Nervous System Flashcards
1
Q
What is Bell’s palsy?
A
Idiopathic lower motor neurone facial (VII) nerve palsy
2
Q
What is the aetiology of Bell’s palsy?
A
- Idiopathic
- 60% are preceded by an upper respiratory tract infection, suggesting a viral or post-viral aetiology
3
Q
What is the epidemiology of Bell’s palsy?
A
- Annual incidence is 14-40 in 100,000
- Most cases: 20-5o year
4
Q
What are the presenting symptoms of Bell’s palsy?
A
- Prodrome of pre-auricular pain in some cases followed by acute (hours/days) onset unilateral facial weakness and droop. Maximum severity within 1-2 days
- 50% experience facial, neck or ear pain or numbness
- Hypersensitivity to sound (hyperacusis caused by stapedius paralysis)
- Loss of taste sense (uncommon)
- Tearing or drying of exposed eye
5
Q
What are the signs of Bell’s palsy on examination?
A
- Lower motor neurone weakness of facial muscles (affects all of the ipsilateral muscles of facial expression and does not spare the muscles of the upper part of the fact as seen in UMN facial nerve palsy)
- Bell’s phenomenon: Eyeball rolls up but eye remains open when trying to close the eyes. Although patient may report unilateral facial numbness, clinical testing of sensation is normal. The ear should be examined to exclude other causes (e.g. otitis media, herpes zoster infection)
6
Q
What are the investigations for Bell’s palsy?
A
- Usually unnecessary except to exclude other causes e.g. Lyme serology, herpes zoster serology
- EMG: May show local axonal conduction block in facial canal. Only useful more than one week after onset
7
Q
How is Bell’s palsy managed?
A
- Protection of cornea with protective glasses/patches and artificial tears
- High dose corticosteroids (prednisolone) is beneficial within 72h (given only if Ramsay Hunt’s syndrome is excluded) Little evidence for aciclovir
- Surgery: Lateral tarsorrhaphy (suturing the lateral parts of the eyelids together) if imminent of established corneal damage
8
Q
What are the possible complications of Bell’s palsy?
A
- Corneal ulcers, eye infection
- Aberrant reinnervation may occur e.g. blinking may cause contraction of the angle of the mouth as a result of simultaneous innervation of obicularis oculi and ori.
- Parasympathetic fibres may also aberrantly reinnervate causing ‘crocodile tears’ when salivating
9
Q
What is the prognosis for Bell’s palsy?
A
Most (85-90%) recover function within 2-12 weeks with or without treatment
10
Q
What is a cluster headache?
A
- Unilateral attacks lasting 15-180 minutes associated with autonomic symptoms secondary to parasympathetic hyperactivity and sympathetic hypo-activity
- Pain often localised to unilateral orbital, supra-orbital and/or temporal areas and can occur from once every other day to 8 times per day
- Considered one of the most painful conditions known to humanity
11
Q
What is the aetiology of a cluster headache?
A
- Unknown
- History of head trauma, heavy cigarette smoking and heavy alcohol intake all associated though no causal relationship found
12
Q
What is the epidemiology of cluster headaches?
A
- One of few primary headaches that affect men predominantly
- Age of onset: 20-40 yrs usually
13
Q
What are the presenting symptoms of a cluster headache?
A
- Male sex
- Family history
- Head injury
- Cigarette smoking
- Heavy drinking
- Repeated attack of unilateral pain
- Excruciating pain
- Nausea, vomiting
- Migrainous aura
14
Q
What are the signs of a cluster headache on examination?
A
- Lacrimation, rhinorrhoea and partial Horner’s syndrome
- Agitation
- Photophobia, phonophobia
15
Q
What are the investigations for a cluster headache?
A
- Brain CT or MRI: normal in primary cluster headache; abnormal results might indicate secondary causes (e.g. tumour, cavernous sinus pathology)
- ESR: normal in primary
- Pituitary function tests: Normal in primary, abnormalities suggest secondary causes resulting from pituitary adenoma
16
Q
What is dementia?
A
Progressive deficits in memory and one or more domains- language, visuospatial, praxis (inability to perform actions e.g. dressing apraxia), in a setting of clear consciousness and interfering with work, social activities, relationships
- Alzheimer’s, Vascular, Lewy body, Pick’s disease
17
Q
What is the aetiology of Alzheimer’s dementia?
A
- Lesions in the brain- tau neurofibrillary tangles, plaques of beta amyloid and neurone loss with corticol atrophy, loss of ACh. Cerebral amyloid angiopathy. Cerebral atrophy
- Neurone loss in: hippocampus, amygdala, temporal neocortex, subcorticol nuclei
- 95% show signs of vascular dementia
18
Q
What is the aetiology of dementia?
A
- Toxic: Alcohol, lead, barbs, drug abuse
- Metabolic: low thiamine, low T4, low B12, low folate, low glucose (repeated), pellagra (niacin or B3 deficiency)
- Head trauma: injury, subdural haemorrhage
- Tumours: frontal, posterior fossa (causing hydrocephalus), brain mets, paraneoplastic, meningioma
- Infection: WHipple’s disease, HIV, syphillis, CNS cysticerosis, Cryptococcosis
- Vascular: multiple infarcts
- Inflammation: SLE, sarcoid, vasculitis, multiple sclerosis
- Inherited: Wilson’s, Huntington’s, cerebellar ataxias
- Degenerative: PD, CJD, Pick’s, Lew body dementia
- Familial autosomal dominant Alzheimer’s
- CADASIL: Cerebral Autosomal-Dominant Arteriopathy with Subcorticol Infarcts and Leykoencephalopathy
19
Q
What is the epidemiology of dementia?
A
- Rare under 55 yrs
- Over 65s: 5-10%
- Over 80: 20%
- Over 100: 70%
20
Q
What are presenting symptoms of dementia?
A
- Initial presentation is usually memory loss over months or years.
- If days: think infection/stroke
- If weeks: depression
- In later stages: non-cognitive symptoms: agitation, aggression, apathy
Positive symptoms: - Aggression, wandering, agitation, hallucinations, flight of ideas, logorrhoea: incoherent talkativeness
Negative symptoms: - Low repetitive speech, apathy, mood disturbance: depression is common but may also cause dementia
21
Q
What are the signs of dementia on examination?
A
- Normal pressure hydrocephalus: dilated ventricles without dilated cerebral sulci. Gait apraxia, incontinence
- Cognitive testing: MMSE score less than 24 abnormal. Severe is less than 9 points
- Verbal recall: Hopkin’s verbal learning test
- Executive function: clock drawing task
- Physical exam: cause of impairment, risk factors for vascular dementia, parkinonism
22
Q
What are the investigations for dementia?
A
- Bedside cognitive testing: impaired recall, nominal dysphasia, disorientation, constructional dyspraxia and impaired executive function
- FBC: rule out anaemia
- Metabolic panel: exclude abnormals odium, calcium, glucose levels
- Serum TSH: TSH may be low or high
- Serum vitamin B12: may be low
- Urine drug screen: may be positive
- CT: may exclude space-occupying lesions or other pathology
- MRI: generalised atrophy with medial temporal lobe and later parietal predominance
23
Q
What is encephalitis?
A
Inflammation of the brain parenchyma
24
Q
What is the aetiology of encephalitis?
A
Majority of cases, it is the result of viral infection
- Virus: Most common in UK is HSV. Others include herpes zoster, mumps, adenovirus, coxsackie, echovirus, enterovirus, measles, EBV, HIV, rabies (Asia) and arboviruses transmitted by mosquitoes e.g. Japanese B encephalitis
- Non-viral: rare e.g. syphilis, S aureus
- Immunocompromised: CMV, toxoplasmosis, Listeria
- Autoimmune or paraneoplastic: May be associated with antibodies e.g. anti-NMDA or anti- VGKC
25
What is the epidemiology of encephalitis?
Annual UK incidence is 7.4 in 100,000
26
What are the presenting symptoms of encephalitis?
- In many cases, it is mild self-limiting illness
- Subacute onset (hours to days) headache, fever, vomiting, neck stiffness, photophobia i.e. symptoms of meningism (meningoencephalitis) with behavioural changes, drowsiness and confusion
- Often history of seizures
- Focal neurological symptoms e.g. dysphagia and hemiplegia may be present
- Important to obtain detailed travel history
27
What are the signs of encephalitis on examination?
- Decreased level of consciousness with deteriorating GCS, seizures, pyrexia
- Signs of meningism: Neck stiffness, photophobia, Kernig's test positive. Signs of raised intracranial pressure: hypertension, bradycardia, papilloedema
- Focal neurological signs
- Minimental examination may reveal cognitive or psychiatric disturbances
28
What are the investigations for encephalitis?
- Blood: FBC (raised lymphocytes), U&E (SIADH may occur, glucose (compare with CSF glucose) viral serology, ABG
- MRI/CT: Excludes mass lesion. HSV produces characteristic oedema of the temporal love on MRI
- Lumbar puncture: Raised lymphocytes, monocytes and protein. Glucose usually normal. CSF culture is difficult, PCR now first line
- EEG: May show epileptiform activity e.g. spiking activity in temporal lobes
- Brain biopsy: now very rarely performed
29
What is epilepsy?
- Epilepsy: More than 2 seizures
| - Seizure (ictus): Paroxysmal synchronised corticol electrical discharges
30
What is a focal seizure?
Seizure localised to specific cortical regions, such as temporal lobe seizures, frontal lobe seizures, occipital seizures, complex partial seizures
31
What is a generalised seizure?
Seizures which affect consciousness typically tonic-clonic, absence attacks myoclonic, atonic (drop attacks) or tonic seizures
32
What is the aetiology of epilepsy?
Majority of cases are idiopathic
- Primary epilepsy syndromes (e.g. idiopathic generalised epilepsy, temporal lobe epilepsy, juvenile myoclonic epilepsy
- Secondary seizures (symptomatic epilepsy): (Tumour, infection:meningitis, encephalitis, abscess, Inflammation: vasculitis, rarely MS, toxic/metabolic: sodium imbalance, hypocalcaemia, drugs: alcohol, benzos, vascular: haemorrhage, infarction, congenital abnormalities: corticol dysplasia, neurodegenerative disease: Alzheimer's, malignant hypertension, trauma
- Common seizure mimics: syncope, migraine, non-epileptiform seizure disorder
33
What is the pathophysiology of epilepsy?
- Seizures result from an imbalance in the inhibitory and excitatory currents (e.g. Na+ or K+ ion channels) or neurotransmission (i.e. glutamate or GABA neurotransmitters) in the brain
- Precipitants include any trigger which promotes excitation of the cerebral cortex (e.g. flashing lights, drugs, sleep deprivation, metabolic) but often cryptogenic
34
What is the epidemiology of epilepsy?
- Common
- Prevalence in 1% of general population
- Peak age of onset is in early childhood or in the elderly
35
What should be obtained from the history of a patient with epilepsy?
Obtain history from a witness as well as a patient
1) Rapidity of onset
2) Duration of episode
3) Any alteration of consciousness
4) Any tongue-biting of incontinence
5) Any rhythmic synchronous limb jerking?
6) Any post-ictal period?
7) Drug history (alcohol, recreational drugs
36
What are the presenting symptoms of focal seizures?
- Frontal lobe focal motor seizures: Motor convulsions. May demonstrate Jacksonian march (spasm spreading from mouth or digit). There may be post-ictal flaccid weakness (Todd's paralysis)
- Temporal love seizures: Aura (visceral and psychic symptoms: fear or deja-vu sensation), Hallucinations (olfactory, gustatory)
- Frontal lobe complex partial seizures: Loss of consciousness with associated automatisms and rapid recover
37
What are the presenting symptoms of generalised seizures?
- Tonic-clonic (grand mal): Vague symptoms before an attack (e.g. irritability), followed by tonic phase (generalised muscle spasm), followed by a clonic phase (repetitive synchronous jerks), and associated faecal or urinary incontinence, tongue biting. After a seizure, there is often impaired consciousness, lethargy, confusion, headache, back pain, stiffness
- Absence (petit mal): Usual onset in childhood. Characterised by loss of consciousness but maintained posture (pt stops talking and stares into space for seconds), blinking of rolling up of eyes with other repetitive motor actions (e.g. chewing). No postictal phase
- Non-convulsive status epilepticus: Acute confusional state. Often fluctuating. Difficult to distinguish from dementia
38
What are the signs of epilepsy on examination?
- Depends on aetiology, usually normal between seizures
| - Look for focal abnormalities indicative of brain lesins
39
What are the investigations for epilepsy?
- Blood: FBC, U&E, LFTs, glucose, Ca, Mg, ABG, toxicology screen, prolactin (transient increase shortly after a true seizure)
- EEG: Helps confirm or refute the diagnosis, assists in classifying the epileptic syndrome. Usually performed inter-ictally and often normal and does not rule out epilepsy. Ictal EEG's combined with video telemetry are more useful but requires adequate facilities
- CT/MRI: for structural, space-occupying and vascular lesions
- Other: Particularly for secondary seizures according to suspected aetiology e.g. lumbar puncture, HIV serology
40
How is status epilepticus (seizure lasting more than 30mins, failure to regain consciousness) managed?
Although defined as more than 30min or repeated seizures with failure to regain consciousness, treatment is often initiated in 5-10 mins as early treatment has higher treatment success
- Resuscitate and protect airway, breathing and circulation
- Check glucose and give if hypoglycaemic. Consider thiamine
- IV lorazepam or IV or PR diazepam (repeat once after 15 mins if needed). If seizures recur fail to respond, IV phenytoin (15mg/kg under ECG monitoring). Alternative IV agents include phenobarbitone, levetiracetam or sodium valproate
- If these measures fail, consider general anaesthesia. Requires intubation and mechanical ventilation
- Treat the cause e.g. correct hypoglycaemia or hyponatraemia
- Check plasma levels of all anticonvulsants
41
What pharmacological treatment is used to manage epilepsy?
- Only start anti-convulsant therapy after more than 2 unprovoked seizures
- There are numerous anti-convulsant agents, but SANAD trial suggests lamotrigine or carbamepine as first line treatment for focal seizures, and sodium valproate for generalised seizure
- Other agents used include phenytoin, levetiracetam, clobazam, tropiramate, gabapentin, vigabatrin, ethrosuximide (absence)
- Start treatment with single anti-epileptic drug (AED)
42
What patient education is advised in order to manage epilepsy?
- Patient education, avoid triggers (e.g. alcohol), encourage seizure diaries
- Recommend supervision for swimming or climbing, driving only permitted if seizure free for 6 months
- Women of childbearing age should be counseled regarding possible teratogenic effects of AEDs and should consider taking supplemental folate to limit the risk
- Drug interactions e.g. enzyme-inducing AEDs can limit the effectiveness of oral contraception
43
How does surgery manage epilepsy?
For refractory epilepsy
- Removal of definable epileptogenic focus (determined from detailed EEG, intracortical recordings, ictal SPECT, neuropsychometry)
- Alternatively, vagus nerve stimulator
44
What are the possible complications of epilepsy?
- Fractures with tonic-clonic seizures
- Behavioural problems
- Sudden death in epilepsy (SUDEP)
- Complications of AEDs (e.g. gingivial hypertrophy with phenytoin, neutropenia or osteoporosis with carbamazepine, Steven's-Johnson syndrome with lamotrigine)
45
What is the prognosis for epilepsy?
- 50% remission at 1 year
| - Mortality 2 in 100,000/year, directly related to seizure of secondary to injury
46
What is Guillain-Barre syndrome?
Acute inflammatory demyelinating polyneuropathy
47
What is the aetiology of Guillain-Barre syndrome?
An inflammatory process where antibodies after a recent infection reacts with self-antigen on myelin or neurons. There are rare axonal variants with no demyelination. Often no-aetiological trigger is identified (idiopathic in about 40%) , in other cases:
- Post-infection (1-3 weeks): bacterial (e.g. Campylobacter jejuni), HIV, herpes viruses (e.g. zoster, CMV)
- Malignancy (lymphoma, Hodgkin's disease)
- Post-vaccination
48
What is the epidemiology of Guillain-Barre syndrome?
Annual incidence is 1-2 in 100,000.
| Affects all age groups
49
What are the presenting symptoms of Guillain-Barre syndrome?
Progressive symptoms of less than 1 month duration:
- Ascending symmetrical limb weakness (lower more than upper)
- Ascending paraesthesia
50
What are the signs of Guillain-Barre syndrome on examination?
General motor examination: Hypotonia, flaccid paralysis, arreflexia (typically ascending upwards from feet to head)
- General sensory examination: Impairment of sensation in multiple modalities (typically ascending upwards from feet to head)
- Cranial nerve palsies (less frequently): Facial nerve weakness (lower motor neurone pattern), abnormality of external ocular movements, signs of bulbar palsy. If pupil constriction is affected, consider boltulism
- Type II respiratory failure: Important to identify early (e.g. C02 flap, bounding pulse drowsiness). Can be insidious and needs regular assessment
- Autonomic function: Assess for postural BP change and arrhythmias
51
What are the investigations for Guillain-Barre syndrome?
- Lumbar puncture: Raised CSF protein, cell count and glucose normal
- Nerve conduction study: Decreased conduction velocity or conduction block, but can be normal in the early phase of the disease
- Blood: Anti-ganglioside antibodies are positive in Miller-Fish variant and 25% of Guillain-Barre syndrome cases: consider C.jejuni serology
- Spirometry: Decreased fixed vital capacity indicated ventilatory weakness
- ECG: Arrhythmias may develop
52
What is Horner's syndrome?
Combination of symptoms that arises when the sympathetic trunk is damaged
53
What is the aetiology of Horner's syndrome?
- Acquired due to disease but may be congenital (inborn, associated with heterochromatic iris) or iatrogenic
- Central: Syringomyelia, MS, Encephalitis, Brain tumours, Lateral medullary syndrome
- Preganglionic: Cervical rib, thyroid carcinoma, thyroidectomy, goiter
- Postganglionic: Cluster headache, middle ear infection
- Results from lesion to sympathetic pathways that supply head and neck
54
What are the presenting symptoms of Horner's syndrome?
- Partial ptosis
- Anhidrosis
- Upside down ptosis (slight elevation of the lower lid)
55
What are the signs of Horner's syndrome on examination?
- Miosis
- Pseudoendopthalmos
- Pupillary dilation lag
- Loss of ciliospinal reflex
- Bloodshot conjuctiva, depending on site of lesion
- Unilateral straight hair (in congenital Hornery's syndrome), hair on affected side may be straight in some cases
- Heterochromia iridum (congenital)
56
What are the investigations for Horner's syndrome?
- Cocaine drop test
- Paredrine test: helps localise cause of miosis
- Dilation lag test
57
How is Horner's syndrome managed?
No specific treatment
| - Often it disappears when an underlying medical condition is effectively treated
58
What are the possible complications of Horner's syndrome?
- Anisocoria
- Enopthalmos
- Hypohidrosis
- Blepharoptosis
- Pupillary constriction
59
What is the prognosis of Horner's syndrome?
Depends on whether treatment of cause is successful
60
What is Huntington's disease?
Autosomal dominant trinucleotide repeat disease characterised by progressive chorea and dementia, typically commencing in middle age
61
What is the aetiology of Huntington's disease?
- Huntingtin gene is located on chromosome 4p and codes for the protein hungtingtin
- In huntingtin gene, there is an extended trinucleotide repeat expansion (CAG) resulting in a toxic gain of function
- Disease is inherited in an autosomal dominant pattern and exhibits anticipation (earlier age of onset in each successive generation)
62
What is the epidemiology of Huntington's disease?
Worldwide prevalence eight in 100,000
- Average onset 30-50 years
- Rare in East Asian populations (particularly Japan)
63
What are the presenting symptoms of Huntington's disease?
- Family history of Huntington's disease
- Insidious onset in middle-age of progressive fidgeting and clumsiness, developing into involuntary, jerky, dyskinetic movements often accompanied by grunting and dysarthia
- In late disease, the patient may become rigid, akinetic and bed-bound
- Early cognitive, emotional and behavioural changes are dominated by lability, dysphoria, mental inflexibility, anxiety, leading on to dementia
- Inquire about drug history (especially cocaine, anti-psychotics)
64
What are the signs of Huntington's disease on examination?
- Classically, patient present with chorea and dysarthria
- Slow voluntary saccades and supranuclear gaze restriction
- Other presentation include parkinsonism and dystonia (especially in juvenile-onset disease)
- Mental state examination reveals cognitive and emotional deficits
65
What are the investigations for Huntington's disease?
- Genetic analysis: Diagnostic if more than 39 CAG repeats in HD gene. Intermediate repeat lengths (27-39) exist with reduced penetrance
- Imaging: Brain MRI or CT may show symmetrical atrophy of the striatum (particularly the caudate nuclei) and butterfly dilation of the lateral ventricles
- Bloods: May be necessary to exclude other pathology: caeruloplasmin, anti-nuclear antibodies blood film (acanthocytes), TFT, ESR
66
What is hydrocephalus?
- Enlargement of the cerebral ventricular system
- Subdivisable into obstructive and non-obstructive (or communicating or non-communicating
- Hydrocephalus ex vacuo is a term used to describe apparent enlargement of ventricles but this is a compensatory change due to brain atrophy
67
What is the aetiology of hydrocephalus?
Abnormal accumulation of CSF in the ventricles can be caused by
1) Impaired outflow of the CSF from ventricular system (obstructive)
- Lesions of the third ventricle, fourth ventricle, cerebral aqueduct
- Posterior fossa lesions (e.g. tumour, blood) compressing the fourth ventricle
- Cerebral aqueduct stenosis
2) Impaired CSF resorption in the subarahnoid villi (non-obstructive)
- Tumours
- Meningitis (typically tuberculosis)
- Normal pressure hydrocephalus (NPH) is the idiopathic chronic ventricular enlargement. The long white matter tract (corona radiata, anterior commisure) are damaged causing gait and cognitive decline)
68
What is the epidemiology of hydrocephalus?
- Bimodal age distribution
| - Congenital malformations and tumours in the young, tumours and stroked in the elderly
69
What are the presenting symptoms of hydrocephalus?
- Obstructive hydrocephalus: Acute drop in conscious level. Diplopia.
- NPH: Chronic cognitive decline falls, urinary incontinence
70
What are the signs of hydrocephalus on examination?
- Obstructive: Impaired GCS, papilloedema, VI nerve palsy ('false localising sign' of increased ICP). In neonates, the head circumference may enlarge, and 'sunset sign' (downward conjugate deviation of eyes)
- NPH: Chronic cognitive decline, Gait apraxia (shuffling), Hyperreflexia
71
What are the investigations for hydrocephalus?
- CT head: First line investigation to detect hydrocephalus, may also detect the cause (e.g. tumour in the brainstem)
- CSF: Obtained from ventricular drains or lumbar puncture may indicate an underlying pathology (e.g. tuberculosis). Check for MC&S, protein, glucose (CSF and plasma)
- Lumbar puncture: This is contra-indicated in obstructive hydrocephalus as can cause tonsilar herniation and death. May be necessary in NPS as a therapeutic trial
72
What is a lumbar puncture?
Medical procedure in which a needle is inserted into the spinal canal, most commonly to collect CSF for diagnostic testing
73
What are the indications for a lumbar puncture?
- Diagnostic: Analysis of CSF may exclude infectious, inflammatory and neoplastic disease affecting the CSF. Meningitis most common. Detects whether someone has Stage 1 or 2 trypanosoma bucrei
- Therapeutic: Inject medications into CSF particularly spinal anaesthesia or chemotherapy
74
What are the possible complications of lumbar puncture?
- Post spinal headache with nausea
- Paresthesia in leg: due to contact between the side of lumbar puncture needle and a spinal nerve root
- Serious but rare: Epidural bleeding, adhesive arachnoiditis, trauma to spinal cord, paraplegia
75
What is meningitis?
Inflammation of the leptomeningeal (pia mater and arachnoid) coverings of the brain, most commonly caused by infection
76
What is the aetiology of meningitis?
Bacterial
- Neonates: Group B streptococci, E. coli. L. monocytogenes
- Children: Haemophilus influenzae, Neisseria meningitidis, S. pneumoniae
- Adults: Neisseria meningitidis (meningococcus), S. pneumoniae, tuberculosis
- Elderly: S. pneumoniae, L. monocytogenes
Viral: Enteroviruses, mumps, HSV, VZV, HIV
- Fungal: Cryptococcus (associated with HIV infection
- Others: Aseptic meningitis, Mollaret's meningitis
- Risk factors: Close communities (e..g dormitories, basal skull fractures, mastoiditis, sinusitis, inner ear infections, alcoholism, immunodeficiency, splenectomy, sickle cell anaemia, CSF shunts, intracranial surgery
77
What is the epidemiology of meningitis?
- Variation according to geography, age, social conditions
| - More common in recent visitors to the Haj, epidemics occur in the meningitis belt of Africa
78
What are the presenting symptoms of meningitis?
- Severe headache, photophobia, neck or backache, irritability, drowsiness, vomiting, high-pitches crying or fits (common in children), clouding of consciousness, fever
- Careful history should include travel and exposure history: exposure to rodents (Lymphocytic choriomeingitis virus), ticks (e.g. Lyme borrelia, Rocky Mountain spotted fever), mosquitoes (West Nile virus), sexual activity (HIV, syphilis), travel, and contact with other individuals with viral exanthems (enteroviruses)
79
What are the signs of meningitis on examination?
- Signs of meningism: Photophobia, neck stiffness (Kernig's sign, with hips flexed, pain/resistance on passive knee extension, Brudzinki's sign, flexion of hips on neck flexion)
- Signs of infection: Fever, tachycardia and hypotension, skin rash (petechiae with meningococcal septicaemia) altered mental state
80
What are the investigations for meningitis?
- Blood: 2 sets of blood cultures (do not delay antibiotics)
- Imaging: CT scan to exclude a mass lesion or increased intracranial pressure before LP (may lead to cerebral herniation during subsequent CSF removal). CT scan of head must be done before LP in pts with immunodeficiency, Hx of CNS disease, decreased consciousness, fit, focal neurological deficit or papilloedema
- Lumbar puncture: Note opening CSF pressure. Send CSF for microscopy with, culture, sensitivity and Gram staining, biochemistry and cytology. Bacterial: Cloudy CSF, increased neutrophils, increased protein, decreased glucose (CSF: serum glucose ratio of less than 0.5)
- Viral: Increased lymphocytes, proteins, normal protein
- TB: Fibrinous CSF, increased lymphocytes and protein, decreased glucose
- Also viral PCR, staining/culture for mycobacteria and fungi, HIV test depending on clinical presenation
81
How is meningitis managed?
- Immediate IV/IM antibiotics if meningitis suspected. 3rd generation cephalorsporin. Benzylpenicillin may be given as initial 'blind' therapy and for sensitive meningococci and pneumococci. Amoxicillin & gentamicin for Listeria. For penicillin and cephalosporin resistant pneumococci: add vancomycin and if necessary rifampicin. If hx of anaphylaxis to penicillin or cephalosporing or organism resistant to these, use chloramphenicol (eliminates nasopharyngeal carriage)
- Dexamethasone: IV, given shortly before or with first dose of antibiotics. Continue in pneumococcal or H. influenzael Avoid dexamethasone if HIV is susoected.
- Resuscitation: Patient is best managed in ITU.
- Prevention (only applicable to meningococcal): Notify public health services ad consult a consultant in communicable disease control for advice regarding chemoprophylaxis
82
What are the possible complications of meningitis?
- Septicaemia
- Shock
- DIC
- Renal failure
- Peripheral gangrene
- Cerebral oedema
- Cranial nerve lesions
- Cerebral venous thrombosis
- Hydrocephalus
- Water-house Friderischsen syndrome (bilateral adrenal haemorrhage)
83
What is the prognosis of meningitis?
- Mortality rate from bacterial meningitis is high
- In developing countries, mortality rate is often higher
- Viral meningitis is self-limiting
84
What is a migraine?
- Severe episodic headache that may have a prodrome of focal neurological symptoms (aura) and associated with systemic disturbance
- Can be subclassified as migraine with aura (classical migraine) or without aura (common migraine) and migraine variants (familial hemiplegic, opthalmoplegic and basilar)
85
What is the aetiology of migraine?
- Precise pathophysiological mechanism poorly understood. Early aura of corticol spreading depression associated with intracranial vasoconstriction resulting in localised ischaemia
- Followed by meningeal and extracranial vasodilation mediated by 5-HT, bradykinin and the trimeninovascular systemic
- Familial hemiplegic migraine: Rare, mutation int he P/Q type calcium channel are the cause of this rare form of migraine
86
What is the epidemiology of migraine?
- Prevalence is 6% in males and 15-20& in females
- Female: Male= 3:1
- Usual onset in adolescence or early adulthood, but can occur in middle age
87
What are the presenting symptoms of migraine?
- Headache: Pulsating. Bilateral. Duration 4-72h. Obtain a detailed history of headache frequency and pattern. Most migraine attacks are episodic and chronic daily headache lasting many weeks suggest either analgesia-overuse headache or secondary headaches
- Associated symptoms: Associated with nausea, vomiting, photophobia or phonophobia. May be preceded by aura that may include visual disturbance, flashing lights, spots, blurring, zigzag lines (fortification spectra), blindspots (scotomas) or other sensory symptoms such as tingling or numbness in limbs
- Triggers or risk factors: Obtain a detailed history of possible triggers, including stress, exercise, lack of sleep, oral contraceptive pill, certain foods (e.g. caffeine, alcohol, cheese, chocolate and the pattern of analgesia use
88
What are the signs of a migraine on examination?
- Usually no specific physical findings
- Examination of mental state, neurological examination, fundoscopy, sinuses cervical spine, general examination to exclude secondary causes. (e.g. meningocephalitis, idiopathic intracranial hypertension, subarachnoid haemorrhage, space-occupying lesion, temporal arteritis)
89
What are the investigations for meningitis?
Diagnosis based on history. Ix may be needed to exclude other diagnoses
- Blood: FBC, ESR
- CT/MRI: If suspicion of secondary headache disorders
- Lumbar puncture: If suspicion of meningitis. Do not perform until space-occupying lesion excluded
90
How are migraines managed?
- Medical: beware of analgesia-overuse headaches as pts use OTC preparations
- Acute: NSAID (e.g. naproxen), paracetamol, codeine and antiemetics (e.g. metoclopramide). Variety of triptans (5-HT, agonists) are available but commonly used ones are sumatriptan and zolmitriptan (which can be given orally, nasally or subcutaneously). Ergotamine is rarely used due to complex dosing schedules
- Prophylaxis (if more than 2/month, 50% pts benefit: B-blockers, amitriptyline, topiramate and sodium valproate and calcium channel blocker. Menstrual migraine can be controlled by oral contraceptive pill
- Advice: Encourage regular meals and sleep, caffeine restriction, measures to reduce stress, avoid triggers, symptoms diary. Rest in quiet dark room during episode
91
What are the possible complications of a migraine?
- Disruption of daily activity
| - Can progress onto analgesia-overuse headache due to chronic use of analgesics
92
What is the prognosis of migraine?
Usually chronic, but majority of cases can be managed well by preventative/early treatment measures
93
What is motor neuron disease?
A progressive neurodegenerative disorder of cortical, brainstem and spinal motor neurons (lower and upper motor neuron
94
What are the various subtypes of motor neuron disease?
- Amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease: combined degeneration of upper and lower motor neurones producing a mix of UMN and LMN neurones
- Progressive muscular atrophy variant: Only LMN signs e.g. flail or flail foot syndrome. Better prognosis.
- Progressive bulbar palsy variant: Dysarthria and dysphagia with wasted fasciculating tongue (LMN) and brisk jaw jerk (UMN)
- Primary lateral sclerosis variant: UMN pattern of weakness, brisk reflexes, extensor plantar responses, without LMN signs
95
What is the aetiology of motor neuron disease?
- Unknown. Free radical damage and glutamate excitotoxicity have been implication as mutation in superoxide dismutase (SOD1 gene) affect 20% with familial motor neuron disease and 1-4% of sporadic cases. SOD1 codes for a metalloenzyme for the conversion of free radicals
- Associated with frontotemporal lobar dementia (FTLD) from proganulin mutations
96
What is the pathology of motor neuron disease?
Progressive motor neuron degeneration and death with gliosis replacing lost neurones. Neurons may exhibit intracellular inclusions (neurofilaments or ubiquinated inclusions) containing the TAR-DNA binding protein 43 (TDP-43)
97
What is the epidemiology of motor neuron disease?
- Rare annual incidence is 2 per 100,000
- Mean age of onset is 55 years
- 5-10% have FHx with autosomal dominant inheritance
98
What are the presenting symptoms of motor neuron disease?
- Weakness of limbs (focal or asymmetrical)
- Speech disturbance (slurring or reduction in volume)
- Swallowing disturbance (e.g. choking on food, nasal regurgitation
- There may be behavioural changes (e.g. disinhibition, emotional lability)
99
What are the signs of motor neuron disease on examination?
Combination of UMN and LMN signs often affecting several regions asymmetrically
- LMN features: Muscle wasting, fasciculations, flaccid weakness, depressed or absent reflexes
- UMN features: Spastic weakness, brisk reflexes, extensor plantars
- Sensory examination: Should be normal
100
What are the investigations for motor neuron disease?
Investigations aimed to confirm the diagnosis by providing evidence of combined UMN and LMN loss and excluding other causes
- Blood: CK (mild increase), ESR. Consider testing for anti-GM1 ganglioside antibodies (present in multifocal motor neuropathy)
- Electromyography: Features of acute or chronic denervation with giant motor unit action potentials in more than 1 limb and/or paraspinals
- Nerve conduction studies: Most often normal
- MRI: To exclude cord or root compression, and brainstem lesion in progressive bulbar palsy variant. May show high signal in motor tract on T2 imaging
- Spirometry: To assess respiratory muscle weakness (FVC)
101
What is Multiple Sclerosis (MS)?
Inflammatory demyelinating disease of the CNS
- Relapsing-remitting MS: Commonest form. Characterised by clinical attack of demyelination with complete recovery in between attacks
- Clinically isolated syndrome: Single clinical attack of demyelination, (does not qualify as MS; 10-50% progress to developing MS
- Primary progressive MS: Steadily accumulation of disability with no clear relapsing-remitting pattern
- Marburg variant: Severe fulminant variant of MS leading to advanced disability of death within a period of weeks. Distinct from acute disseminated encephalomyelitis (ADEM)
102
What is the aetiology of Multiple Sclerosis?
Unknown. Autoimmune basis with postulated environmental trigger in a genetically susceptible individual. Immune-mediated damage to CNS myelin results in impaired conduction along axons. there is also associated grey matter atrophy
103
What are the risk factors for Multiple Sclerosis?
- A role for EBV exposure and prenatal vitamin D levels have been proposed based on epidemiological studies.
- Strong concordance in monozygotic versus dizygotic twins
- Geographical variation with individuals carrying the risk of their pre-pubertal country of origin
104
What is the epidemiology of Multiple Sclerosis?
- Prevalence in UK is 1/1000 (rare in Far East
- Female: Male 2:1
- Usually presents at 20-40 years
105
What are the presenting symptoms of multiple sclerosis?
Varies depending on site of inflammation
- Optic neuritis (commonest): Unilateral deterioration in visual acuity and colour perception. Pain on eye movement
- Sensory system: Pins and needles, numbness, burning
- Motor: Limb weakness, spasms, stiffness, heaviness
- Autonomic: Urinary urgency, hesitancy, incontinence, impotence
- Psychological: Depression, psychosis
- Uhtoff's phenomenon: Transient increase or recurrence of symptoms due to conduction block precipitated by a rise in body temperature
106
What are the signs of multiple sclerosis on examination?
- Optic neuritis: Impaired visual acuity (most common), loss of coloured vision. On fundoscopy, in active disease, there is a swollen optic nerve head, in chronic disease, may be optic atrophy
- Visual field testing: Central scotoma (optic nerve affected) or field defects (optic radiations affected)
- Relative afference pupillary defect: Testing with a swinging torch test. Both pupils contract when light is shone on the unaffected side, both pupils dilate when light is swung to diseased eye
- Internuclear ophthalmoplegia: Lateral horizontal gaze produces a failure of adduction of the contralateral eye. Indicates a lesion of the contralateral medial longitudinal fasciculus
- Sensory: Paraesthesia (vibration and joint position sense loss more common than pain and temperature)
- Motor: UMN signs (e.g. spastic weakness, brisk reflexes)
- Cerebellar: Limb ataxia (intention tremor, past-pointing and dysmetria on finger-nose test and heel-shin test) dysdiadochoinesis, ataxic wide-based gait, scanning speech
- Lhermitte's phenomenon: Electric shock-like sensation in arms and legs precipitated in neck flexion
107
What are the investigations of multiple sclerosis?
Diagnosis based on two or more CNS lesions with corresponding symptoms, separated in time and space (McDonald criteria)
- Lumbar puncture: Microscopy to exclude other infective or inflammatory causes. CSF electrophoresis shows unmatched oligoclonal bands
- MRI-brain, cervical and thoracic spine (with gadolinium): Plaque detection is highlighted as high-signal lesions. Gadolinium enhancement indicates an active lesion
- Evoked potentials: Visual, auditory or somatosensory evoked potential (VEP, BEP, SEP) may show delayed conduction velocity. VEPs are delayed in approx 90% of pts with MS
108
What is myasthenia gravis?
An autoimmune disease affecting the neuromuscular junction producing weakness of skeletal muscles
109
What is the aetiology of Myasthenia gravis?
- Impairment of neuromuscular junction transmission, most commonly due to auto-antibodies against the nicotinic acetylcholine receptor (nAChR). A paraneoplastic subtype (Lamber-Eaton myasthenic syndrome) is caused by auto-antibodies against pre-synaptic calcium ion channels impairing acetylcholine release
- Myasthenia gravis associated with other autoimmune conditions (e.g. pericious anaemia) and thymoma development. Breakdown in immune tolerance though to arise thymus (75% have thymoma)
110
What is the aetiology of myasthenia gravis?
- Prevalence is 8-9 in 100,000
| - More common in females at younger ages, but equal gender distribution in middle age
111
What are the presenting symptoms of myasthenia gravis?
- Muscle weakness that worsens with repetitive use or towards end of day
- In Lamber-Eaton syndrome, the muscle weakness improves after repeated use
- Ocular symptoms: Drooping eyelids, diplopia
- Bulbar symptoms: Facial weakness (myasthenic snarl, distributed hypernasal speech, difficulty in smiling, chewing or swallowing (nasal regurgitation of fluids)
112
What are the signs of myasthenia gravis on examination?
May be generalised (affecting many muscle groups), bulbar (affecting bulbar muscles) or ocular (affecting only the eyes)
- Eyes: bilateral ptosis, may be asymmetrical. Complex opthaoplegia. Test for ocular fatigueability by asking pt to sustain upward gaze for 1 min and watch for progressive ptosis
- 'Ice on eyes' test: Placing ice packs on closed eyelids for 2 min can improve neuromuscular transmission, reducing ptosis. Considered positive when ptosis improves by more than 2mm from baseline
- Bulbar: Reading aloud may provoke dysarthria or nasal speech after 3mins
- Limbs: Test the power of a muscle before and after repeated use of the muscle (e.g. 20 repetitions)
113
What are the investigations for myasthenia gravis?
- Blood: CK (to exclude myopathies). Serum acetylcholine receptor antibody (positive in 80%), TFT (associated hyperthyroidism). Atypical features may warrant testing of anti-MUSK antibody (uncommon variant) and anti-voltage-gated-calcium antibody (Lamber-Eaton syndrome)
- Tensilon test: Short-acting- anti-cholinesterase (e.g. edrophonium) increases acetylcholin levels by blocking its metabolism and causes rapid and transient improvement in clinical features. Generally avoided due to risk of bradycardia (atropine and cardiac resuscitation equipment must be kept at hand) and subjectively of most clinical features
- Nerve conduction study: repetitive stimulation demonstrating decrements of the muscle action potential. May differentiate between myasthenic gravis and Lamber-Eaton myasthenic syndrome
- EMG: single-fibre EMG may demonstrate jitter (variability in latency from stimulus to muscle potential) indicating fluctuation in neuromuscular conduction
- CT-thorax and or CR: to visualise thymoma in the mediastinum or malignancies in the lung
114
What is neurofibromatosis?
An autosomal dominant genetic disorder affecting cells of neural crest origin, resulting in the development of multiple neurocutaneous tumours
- Type 1 NF (von Recklinghausen's disease): Characterised by peripheral and spina neurofibromas, multiple cafe au lait spots, freckling (axillary/inguinal), optic nerve glioma, Lisch nodules (on iris), skeletal deformaities, phaeochromocytomas and renal artery stenosis
- Type 2 NF: Characterised by schwannomas e.g. bilateral vestibular swchwannomas (acoustic neuromas), peripheral/spinal schwannomas, meningiomas, gliomas, cataracts
115
What is the aetiology of neurofibromatosis?
Multiple mutations have been described in tumour suppressor genes NF1 and NF2
- Type 1: Mutations in NF1 gene (chromosome 17) which encodes neurofibromin (a GTPase activating protein). Mutations in neurofobromin result in excessive activity of the proto-oncogene p21-ras
- Type 2: Mutations in NF2 (chromsome 22) which encodes merlin (or schwannomin)
116
What is the epidemiology of neurofibromatosis?
- Incidence is one in 3000 births for type 1 NF and one in 40,000 for type 2.
- No gender or racial predilection
117
What are the presenting symptoms of neurofibromatosis?
Positive FHx (but 50% caused by new mutations)
- Type 1: Skin lesions, learning difficulties (in 40%), headaches, disturbed vision (optic gliomas), precocious puberty (may indicate lesions of the pituitary from optic glioma involving the chiasm
- Type 2: Hearing loss, tinnitus, balance problems, headache, facial pain or numbness
118
What are the signs of neurofibromatosis on examination?
- Type 1: More than 5 cafe au lait macules of more than 5mm (pre-pubertal individuals), or more than 25 mm (post-pubertal individuals), neurofibromas (appear as cutaneous nodules or complex plexiform neuromas), freckling in armpit or groin, Lisch nodules (hamartomas on iris), spinal scoliosis
- Type 2: Few or no skin lesions, sensorineural deafness with facial nerve palsy or cerebellar signs if schwannoma large
119
What are the investigations for neurofibromatosis?
- Ophthalmological assessment
- Audiometry
- MRI brain and spinal cord: For vestibular schwannomas meningiomas and nerve roots neurofibromas
- Skull X-Ray: Splenoid dysplasia in type 1 NF
- Genetic testing: Possible but difficult as NF1 gene is very long
120
What is Parkinson's disease?
Neurodegenerative disease of the dopaminergic neurones of the substantia nigra, characterised by bradykinesia, rigidity, tremor and postural instability
121
What is the aetiology of Parkinson's disease?
1) Sporadic and idiopathic (most common): Unknown. Environmental toxins and oxidative stress have been proposed (e.g. pesticides, wood pulp)
2) Secondary
- Neuroleptic therapy (e.g. in schizophrenia)
- Vascular insults (e.g. basal ganglia or midbrain strokes)
- MPTP toxin from illicit drug contamination
- Post-encephalitis (e.g. influenza)
- Repeated head injury (e.g. boxing
3) Familial forms: Genes mutations that cause Parkinson's disease are in LRRK2, PARK2 (Parkin), PARK7, PINK1 and SNCA genes
122
What is the epidemiology of Parkinson's disease?
- Very common
- 1-2% of over 60yr olds.
- Annual incidence is 20 in 100000
- Mean age of onset is 57 yrs
123
What are the presenting symptoms of Parkinson's disease?
- Insidious onset
- Tremor at rest, usually noticed in hands
- Stiffness and slowness of movements
- Difficulty in initiating movements (e.g. getting out of chair, rolling in bed)
- Frequent falls
- Smaller hand writing (micrographia)
- Insomnia, mental slowness (bradyphenia)
124
What are the signs of Parkinson's disease on examination?
- Tremor: Classically 'pill rolling' rest tremor in the hands of about 4-6 Hz frequency. Decreased on action or flexed poster. Usually asymmetrical
- Rigidity: Lead pipe rigidity of muscle tone, with superimposed tremor (cogwheel rigidity). Rigidity can be enhanced by distraction (asking the pt to keep raising and lowering the other arm)
- Gait: Stooped, simian', shuffling, small-stepped gait with reduced arm swig. Freezing (difficulty in initiation of walking)
- Postural instability: Falls easily with little pressure from back (propulsion) or the front (retropulson
- Other features: Frontalis overactivations (furrowing of the brow), expressionless face (hypomimia), soft monotonous voice (hypophona), impaired olfaction on formal testing. There may be mild impairment of up-gaze and tendency to droop (sialorrhoea). Involuntary movement in one part of face associated with voluntary movement in another part of face (synkinesis)
- Psychiatric: Depression is very common. Cognitive problems and dementia may occur in late disease
125
What is the pathogenesis of Parkinson's disease?
- Degeneration of midbrain dopaminergic neurones projecting from the substantia nigra to the striatum (caudate nucleus and putamen)
- Surviving neurones often contain eosinophilic, cytoplasmic inclusions (Lewy bodies)
- Patients only symptomatic after more than 70% neuronal loss. Nigrostriatal dopaminergic deficiency causes abnormalities of plasticity in the basal ganglia and cerebral cortex
126
What are the investigations for Parkinson's disease?
Diagnosis is clinical
- Levodopa trial: Timed walking and clinical assessment after levodopa may be informative. Antiemetic (domperidone) may be needed
- Blood: Serum ceruloplasmin (excludes Wilson's disease in young onset)
- CT or MRI brain: Useful for excluding other causes of gait decline (e.g. hydrocephalus, vascular disease)
- Dopamine transporter scintigraphy (DAT-scan): Reduction in striatum and putamen. May be necessary for distinguishing from essential tremor
127
What is spinal cord compression?
Results from processes that compress or displace arterial, venous and cerebrospinal fluid spaces, as well as the cord itself. Can occur as a result of extrinsic causes and lesions, or intrinsic aetiologies of the cord substance
128
What is the aetiology of spinal cord compression?
Can occur as result of spine trauma, vertebral fracture, intervertebral disc herniation, primary or metastatic spinal tumour, or infection
- Trauma: car accidents, falls, gunshot wounds, sports injuries, diving
- Vertebral fracture: osteoporosis, corticosteroid therapy, osteomalacia, osteomyelitis
- Tumours: primary sarcoma, CNS tumours, multiple myeloma
129
What is the epidemiology of spinal cord compression?
- Affects people across all age groups worldwide
| - Trauma is main cause
130
What are the presenting symptoms of spinal cord compression?
- Presence of risk factors (16-30 male, trauma, tumour, osteoporosis, high risk occupation)
- Acute onset and duration of symptoms
- Chronic onset and duration of symptoms
- Back pain
- Weakness of paralysis
- Bladder or bowel dysfunction
131
What are the signs of spinal cord compression on examination?
- Numbness or paraesthesias
- Hyper-reflexia
- Sensory loss
- Muscle weakness or wasting
- Loss of tone below level of suspected injury (spinal shock)
- Hypotension and bradycardia (neurogenic shock)
- Complete cord transection syndrome
- Cauda equina syndrome
- Central cord syndrome
132
What are the investigations for spinal cord compression?
- MRI spine: disc displacement, epidural enhancement, mass effect, T2 cord signal
- Gadolinium-enhanced MRI spine: infection, epidural space and bone involvement, metastatic disease, visualisation of tumour
- Plain spine x-ray: decreased disc space height (disc compression), loss of bony detail (tumour, infection
- CT spine: cord compression from tumour expansion
- CT myelography: classical hour-glass constriction shape of the dye column
133
What is a stroke?
- Rapid permanent neurological deficit from cerebrovascular insult.
- Also defined clinically, as focal or global impairment of CNS function developing rapidly and lasting more than 24h
- Can be subdivided by location (anterior circulation or posterior circulation) or by pathological process (infarction, haemorrhage)
134
What is the aetiology of an ischaemic stroke?
- Thrombosis: in the elderly, arises from arthersclerosis within cerebral vessels affecting mainly small vessels (causing lacunar infarcts) and less commonly large vessels (e.g. middle cerebral artery). Can also arise from prothrombotic states (e.g. dehydration or thrombophilia)
- Emboli: From intimal flap of carotid dissection, atheromatous plaques in the carotid arteries or from the heart (e.g. atrial fibrillation). Rarely, they can arise from venous circulation and pass through right-left heart defect (e.g. VSD)
- Others: vasculitis, cocaine
135
What is the aetiology of haemorrhagic stroke?
- Hypertension
- Charcot-Bouchard microaneurysm rupture
- Amyloid angiopathy
- Arteriovenous malformations
- Less commonly: trauma, tumour, arteriovenous malformations, vasculitis
136
What is the epidemiology of strokes?
- Common
- Annual incidence is 2/1000
- 3rd most common cause of death in industrialised countries
- Most patients are in seventh decade
- Young strokes (less than 50 years merit extensive investigation)
137
What are the presenting symptoms of a stroke?
- Sudden onset (deterioration within seconds)
- Weakness, sensory, visual or cognitive impairment, impaired coordination, or consciousness
- Head or neck pain (in carotid or vertebral artery dissection
- Enquire time of onset (critical for emergency management if more than 4.5h)
- Enquire if history of atrial fibrillation, MI, valvular heart disease, carotid artery stenosis, recent neck trauma or pain
138
What are the signs of ischaemic stroke on examination if the infarction is in the anterior circulation?
- Anterior cerebral: lower limb weakness (motor cortex), confusion (frontal lobe)
- Middle cerebral: Facial weakness, hemiparesis (motor cortex), hemisensory loss (somatosensory cortex), apraxia, hemineglect (parietal lobe), receptive or expressive dysphagia (language centres), quadrantanopia (superior or inferior optic radiations)
139
What are the signs of ischaemic stroke on examination if the infarction is in the small vessels (lacunar)?
Disease in the deep perforating arteries
- Internal capsule or pons: Pure sensory or motor deficit (or combination of both)
- Thalamus: Loss of consciousness, hemisensory deficit
- Basal ganglia: Hemichorea, hemiballismus, parkinsonism
140
What are the signs of ischaemic stroke if the infarction is in the posterior circulation?
- Posterior cerebral: Hemianopia
- Anterior inferior cerebellar artery: Vertigo, ipsilateral ataxia, ipsilateral deafness (or tinnitus), ipsilateral facial weakness
- Posterior inferior cerebellar artery (lateral medullary syndrome of Wallenberg): Vertigo ipsilateral ataxia, ipsilateral Horner's syndrome, ipsilateral hemifacial sensory loss, dysarthria and contralateral spinothalamic sensory loss
- Basilar artery: Combination of cranial nerve pathology and impaired consciousness (emergency)
- Multiple lacunar infarcts: Vascular dementia, urinary incontinence, gait apraxia ('marche a petits pas', shuffling small stepped gait, with upright posture and often normal or excessive arm-swing)
141
What are the signs of a haemorrhagic stroke on examination?
- Intracerebral: Headache, meningism, focal neurological signs, nausea and vomiting, signs of raised ICP, seizures
- Subarachnoid: subarachnoid haemorrhage signs
142
What is the pathology of a stroke?
Ischaemic brain becomes soft due to vasogenic oedema from breakdown of blood-brain barrier and prone to haemorrhagic transformation. This can cause secondary damage to the CNS.
143
What are the investigations for a stroke?
- Blood: FBC, U&E, glucose, clotting profile, lipids (consider thrombophilia screen especially in young pts)
- ECG: identify arrhythmias which predispose to embolism
- Echo: Identifies cardiac thrombus, valvular endocarditis or other sources of embolism. Consider bubble contrast study for right-to-left shunt (e.g. VSD)
- Carotid Doppler ultrasound: Important to exclude carotid artery disease
- CT head: For rapid detection of haemorrhages. Often normal especially in lacunar infarcts or very early in stroke.
- MRI brain: Rarely available acutely, but much higher sensitivity for infarction.
- CT-cerebral angiogram: Detect artery dissections and intracranial stenosis
144
How is a hyperacute stroke managed?
If less than 4.5 h from onset and haemorrhage excluded on CT head, IV thrombolysis may be considered. Do not give aspirin in first 24h. Follow local protocols due to very strict inclusion and exclusion criteria
145
How is an acute ischaemic stroke managed?
- Aspirin or clopidogrel to prevent further thrombosis once haemorrhage excluded on CT head
- Heparin anti-coagulation may be considered in certain subgroups where there is a high risk of emboli recurrence or stroke progression (e.g. carotid dissection, recurrent cardiac emboli, critical carotid artery stenosis)
- Formal swallow assessment is essential (NG tube may be required)
- Close nursing and GCS monitoring
- Thromboprophylaxis (but no evidence of net benefit from graded compression stockings in CLOTS trial)
- Hemicraniectomy may be indicated for mass effect from infarcted tissue in first 48h (DESTINY and HAMLET) trials
146
How is intracerebral haemorrhage managed?
- Control hypertension and seizures
- IV mannitol and hyperventilation helps lower intracranial pressure
- Evacuation of haematoma or ventricular drainage may be required
147
What is the secondary prevention for stroke?
- Aspirin and dypyridamole
- Warfarin anticoagulation (if atrial fibrillation)
- Stop smoking
- Control hypertension and hyperlipidaemia
- Treatment if CAD
148
How is multidisciplinary rehabilitation used to manage stroke?
- Speech and language therapy
- Occupational therapy
- Physiotherapy
- Neuropsychology
149
What are the possible complications of a stroke?
- Cerebral oedema (raised ICP and local compression)
- Immobility
- Infections (e.g. pneumonia, UTI, from pressure sores)
- DVT
- Cardiovascular events (arrhythmias, MI, cardiac failure)
- Death
150
What is the prognosis for a stroke?
- 10% mortality in first month
- Up to 50% of those who survive remain dependent
- 10% have a recurrence in 1 year
- Generally, poorer for haemorrhages than for infarction
151
What is a subarachnoid haemorrhage?
Arterial haemorrhage into the subarachnoid space
152
What is the aetiology of subarachnoid haemorrhage?
- Rupture of a saccular aneurysm at the base of brain (usually Circle of Willis): 85%
- Perimesencephalic haemorrhage (e.g. parenchymal haemorrhages tracking onto surface of brain): 10%
- Arteriovenous malformations, bleeding diatheses, vertebral or carotid artery dissection with intracranial extension, myotic aneurysms, drug abuse (e.g. cocaine, amphetamines): 5%
- Associated with hypertension, smoking, excess alcohol intake, saccular aneurysms are associated with polycystic kidney disease, Marfan's syndrome, pseudoaxanthoma elasticum and Ehler's Danlos syndrome
153
What is the epidemiology of Subarachnoid haemorrhage?
- Annual incidence is 10/100000
| - Peak age of incidence in the fifth decade
154
What are the presenting symptoms of a subarachnoid haemorrhage?
- Sudden onset severe headache (classically described 'as if hit at back of the head)
- Nausea, vomiting, neck stiffness, photophobia
- Decreased level of consciousness
155
What are the signs of a subarachnoid haemorrhage on examination?
- Meningism: Neck stiffness, Kernig's sign (resistance or pain on knee extension when hip is flexed) because of irritation of the meninges by blood. Pyrexia may also occur
- GCS: Assess and regularly monitor for deterioration.
- Signs of increased intracranial pressure: Papilloedema, IV or III cranial nerve palsy. Hypertension and bradycardia
- Fundoscopy: Rarely subhyaloid haemorrhage (between retina and virtreous membrane)
- Focal neurological signs: Usually develop on second day and are caused by ischaemic from vasospasm and reduced brain perfusion. Aneurysms may cause pressure on cranial nerves causing ophthalmoplegia (classically III nerve or VI nerve palsy)
156
What are the investigations for subarachnoid haemorrhage?
- Blood: FBC, U&E, ESR/CRP, clotting
- CT scan: Hyperdense areas in the basal regions of the skull (caused by blood in the subarachnoid space). Identifies any intraparenchymal or intraventricular haemorrhages as well
- Angiography (CT or intra-arterial): TO detect the source of bleeding if the patient is a candidate for surgery or endovascular treatment
- Lumbar puncture: Raised opening pressure, increased red cells, few white cells xanthochromia (strawberry coloured CSF) because of breakdown of Hb, confirmed by spectrophometry of CSF supernatant after centrifugation
157
What is a subdural haemorrhage?
A collection of blood that develops between the surface of the brain and the dura mater
Acute: within 72h
Subacute: 3-20 days
Chronic: After 3 weeks
158
What is the aetiology of a subdural haemorrhage?
- Trauma causing rapid acceleration and deceleration of the brain results inn shearing forces which tear veins (bridging veins) that travel from the dura to the cortex
- Bleeding occurs between the dura and arachnoid membranes
- In children, non- accidental injury should always be considered
159
What is the epidemiology of subdural haemorrhage?
- Acute: Tend to occur in younger patients/associated with major trauma. More common than extradural haemorrhage
- Chronic: More common in elderly
160
What are the presenting symptoms of an acute subdural haemorrhage?
- History of trauma with head injury
| - Patient has decreased conscious level
161
What are the presenting symptoms of a subacute subdural haemorrhage?
- Worsening headaches 7-14 days after injury
| - Altered mental status
162
What are the presenting symptoms of a chronic subdural haemorrhage?
- Can present with headache, confusion, cognitive impairment, psychiatric symptoms, gait deterioration, focal weakness, seizures
- May not be history of fall or trauma, hence have low index of suspicion especially in the elderly and alcoholics
163
What are the signs of an acute subdural haemorrhage on examination?
- Decreased GCS
- With large haematomas resulting in midline shift, and ipsilateral fixed dilated pupil may be seen (compression of the ipsilateral third nerve parasympathetic fibres)
- Pressure on brainstem: reduced consciousness, bradycardia
164
What are the signs of a chronic subdural haemorrhage on examination?
- Neurological examination may be normal
| - May be focal neurological signs (III or VI nerve dysfunction, papilloedema, hemiparesis or reflex asymmetry)
165
What are the investigations for a subdural haemorrhage?
- CT head: Crescent or sickle shaped mass, concave over brain surface (extradural is lentiform shape). CT appearance changes with time. Acute subdurals are hyperdense, becoming isodense over 1-3 weeks (such as presence may be inferred from signs such as effacement of sulci, midline shift, ventricular compression and obliteration of basal cisterns) and chronic subdurals are hypodense (approaching that of CSF)
- MRI brain: has higher sensitivity especially for isodense or small SDHs
166
How is an acute subdural haemorrhage managed?
- ALS protocol with priorities of cervical spin control and ABC
- With a head injury, significant risk of cervical spine injury
- Disability: GCS, pupillary reactivity
- If signs of raised ICP, head elevation and consider osmotic diuresis with mannitol and/or hyperventilation.
- Once stabilised, obtain CT head
167
When is conservative management for a subdural haemorrhage opted for?
If small and minimal midline shift (SDH less than 10mm thickness and midline shift less than 5mm
168
What is the surgical management for a subdural haemorrhage?
- Prompt Burr hole or craniotomy and evacuation for symptomatic subdurals, more than 10mm, with more than 5mm midline shift (better outcome if within 4h)
- ICP monitoring devices may be placed
169
How are chronic subdural haemorrhages managed?
- If symptomatic or if there is mass effect on imagine, surgical treatment with Burr hole or cranitomoy and drainage.
- Asymptomatic SDH without significant mass effect is best managed conservatively with serial imaging to monitor for spontaneous resorption
- Haematomas that have not fully liquefied may require craniotomy and membranectomy
170
How are subdural haemorrhages managed in children?
Younger children may be treated by percutaneous aspiration via an open fontanelle or if this fails, placement of a subdural to peritoneal shunt
171
What are the possible complications of a subdural haemorrhage?
- Raised ICP, cerebral oedema pre-disposing to secondary ischaemic brain damage, mass effect (transtentorial or uncal herniation)
- Post-op: Seizures are relatively common, recurrence (up to 33% for SDH), intracerebral haemorrhage, subdural empyema, brain abscess or meningitis, tension pneumocephalus
172
What is the prognosis for a subdural haemorrhage?
- Acute: Underlying brain injury is the most important factor on outcome
- Chronic: Generally have a better outcome than acute SDHs, reflecting on lower incidence of underlying brain injury, with good outcomes in 3/4 of those treated by surgery
173
What is a tension headache?
- Can be either chronic or episodic
- Rarely disabling or associated with any significant autonomic phenomena, thus pts do not usually seek medical care and usually successfully self-treat
- Attacks are generalised throughout the head with a predilection for involving the frontal and occipital regions
- Pain typically expressed as being a 'tight band' around the head.
- Does not worsen with routine physical activity
174
What is the aetiology of a tension headache?
- Muscle contraction is often considered the cause of pain but little evidence supports this
- Psychological stress is most common trigger
- Extended periods of mental tension of psychological stress may play a role in central sensitisation and the development of chronic tension type headache
- Disturbed sleep patterns can trigger and episodic tension-type headache
- Insomnia and other sleep disorders are associated with chronic tension headaches
175
What is the epidemiology of tension headaches?
- Most common type of headache
| - Means global prevalence in adults=42%
176
What are the presenting symptoms of a tension headache?
- Presence of risk factors (mental tension, stress, missing meals, fatigue)
- Generalised head pain
- Non-pulsatile head pain
- Frontal or occipital head pain
- Constricting pain
177
What are the signs of a tension headache on examination?
- Pericranial tenderness
- Normal neurological examination
- Sternocleidomastoid muscle tenderness
- Temporalis muscle tenderness
- Lateral pterygoid muscle tenderness
- Masseter muscle tenderness
178
What are the investigations for a tension headache?
- Clinical diagnosis: typical headache without associated features (nausea, vomiting); normal neurological examination
- CT sinus: normal
- MRI brain: normal
- Lumbar puncture: normal
179
How are tension headaches managed?
- Antidepressants (low dose not used to treat depression)- amitriptyline
- Non- drug therapies: relaxation training, CBT, EMG biofeedback
- Muscle relaxants: tizanidine
180
What are the possible complications of a tension headache?
Peptic ulcer: occurs secondary to NSAID use
181
What is the prognosis for a tension headache?
Most common type of headache, most common between 20-39 yrs
| - Self treatment with simple analgesic medicine is usually effective
182
What is a transient ischaemic attack?
A transient episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischaemia without acute infarction
- Majority of TIAs resolve within first hours
183
What is the aetiology of a transient ischaemic attack?
- In situ thrombosis of an intracranial artery or artery-to-artery embolism of thrombus as a result of stenosis or unstable atherosclerotic plaque
- Cardioembolic events. Intracardiac thrombus may form in response to some secondary risk factor such as stasis from impaired ejection fraction of atrial fibrillation
- Small-vessel occlusion. microatheromas, microatheromas, fibrinoid necrosis of small penetrating vessels are seen
- Occlusion due to hypercoagulability, dissection, vasculitis, vasospasm or sickle cell occlusive disease
184
What is the epidemiology of a transient ischaemic attack?
- 11% of all deaths in England and Wales
| - More common in males and individuals of non-Hispanic black race
185
What are the presenting symptoms of a transient ischaemic attack?
- Patient/caregiver report of focal neurological deficit
- Brief duration of symptoms
- History of extracranial atherosclerosis
- History of cardiac disease
- No history of epilepsy
- Absence of seizure prior to neurological deficit
- History of migraine
- Temporary loss of vision, aphasia, paraesthesia, hemiparesis
186
What are the signs of a transient ischaemic attack on examination?
- Unilateral symptoms
- Increased BP on presentation
- Focal neurological deficit on examination
- Absence of positive symptoms (shaking, scotoma, spasm)
- Absence of headache
187
What are the risk factors for a transient ischaemic attack?
- Atrial fibrillation
- Valvular disease
- Cigarette smoking
- Alcohol abuse
- Advanced age
- Hypertension
- Congestive heart failure
- Carotid stenosis
188
What are the investigations for transient ischaemic attack?
- Blood glucose: less than 3.3mmol suggests hypoglucaemia as mimic of TIA
- Chemistry profile: very low or high sodium, potassium, or calcium suggests non-ischaemic cause of symptoms
- FBC: usually normal
- ECG: AF may be present
- Brain MRI with diffusion: half will have positive diffusion images
189
How is transient ischaemic attack managed?
- Antiplatelet therapy
- Lipid lowering agent
- Lifestyle modifications with or without antihypertensive therapy
- Carotid endartectomy or stent
- Lifestyle modifications
190
What are the complications of a transient ischaemic attack?
- Stroke
| - MI
191
What is the prognosis of a transient ischaemic attack?
- A patient with TIA has no residual symptoms from a primary event by definition
- Most significant risk to the patient is a second ischaemic event causing permanent disability
192
What is trigeminal neuralgia?
- Facial pain syndrome in more than 1 divisions of trigeminal nerve
- Characterised by sharp, stabbing pain up to 2 mins
- And/or constant facial pain without associated neurological deficit
193
What is the aetiology of trigeminal neuralgia?
- Compression: focal compression of trigeminal nerve root
- Demyelinating disease: 20x more prevalent in MS sufferres.
- Other brainstem lesions: brainstem infarcts and amyloid or calcium deposition
194
What is the epidemiology of trigeminal neuralgia?
- Incidence gradually increase with age and is rare below 40 yrs
195
What are the presenting symptoms of trigeminal neuralgia?
- Facial pain
| - Presence of risk factors (increased age, MS)
196
What are the signs of trigeminal neuralgia?
- Prior oropharyngeal or facial trauma
- Prior herpetic outbreak
- Sensory/motor changes
197
What are the investigations for trigeminal neuralgia?
- No first test: Diagnosis is uaully clinical
- MRI: May demonstrate presence of abnormal vessel loop in association with the trigeminal nerve, presence of other pathologies
- Intra-oral x-ray: No dental cause of pain demonstrated
198
What is Wernicke's encephalopathy?
Neurological emergency resulting from thiamine deficiency with varied neurocognitive manifestations, typically involving mental status changes, gait and oculomotor dysfunction
199
What is the aetiology of Wernicke's encephalopathy?
- Acute or sub-acute deficiency of thiamine in a susceptible person is the usualy precipitant cause of Wernicke's encephalopathy
- Thiamine deficiency could be result of decreased intake (either oral or parenteral), relative deficiency due to increased demand, or malabsorption from the GI tract
200
What are the presenting symptoms of Wernicke's encephalopathy?
- Mental slowing, impared concentration and apathy
- Frank confusion
- Hx of GI surfery
- Mental state cahnges, ophthalmoplegia and gait dysfunction
201
What are the signs of Wernicke's encephalopathy on examination?
- Ocular motor findings
- Alcohol dependence
- Pre-existing conditions that predispose to malnutrition: for example, AIDS, cancer, prolonged,vomiting, or diarrhoea
- Mild irritability
- Delirium
- Acute psychosis
202
What are the risk factors of Wernicke's encephalopathy?
- Alcohol dependence
- AIDS
- Cancer and treatment with chemotherapeutic agents
- Malnutrition
- Hx of GI surgery
203
What are the investigations for Wernicke's encephalopathy?
- Therapeutic trial of parenteral thiamine
- Finger prick glucose: usually normal unless there are co-existent conditions
- FBC: normal unless WBC count raised by infection
- LFTs: elevated
