Neurology Flashcards
The presence of headaches, nausea, and transient vision loss in an obese woman with an unremarkable MRI and a raised opening pressure on lumbar puncture indicates what disease?
Idiopathic intracranial hypertension
How do you diagnose IIH?
1st - MRI to look for any features - if unremarkable then 2nd - LP for opening pressure
Management of IIH
weight loss, acetazolamide therapy
What group of ppl do you suspect IIH in
Obese females
what do you suspect in patients with headaches, nausea and vision loss
SOL, tumour, IIH
How do you differentiate between syringomyelia and degenerative cervical myelopathy
Cervical myelopathy - sensory loss, neck stiffness, LMN signs at level of lesion and UMN signs below the level of the lesion
Synringomyelia - Typically presents with bilateral loss of sensory function limited to the upper extremities
what is the management of suspected cervical myelopathy
Immediate referral to neurosurgery for decompression as the damage can be permanent
What blood vessel is affected in EDH?
Middle meningeal artery
What are the specific side effects of ergot derived dopamine agonists such as bromocriptine, cabergoline
Pulmonary, retroperitoneal and cardiac fibrosis - need echo, ESR, creatinine and CXR
What are the side effects of dopamine agonists
impulse control disorders (gambling) and excessive daytime somnolence
What are the side effects of levodopa
dyskinesia (involuntary writhing movements), ‘on-off’ effect, dry mouth, anorexia, palpitations, postural hypotension, psychosis, drowsiness
no use in neuroleptic induced parkinsonism
WHat is the defect seen in cranial nerve IV palsy
Eye deviated upwards and rotated outwards
What is the difference between communicating and non-communicating hydrocephalus
Communicating - There is a problem with the secretion or absorption
Non-communicating - there is a problem of flow from the ventricles to the subarachnoid space
What are the special features of cluster headaches?
Cluster headaches are typically characterized by unilateral and severe headaches often associated with autonomic symptoms such as ptosis, miosis, conjunctival injection and excessive lacrimation.
Why are triptans contraindicated in patients with heart problems?
It should be avoided in patients with a history of coronary artery disease (CAD) as it has the potential to cause coronary vasospasm.
What are the antibodies detected in myanesthia gravis
anti-achR antibodies
anti-muscle specific kinase (anti-MUSK) - seronegative
What are the diagnostic tests for MG?
1st line - blood antibodies (anti-achR and anti-MUSK)
2nd- EMG - electromyography - decremental response to repetitive nerve stimulation
What is the most common sequelae of meningitis
sensorineural hearing loss (most common)
What is the pathophysiology of Narcoplexy?
Loss of lateral hypothalamic neurons, which produce orexin A and orexin B (i.e., hypocretin-1 and hypocretin-2) → severe orexin deficiency → dysregulation of sleep-wake cycles
Orexin is a neurotransmitter essential for promoting wakefulness and inhibiting REM sleep.
What are the characteristic features of narcoplexy?
- typical onset in teenage years
- hypersomnolence - excessive daytime sleepiness despite night sleep
- cataplexy (sudden loss of muscle tone often triggered by emotion - laughing or crying)
- sleep paralysis
- vivid hallucinations on going to sleep or waking up
what is the investigation for narcoplexy?
multiple sleep latency EEG
What is the treatment for narcoplexy?
daytime stimulants (e.g. modafinil) and nighttime sodium oxybate
What is the precaution to be taken with sodium oxybate?
Sodium oxybate should never be taken with alcohol or other CNS depressants because doing so may cause life-threatening respiratory depression!
What do you suspect in Bilateral acoustic neuromas ?
Neurofibromatosis type II
What are the most common primary cancers with brain mets?
lung, breast, kidney, melanoma and colorectal cancers metastases.
What is the first thing to do in a patient with a newly discovered tumour?
imaging (CT chest, abdomen and pelvis).
What is the management for acoustic neuroma?
Immediate referral to ENT
How do you differentiate the acute vs chronic subdural haemorrhage?
Acute- CT imaging is the first-line investigation and will show a crescentic collection, not limited by suture lines. They will appear hyperdense (bright) in comparison to the brain. Large acute subdural haematomas will push on the brain (‘mass effect’) and cause midline shift or herniation.
Chronic- On CT imaging they similarly are crescentic in shape, not restricted by suture lines and compress the brain (‘mass effect’). In contrast to acute subdurals, chronic subdurals are hypodense (dark) compared to the substance of the brain.
What is the first line medication for migraine
Triptans + NSAIDs / Triptans + Paracetamol
What is the prophylaxis medication for migraine?
Propanolol + Topiramate
What prophylaxis is preferred in women of child bearing age?
Propanolol is preferred
Topiramate - teratogenic effects and it can reduce the effects of hormonal contraceptives
How do you differentiate Multiple system atrophy from Parkinson’s disease?
Parkinsonism with associated autonomic disturbance (atonic bladder, postural hypotension) points towards Multiple System Atrophy
Key features to help you differentiate are the presence of unilateral symptoms, and more severe/early onset autonomic dysfunction (postural hypotension/erectile dysfunction).
How do you differentiate parkinson plus syndromes from parkinson’s disease?
- Poor response to levodopa
- Early involvement of the autonomic nervous system (orthostatic hypotension, impotence, incontinence, anhidrosis)
- Early onset of postural instability with frequent falls = although common in parkinsons, it occurs late
- Dementia
What is Multiple system atrophy?
Multiple system atrophy (MSA) is a rare, adult-onset, neurodegenerative disease characterized by neuronal degeneration in the substantia nigra
What are the subtypes of multiple system atrophy MSA?
MSA-P: predominantly parkinsonian features
MSA-C: predominantly cerebellar features (ataxia, tremor, dysarthria)
How do you differentiate multiple system atrophy from lewy body dementia?
MSA - Autonomic dysfunction with urogenital problems (othostatic hypotension, erectile dysfunction and atonic bladder)
Lew body dementia- visual hallucinations
What could be the causes of postural hypotension in a man with diagnosed parkinsons disease
Could be due to parkinsons disease progression
Could be a side effect of co-careldopa
Could be a parkinson’s plus syndrome (presents earlier)
What is neuroleptic malignant syndrome?
Life-threatening neurological disorder usually associated with antipsychotics that is characterized by a tetrad of features (fever, muscle rigidity, autonomic instability, and mental status changes) as well as rhabdomyolysis and elevated creatine kinase
What are the features of neuroleptic malignant syndrome?
- Fever,
- Muscle rigidity
- Autonomic instability - hypertension, tachycardia and tachypnoea
- Mental status changes (delerium)
FALTER”: Fever, Autonomic instability, Leukocytosis, Tremor, Elevated enzymes (creatine kinase, transaminases), Rigidity
What causes Neuroleptic malignant syndrome?
Use antipsychotics, dopaminergic drugs (eg. levodopa)
What is the important complication in NMS?
ACUTE KIDNEY INJURY secondary to rhabdomyolsis in severe cases
What is the diagnostic testing of NMS?
↑↑ Creatine kinase
Leukocytosis
↑ Transaminases
What is the management of the NMS?
- Discontinue/Stop the antipsychotic drugs
- IV fluids if in renal failure
- Dantrolene (ryanodine receptor antagonist) - might be helpful (still dubious)
- bromocriptine, dopamine agonist, may also be used
When does NMS present?
Hours to days after the start of a new antipsychotic drug
What type of drug is ondensetron and where does its action occur?
Serotonin receptor antagonists
(5-HT3 antagonists)
- Strong central antiemetic effect at the area postrema
- Peripheral antiemetic effect via inhibition of the vagus nerve
What are the settings where ondensetron are used?
- Management of generalised nausea
2. Management of chemotherapy-related nausea.
What are the side effects of odensetron?
Headaches
constipation is common
prolonged QT interval
What is the mechanism of action of Procyclidine and when is it used in Parkinsons’s disease?
Antimusucranic - block cholinergic receptors
Now used more to treat drug-induced parkinsonism rather than idiopathic Parkinson’s disease
Help tremor and rigidity
e.g. procyclidine, benzotropine, trihexyphenidyl (benzhexol)
What are the side effects specifically in ergot derived dopamine agonists such as cabergoline and bromocriptine?
pulmonary, retroperitoneal and cardiac fibrosis
echocardiogram, ESR, creatinine and chest x-ray should be obtained prior to treatment and patients should be closely monitored
What are the general side effects of dopamine agonists?
- Patients should be warned about the potential for dopamine receptor agonists to cause impulse control disorders and excessive daytime somnolence
- More likely than levodopa to cause hallucinations in older patients. Nasal congestion and postural hypotension are also seen in some patients
What are the possible aetiologies of restless leg syndrome?
Primary: positive family history in 50% of patients with idiopathic RLS
Secondary:
- iron deficiency with or without anaemia
- uraemia - end stage renal disease
- diabetes mellitus - peripheral neuropathy
- pregnancy
- Inflammatory conditions: celiac disease, rheumatoid arthritis, inflammatory bowel diseases
What are the clinical features of restless leg syndorme
- A recurrent urge to move the legs that is typically relieved by movement and worsened by rest. (Akathisia)
Often worse in the evening and at night. May occur exclusively at night. - Paraesthesias e.g. ‘crawling’ or ‘throbbing’ sensations
- movements during sleep may be noted by the partner - periodic limb movements of sleeps (PLMS)
Management of restless leg syndrome
- simple measures: walking, stretching, massaging affected limbs
- treat any iron deficiency
- Dopamine agonists are first-line treatment (e.g. Pramipexole, ropinirole)
- Benzodiazepines
- Gabapentin
What are drugs that make MG worse?
penicillamine quinidine, procainamide beta-blockers lithium phenytoin antibiotics: gentamicin, macrolides, quinolones, tetracyclines
What is the difference between the effects of suxamethonium and rocuronium in MG
Suxamethonium = succinylcholine (depolarizing NMA) It is a strong Ach agonist and produces sustained depolarization, so much so that muscle cannot repolarize to depolarize, so patient cannot have further muscle contraction
It acts by binding to and activating the receptor, at first causing muscle contraction, then paralysis.
Suxamethonium needs to bind to the receptors AND depolarise the muscle to work, and as in MG they’re being taken up by antibodies there’s fewer places to bind and so more Sux will be needed to depolarise. Thus it cannot be used in the patients as a neuromuscular blocker in patients with NMD
Rocuronium instead works by binding to the receptors and stopping acetylcholine from binding, BUT does not need to depolarise the cell. This basically means it’s doing the same thing as the MG antibodies and so you need less Roc as it’s already having it’s work done by the MG
What is the aetiology of essential tremor?
Positive family history (50–70%; autosomal dominant inheritance) or sporadic
What are the features of essential tremors?
postural tremor: worse if arms outstretched
improved by alcohol and rest
most common cause of titubation (head tremor)
What is the management of essential tremors?
1st line - propanolol
2nd line- primidone
When do you treat for status epilepticus?
If the seizure hasn’t stopped for >5 mins, then it is unlikely to stop. so despite the definition being 30 mins, treat if seizure is unstopped after 5 mins
What is the treatment protocol for status epilepticus?
ABC
- Benzodiazepines such as diazepam or lorazepam (diazepam- rectally, lorazepam - IV - repeated after 10-20mins)
- If ongoing (or ‘established’) status it is appropriate to start a second-line agent such as phenytoin or phenobarbital infusion
- If no response (‘refractory status’) within 45 minutes from onset, then the best way to achieve rapid control of seizure activity is induction of general anaesthesia.
What are the side effects of phenytoin?
PHENYTOIN: cytochrome P-450 interaction, Hirsutism, Enlarged gums (gingival hyperplasia), Nystagmus, Yellow-browning of skin (melasma), Teratogenicity, Osteomalacia, Interacts with folate, Neuropathy
Can’t PHEEL-y-TOE-n
Inducer of the P450 system
which condition is commonly associated with MND
Frontotemporal dementia and MND are linked by the mutation in the same gene.
C9orf72 gene mutation is associated with both ALS and frontotemporal dementia
What is the pathophysiology of Lambert-Eaton syndrome
Autoantibodies are directed against presynaptic voltage-gated calcium channels → impaired acetylcholine release in the NMJ.
What is associated with Lambert-Eaton syndrome?
small-cell lung carcinoma (in ⅔ of LEMS cases)
How do you differentiate drug induced parkinsons from idiopathic parkinsons disease?
Symmetrical tremor, young age - drug induced
Asymmetrical tremor - Idiopathic
What are the causes of parkinsonism
- Idiopathic Parkinson’s disease
- drug-induced e.g. antipsychotics, metoclopramide*
- progressive supranuclear palsy
- multiple system atrophy
- Wilson’s disease
- post-encephalitis
- dementia pugilistica (secondary to chronic head trauma e.g. boxing)
- toxins: carbon monoxide, MPTP
What is the secondary prevention in stroke?
1st line - clopidogrel
2nd line - if clopidogrel CI / aspirin + modified release dipyridamole
3rd - if both clopidrogel and aspirin CI - only modified release dipyridamole
How do you differentiate progressive supranuclear palsy (PSP) from MSA and Lew body dementia
PSP - vertical gaze palsy, frontal lobe problems (apathy, disinhibition, impaired reasoning)
MSA - autonomic dysfunction with urogenital problems
Lewy body dementia - visual hallucinations
What is the management of generalised tonic-clonic seizures?
sodium valproate
second line: lamotrigine, carbamazepine
Monotherapy with another drug should be attempted before combination therapy is started. Caution should be exercised when combining sodium valproate and lamotrigine as serious skin rashes such as Steven-Johnson’s syndrome may be provoked
What are the nerves affected in acoustic neuroma and what are the features it presents with?
cranial nerve VIII: vertigo, unilateral sensorineural hearing loss, unilateral tinnitus
cranial nerve V: absent corneal reflex
cranial nerve VII: facial palsy
What is the mechanism of action of lamotrigine and what are its side effects?
Inhibition of voltage-gated Na+channels → ↓ glutamate release
Side effect = Stevens-Johnson syndrome (slow titration is necessary to prevent skin and mucous membrane reactions)