Neurological Emergancies Flashcards
What are the signs and symptoms of meningitis?
- generalised headache, gradual onset
- vomiting, neck stiffness, fever, photophobia, altered consciousness
- Kernig’s sign - difficult to bend knee
- non-blanching rash
What the main risk factors for menginitis?
- extremes of age
- diabetes
- immunosuppression
- splenectomy
- alcoholism
- contagious infection
- defects in dura mater
- IV drug abuse
- ## malignancy
What are the most common causative organisms for bacterial meningitis?
- S.pneumoniae
- N. meningitides
- If pregnant or over 60 its more likely to be L. monocytogenes
- recently had surgery = S.aureus
What is the essential treatment if bacterial meningitis is suspected?
- start benzylpenicllins in case its meningococcus
What are the diagnostic tests for meningitis?
- CT indicated if impaired conciousness or focal neurological deficit
- LP to diagnose
- blood tests to look for DIC
What the CSF findings for bacterial meningitis?
- marked elevation of WBCs, mainly polymorphs
- usually elevated protein
- reduced glucose by 50%
What are the CSF findings for viral meningitis?
- WBC elevated, usually lymphocytes
- protein elevated
- normal glucose
What are the CSF findings for TB meningitis?
- elevated WBCs, mixed,
- usually very high protein
- reduced glucose
Malignant CSF findings
WBCs elevated
- often elevated protein
- reduced glucose
How does TB meningitis present?
- insidious onset, however acute presentation can occur if it is complicated by hydrocephalus or vasculitis
- often presents with mild heachace, lesions of CN 6, 3 and 4
- papilloemea, and optic nerve damage
How is TB meningitis treated?
- rifampicin
- isoniazid
- pyrazinamide
- ethambutol
+ steroid over two months
How is viral meningitis treated?
- antipyretics and support until full recovery occurs
What is the treated of the following causes of bacterial meningitis?
- unknown
- meningococcus
- pneumococcus
- s.aureas
- unknown = cefotaximine
- meningococcus = cefotaximine/benzylpenicillin, if allergic chloramphenicol can be used, also give dexamethasone
- pneumococcus = cefotaximine
- s.aureas = rifampicin
What is encephalitis?
What are the symptoms?
- inflammation of the brain parenchyma
- symptoms include headache, fever, focal neurological deficit (dysphagia, weakness), seizures, and encephalopathy
What is the typical cause of encephalitis?
- typically viral in cause, usually HSV and other human herpesvirus
, but can also be due to bacteria such as listeria. Additionally autoimmune is increasing in prevelance
How should HSV encephalitis be treated?
- if suspected acyclovir should commence before investigation
What are the investigations for encephalitis?
- MRI, EEG, LP to culture virus
In all episodes of acute and sub-acute flaccid weakness it is important to…
- monitor respiration in all causes using FVC
What are the causes of acute and subacute neuromuscular failure?
- Nerve lesions include Guillain Barre
- Muscle disease such as inflammatory dermatomyositis and metabolic disorders such as acid maltase
- NMJ pathology includes myasthenia graves and botulism
What are the features of Guillain Barre?
most common cause of acute NMJ weakness, leading to inflammatory polyradiculopathy
- it normally is preceded by respiratory tract infection, generating antibodies that then cross-react with the myelin sheath of neurones
What are the symptoms of GBS?
- parastheisa but little sensory loss, back pain is common
- distal upper and proximal lower limb weakness, facial and bulbar involvement
- respiratory muscles may be involved
What are the investigations for GBS?
- LP, CSF will show elevated protein, and nerve conduction studies
Prognosis in GBS is poor if it is caused by …….. . Why?
Treatment?
campylobacter
- axonal loss, and the time to nadir is short-
Treatment - plasma exchange and IV Ig to accelerate recovery
What is MG?
- an autoimmune condition characterised by the presence of AChR antibodies that block the post-synaptic receptor at the NMJ
- this will present with fatiguable weakness of muscle function with no autonomic features
What are the investigations for MG?
- the ice test (placing ice over brow will decrease ptosis), the tenilson test (give a short active acetyl- cholinesterase inhibitor will increase function) and repetitive stimulate EMG
- blood test should shoe AChR antibodies and/or MuSK antibodies
- CXR and CR thorax can show thymoma
What is the treatment for MG?
Treatment is both symptomatic and immunosuppressive
- long acting acetyl-cholinesterase inhibitors such as pyridostigmine and steroids such as methotrexate and prednisolone
- thymectomy may be indicated
- in acute cases, plasma exahcnage and IV Ig
What is status epilepticus?
- continuous seizures for 30 minutes or serial seizures over 30 minutes without regaining conciseness
What are the causes of status epilepticus?
- non-compliance to anti-epileptics
- alcohol
- drug overdose
- metabolic disorders
- hypoxia
- tumour
- trauma
How is status epilepticus traeted?
- manage ABCDE
- cause of precipitating factor should be addressed, this include 50ml of 20% IV glucose if BM is kit
- 1-2mg lorazepam
- if not effective then phenytoin and fosphentoin can be used
- if the patient remains in status they need to be paralysed using thiopentone/propofol and supported in ITU
How should status epileptics be investigated?
urgent biochemistry, haematology, BMs,
- AED, calcium and Mg levels measured
- blood gases taken
CT scanning, LP, EEG monitoring
What are the causes of coma?
Neurological - infection, neoplasm
Systemic - metabolic, endocrine, infection
Extrinsic - drugs, toxins
What is the difference in signs and symptoms between cord compression and cauda equina compression?
- cord compression - weakness is asymmetrical and reflexes are absent
- cauda equina - weakness is equal and bilateral and reflexes are brisk
