Neuroscience Flashcards
Cause of Bell’s palsy?
Idiopathic
• 60% preceded by upper respiratory tract infection
Symptoms and signs of Bell’s palsy?
- Prodromal pre-auricular pain
- Unilateral facial weakness and drop
- Hyperacusis (stapedius paralysis)
- Tearing or drying of exposed eye
• Bell’s phenomenon - eyeball rolls up but eyelids remain open when trying to close their eyes
Investigation for Bell’s palsy?
- Clinical diagnosis
- Serology for Borrelia (Lyme disease)
- EMG, ENoG
- Glucose - exclude DM
- MRI - check for SOL
Management for Bell’s palsy?
- Corticosteroid - oral prednisolone within 72 hours
• eye protection - Valaciclovir
- Surgical decompression
Differentiation of CNS tumours
Low-grade
• Grows slowly
• May or may not be treated
• e.g. meningioma
High-grade
• Grows rapidly and aggresively
• e.g. glioma, medulloblastoma
Presentation of CNS tumours?
- Headache - worse in morning when lying down
- Seizures
- Progressive focal neurological deficits
- Papilloedema
- Behavioural symptoms
Investigation of CNS tumours?
- CT - quicker
- MRI - gold standard (diagnostic)
- Histology
- Lumbar puncture
Most common cause of encephalitis in UK?
HSV-1
Signs of encephalitis?
- Bizzare encephalopathic behaviours
- Seizures
- Pyrexia
- Signs of meningism (neck stiffness, photophobia, Kernig’s test positive)
- Signs of raised ICP
Investigations for encephalitis?
- CSF - lymphocytosis, elevated protein
- PCR - HSV
- CT
- MRI - better
- EEG
Classify the different types of seizure?
Partial - focal onset
• Simple - consciousness not affected
• Complex - consciousness affected
Generalised - whole brain • Tonic-clonic - LOC, stiff then jerk • Absence • Myoclonic - sudden jerk • Atonic
Investigations for epilepsy?
- Bloods - transient increase in prolactin
- EEG
- CT/MRI
Management of status epilepticus?
(seizure >30min but treatment initated 5-10mins)
- Resus and ABC
- Thiamine + glucose (if hypoglycaemic)
- IV lorazepam
- IV phenytoin
- IV phenobarbital
- GA
Management of partial and generalised seizures?
> 2 unprovoked seizures
Partial
1. Carbamazepine
Generalised
1. Sodium valproate or Lamotrigine
Start with one, slowly build up dose. If ineffective, switch to next drug and withdraw first drug when second is established.
Location of epi/extradural, subdural and subarachnoid haemorrhage?
- Epidural - between dura mater and skull
- Subdural - between dura mater and arachnoid mater
- Subarachnoid - between arachnoid mater and pia mater
Symptoms and signs of epidural haemorrhage?
- Head injury with temporary LOC
- Lucid interval
- GCS deterioration and rising ICP
- Cushing’s reflex - HTN, bradycardia, irregular breathing
What is Guillain-Barre syndrome?
- Acute inflammatory demyelinating polyneuropathy
* Antibodies after recent infection react with self-antigen on myelin
Presentation of GB syndrome?
- < 1 months of ascending symmetrical limb weakness (lower > upper)
- Ascending paraesthesia
- Impaired sensation
- Autonomic dysfunction - sweating, raised pulse, arrhythmias
- LMN signs
- Facial nerve weakness
- Type II resp failure
Miller-Fisher - eyes affected first, descending, anti-GQ1b
Investigation for GB syndrome?
- Nerve conduction studies - slow
- LP - elevated protein
- Spirometry - reduced FVC
Causes and presentation of Horner’s syndrome?
- Brainstem - demyelination, stroke
- Thoracic outlet - Pancoast’s tumour (apical lung)
- Disruption to nerve at internal carotid artery entry into skull
- Ptosis
- Miosis
- Anhydrosis
Cause of Huntington’s disease?
- Autosomal dominant CAG repeat on Chr 4
* Atrophy - loss of striatum and cortex
Signs of Huntington’s?
(• Dementia) • Chorea • Dysarthria • Slow voluntary saccades • Supranuclear gaze restriction
Investigation for Huntington’s?
- Genetic - CAG repeat test (>39 repeats)
* MRI/CT - butterfly dilation of lateral ventricles, symmetrical atrophy of striatum
2 main types/causes of hydrocephalus?
Obstructive
• Impaired outflow of CSF from ventricular system
• e.g. Lesions of 3rd/4th ventricle or aqueduct
Non-obstructive
• Impaired CSF reabsorption into subarachnoid villi
• e.g. meningitis
Symptoms and signs of obstructive hydrocephalus?
- Acute drop in conscious level
- Diplopia
- Papilloedema
- 6th nerve palsy (diplopia), - longest intracranial path
- Neonates: increased head circumference, sunset sign
Symptoms and signs of normal pressure hydrocephalus (non-obstructive)?
Triad:
• Dementia
• Gait apraxia
• Urinary incontinence
• Hyperreflexia
Investigations for hydrocephalus?
- CT head (first line but not diagnostic by itself)
- CSF - ventricular drain or LP
- LP - contraindicated if raised ICP, therapeutic in normal pressure hydrocephalus
Which layers around the brain are inflamed in meningitis?
Pia and arachnoid mater
Most common cause of meningitis?
- Neisseria meningitidis
- Streptococcus pneumonia (more common in > 60)
(• Group B strep. most common in neonates)
Signs of meningitis?
Meningism
• Photophobia
• Neck stiffness
• Kernig’s sign (knee extension with flexed hips)
• Brudzinski’s sign (hip flexion with flexed neck)
Infection • Pyrexia • Tachycardia • Hypotension • Skin rash • Altered mental state
Investigations for meningitis?
- CT head - exclude lesion or raised ICP
2. CSF (LP) - high WCC (pleocytosis) - most important, can be no.1 if no focal neurology/raised ICP