Core: Neurology Flashcards
MND Aetiology
- Often unknown
- Mutations in SOD-1, TDP43, FUS
- Familial - C9orf72 w/ hexanucleotide repeat GGGGCC on chromosome 9
MND pathophysiology
- Oxidative damage to neurones
- Damaged motor neurones then die.
- Progressive weakness UMN and LMN
MND Fasciculation causes
- Abnormally large motor units due to MN death, fewer nerve fibres to innervate large units.
MND classic presentation
- Weakness + wasting + fasciculation
- UMN and LMN signs = wasted muscle + brisk reflexes.
MND other presentations
- Progressive muscular atrophy - purely LMN. Starting in one limb and progressively involving others.
- Progressive bulbar and pseudobulbar palsy - lower CN nuclei involvement. Dysarthria, dysphagia, nasal regurgitation and choking. Tongue fasciculations and emotional incontinence.
- Primary lateral sclerosis - Slow progressive tetraparesis and pseudobulbar palsy.
Patient - Over 40, stumbling spastic gait, foot drop, proximal myopathy, weak grip, fasciculations
MND
MND Ix
- Often clinical
2. EMG
MND Rx
- Riluzole - antiglutaminergic
- Symptom management; Drooling = propantheine, amitriptyline
Dysphagia = blend foods
Pain = analgesic ladder
Respiratory distress = NIV
Patient - Any age, acute onset headache, neck stiffness and fever. ?purpuric rash
Meningitis
Meningitis Aetiology
- Bacteria - Meningococcus, S.pneumoniae, S.aureus, GBS, TB, listeria, E.coli
- Viral - Enterovirus, mumps, HSV, HIV, EBV
- Fungal - Crytococcus (HIV), candida.
- IT drugs
Meningitis Pathology
- Inflammation of the meninges
- Transmission often via direct extension from ear, nose, throat, blood or direct trauma.
- Pia-arachnoid space becomes congested w/ neutrophils and a layer of pus forms.
- Adhesions can be formed which can cause CN palsies.
Meningitis Presentation
- Headache
- Neck stiffness
- Fever
- Photophobia
- N&V
- Rash
- SHOCK
- Kernig’s sign.
- Bulging fontanelle
Meningitis Ix
- Clinically suggested
- Sepsis 6
- FBC
- LP if not contraindicated
Meningitis Rx
- In the community = 1.2g benpen stat or 1g cefotaxime IM
- Sepsis 6
- Cefotaxime IV 2g/6hr + amoxicillin (if listeria suspected)
- Rx empirically according to MC&S
- Notify PHE
Meningitis Contact prophylaxis
- Rifampicin 600mg/12hr 2 days or ciprofloxacin 500mg PO 1 dose
Patient - Any age, meningism, no rash, behavioural changes, seizures and focal neurology
Encephalitis
Encephalitis Aetiology
- Viral - HSV, VZV, Enterovirus, adenovirus. SSPE following measles.
Encephalitis Pathology
- Virus replicates in the bloodstream.
- Enters neural cells and causes congestion and disruption of function within the brain.
Encephalitis Presentation
- Meningism (often less severe than meningitis)
- Personality and behavioural change
- Viral prodrome
- lethargy
- Seizure
- CN issues
Encephalitis Ix
- MRI brain - parenchymal inflammation and swelling.
- EEG - Periodic sharp and slow wave complexes
- CSF - raised lymphocytes
- Viral PCR.
Encephalitis Rx
- Immediate IV acyclovir (10mg/kg 3xdaily for 14-21 days)
2. Symptom control –> Seizure
Patient - Headaches (worse on coughing, leaning forward), vomiting, new onset seizure, progressive defect.
Mass lesion in the brain
Mass lesion aetiology
- Commonly metastasis from the bronchus, breast, stomach, prostate, thyroid and kidney.
- Primary = astrocytoma, oligodendroglioma, cerebral lymphoma
- Benign = meningioma, neurofibroma.
Mass lesion pathology
- Mass effect.
- As the lesion grows, its shifts structures within the brain creating pressure against the cranium.
- Direct infiltration of brain tissue.