilise glucose
- Ketosis & acidosis
What is the normal anion gap?
8-12
How do you calculate anion gap?
(Na + K) - (HCO + Cl) =
Causes of NAG metabolic acidosis?
Note: Normally loss of HCO & Na - Tx - NaHCO3
- Hyperchloraemia
- Ileal-conduit
- Diarrhoea, ileostomy & fistula
- Renal tubular acidosis
- Addison’s disease
SGLT2 inhibitors? (Dapagliflozin)
- Associated with HAG metabolic acidosis
- Normal blood sugar (Euglycaemic DKA)
- ## Prevents re-absorption of glucose in the PCT (Blocks SGLT2 proteins)
SGLT2 inhibitors? (Dapagliflozin)
- Associated with HAG metabolic acidosis
- Normal blood sugar (Euglycaemic DKA)
- Prevents re-absorption of glucose in the PCT (Blocks SGLT2 proteins)
- Decreases insulin production & increases glucagon production
- Increases urinary glucose excretion
- Promotes shift from glucose to fat metabolism
Diagnosis & management of hyponatraemia?
See picture attached
Rapid correction requires 1.8% Normal Saline.
Reasons for weakness needing ICU admission?
- Malnutrition / Sepsis
- Myasthenia gravis / Guillain-Barre Syndrome / Botulism / Tetanus
- Respiratory muscles weakness / Weak swallowing
Common causes of weakness?
- Guillain-Barre Syndrom
- Myasthenia Gravis
- Botulism
- Acquired critical illness neuropathy
Differential diagnosis of NM weakness?
- Brainstem
- Spinal cord transverse myelitis
- GBS
- Myasthenia gravis
- Botulism
- Lambert-Eaton Syndrome (lung cancer)
- Steroid myopathy
- Polio
- Periodic paralysis associated with low potassium
- Porphyria
- MND
Clinical signs of bulbar involvement ?
- Reduced cough strength
- Difficulty in swallowing
- Deviation of the tongue on protrusion
- Changes in voice
How to measure the strength of respiratory muscles ?
- Maximal Inspiratory Pressure (manual occlusion of circuit)
- Maximal expiratory pressure
- Forced vital capacity (Spirometry)
How to measure weakness?
- MRC sum score (48 cut-off score)
Components tested in MRC sum score?
- Shoulder forward flexion
- Forearm flexion
- Writst flexion
- Thigh flexion
- Leg extension
- Foot flexion
What is GBS?
- Ascending paralysis
- Associated with Campylobacter diarrhoea (stool)
- It can be immunilogically mediated
- Raised proteins in CSF
- Bulbar palsy + Peripheral weakness
- Associated with Anti-GM1 & Anti-GQ1b
- Loss of reflexes
Management of GBS?
- Consider IVIG
- Plasma exchange
- Supportive care
Signs & symptoms of Miller-Fisher Syndrome?
- Ophthalmoplegia
- Sensory ataxia
- Areflexia
Drugs exacerbating myasthenia gravis ?
- Gentamicin/ Streptomycin
- Tetracycline
- Quinine
- Lignocaine
- Muscle relaxant
What is botulism?
- Associated with drug users
- Visual disturbance
- Diplopia
- Muscle weakness
- Droopy eye-lids
- Pre-synaptic disorder of NMJ
Diagnosis of GBS and other neurological conditions?
- Neurophysiological studies
