Neuro Flashcards
Which dermatomes supply which areas of the arm?
C5 = just below shoulder C6 = radial forearm. thumb and first finger C7 = middle two digits C8 = little finger and part of ulnar forearm T1 = ulnar top part of arm
Which lumbar root controls the ankle jerk reflex?
S1
Which cervical roots control the biceps and triceps reflexes?
C6 and C7
What happens in Brown Sequard syndrome?
A hemisection of the spinal cord occurs causing ipsilateral loss of proprioception, fine touch and motor function and contralateral loss of pain and temperature
Name 2 ascending spinal tracts and their functions
Spinothalamic = pain and temp laterally and crude touch and pressure anteriorly
Dorsal column medial lemniscus (DCML) = proprioception, fine touch and vibration
Name 2 descending spinal tracts and their functions
Corticospinal = motor control of skeletal body muscles Corticobulbar = motor control of head and neck muscles
Which spinal tracts are affected in Brown Sequard syndrome?
DCML (proprioception and fine touch) and Corticospinal (motor function) which decussate in brain
Spinothalamic = pain, temp, crude touch and pressure which decussates in spinal cord so causes contralateral symptoms
List the symptoms that cerebellar dysfunction causes
D-ysdiadochokinesia A-taxia N-ystagmus I-ntention tremor S-lurred speech H-ypotonia
What are the 3 layers of the meninges (from outer to inner)?
Dura mater
Arachnoid mater
Pia mater
Where is CSF contained?
The sub arachnoid space
How does CSF re enter circulation
Arachnoid granulations into the dura allow it to re enter circulation via the dural venous sinuses
Describe the pathway of vessels in the circle of willis from bottom to top
Basilar artery (pontine arteries coming off)
Superior cerebellar artery
Posterior cerebral artery
Posterior communicating artery
Middle cerebral artery feeding into internal carotid
Anterior communicating artery
Anterior cerebral artery
Which foramina do the 1st and 2nd CNs leave by?
Cribriform plate = olfactory
Optic canal = optic nerve
Which CNs leave the brain via the superior orbital fissure?
Oculomotor (3)
Trochlear (4)
Ophthalmic (5)
Abducens (6)
Which foramina do the mandibular and maxillary CNs leave by?
Maxillary = foramen rotundum Mandibular = foramen ovale
Which CNs leave via the internal acoustic meatus?
Facial (7) and vestibulocochlear (8)
Which foramina do the glosopharyngeal, vagus and accessory CN leave by?
Jugular foramen
Which foramina does the hypoglossal CN leave by?
Hypoglossal canal
Name some structures that make up the basal ganglia
Caudate nucleus, Lentiform nucleus (putamen and globus pallidus), claustrum, subthalamic nucleus and substantia nigra
What is the role of glial cells?
Support, nourish and insulate neurones by removing waste products of metabolism
Give 4 example of glial cells
Astrocytes, oligodendrocytes, microglia and ependymal cells
What is CSF produced by?
Choroid plexus which covers both the lateral ventricles and the roof of the 3rd and 4th ventricles
Give 4 roles of CSF
Buoyancy, protection, homeostasis and clearing waste
What are some UMN signs?
Hypertonia, hyperreflexia, weakness/paralysis, spasticity and clonus
What are LMN signs?
Hypotonia, hyporeflexia, flaccid muscle weakness or paralysis, fasciculations and muscle atrophy
What causes Horners syndrome?
A lesion of the sympathetic chain supplying the eye
What triad of symptoms is Horner syndrome characterised by?
Ptosis (drooping of eyelid)
Anhidrosis (lack of sweating)
Miosis (constricted pupil on ipsilateral side)
What is MS?
A chronic inflammatory autoimmune disorder of the CNS causing multiple areas of demyelination within the brain and spinal cord (oligodendrocytes are targeted)
What are the patterns of MS?
Relapsing remitting (80%) symptoms come and go Secondary progressive following on from relapsing remitting Primary progressive (10-15%)
State some signs and symptoms of MS
Limb numbness, tingling and weakness
Visual = unilateral optic neuritis (acute pain in eye on movement), blurred vision or hemianopia
Brainstem demyelination = diplopia, vertigo, dysphagia or nystagmus
Autonomic symptoms = bladder symptoms, sexual dysfunction and loss of thermoregulation
Lhermittes sign = tingling electric shock shooting up spine
Uhthoffs phenomenon = symptoms worse in heat
What is the key diagnostic criteria of MS?
Lesions must be disseminated in both time and space
What is the management of MS?
Acute relapse = steroids eg IV methylprednisolone
Frequent relapse = sc interferon beta, monoclonal abs, physio, muscle relaxants
What are the 2 types of stroke (CVA) and state causes of both
Ischaemic (85%) = small vessel occlusion, cardiac emboli eg due to AF, vasculitis
Haemorrhagic (15%) = trauma, aneurysm rupture, thrombolysis, SAH
What are common symptoms of an ACA stroke?
Leg weakness and sensory disturbance
Gait apraxia
Incontinence
Drowsiness
What are common symptoms of an MCA stroke?
Contralateral hemiplegia (more in arms)
Contralateral sensory loss
Hemianopia
Dysphasia
State some symptoms that may occur in a posterior circulation stroke
Very catastrophic Motor deficits eg weakness, clumsiness and paralysis Dysphagia Visual disturbances Altered consciousness
What are lacunar infarcts and what symptoms do they cause?
Small infarcts around the midbrain and internal capsule eg basal ganglia, thalamus and pons and cause pure motor or sensory signs
What is the management for an ischaemic stroke?
Thrombolysis within 4.5 hours of symptom onset
Give tissue plasminogen activator eg Alteplase
Start antiplatelet therapy eg Clopidogrel after
What is the management for a haemorrhagic stroke?
Control hypertension,
Frequent GCS monitoring
May need surgery
What are the most common type of primary brain tumours?
Gliomas (glial cell in origin) eg astrocytoma
Why are brain tumours not truly differentiated as benign or malignant?
All tumours even “benign” ones cause significant morbidity and mortality as are space occupying and increase the ICP
What are the 4 main symptoms of brain tumours?
Symptoms of raised ICP eg progressive headache, drowsiness, papilloedema (swelling of optic disc)
Progressive neurological deficit depending on area affected
Seizures
Lethargy/tiredness
What are the most common neoplasms that metastasise to the brain?
Non small cell lung cancer Small cell lung cancer Breast Melanoma Renal cell GI
What is charcot marie tooth syndrome?
A group of inherited peripheral neuropathies causing muscle weakness starting from feet, sensory loss and spinal deformities
What are the main causes of bacterial meningitis in adults and children?
Streptococcus pneumoniae
Haemophilus influenzae
Neisseria meningitidis
What are common causes of viral meningitis?
EBV
Mumps
Herpes simplex
HIV
What are risk factors of meningitis?
Intrathecal drug administration, immunocompromised, crowding, IVDU, malignancy and diabetes
What are signs and symptoms of bacterial meningitis?
Non specific features eg fever, vomiting, rigors, headache, lethargy
Photophobia
Stiff neck
Meningococcal septicaemia = a non blanching petechial rash
Positive kernigs sign (resistance on passive knee extension when hips fully flexed)
Positive brudzinkis sign (hips flex on bending head forward)
How is bacterial meningitis diagnosed?
Blood cultures to see if septicaemia is present
Lumbar puncture at L4 and CSF microscopy (give empirical abs if not done within 30 mins)
How is bacterial meningitis managed?
IV Ceftriaxone is initial treatment because is broad spectrum and crosses the BBB
If >50/immunocompromised add Amoxicillin to cover listeria
What further actions do you need to take if it is found that the cause of meningitis is N meningitidis?
Alert public health and give prophylaxis to close contacts - Rifampicin or Ciprofloxacin to eradicate nasopharyngeal carriage of the organism
What is encephalitis?
Inflammation of the brain parenchyma
What causes encephalitis?
Mainly viral causes eg Herpes simplex, mumps, HIV
How does encephalitis present?
Triad of fever, headache and altered GCS
May begin with prodrome phase = flu like illness then is acute rapid development of altered consciousness with confusion, drowsiness, coma and seizure
May have signs of meningitis eg fever, headache and neck stiffness
How is encephalitis managed?
Give antivirals eg Acyclovir to cover herpes simplex
What is the pathophysiology of herpes zoster (shingles)?
It affects the peripheral nerves
If reactivated in the dorsal root ganglion it travels down the affected nerve via the sensory root in dermatomal distribution
How does Herpes Zoster present?
Pre eruptive = pain and paraesthesia in a dermatomal distribution and may feel generally unwell
Eruptive phase = rash appears consisting of papules and vesicles, neuritic pain
What is the management of Herpes Zoster?
Oral antiviral therapy within 72 hours of rash eg Acyclovir
Name some types of dementia
Alzheimers disease Vascular dementia Lewy body dementia Fronto temporal dementia Parkinsons
How does Alzheimers disease present?
Insidious onset with steady progression
STM loss is most prominent early symptom
Slow disintegration of personality, intellect, language and visuospatial skills
How does Vascular dementia present?
Stepwise deterioration
History of TIAs or strokes
How does dementia with lewy bodies present?
Fluctuating cognition
Impairment in attention or cognition before memory loss
Visual hallucinations and parkinsonian features
What drugs can be given in Alzheimers?
Acetylcholinesterases eg Donepezil, Rivastigmine
What is an epileptic seizure?
A convulsion or transient abnormal event from a paroxysmal discharge of cerebral neurones
What is the definition of epilepsy?
At least 2 unprovoked seizures occurring more than 24hrs apart
One unprovoked seizure and a probability for further seizures similar to general recurrence risk after 2 unprovoked
What are causes of an epileptic seizure?
2/3 are idiopathic CVD eg cerebral infarction Alcohol withdrawal Cerebral tumour CNS infections Metabolic disturbances Drugs eg cocaine
What are the elements of a seizure?
Prodrome = precedes seizure eg change in behaviour
Aura = part of seizure where patient is aware eg strange smell, deja vu or flashing lights
Ictus = the seizure itself
Post ictally = headahce, confusion, sore tongue
What are types of primary generalised seizures?
Generalised tonic clonic (grand mal) = no aura, loss of conc, tonic phase eg stiff limbs and clonic phase eg rhythmic jerking, may be incontinent and bite tongue and followed by confusion
Typical absence seizure (petit mal) = stare and pale for a few seconds
Myoclonic seizure = sudden isolated jerk of a limb, face or trunk
What is the jacksonian march symptom of epilepsy?
The seizure starts distally and moves more proximally and is more of motor origin (in frontal lobe seizures)
Which anti epileptic is first line for primary generalised tonic clonic seizure?
Lamotrigine
Which anti epileptic is first line for focal temporal seizure?
Carbamazepine
When are anti epileptics started?
Only if there is a high risk of recurrence
What advice should be given to patients with epilepsy?
Avoid swimming alone
Leave the door open when taking a bath
Inform the DVLA
What is Guillain Barre Syndrome (GBS)?
An acute inflammatory demyelination ascending polyneuropathy affecting the peripheral nervous system (schwann cells)
What is the aetiology of GBS?
75% have a preceding infection of resp/GI tract 1-3 weeks before eg campylobacter jejuni, HIV or EBV
How does GBS present?
An ascending pattern of progressive symmetrical muscle weakness “toes to nose”
In 20% respiratory and facial muscles are affected putting patients at risk of resp failure
How is GBS managed?
Monitor FVC hourly and if below 80% admit to ITU
IV immunoglobulins for 5 days and/or plasma exchange
AVOID CORTICOSTEROIDS as make it worse
What are common causes of migraines?
C-heese H-angovers O-rgasms C-hocolate O-ral contraceptive pill L-ie ins A-lcohol T-umult (loud noise) E-xercise
What are 2 different types of migraines?
With aura = progressive neuro deficits that recover completely eg hemianopia, paraesthesia, numbness
Without aura = usually have nausea/vomiting, photophobia or phonophobia (sounds) with headache
How are migraines managed?
Simple analgesia and anti emetics
Triptans eg sumatriptan
Beta blockers
Tricyclic antideps eg Amitryptiline
What is the most common primary headache?
Tension headache?
What are risk factors of a tension headache?
Stress, sleep deprivation, bad posture, hunger, eye strain, anxiety, noise
How do cluster headaches present?
Rapid onset of severe unilateral headache usually beginning around eye or temple
Pain is unilateral and localised
Ipsilateral cranial autonomic features eg lacrimation, rhinorrhoea (nasal discharge)
How are cluster headaches managed?
Acute = inhalation of 100% O2 and triptan (analgesics dont help) Prophylaxis = CCB eg verapimil, steroids, reduce alcohol and stop smoking
How does trigeminal neuralgia present?
Severe paroxysms of knife like pain in one or more of the trigeminal nerve divisions
Pain usually shoots from mouth to angle of the jaw
Triggered by stimulation of a specific trigger zone eg by shaving, eating or talking
How is trigeminal neuralgia treated?
Anticonvulsants eg Carbamazepine
What causes trigeminal neuralgia?
Compression of the trigeminal nerve by a loop of a vein or artery
What is a subarachnoid haemorrhage (SAH)?
Spontaneous bleeding into the subarachnoid space (between arachnoid and pia mater)
What is the aetiology of SAHs?
Rupture of saccular berry aneurysms (80%) usually at branching points in the circle of willis
Congenital arteriovenous malformations eg fistula between arterial and venous systems (10%)
No cause found (15%)
How do SAHs present?
Sudden onset of a severe occipital “thunder clap” headache eg like being kicked in the head
Vomiting, collapse, seizures and coma
Meningeal irritation
How are SAH diagnosed?
Gold standard = Head CT showing star shaped lesion and hyperattenuation around circle of willis
Lumbar puncture = xanthocromia
How are SAH managed?
ABCDE
Give CCB eg Nimodipine to reduce cerebral artery spasm
Prevent re bleeding eg by neurosurgical clipping or endovascular coiling
What is a subdural haematoma?
An accumulation of blood in the subdural space (between dura and arachnoid mater) due to rupture of a bridging vein
What are causes of subdural haematomas?
Blunt head trauma with a latent interval after injury eg shaking baby syndrome
Clotting disorders
AV malformations
What are risk factors of subdural haematomas?
Infants eg due to abuse
Elderly as cerebral atrophy makes brains weaker
Alcoholism
How do subdural haematomas present?
Fluctuating levels of consciousness
Progressive headache
Raised ICP = vomiting, seizure and raised BP
What is shown on a CT head in a subdural?
Hyperdense crescent shaped collection of blood over one hemisphere like a banana
Shifting midline structures
How are subdural haematomas treated?
Surgical removal IV Mannitol (diuretic) to reduce ICP If chronic do burr holes
What is an extradural haemorrhage?
A collection of blood between the duramater and bone usually caused by a head injury
What causes extradural haemorrhages?
Usually due to a traumatic head injury which fractures the temporal or parietal bone
The fracture ruptures the underlying middle meningeal artery
How do extradural haemorrhages present?
Usually have a head injury with brief loss of conc or initial drowsiness followed by a lucid period of recovery and then a rapid decline once the ICP has built up
How do extradural haemorrhages appear on CT?
A lemon shaped haematoma adjacent to the skull
What is Huntingtons Chorea?
An autosomal dominant condition (with full penetrance) causing chorea and characterised by a lack of GABA
What are clinical manifestations of huntingtons?
Often a prodromal phase of mild psychotic and behavioural symptoms eg personality change, clumsiness and apathy
Chorea develops = relentless, progressive jerky involuntary movements
Causes dementia and eventually death
What is Lambert Eaton Myasthenic Syndrome?
A disorder of neuromuscular transmission caused by impaired presynaptic release of ACh
It causes proximal muscle weakness, autonomic symptoms eg dry mouth, impotence and postural hypotension and eyelid ptosis and mild diplopia
What causes lambert eaton myasthenic syndrome?
An autoimmune attack against P/Q type voltage gated calcium channels on PREsynaptic neurones
What are risk factors of lambert eaton myasthenic syndrome?
Cancer = 50% have SCLCs found
How is Lambert Eaton Myasthenic Syndrome differentiated from Myasthenia gravis?
Detection of ACh receptor antibodies characteristic of myasthenia gravis or malignancy
How is Lambert Eaton Myasthenic Syndrome treated?
IV 3,4-diaminopyridine which blocks K+ channels improving muscle strength
Immunosuppression by steroids if really severe
What is motor neurone disease (MND)?
A cluster of major degenerative diseases characterised by destruction of upper and lower motor neurones, cranial nerve nuclei and anterior horn cells in the brain and spinal cord
But no sensory loss, sphincter disturbance or affect on eye movements
What are the different types of MND?
Amyotrophic lateral sclerosis (AML) 80% = UMN and LMN tends to be focal and asymmetrical in onset
Progressive muscular atrophy (PMA) 10-20% LMN causing weakness and wasting
Progressive bulbar palsy (PBP) 10-20% LMN only lower cranial nerves
Primary lateral sclerosis (PLS) UMN least common
What is the management of MND?
Antiglutamatergic drugs eg Riluzole a Na channel blocker inhibiting glutamate release and slows progression very slightly
Treat symptoms
What is myasthenia gravis?
An autoimmune disease against nicotinic acetylcholine receptors in the neuromuscular junction
How does myasthenic gravis present?
Increasing muscular fatigue on sustained activity
Usually proximal limb muscles, extra ocular muscles and muscles of mastication, speech and facial expression
Ocular palsies, ptosis and diplopia
How is myasthenic gravis diagnosed?
Elicit fatiguability eg ask to count to 50 and voice will become less audible
Serum anti AChR raised in 90%
Tensilon test positive
How is myasthenia gravis treated?
Anti cholinesterase eg pyridostigmine to increase ACh in NMJ
Immunosuppression
Thymectomy
What is a complication of myasthenic gravis?
Weakening of respiratory muscles
What is Parkinsons disease?
A degenerative movement disorder characterised by a triad of rigidity, bradykinesia and a resting tremor due to reduced DA in the substantia nigra
Describe the signs and symptoms present in Parkinsons disease
Resting tremor (4-7Hz) often asymmetrical and most obvious in thumbs eg pill rolling Rigidity "cog wheel" Bradykinesia = progressive reduction in amplitude of receptive movements, face is expressionless, hypophonia (speech slow and quiet) and micrographia ( writing becomes small Postural changes eg stooped, small shuffling steps and reduced asymmetrical arm swing Other features = drooling of saliva, depression and constipation
How can Parkinsons be managed?
If <60 can use DA agonist eg pramipexole or ropinirole to treat motor features and delay starting L-dopa
Gold standard = Levodopa with a peripheral dopa decarboxylase inhibitor eg Madopar preventing peripheral conversion of Ldopa to DA and reducing side effects eg nausea
Over time efficacy is reduced
Monoamine oxidase B inhibitors (MAOIs) eg selegline inhibit MAO enzymes which usually breakdown DA so reduce DA breakdown
COMT inhibitors = similar mechanism as MAOIs
What nerve and spinal roots are affected in carpal tunnel syndrome?
Median nerve C6-T1
Which muscles does the median nerve innervate?
LL(2 lumbricals), O(opponens pollicus), A(abductor pollicus brevis), F(flexor pollicus brevis)
Which investigations are positive in carpal tunnel syndrome?
Phalens test = patient can only maximally flex wrist for 1 min
Tinnels test = tapping on nerve at wrist induces tingling
What causes wrist drop?
Radial nerve neuropathy (C5-T1)
What causes claw hand deformity?
Ulnar nerve neuropathy (C7-T1)
What causes foot drop?
Common peroneal/fibular nerve
What signs and symptoms are present in bells palsy?
Unilateral paralysis of the whole side of the face Inability to close eye Hyperacusis (due to noise sensitivity) Dry mouth Loss of taste in anterior 2/3 of tongue
How can you differentiate Bells palsy from a stroke?
Strokes = forehead sparing because there is bilateral innervation of the forehead so the contralateral lower face is affected only
Bells palsy = no forehead sparing and the whole side of the face is affected unilaterally as it affects the motor innervation after both of the hemispheres have joined
How do you manage Bells palsy?
Corticosteroids 1st line within 72 hours
Eye protection to prevent corneal injury due to dry eyes
If severe add antiviral
What are causes of cauda equina?
Herniation of lumbar disc eg at L4/5 or L4/S1
Tumours
Trauma
Infection
How does cauda equina present?
Flaccid paralysis = LMN signa
Lower limb neuro deficit or lower back pain
Saddle anaesthesia
Bladder/bowel dysfunction
What is syncope?
A transient LOC due to cerebral hypoperfusion
What are causes of syncope?
Vasovagal = emotional eg due to fear or pain or orthostatic stress eg prolonged standing
Situational syncope eg due to cough, sneeze or micturition
Orthostatic hypotension
Carotid sinus
Cardiac arryhthmias
Hypoglycaemia
What investigations are done for syncope?
Orthostatic BP (standing)
ECG
FBC
Tilt testing
What is the definition of a TIA?
A brief episode of neurological dysfunction due to focal brain, spinal cord or retinal ischaemia without infarction
Duration is no more than 24 hours
What risk score is conducted after someone has a TIA?
ABCD2 Age>60 BP>140/90 Clinical features - unilateral weakness (2) or speech disturbance without weakness (1) Duration of symptoms >60 mins (2) and 10-59 mins (1) Diabetes >6 strongly predicts a stroke >4 need assessment within 24 hrs All should be seen within 7 days
What is Wernickes encephalopathy?
A neurological emergency resulting from thiamine (B1) deficiency usually caused by chronic alcohol consumption
How does Wernickes encephalopathy present?
Cognitive dysfunction eg loss of memory and confusion Vision changes eg diplopia Abnormal gait Muscle weakness Tachycardia Asterixis
What is Wernicke Korsakoff syndrome?
A long term condition that develops when Wernickes encephalopathy is left untreated or not treated soon enough
Causes confusion, memory loss, changes in personality
What is strabismus (squint)?
A misalignment of the visual axis meaning the eyes aren’t directed at an object at the same time
What is radiculopathy?
A neurological state in which conduction is limited or blocked along a spinal nerve or its roots
What is myelopathy?
An injury to the spinal cord due to severe compression of the cord itself
What causes sciatica (lumbar radiculopathy)?
Compression of the lumbosacral nerve roots L4-S1 forming the sciatic nerve
What are the clinical manifestations of sciatica?
Unilateral leg pain radiating below the knee to the foot or toes
Low back pain
Numbness or tingling in dermatome
Positive result on a straight leg test
What is hydrocephalus?
Build up of fluid in the brain/elevated CSF pressure
What are clinical features of hydrocephalus?
Levodopa unresponsive gait apraxia
Urinary/faecal incontinence
Cognitive impairment
What is non epileptic attack disorder?
A type of seizure that can look similar to epileptic seizures or fainting but isnt caused by abnormal discharges or blood pressure
They can happen when the brain cant handle thought, memories, emotions or sensations (overwhelming stress)
What are clinical manifestations of non epileptic attack disorder?
May have tonic clonic seziure like convulsions but movements aren’t rhythmical
Dont lose conc
Last longer than epileptic seizures
What is narcolepsy?
A chronic condition caused by disruption of the sleep wake cycle and rapid eye movement intrusion in the wake state
What are clinical manifestations of narcolepsy?
Excessive daytime sleepiness Cataplexy (generalised muscle weakness leading to partial or complete collapse) Sleep paralysis Poor memory and conc Sleep attacks
What are the 3 components of GCS and the maximum scores for each?
Eye opening = 4 points
Verbal response = 5 points
Motor response = 6 points
What are bulbar palsy?
Signs and symptoms linked to impaired function of the lower cranial nerves typically caused by damage to LMNs eg due to tumours or brainstem strokes
