Neuro Flashcards
Multi-system atrophy?
o Rare condition where the neurons of multiple systems in the brain degenerate, affects the basal ganglia as well as multiple other areas.
o The degeneration of the basal ganglia which can occur in this disease process present with Parkinonism
o The degeneration in other areas lead to conditions such as Autonomic dysfunction (post hypotension, constipation, abnormal sweating and sexual dysfunction) and cerebellar dysfunction (causing ataxia)
• Dementia with Lewy bodies:
o This is a type of dementia that is associated with features of parkinsonism.
o Leads to progressive cognitive decline.
o Associated visual hallucinations, delusions, disorders of REM sleep and fluctuating consciousness.
What do you need to give with levodopa?
peripheral decarboxylase inhibitors- prevent it being broken down before it reaches the brain
COMT inhibitors?
o Used in PD
The main example of these is entacapone.
o These are inhibitors of catechol-o-methyltransferase, an enzyme that metabolises levodopa in the body and the brain.
o Entacapone is taken with levodopa (and a decarboxylase inhibitor) to slow breakdown of the levodopa in the brain. Increasing the lengths of affect it has
Progressive Supranuclear palsy
o Aka- steele-richardson-olszewski syndrome o Features; Impairement of the vertical gaze (difficulty reading or climbing stairs) Parkinsonism Falls Slurring of speech Cognitivie impairement o Management: Poor response to levodopa
What chromosome and gene is affected in huntington’s?
ch4
o MUTATION on ch4 leading to a repeated CAG sequence Huntingtin gene (HTT) (Trinucleotide repeat)
First line generalised seizures?
Sodium valproate, usually second line is lamotrigine
EEG finding for west syndrome?
hypsarrithmia
Hypsarrhythmia is very chaotic and disorganized brain electrical activity with no recognizable pattern, whereas a normal brain electrical activity shows clear separation between each signal and visible pattern. It is an abnormal interictal pattern, consisting of high amplitude and irregular waves and spikes in a background of chaotic and disorganized activity seen on electroencephalogram (EEG), and frequently encountered in infants diagnosed with infantile spasms, although it can be found in other conditions
Lennoux-Gastaut syndrome:
o Need the 3 findings to diagnose:
Atypical absences, falls and jerks (multiple seizure types)
90% have a moderate to severe handicap
EEG- abnormally slow basic rhythm interrupted with Slow spike and wave pattern.
How is status epilepticus defined?
• Defined as seizures lasting more than 5 mins or more than 3 seziures in an hour.
EEG: 3Hz generalized, symmetrical
Absence seizures
3 Hz spike-and-wave discharge
(petit mal)
Ix after seizure?
Blood tests including serum calcium, and an ECG (rhythm, conduction abnormalities, QT interval) are necessary in most patients following an episode of loss of consciousness
MRI in most after first seizure- particularly focal onset and elderly
What are the 4 meds used for neuropathic pain?
Amitriptyline is a tricyclic antidepressant
Duloxetine is an SNRI antidepressant
Gabapentin is an anticonvulsant
Pregabalin is an anticonvulsant
Typical features of neuropathic pain?
Burning Tingling Pins and needles Electric shocks Loss of sensation to touch of the affected area
Features of complex regional pain syndrome?
Occurs after local injury/ surgery to an area, within this area:
Features progressive, disproportionate symptoms to the original injury/surgery allodynia temperature and skin colour changes oedema and sweating motor dysfunction
Manage like other neuropathic pain
Causes of CNVII LMN (excluding bells and RHS)?
• Infection: o Otitis media o Malignant Otitis externa o HIV o Lyme disease • Systemic disease: o DM o Sarcoidosis o Leukaemia o MS o GBS • Tumours: o Acoustic neuroma o Parotid tumours o Cholesteatomas • Trauma: o Direct nerve damage o Damage in parotid surgery o Base of skull fracture.
Mx of ramsay hunt syndrome?
o Treat with Prednisolone and Aciclovir
Ab in myasthenia Gravis?
o Acetylcholine receptor Ab (Ach-R) Ab (85%)
o Muscle-specific kinase (MuSK) Ab (10%)
o LRP4 (less than 5%)
Typical features of myasthenia gravis?
o Diploplia- Extraocular muscle weakness causing double vision
o Ptosis- Eyelid weakness leading to drooping of the eyelid
o Weakness in the facial movements
o Issues swallowing
o Fatigue in the jaw when chewing
o Slurred speech
o Progressive weakness in repetitive movements
The edrophonium test?
• The edrophonium test can be helpful if there is a doubt re diagnosis
o Patients are given an IV dose of edrophonium (or neostigmine).
o Normally these cholinesterase enzymes in the neuromuscular joints break down Ach.
o Edrophonium stops this process to stop the breakdown of Ach.
o This leads to raise in Ach at the NM joint.
o It briefly relieves the weakness- diagnosis of MG
Treatment of myasthenia gravis?
Treatment options:
• Reversible acetylcholinesterase inhibitors (usually pyridostigmine or neostigmine) increases the amount of Ach in the neuromuscular joints and improve the symptoms
• Immunosuppression (e.g. prednisolone or azathioprine) supresses the Ab
• Thymectomy can improve symptoms even in patients without a thymoma
Monoclonal Ab:
• Rituximab: Is a monoclonal Ab that targers B cells and reduces the production of Ab. (on NHS if other meds don’t work)
• Eculizumab: A monoclonal Ab that targets complement protein C5. Could prevent the complement activation and destruction of the Ach receptors. Ongoing research and debate if it is good enough to use on NHS.
Myasthenic crisis management?
o Immunomodulatory therapies such as IV Ig and plasma exchange
• Patients may need non-invasive ventilation with BiPAP or full intubation and ventilation.
What is a myasthenic crisis?
worsening of symptoms, often triggered by another illness such as a RTI
EMG findings for MG?
Decrement and increment. In myasthenia gravis, a
characteristic decrement in evoked muscle action
potential follows repetitive motor nerve stimulation.
The reverse occurs, i.e. increment, following repetitive
stimulation in LEMS,
Causes of GBS?
o Campylobacter Jejuni
o CMV
o Epstein Barr virus
Criteria for diagnosis neurofibromatosis type 1?
o There are clear diagnostic criteria for NF1 based on the classical features of the condition. There must be at least 2 of the 7 features to indicate a diagnosis. You can remember the mnemonic CRABBING.
C- Café au lait spots (6 or more) measuring >5 mm in children or >15 mm in adults
R- Relative with the NF1 gene
A- Axillary or inguinal freckles
BB- Bony dysplasia such as Bowing of a long bone or sphenoid wing dysplasia
I- Iris hamartomas (Lisch nodules) (2 or more) are yellow brown spots on the iris
N- Neurofibromas (2 or more) or 1 plexiform neurofibroma
G- Glioma of the optic nerve
NFT1 gene?
o The neurofibromatosis type 1 gene is found on chromosome 17.
o It codes for a protein called neurofibromin, which is a tumour suppressor protein.
o Inheritance of this mutation follow an AD pattern.
Complications of NFT1?
• Complications:
o Migraines
o Epilepsy
o Renal artery stenosis causing hypertension
o Learning and behavioural problems (e.g. ADHD)
o Scoliosis of the spine
o Vision loss (secondary to optic nerve glioma)
o Malignant peripheral sheath tumours
o GI stromal tumours
o Brain tumours
o Spinal cord tumours with associated neurology (paraplegia)
o Increased risk of cancer (e.g. breast cancer)
o Leukaemia
Neurofibromatosis Type 2:
• The neurofibromatosis type 2 gene is found on chromosome 22 .
• It codes for a protein called merlin, which is a tumour suppressor protein particularly important in schwann cells.
• Mutations in this gene lead to the development of schwannomas (benign nerve sheath tumours of the Schwann cells).
• Inheritance is autosomal dominant.
• NFT2 is most associated with acoustic neuromas.
• These are tumours of the auditory nerve innervating the ear.
• Symptoms are:
o Hearing loss
o Tinnitus
o Balance issues
• Schwannomas can also develop in the brain and spinal cord with symptoms based on the location of the lesion.
• Surgery can be used to resect them but there is a risk of permanent nerve damage.
What is the classical presentation of idiopathic normal pressure hydrocephalus?
Reversible cause of dementia in elderly patients:
- urinary incontinence
- dementia and bradyphrenia
- gait abnormality (may be similar to Parkinson’s disease)
Imaging findings in normal pressure hydrocephalus?
hydrocephalus with an enlarged fourth ventricle
in addition to the ventriculomegaly there is typically an absence of substantial sulcal atrophy
Management of NPH?
- ventriculoperitoneal shunting
- around 10% of patients who have shunts experience -significant complications such as seizures, infection and intracerebral haemorrhages
2 reversible causes of dementia picked up on imaging (MRI/CT)?
NPH, SDH
What EEG changes would you find in CJD?
• EEG- biphasic, high amplitude sharp waves - unique
Myopathic EMG?
Myopathy. Short-duration spiky polyphasic muscle
action potentials are seen. Spontaneous fibrillation is
occasionally recorded.
Myotonic discharges. A characteristic high-frequency
whine is heard.
Decrement and increment. In myasthenia gravis, a
characteristic decrement in evoked muscle action
potential follows repetitive motor nerve stimulation.
The reverse occurs, i.e. increment, following repetitive
stimulation in LEMS, page 1152.
In denervation, profuse fibrillation potentials are seen.
