Neurology Flashcards
32 y male Lt LL weakness
weight loss, epistaxis
MRI brain showed bilateral multiple hyperintense demyelinating lesions
history of travel
Progressive multifocal leukoencephalopathy (PML)
widespread demyelination
due to infection of oligodendrocytes by JC virus (a polyoma DNA virus)
symptoms, subacute onset : behavioural changes, speech, motor, visual impairment
CT: single or multiple lesions, no mass effect, don’t usually enhance. MRI is better - high-signal demyelinating white matter lesions are seen
2-week history of involuntary hand flexion preventing writing, with a normal neurological exam
writers cramp, a focal dystonia characterised by flexion, extension or rotation of the muscles of the hand. The underlying pathophysiology is unclear but is thought to relate to a change in the plasticity of cortical networks.
2 hours proximal MCA
management
Thrombectomy in occlusion of proximal anterior circulation:
- 6 h of symptom + (IV Thrombolysis if within 4.5 h)
- Last known to be well between 6 and 24 h previously (including wake-up strokes)
Thrombectomy in occlusion of the proximal posterior circulation (basilar or posterior cerebral artery)
- Last known to be well up to 24 h previously (including wake-up strokes) + IV Thrombolysis (if within 4.5 h)
Dementia, which is likely Parkinson’s disease dementia (PDD), as he has Parkinson’s disease and is experiencing progressive cognitive decline. Management
Most common treatments are acetylcholinesterase inhibitors.
Rivastigmine is one of the first-line treatments for cognitive symptoms in Parkinson’s disease dementia.
Donepezil is also used for dementia, but rivastigmine is generally considered more effective in Parkinson’s dementia.
Patient is presenting with symptoms and signs consistent with myasthenia gravis
Association
Investigation
Management
MG crisis
Associations
- thymomas in 15%
- autoimmune disorders: pernicious anaemia, autoimmune thyroid disorders, rheumatoid, SLE
- thymic hyperplasia in 50-70%
Investigations
- single fibre electromyography: high sensitivity (92-100%)
- CT thorax to exclude thymoma
- CK normal
- antibodies to acetylcholine receptors
positive (85-90%), about 40% are positive for anti-muscle-specific tyrosine kinase antibodies
- Tensilon test: IV edrophonium reduces muscle weakness temporarily - not commonly used any more due to the risk of cardiac arrhythmia
Management
- long-acting acetylcholinesterase inhibitors
(pyridostigmine)
- immunosuppression:
prednisolone initially, then, azathioprine, cyclosporine, MMF
- thymectomy
Management of myasthenic crisis:
- plasmapheresis
- intravenous immunoglobulins
Natalizumab is a humanised monoclonal antibody against the cell adhesion molecule 4-integrin and is licensed as a monotherapy for the treatment of multiple sclerosis relapse.
Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection caused by the JC virus that only occurs in patients who are immunocompromised and has a risk of 2.1 in every 1,000 using natalizumab.
Gynecomastia + Headache + Erectile dysfunction
Hypogonadism secondary to prolactinaemia would be associated with low testosterone and low or normal FSH and LH
Causes of hypogonadism in men
- primary (disease of the testes)
childhood mumps
- secondary (disease of the hypothalamus or pituitary)
Klinefelter syndrome, Kallman syndrome
Investigation: S. Prolactin
Hereditary sensorimotor neuropathy (HSMN)
a relatively new term which encompasses Charcot-Marie-Tooth disease (also known as peroneal muscular atrophy). Over 7 types have been characterised - however only 2 are common to clinical practice
HSMN type I: primarily due to demyelinating pathology
HSMN type II: primarily due to axonal pathology
HSMN type I AD due to defect in PMP-22 gene (which codes for myelin)
- features often start at puberty
- motor symptoms predominate
- distal muscle wasting, pes cavus, clawed toes
- foot drop, leg weakness often first features
Notes on Palliative care prescribing for pain
if no comorbidities use 20-30mg of MR a day with 5mg morphine for breakthrough pain.
Oral MR morphine prefer to transdermal patches
Laxatives in all patients initiating strong opioids
Nausea is often transient. If it persists antiemetic
Drowsiness is usually transient - dose adjustment
the breakthrough dose of morphine is one-sixth the daily dose of morphine
CKD: oxycodone is preferred to morphine in palliative patients with mild-moderate renal impairment, if severe alfentanil, buprenorphine and fentanyl are preferred
Metastatic bone pain may respond to strong opioids, bisphosphonates, radiotherapy or Denosumab.
When increasing the dose of opioids the next dose should be increased by 30-50%.
Conversion of oral codeine/tramadol to oral morphine (Divide by 10)
Oral morphine to SC morphine Divide by 2
Oral morphine to SC diamorphine Divide by 3
Oral oxycodone to SC diamorphine Divide by 1.5
Oral morphine to Oral oxycodone (Divide by 1.5-2)
Oxycodone generally causes less sedation, vomiting and pruritis than morphine but more constipation.
Transdermal fentanyl 12 microgram patch = 30 mg oral morphine daily
Transdermal buprenorphine 10 microgram patch = 24 mg oral morphine daily
Cryptococcus neoformans is an encapsulated yeast that is found in the environment and is a common cause of meningitis in patients with HIV with a CD4 count of less than 100
Most common fungal infection of CNS
Headache, fever, malaise, nausea/vomiting, seizures, focal neurological deficit
CSF (high opening pressure, elevated protein, reduced glucose, normally a lymphocyte predominance but in HIV white cell count many be normal, India ink test positive 70-90%)
CT: meningeal enhancement, cerebral edema
Meningitis is typical presentation but may occasionally cause a space-occupying lesion
Pyrexia and opoid toxicity
Transdermal fentanyl absorption is increased by heat (e.g. hot water bottle) or pyrexia, potentially leading to opioid toxicity
Clozapine (Atypical antipschotic)
Adverse effects of clozapine
- agranulocytosis (1%), neutropenia (3%), eosinophilia
- reduced seizure threshold - can induce seizures in up to 3% of patients
- constipation (increased weight gain)
- myocarditis: a baseline ECG should be taken before starting treatment (prolongation of the QTc)
- hypersalivation (reduced insulin tolerance)
