Neuro Flashcards
Sources: InnovAiT 6:7 (July 2013)
What are the differentials for tremour?
Essential tremour.Parkinsonism.Cerebellum disease.Physiological tremour.(There are other causes, but in GP these are the commoner causes of a tremour).
Define tremour?
An involuntary movement of the body, usually the hands and arms, which has a rhythmic quality.Sometimes it is suppressable.
What is the one to type of tremor that does not require referral to secondary care? When does it occur?
Essential tremour. This is an action tremor that occurs throughout movement.
If a postural tremour is present, what diagnosis does this suggest?
Enhanced physiological tremor.
If there is increased movement, what diagnoses should be considered?
TicsDystoniaMyoclonusChoreaBallismus
What sets dystonias apart from other movement disorders?What is it characterised by?
Dystonia is sustained.Characterised by the simultaneous contraction of opposing muscle groups.Leads to painful abnormal posturing, sometimes writhing movements.
What are the causes of dystonias?
1) primary - usually dominantly inherited (a few are sporadic new mutations)2) secondary - usually part of an underlying neuro degenerative disease, e.g., Huntingtons, Wilsons. Also may be due to an insult to basal ganglia (e.g., stroke, infection, tumour), or iatrogenic (e.g., older antipsychotics, metoclopraide - dopamine antagonists).
Other than by cause, how else can dystonias be categorised?
By area affected:-focal affects one muscle group.-segmental affects two adjacent groups.-generalised - most muscle groups affected.In GP, Focal and segmental are most commonly seen.
How are dystonias treated?
Multidisciplinary approach.PT, OT, psychiatry, SALT.MEdically, Rx may involve benzodiazepines, anti-spasmodics, anti-convulsants, and anti-PD drugs.Recently, botulin toxin injections has revolutionised treatment - especially for focal and segmental dystonias - a single injection can ‘cure’ the symptoms for up to 4/12.Surgical options include deep brain stimulation or surgery to the affected muscles, but are only considered in severe cases.
Define chorea?What is the most common cause?
A sudden jerky movement that is random in distribution, non-rhythmic, and non sustained.Can affect any part of body, and is usually bilateral.The most common cause is Huntington’s disease, but there are others.
What are causes of chorea? Name five. (Though there are at least ten!)
Huntongton’s disease.Benign hereditary choreas.Wilson’s disease.Hyperthyroidism.SLE.Rheumatic fever (AKA Sydenham’s Chorea).Chorea gravidarum in pregnancy.Drug induced (e.g., oral contraceptives, levodopa, anticholinergics).Toxins - e.g., alcohol.Stroke or tumour affecting the contralateral basal ganglia.
Patients with chorea should be refereed to secondary care, to a neurologist with an interest in movement disorders. What is the crux of the history here? And what tests might be carried out?
The main history point to determine is a detailed Fx to see if there is evidence of Huntongton’s in the family.If this is not possible or is negative, tests to consider include TFT’s, autoimmune screen, and serum caeruplasmin. Brain imaging with MRI is usually also done to look for structural abnormalities.
What is the management of chorea?
Depends on the underlying cause, but if the chorea is drug-induced, then adjusting or stopping the offending drug may be all that is required.Haloperidol (and other dopamine depleting drugs) can help also.
What are the five common dystonia syndromes?
1) cervical dystonia - AKA spasmodic torticollis; muscles in the head and neck are involved, resulting in head posturing.2) tardive dyskinesea - usually associate with prolonged dopa,one antagonist use, causes a combination of cervical dystonia, oromandibular dystonia, and blepharospasm.3) occupational dystonia - occurs with prolonged activity - most common is writer’s cramp (wrist and/or fingers undergo sustained flex ion or extension).4) oromandibular dystonia - affects the lips (pouting), jaw (opening and closing), and tongue (sticking out) –> difficulty speaking, chewing, swallowing.5) blepharospasm - eyelids close involuntarily, leading to prolonged closure or excessive blinking.
What are the five types of tremour?
1) resting tremour. Occurs at rest, e.g., patient asked to keep arms on lap. Distraction my be needed, e.g., count backwards from 100; PD most common cause.2) intention tremour. As target approaches, tremor increase. Best elicited using finger-nose test. Cerebellum lesion most common cause.3) postural tremour. Occurs when affected part adopts a fixed position, e.g., asking patient to keep arms stretched out in front of them. Occurs in physiological tremour.4) kinetic tremour. Present throughout full range of movement. Typical of essential tremour.5) rubral tremour. A combination of rest, postural, and intention tremour.
Akinetic/rigid syndrome is also known as Parkinsonism. PD accounts for the vast majority of cases, but there are other causes, such as…?
Common:PDParkinson’s plus syndromeVascular Parkinsonism DrugsRare:ToxinsTraumaPost-encephalitis
What are the core features of Parkinsonism?
1) rigidity - lead pipe rigidity best elicited at elbow; cogwheel ing best elicited at the wrist2) akinesia - bradykinesea, hypokinesea, repeated movements leads to progressive slowing and reduction of amplitude. Note that the strength remains unaffected. Other features include mask-like face, monotonous speech, reduced swallowing, and reduced blinking. There may also be micrographia, and reduced arm swinging, as well as freezing episodes affecting the legs.3) tremor - a resting tremor, usually affecting the hand (“pill rolling”) but may also affect jaw and tongue. There is a reduction with move event and sleeping.4) posture - usually displays a fixed posture, with postural instability, and a “festinant gait”: the other features lead to legs trying to catch up with the body, leading to an increased risk of falling.
How is essential tremor treated?
In primary care, once the diagnosis is not in doubt.In mild cases, PRN propranolol may be used(20-80mg as single dose), e.g., prior to important occasion, or on activity that often provokes tremor. Alcohol can also help, though obviously advise against excess!More severe - regular propranolol or primidone may be used (sometimes, the beta blocker is used in younger patients, primidone older patients - but this is arbitrary).In both cases, start low and go slow.Propanolol usually started at 10-60mg/day as a single M/R dose or in divided doses. It is contraindicated in asthma, bradycardia, or hypotension.Primidone is taken once at night, again start v low, and go up weekly.
What are the important side effects of Propanolol (as used for essential tremour)?
HypotensionBradycardiaPeripheral vasoconstrictionImpotenceBronchospasmGastrointestinal symptoms
What are important side effects of primidone (as used for essential tremor)?
Nausea, vomiting, sedation, ataxia - but these usually settle after a few days use.
If drug treatments for essential tremor fail, what other options are there?
Off licence high primidone doses.Combination of primidone and propanolol.IM botulinum toxin.Deep brain stimulation.
What causes Parkinson’s disease on a neurological level?
Loss of neurones in the substantia nigra in the basal ganglia.Presence of alpha-synuclein containing Lewey bodies.
What is chorea?
A sudden jerky involuntary movement of any part of the body that is not rhythmic and non-sustained. It has a random distribution and is usually bilateral.Huntington’s disease is the most common cause, but there are ores
What is ballismus?
Dramatic sudden flinging motions, mainly affecting the limbs.It can be limited to one side of the body, in which case it is called hemiballismus.Hemiballismus is more common than ballismus, though both are rare.The most common cause of hemiballismus is stroke.
What is myoclonus?
Brief, non-sustained electric shock like movements that occur due to involuntary muscle contractions.
What are the causes of myoclonus?
Physiological - e.g., hiccoughs, hyping jerks during sleep.Drugs - SSRI’s, morphone.Conditions - epilepsy, prion disease.
What is asterixis, and what are two common causes?
A sort of negative myoclonus - a sudden involuntary relaxation of a contracted muscle.Commonly caused by dioxide retention (e.g., type 2 Resp failure in COPD), and encephalopathy of liver disease.
What are tics?
Brief intermittent meaningless movements (motor ticks) or sounds (phonic tics) which are preceded by premonitory urges.They can be wilfully repressed and often disappear with distraction - they may be semi voluntary.Premonitory urges are unpleasant sensations which are relieved by carrying out the tic.
What are the three main tic disorders? How are they characterised? By what age do they usually start?
1) transient tic disorder - motor and/or phonetic tics which last between 1 and 12 months.2) chronic tic disorder - has motor OR phonetic tics that last more than 1 year.3) Torette’s syndrome has motor and phonetic tics that last more than 1 year.
What are the principles of managing tic disorders?
-education and reassurance that most tic disorders will resolve spontaneously.-CBD and habit reversal therapy have been shown to be effective.-Drug treatments include antipsychotics and clonidine, but must be supervised by a specialist.-In very severe cases, referral to a specialist to consider deep brain stimulation and/or botulinum toxin injection, but only if there has been a failure to respond to any of the other treatments.
Typically, what percentage of pigmented cells need to be lost from the substantia nigra for the motor symptoms of PD to present?
60%
In terms of presentation of PD, how does the distribution differentiate it from other forms of parkinsonism?
PD often initially presents asymmetrically, with symptoms on one Sid of the body. As the disease progresses, this will tend to become bilateral and functional ability is reduced, until the patient becomes fully dependent, with a reduced life expectancy.
What is the usual cause of reduced life expectancy in PD?
Respiratory tract infections, falls, and VTE’s.
Should a GP be making the diagnosis of PD?
Although the condition is frequently clinically obvious even to a humble GP, the patient with suspected PD should always be referred to a specialist, for confirmation and for initiation of medical treatment. Note that it may not always be desirable to initiate drug treatment straight away, as adverse affects may outweigh benefits.Once drugs are initiated by a specialist, they can be continued by the GP. A multidisciplinary approach is desired.
What is the ‘on-off’ syndrome?What might patients with this syndrome benefit from?
In PD, patients who have been retreated for some time with with L-dopa and as the disease progresses.In these cases, they fluctuate between almost complete akenetic states and florid dyskinesia.They may benefit from dopamine agonists, especially subcutaneous apomorphine during the off periods.
What is the most common initial treatment for PD?
L-dopa with a dopa de-carboxylase inhibitor. Patients may then develop dopamine-induced dyskinesia, in which case the dose of L-dopa can be reduced and a dopamine agonist added.
