Neurology Flashcards
A stroke is also referred to as cerebrovascular accident (CVA). CVA’s are either ?
-Ischaemia or infarction of brain tissue secondary to inadequate blood supply
-Intracranial haemorrhage
In regards to a CVA, disruption of blood supply can be caused by ? (4 points)
-Thrombus formation or embolus, for example in patients with atrial fibrillation
-Atherosclerosis
-Shock
-Vasculitis
Note:
Transient ischaemic attack (TIA) was originally defined as symptoms of a stroke that resolve within 24 hours. It has been updated based on advanced imaging to now be defined as transient neurological dysfunction secondary to ischaemia without infarction.
TIA’s often precede a full a stroke. What is a crescendo TIA ?
Where there are two or more TIAs within a week.
Note: This carries a high risk of developing in to a stroke.
In neurology, suspect a vascular cause where there is a sudden onset of neurological symptoms. What are the symptoms of a stroke ?
Stoke symptoms are typically asymmetrical:
-Sudden weakness of limbs
-Sudden facial weakness
-Sudden onset dysphasia (speech disturbance)
-Sudden onset visual or sensory loss
RF’s for a stroke ? (10 points)
-Cardiovascular disease such as angina, myocardial infarction and peripheral vascular disease
-Previous stroke or TIA
-Atrial fibrillation
-Carotid artery disease
-Hypertension
-Diabetes
-Smoking
-Vasculitis
-Thrombophilia
-Combined contraceptive pill
FAST tool for identifying a stroke in the community ?
F – Face
A – Arm
S – Speech
T – Time (act fast and call 999)
What is the ROSIER tool + what does it indicate ?
Tool for Recognition Of Stroke In Emergency Room.
Stroke is likely if the pt scores anything above a 0.
Tool used for assessing pts with a suspected TIA to estimate their risk of subsequently having a stroke + what are its components ?
ABCD2 score
A - Age (>60 = 1)
B - Blood pressure (>140/90 = 1)
C - Clinical features (unilateral weakness = 2, dysphasia without weakness = 1)
D - Duration (more than 60 minutes = 2, 10 to 60 minutes = 1, less than 10 minutes = 0)
D - Diabeters = 1
Management of a stroke ?
-Admit pts to a specialist stroke centre
-Exclude hypoglycaemia
-Immediate CT brain to exclude primary intracerebral haemorrhage
-Aspirin 300mg stat (after the CT) and continued for 2 weeks
-Thrombolysis with alteplase can be used after the CT brain scan has excluded an intracranial haemorrhage. Alteplase is a tissue plasminogen activator that rapidly breaks down clots and can reverse the effects of a stroke if given in time. It is given based on local protocols by an experienced physician. It needs to be given within a defined window of opportunity, for example 4.5 hours. Patients need monitoring for post thrombolysis complications such as intracranial or systemic haemorrhage. This includes using repeated CT scans of the brain.
-Thrombectomy (mechanical removal of the clot) may be offered if an occlusion is confirmed on imaging, depending on the location and the time since the symptoms started. It is not used after 24 hours since the onset of symptoms.
Note: Generally, blood pressure should not be lowered during a stroke because this risks reducing the perfusion to the brain.
Management of TIA ?
-Start aspirin 300mg daily. Start secondary prevention measures for cardiovascular disease. They should be referred and seen within 24 hours by a stroke specialist.
Specialist imaging used to investigate strokes / TIAs + what is the aim of this imaging ?
-The aim of imaging is to establish the vascular territory that is affected. It is guided by specialist assessment.
-Diffusion-weighted MRI is the gold standard imaging technique. CT is an alternative.
-Carotid ultrasound can be used to assess for carotid stenosis. Endarterectomy to remove plaques or carotid stenting to widen the lumen should be considered if there is carotid stenosis.
Secondary prevention of stroke ? (4 points)
-Clopidogrel 75mg once daily (alternatively dipyridamole 200mg twice daily)
-Atorvastatin 80mg should be started but not immediately
-Carotid endarterectomy or stenting in patients with carotid artery disease
-Treat modifiable risk factors such as hypertension and diabetes
Stroke rehabilitation ?
Once patients have had a stroke they require a period of adjustment and rehabilitation. This is an essential and central to stroke care. It involves a multidisciplinary team including:
-Nurses
-Speech and language (SALT)
-Nutrition and dietetics
-Physiotherapy
-Occupational therapy
-Social services
-Optometry and ophthalmology
-Psychology
-Orthotics
Around 10-20% of strokes are caused by intracranial bleeds. Name 6 RF’s ?
-Head injury
-Hypertension
-Aneurysms
-Ischaemic stroke can progress to haemorrhage
-Brain tumours
-Anticoagulants such as warfarin
Presentation of intracranial bleeds ? (include key feature)
Sudden onset headache is a key feature. They can also present with:
-Seizures
-Weakness
-Vomiting
-Reduced consciousness
-Other sudden onset neurological symptoms
In terms of a pts GCS, when do you need to consider securing their airway ?
When someone has a score of 8 or below.
What causes a subdural haemorrhage + where do they occur, what would a CT scan show and in which pts do they occur more frequently + why ?
-Subdural haemorrhage is caused by rupture of the bridging veins in the outermost meningeal layer. They occur between the dura mater and arachnoid mater.
-On a CT scan they have a crescent shape and are not limited by the cranial sutures (they can cross over the sutures).
-Subdural haemorrhages occur more frequently in elderly or alcoholic patients. These patients have more atrophy in their brains making vessels more likely to rupture.
What causes an extradural haemorrhage, what is it associated with, where does it occur, what would a CT scan show ?
-Extradural haemorrhage is usually caused by rupture of the middle meningeal artery in the temporo-parietal region.
-It can be associated with a fracture of the temporal bone.
-It occurs between the skull and dura mater.
-On a CT scan they have a bi-convex shape and are limited by the cranial sutures (they can’t cross over the sutures).
Note:
The typical history for someone presenting with an extradural haemorrhage is a young patient with a traumatic head injury that has an ongoing headache. They have a period of improved neurological symptoms and consciousness followed by a rapid decline over hours as the haematoma gets large enough to compress the intracranial contents.
Intracerebral haemorrhage involves bleeding into the brain tissue. How does it present ?
It presents similarly to an ischaemic stroke.
Note: These can be anywhere in the brain tissue:
-Lobar intracerebral haemorrhage
-Deep intracerebral haemorrhage
-Intraventricular haemorrhage
-Basal ganglia haemorrhage
-Cerebellar haemorrhage
They can occur spontaneously or as the result of bleeding into an ischaemic infarct or tumour or rupture of an aneurysm.
Principles of managing an intracranial bleed ?
-Immediate CT head to establish the diagnosis
-Check FBC and clotting
-Admit to a specialist stroke unit
-Discuss with a specialist neurosurgical centre to consider surgical treatment
-Consider intubation, ventilation and ICU care if they have reduced consciousness
-Correct any clotting abnormality
-Correct severe hypertension but avoid hypotension
Subarachnoid haemorrhage involves bleeding in to the subarachnoid space, where the cerebrospinal fluid is located, between the pia mater and the arachnoid membrane. This is usually the result of what ?
A ruptured cerebral aneurysm.
Note:
Subarachnoid haemorrhage has a very high mortality and morbidity. It is very important not to miss the diagnosis and you need to have a low suspicion to trigger full investigations. It needs to be discussed with the neurosurgical unit with a view to surgical intervention.
The typical history of a subarachnoid haemorrhage is a sudden onset occipital headache that occurs during strenuous activity such as weight lifting or sex. This occurs so suddenly that it is known as a what + name 3 other features ?
A thunderclap headache. It is is described like being hit really hard on the back of the head.
Other features are:
-Neck stiffness
-Photophobia
-Neurological symptoms such as visual changes, speech changes, weakness, seizures and loss of consciousness
Name 5 RF’s for a SAH ?
-Hypertension
-Smoking
-Excessive alcohol consumption
-Cocaine use
-Family history
SAH is more common in ? (3 points)
-Black patients
-Female patients
-Age 45-70
SAH is particularly associated with ? (5 points)
-Cocaine use
-Sickle cell anaemia
-Connective tissue disorders (such as Marfan syndrome or Ehlers-Danlos)
-Neurofibromatosis
-Autosomal dominant polycystic kidney disease
Investigations for SAH + what will they show ?
CT head is the first line investigation. Immediate CT head is required. Blood will cause hyperattenuation in the subarachnoid space.
Lumbar puncture is used to collect a sample of the cerebrospinal fluid if the CT head is negative. CSF can be tested for signs of subarachnoid haemorrhage:
-Red cell count will be raised. If the cell count is decreasing in number over the samples, this could be due to a traumatic lumbar puncture.
-Xanthochromia (the yellow colour of CSF caused by bilirubin)
Angiography (CT or MRI) can be used once a subarachnoid haemorrhage is confirmed to locate the source of the bleeding.
Management of a SAH ? (5 points)
-Patients should be managed by a specialist neurosurgical unit. Patients with reduced consciousness may require intubation and ventilation. Supportive care as part of a multi-disciplinary team is important with good nursing, nutrition, physiotherapy and occupational therapy involved during the initial stages and recovery.
-Surgical intervention may be used to treat aneurysms. The aim is to repair the vessel and prevent re-bleeding. This can done by coiling, which involves inserting a catheter into the arterial system (taking an “endovascular approach”), placing platinum coils into the aneurysm and sealing it off from the artery. An alternative is clipping, which involves cranial surgery and putting a clip on the aneurysm to seal it.
-Nimodipine is a calcium channel blocker that is used to prevent vasospasm. Vasospasm is a common complication that can result in brain ischaemia following a subarachnoid haemorrhage.
-Lumbar puncture or insertion of a shunt may be required to treat hydrocephalus.
-Antiepileptic medications can be used to treat seizures.
What is MS + what causes it ?
Multiple sclerosis (MS) is a chronic and progressive condition that involves demyelination of the myelinated neurones in the central nervous system.
This is caused by an inflammatory process involving activation of immune cells against the myelin.
Note:
MS typically presents in young adults (under 50 years) and is more common women. Symptoms tend to improving in pregnancy and in the postpartum period.
Pathophysiology of MS ?
Myelin covers the axons of neurones in the central nervous system. This myelin helps the electrical impulse move faster along the axon. Myelin is provided by cells that wrap themselves around the axons. These are Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.
Multiple sclerosis typically only affects the central nervous system (the oligodendrocytes). There is inflammation around myelin and infiltration of immune cells that cause damage to the myelin. This affects the way electrical signals travel along the nerve leading to the symptoms of multiple sclerosis.
When a patient presents with symptoms of a clinical “attack” of MS, for example an episode of optic neuritis, there are usually other lesions of demyelination at the same time throughout the central nervous system, most of which are not causing symptoms.
In early disease, re-myelination can occur and symptoms can resolve. In the later stages of the disease, re-myelination is incomplete and symptoms gradually become more permanent.
A characteristic features of MS is that lesions vary in their location over time, meaning that different nerves are affected and symptoms change over time. The key expression to remember to describe the way MS lesions change location over time is that they are “disseminated in time and space”.
Cause of MS ?
The cause of the demyelination is unclear, but there is growing evidence that it is influenced by a combination of:
-Multiple genes
-Epstein–Barr virus (EBV)
-Low vitamin D
-Smoking
-Obesity
Signs + symptoms of MS ?
Symptoms usually progress over more than 24 hours. At the first presentation symptoms tend to last days to weeks and then improve. There are a number of ways MS can present. These are described below.
-Optic neuritis
Eye movement abnormalities:
-May present with diplopia (due to lesions affecting CN VI)
-Internuclear opthalmoplegia
-Conjugate lateral gaze disorder
Focal weakness:
-Bells palsy
-Horners syndrome
-Limb paralysis
-Incontinence
Focal sensory symptoms
-Trigeminal neuralgia
-Numbness
-Paraesthesia (pins and needles)
-Lhermitte’s sign is an electric shock sensation travels down the spine and into the limbs when flexing the neck.
It indicates disease in the cervical spinal cord in the dorsal column. It is caused by stretching the demyelinated dorsal column.
Ataxia:
Ataxia is a problem with coordinated movement. It can be sensory or cerebellar:
-Sensory ataxia is the result of loss of the proprioceptive sense, which is the ability to sense the position of the joint (e.g. is the joint flexed or extended). This results in a positive Romberg’s test and can cause pseudoathetosis.
-Cerebellar ataxia is the result of problems with the cerebellum coordinating movement. This suggestions cerebellar lesions.
Disease patterns of MS note :
The disease course is highly variable between individuals. Some patients may have mild relapsing-remitting episodes for life whereas others have primary progressive MS that progresses without any improvement in symptoms. There are certain classifications used to describe the pattern of MS in an individual. These patterns are not separate conditions but part of a spectrum of disease activity.
Clinically Isolated Syndrome
This describes the first episode of demyelination and neurological signs and symptoms. MS cannot be diagnosed on one episode as the lesions have not been “disseminated in time and space”. Patients with clinically isolated syndrome may never have another episode or develop MS. If lesions are seen on MRI scan then they are more likely to progress to MS.
Relapsing-Remitting
Relapsing-remitting MS is the most common pattern at initial diagnosis. It is characterised by episodes of disease and neurological symptoms followed by recovery. In MS the symptoms occur in different areas with different episodes. This can be further classified based on whether the disease is active and/or worsening:
Active: new symptoms are developing or new lesions are appearing on MRI
Not active: no new symptoms or MRI lesions are developing
Worsening: there is an overall worsening of disability over time
Not worsening: there is no worsening of disability over time
Secondary Progressive
Secondary progressive MS is where there was relapsing-remitting disease at first, but now there is a progressive worsening of symptoms with incomplete remissions. Symptoms become more and more permanent. Secondary progressive MS can be further classified based on whether the disease is active and/or progressing.
Active: new symptoms are developing or new lesions are appearing on MRI
Not active: no new symptoms or MRI lesions are developing
Progressing: there is an overall worsening of disease over time (regardless of relapses)
Not progressing: there is no worsening of disease over time
Primary Progressive
Primary progressive MS is where there is a worsening of disease and neurological symptoms from the point of diagnosis without initial relapses and remissions. This can be further classified in a similar way to secondary progressive based on whether it is active and/or progressing.
Diagnosis of MS (include investigations) ?
Diagnosis is made by a neurologist based on the clinical picture and symptoms suggesting lesions that change location over time. Symptoms have to be progressive over a period of 1 year to diagnose primary progressive MS. Other causes for the symptoms need to be excluded.
Investigations can support the diagnosis:
-MRI scans can demonstrate typical lesions
-Lumbar puncture can detect “oligoclonal bands” in the cerebrospinal fluid (CSF)
What is optic neuritis (include key features) ?
Optic neuritis presents with unilateral reduced vision developing over hours to days. Key features are:
-Central scotoma. This is an enlarged blind spot.
-Pain on eye movement
-Impaired colour vision
-Relative afferent pupillary defect
Multiple sclerosis is the main cause of optic neuritis, however it can also be caused by what (7 points) ?
-Sarcoidosis
-Systemic lupus erythematosus
-Diabetes
-Syphilis
-Measles
-Mumps
-Lyme disease
Note:
Patients presenting with acute loss of vision should be seen urgently by an ophthalmologist for assessment. It is treated with steroids and recovery takes 2-6 weeks. Around 50% of patients with a single episode of optic neuritis will go on to develop MS over the next 15 years. Changes on an MRI scan help to predict which patients will go on to develop MS.
Management of MS ?
Multiple sclerosis is managed by a specialist multidisciplinary team (MDT) including neurologists, specialist nurses, physiotherapy, occupational therapy and others. Patient should be fully educated about their condition and treatment.
Disease Modification
Treatment with disease-modifying drugs and biologic therapy has changed the management of multiple sclerosis so that the aim of treatment is now to induce long term remission with no evidence of disease activity. There are many options that target various mechanisms such as interleukins, inflammatory cytokines and various immune cells. Going into detail about these drugs is beyond what would be expected in your exams. Disease-modifying drug treatment will be coordinated by specialists in multiple sclerosis.
Treating Relapses:
Relapses can be treated with steroids. NICE recommend methylprednisolone:
-500mg orally daily for 5 days
-1g intravenously daily for 3–5 days where oral treatment has failed previously or where relapses are severe
Symptomatic Treatments
It is important to treat the symptoms that result from the disease process along with treating the disease process itself:
-Exercise to maintain activity and strength
-Neuropathic pain can be managed with medication such as amitriptyline or gabapentin
-Depression can be managed with antidepressants such as SSRIs
-Urge incontinence can be managed with anticholinergic medications such as tolterodine or oxybutynin (although be aware these can cause or worsen cognitive impairment)
-Spasticity can be managed with baclofen, gabapentin and physiotherapy
What is motor neurone disease ?
An umbrella term that encompasses a variety of specific diagnoses.
Note: Motor neurone disease is a progressive, ultimately fatal condition where the motor neurones stop functioning. There is no effect on the sensory neurones and patients should not experience any sensory symptoms.
Name some of the different types of MND ?
-Amylotropic lateral sclerosis (AML) is the most common and well known specific type of motor neurone disease. Stephen Hawking had amylotropic lateral sclerosis.
-Progressive bulbar palsy is the second most common form of motor neurone disease. It affects primarily the muscles of talking and swallowing.
-Other types of motor neurone disease to be aware of are progressive muscular atrophy and primary lateral sclerosis.
Pathophysiology of MND ?
There is progressive degeneration of both upper and lower motor neurones. The sensory neurones are spared.
Typical MND patient note:
The typical patient is a late middle aged (e.g. 60) man, possibly with an affected relative. There is an insidious, progressive weakness of the muscles throughout the body affecting the limbs, trunk, face and speech. The weakness is often first noticed in the upper limbs. There may be increased fatigue when exercising. They may complain of clumsiness, dropping things more often or tripping over. They can develop slurred speech (dysarthria).
Signs of lower and upper MND ?
Signs of lower motor neurone disease:
-Muscle wasting
-Reduced tone
-Fasciculations (twitches in the muscles)
-Reduced reflexes
Signs of upper motor neurone disease:
-Increased tone or spasticity
-Brisk reflexes
-Upgoing plantar responses
Diagnosis of MND note:
The diagnosis of motor neurone disease needs to be made very carefully. It is based on the clinical presentation and excluding other conditions that can cause motor neurone symptoms. It should only be made by a specialist when there is certainty. Unfortunately, the diagnosis is often delayed, which causes considerable anxiety and stress.
Management of MND note:
Unfortunately, there are no effective treatments for halting or reversing the progression of the disease.
Riluzole can slow the progression of the disease and extend survival by a few months in AML. It is licensed in the UK and should be initiated by a specialist.
Edaravone is currently used in the United States but not the UK. Recent studies suggest it has the potential to slow the progression of the disease and it may come in to use in the future.
Non-invasive ventilation (NIV) used at home to support breathing at night improves survival and quality of life.
The key to management of the condition is supporting the person and their family:
-Effectively breaking bad news
-Involving the multidisciplinary team (MDT) in supporting and maintaining their quality of life
-Advanced directives to document the patients wishes as the disease progresses
-End of life care planning
-Patients usually die of respiratory failure or pneumonia
What is Parkinson’s disease ?
Parkinson’s disease is a condition where there is a progressive reduction of dopamine in the basal ganglia of the brain, leading to disorders of movement.
Classic triad of features in Parkinson’s disease ?
-Resting tremor
-Rigidity
-Bradykinesia
The symptoms are characteristically asymmetrical, with one side affected more than the other.
Pathophysiology of Parkinson’s ?
The basal ganglia are a group of structures situated in the middle of the brain. They is responsible for coordinating habitual movements such as walking or looking around, controlling voluntary movements and learning specific movement patterns. Part of the basal ganglia called the substantia nigra produces a neurotransmitter called dopamine. Dopamine is essential for the correct functioning of the basal ganglia. In Parkinson’s disease, there is a gradual but progressive fall in the production of dopamine due to the destruction of the substantia nigra.
Presentation of Parkinson’s note:
The typical patient is an older aged man around the age of 70.
Unilateral Tremor:
The tremor in Parkinsons has a frequency of 4-6 Hz, meaning it occurs 4-6 times a second. This is described as a “pill rolling tremor” because it looks like they are rolling a pill between their fingertips and thumb. It is more pronounced when resting and improves on voluntary movement. The tremor is worsened if the patient is distracted. Asking them to do a task with the other hand, such as miming the motion of painting a fence, can exaggerate the tremor.
“Cogwheel” Rigidity:
Rigidity is a resistance to passive movement of a joint. If you take their hand and passively flex and extend their arm at the elbow, you will feel a tension in their arm that gives way to movement in small increments (like little jerks). This is what leads to the cogwheel description.
Bradykinesia
Bradykinesia describes how their movements get slower and smaller. This presents in a number of ways:
-Their handwriting gets smaller and smaller (this is a classic presenting complaint in exams)
-They can only take small steps when walking (“shuffling gait”)
-They have difficulty initiating movement (e.g. from standing still to walking)
-They have difficulty in turning around when standing, having to take lots of little steps
-They have reduced facial movements and facial expressions (hypomimia)
Other Features:
There are a number of other features that often affect patients with Parkinson’s disease:
-Depression
-Sleep disturbance and insomnia
-Loss of the sense of smell (anosmia)
-Postural instability
-Cognitive impairment and memory problems
Tom tip:
A common exam task challenges you to distinguish between the tremor of Parkinson’s disease and benign essential tremor. The table below gives some tips on this:
Parkinson’s Tremor:
-Asymmetrical
-4-6 hertz
-Worse at rest
-Improves with intentional movement
-Other Parkinson’s features
-No change with alcohol
Benign essential tremor:
-Symmetrical
-5-8 hertz
-Improves at rest
-Worst with intentional movement
-No other Parkinson’s features
-Improves with alcohol
Parkinson plus syndromes ?
Multiple System Atrophy
This is a rare condition where the neurones of multiple systems in the brain degenerate. It affects the basal ganglia as well as multiple other areas. The degeneration of the basal ganglia lead to a Parkinson’s presentation. The degeneration in other areas lead to autonomic dysfunction (causing postural hypotension, constipation, abnormal sweating and sexual dysfunction) and cerebellar dysfunction (causing ataxia).
Dementia with Lewy Bodies
This is a type of dementia associated with features of Parkinsonism. It causes a progressive cognitive decline. There are associated symptoms of visual hallucinations, delusions, disorders of REM sleep and fluctuating consciousness.
Others
Two other Parkinson’s-plus syndromes exist that involves a number of complex progressive neurological features:
Progressive Supranuclear Palsy
Corticobasal Degeneration
Diagnosis of Parkinson’s note:
Parkinson’s disease is diagnosed clinically based on symptoms and examination. The diagnosis should be made by a specialist with experience in diagnosing Parkinson’s. NICE recommend using the UK Parkinson’s Disease Society Brain Bank Clinical Diagnostic Criteria.
Management of Parkinson’s note:
Treatment is initiated and guided by a specialist, and is tailored to each individual patient and their response to different medications. There is no cure, so treatment is focused on controlling symptoms and minimising side effects.
Patients describe themselves as “on” when the medications are acting and they are moving freely, and “off” when the medications wear out, they have significant symptoms and their next dose is due.
Treatment’s of Parkinson’s ? (for each include how they work and any relevant side effects)
Levodopa
This is synthetic dopamine given orally to boost their own dopamine levels. It is usually combined with a drug that stops levodopa being broken down in the body before it gets the chance to enter the brain. These are peripheral decarboxylase inhibitors. Examples are carbidopa and benserazide.
Combination drugs are:
Co-benyldopa (levodopa and benserazide)
Co-careldopa (levodopa and carbidopa)
Levodopa is the most effective treatment for symptoms but becomes less effective over time. It is often reserved for when other treatments are not managing to control symptoms.
The main side effect of dopamine is when the dose is too high patients develop dyskinesias. Theses are abnormal movements associated with excessive motor activity. Examples are:
Dystonia: This is where excessive muscle contraction leads to abnormal postures or exaggerated movements.
Chorea: These are abnormal involuntary movements that can be jerking and random.
Athetosis: These are involuntary twisting or writhing movements usually in the fingers, hands or feet.
COMT Inhibitors
The main example of this is entacapone. These are inhibitors of catechol-o-methyltransferase (COMT). The COMT enzyme metabolises levodopa in both the body and brain. Entacapone is taken with levodopa (and a decarboxylase inhibitor) to slow breakdown of the levodopa in the brain. It extends the effective duration of the levodopa.
Dopamine Agonists
These mimic dopamine in the basal ganglia and stimulate the dopamine receptors. They are less effective than levodopa in reducing symptoms. They are usually used to delay the use of levodopa and are then used in combination with levodopa to reduce the dose of levodopa that is required to control symptoms. One notable side effect with prolonged use is pulmonary fibrosis. Examples are:
Bromocryptine
Pergolide
Carbergoline
Monoamine Oxidase-B Inhibitors
Monoamine oxidase enzymes break down neurotransmitters such as dopamine, serotonin and adrenaline. The monoamine oxidase-B enzyme is more specific to dopamine and does not act on serotonin or adrenalin. These medications block this enzyme and therefore help increase the circulating dopamine. Similarly to dopamine agonists, they are usually used to delay the use of levodopa and then in combination with levodopa to reduce the required dose. Examples are:
Selegiline
Rasagiline
Benign essential tremor is a relatively common condition associated with older age. It is characterised by what + where is it most notable ?
It is characterised by a fine tremor affecting all the voluntary muscles.
It is most notable in the hands but affects other areas, for example causing a head tremor, jaw tremor and vocal tremor.
6 features of a benign essential tremor ?
-Fine tremor
-Symmetrical
-More prominent on voluntary movement
-Worse when tired, stressed or after caffeine
-Improved by alcohol
-Absent during sleep
Benign essential tremor is diagnosed clinically based on the presenting features. It is important to look for features to exclude other causes of a tremor.
The key differential diagnoses of a tremor are ?
-Parkinson’s disease
-Multiple sclerosis
-Huntington’s Chorea
-Hyperthyroidism
-Fever
-Medications (e.g. antipsychotics)
Management of benign essential tremor ?
There is no definitive treatment for benign essential tremor. The tremor is not harmful and does not require treatment if not causing functional or psychological problems.
Medications that can be tried to improve symptoms are:
-Propranolol (a non-selective beta blocker)
-Primidone (a barbiturate anti-epileptic medication)
Epilepsy note:
Epilepsy is an umbrella term for a condition where there is a tendency to have seizures. Seizures are transient episodes of abnormal electrical activity in the brain. There are many different types of seizures.
A diagnosis of epilepsy is made by a specialist based on the characteristics of the seizure episodes.
2 main ix for epilepsy + any other ix’s ?
-Electroencephalogram (EEG)
-MRI brain - can be used to visualise the structure of the brain. It is used to diagnose structural problems that may be associated with seizures and other pathology such as tumours
Other investigations can be used to exclude other pathology, particularly and ECG to exclude problems in the heart.
Name 6 different types of seizures (excluding status epilepticus) ?
-Generalised Tonic-Clonic Seizures
-Focal Seizures
-Absence Seizures
-Atonic Seizures
-Myoclonic Seizures
-Infantile spasms
What are Generalised Tonic-Clonic seizures, what are the associated symptoms + signs, what happens following the seizure and what is the management ?
These are what most people think of with an epileptic seizure. There is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) episodes. Typically the tonic phase comes before the clonic phase. There may be associated tongue biting, incontinence, groaning and irregular breathing.
After the seizure there is a prolonged post-ictal period where the person is confused, drowsy and feels irritable or depressed.
Management of tonic-clonic seizures is with:
-First line: sodium valproate
-Second line: lamotrigine or carbamazepine
Where do focal seizures start, what can they affect, how can they present and how are they managed ?
Focal seizures start in temporal lobes. They affect hearing, speech, memory and emotions. There are various ways that focal seizures can present:
Hallucinations
Memory flashbacks
Déjà vu
Doing strange things on autopilot
One way to remember the treatment is that they are the reverse of tonic-clonic seizures:
-First line: carbamazepine or lamotrigine
-Second line: sodium valproate or levetiracetam
Who do absence seizures typically occur in, what happens, how long do they last and how are they managed ?
Absence seizures typically happen in children. The patient becomes blank, stares into space and then abruptly returns to normal. During the episode they are unaware of their surroundings and won’t respond. These typically only lasts 10-20 seconds. Most patients (> 90%) stop having absence seizures as they get older.
Management is:
-First line: sodium valproate or ethosuximide
What are atonic seizures also known as, what happens in them, how long do they last, when do they begin, what can they be indicative of and how are they managed ?
Atonic seizures are also known as “drop attacks”. They are characterised by brief lapses in muscle tone. These don’t usually last more than 3 minutes. They typically begin in childhood. They may be indicative of Lennox-Gastaut syndrome.
Management is:
-First line: sodium valproate
-Second line: lamotrigine
How do myoclonic seizures present, does the patient remain awake, when do they occur and how are they managed ?
Myoclonic seizures present as sudden brief muscle contractions, like a sudden “jump”. The patient usually remains awake during the episode. They occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy.
Management is:
-First line: sodium valproate
-Other options: lamotrigine, levetiracetam or topiramate
What are Infantile spasms also known as, are they rare, what are they characterised by, what is the prognosis like and how are they treated ?
This is also known as West syndrome. It is a rare (1 in 4000) disorder starting in infancy at around 6 months of age. It is characterised by clusters of full body spasms. There is a poor prognosis: 1/3 die by age 25, however 1/3 are seizure free.
It can be difficult to treat but first line treatments are:
-Prednisolone
-Vigabatrin
Name 5 medications used to treat epilepsy ?
-Sodium valproate
-Carbamazepine
-Phenytoin
-Ethosuximide
-Lamotrigine
What is sodium valproate, how does it work and name 4 notable side effects ?
This is a first line option for most forms of epilepsy (except focal seizures). It works by increasing the activity of GABA, which has a relaxing effect on the brain.
Notable side effects:
-Teratogenic so patients need careful advice about contraception
-Liver damage and hepatitis
-Hair loss
-Tremor
Note: There are a lot of warning about the teratogenic effects of sodium valproate and NICE updated their guidelines in 2018 to reflect this. It must be avoided in girls or women unless there are no suitable alternatives and strict criteria are met to ensure they do not get pregnant.
What is carbamazepine + name 3 notable side effects ?
This is first line for focal seizures. Notable side effects are:
-Agranulocytosis
-Aplastic anaemia
-Induces the P450 system so there are many drug interactions
Name 3 notable side effects of Phenytoin ?
-Folate and vitamin D deficiency
-Megaloblastic anaemia (folate deficiency)
-Osteomalacia (vitamin D deficiency)
Name 2 side effects of ethosuximide ?
-Night terrors
-Rashes
Name 2 side effects of lamotrigine ?
-Stevens-Johnson syndrome or DRESS syndrome. These are life threatening skin rashes
-Leukopenia
Status epilepticus is a medical emergency. What is it ?
Seizures lasting more than 5 minutes or more than 3 seizures in one hour.
Management of status epilepticus (in hospital and in the community) ?
Management of status epileptics in the hospital:
Take an ABCDE approach:
-Secure the airway
-Give high-concentration oxygen
-Assess cardiac and respiratory function
-Check blood glucose levels
-Gain intravenous access (insert a cannula)
-IV lorazepam 4mg, repeated after 10 minutes if the seizure continues
-If seizures persist: IV phenobarbital or phenytoin
Medical options in the community:
-Buccal midazolam
-Rectal diazepam
Neuropathic pain is caused by ?
Abnormal functioning of the sensory nerves, delivering abnormal and painful signals to the brain.
Abnormal sensations form the skin, such as burning, tingling, pins and needles and numbness is called ?
Paresthesia
Neuropathic pain can affect a wide variety of areas with a number of different causes, name 6 of these ?
-Postherpetic neuralgia from shingles is in the distribution of a dermatome and usually on the trunk
-Nerve damage from surgery
-Multiple sclerosis
-Diabetic neuralgia typically affects the feet
-Trigeminal neuralgia
-Complex Regional Pain Syndrome (CRPS)
