Neurology Flashcards
Headaches:
Red flags?
- Fever
- Focal neurological deficits
- Seizures
- Meningism
- Signs of โICP e.g. papilloedema
- Reduced consciousness level
- Age >50
- Progressively worsening headache
Headaches:
Tension headache features?
- F > M
- 30mins to a few days
- Whole head/frontal
- Constant, like a band around the head
- Often associated with neck tightness
- May be triggered by stress/lack of sleep
Headaches:
Tension headache management & prophylaxis?
- Acute management: NSAIDs and paracetamol
- Prophylaxis: acupuncture
Headaches:
Migraine headache features?
- F > M
Features = ๐ฃ๐ข๐จ๐ก๐๐ฆ - ๐ฃulsatile
- ๐ขne to three days (4-72hrs) in duration
- ๐จnilateral pain (often bilateral in children)
- ๐กausea ยฑ vomiting
- ๐isabling intensity (moderate-severe, worse with movement)
- ๐ฆensitive to sound and light (photo-/phonophobia)
Headaches:
Migraine headache management & prophylaxis?
- Acute management: oral triptan + paracetamol/ibuprofen
- Prophylaxis: propranolol or topiramate (teratogenic so contraindicated in pregnant women)
(Other treatment options can be started at a specialist headache clinic)
Headaches:
Cluster headache features?
- M > F (only headache commoner in males)
- Last 15mins - 3hrs
- Occur in clusters, 1 - 3 per 24hrs
- Retro-orbital/temporal, burning/piercing pain
- Associated with lacrimation, ptosis & miosis, suicidal ideation
- Can be triggered by drinking alcohol
Headaches:
Cluster headache management & prophylaxis?
- Acute management : High flow 100% FiOโ oxygen & subcutaneous sumatriptan
- Prophylaxis: verapamil
Headaches:
Causes of secondary headaches?
(Dozens, name a few)
- Meningitis
- Intracerebral haemorrhage
- Subarachnoid haemorrhage
- Subdural haematoma
- Epidural haematoma
- Cerebral venous sinus thrombosis
- Giant cell arteritis
- Hypertensive crisis
- Medication overuse headache
- Trigeminal neuralgia
- Space-occupying lesion
etcโฆ.
Headaches:
Typical patient with idiopathic intracranial hypertension?
Obese woman aged 15-35
Headaches:
Risk factors for idiopathic intracranial hypertension?
- Female sex
- Obesity
- Drugs: tetracyclines, retinoids, lithium, nitrofurantoin
Headaches:
Features of idiopathic intracranial hypertension?
- Diffuse headaches
- Visual symptoms (transient vision loss, photopsia)
- Cranial nerve VI dysfunction โ double vision
- No changes in consciousness
Headaches:
Diagnosis of idiopathic intracranial hypertension?
- MRI โ rules out other causes of raised ICP
- Fundoscopy โ bilateral papilloedema
- Lumbar puncture โ increased opening pressure (โฅ20cmHโO), normal CSF
Headaches:
Management of idiopathic intracranial hypertension?
Conservative measures:
- Weight loss
- Withdraw any causative drugs
Medical management:
- Acetazolamide
- Add furosemide if insufficient
- Alternative = indomethacin
Surgery:
- Optic nerve sheath fenestration (pierces holes in dura mater surrounding optic nerve to allow CSF drainage)
- CSF shunt
Headaches:
Prognosis of idiopathic intracranial hypertension?
- May be self-limiting, but recurs in roughly 20%
- Permanent, severe vision loss/blindness in 10%
- Life expectancy normal
Headaches:
Features of trigeminal neuralgia?
- Unilateral, paroxysmal facial pain
- Severe shooting/stabbing pain (like an electric shock)
- Lasts several seconds and may occur 100 times per day
- Triggered by movements like chewing or by touch
Headaches:
Diagnosis of trigeminal neuralgia?
Diagnosed clinically
Headaches:
Management of trigeminal neuralgia?
- Carbamazepine first line
- Failure to respond or atypical features (e.g. under-50) should prompt referral to neurology
Seizure disorders:
Causes of provoked seizures?
- Traumatic brain injury
- Stroke
- CNS infection (e.g. meningitis, encephalitis)
- Alcohol withdrawal
- Metabolic disturbances (e.g. hyponatraemia)
- Recreational drug use
Seizure disorders:
Classification of epileptic seizures?
Depends on three criteria:
- Where the seizure originated (focal/generalised)
- The patientโs level of awareness during the seizure (aware/impaired awareness)
- Other features of the seizure (pattern of evolution/change)
Seizure disorders:
Localising features of temporal lobe seizures?
- Automatisms (usually lip smacking, chewing, may also be plucking/grabbing movements)
- Dysphasia
- Dรฉjร vu or jamais vu
- Emotional disturbances (e.g. sudden terror, anger, or derealisation)
- Hallucinations
Seizure disorders:
Localising features of frontal lobe seizures?
- Motor features such as dystonic posturing
- Jacksonian march
- Motor arrest
- Dysphasia or speech arrest
- Toddโs palsy (post-ictal weakness and paralysis of the face and/or limbs, may last minutes or hours)
Seizure disorders:
Localising features of parietal lobe seizures?
- Sensory disturbances - tingling, numbness, pain (rare)
- Motor disturbances (seizure spreads to primary motor cortex)
Seizure disorders:
Localising features of occipital lobe seizures?
- Visual phenomena such as spots, lines, and flashes
Seizure disorders:
Types of generalised seizures?
Motor onset
- Tonic-clonic seizure
- Clonic seizure
- Tonic seizure
- Myoclonic seizure
- Atonic seizure
Nonmotor (absence seizures)
- Typical - blank stare, unresponsive
- Atypical - may be responsive
Seizure disorders:
Management of first seizure episode (unprovoked)?
- Refer to โfirst fitโ clinic
- Patient education and advice (e.g. film/note description of any future events)
- Long-term medical management NOT typically needed
- Advise patient not to drive for 6 months, inform DVLA
Seizure disorders:
Pharmacological management of epilepsy?
(Focal seizures)
1st line = carbamazepine or lamotrigine
2nd line = levetiracetam (Keppra) or sodium valproate
Seizure disorders:
Pharmacological management of epilepsy?
(Tonic-clonic seizures)
1st line = sodium valproate
2nd line = carbamazepine or lamotrigine
Seizure disorders:
Pharmacological management of epilepsy?
(Absence seizures)
Sodium valproate or ethosuximide
Carbamazepine may worsen absence seizures
Seizure disorders:
Pharmacological management of epilepsy?
(Myotonic/clonic seizures)
1st line = sodium valproate
2nd line = lamotrigine or clonazepam
Seizure disorders:
When can you drive after having a seizure?
- First unprovoked seizure = 6 months
- Epilepsy = 12 months
- If epilepsy is controlled (no seizures) for 5 years, may apply for a normal โtil 70 driving license
Seizure disorders:
What is status epilepticus?
Either:
- Continuous seizure activity lasting >5 mins without stopping
OR
- โฅ2 seizures occurring within 5 minutes without the patient returning to normal in between
Seizure disorders:
How do you manage status epilepticus?
- ABCDE approach as it is a medical emergency, then:
- Stage 1 - IV lorazepam, if no access โ rectal diazepam. Repeat after 10-20 minutes
- Stage 2 (established S.E.) - IV phenytoin or fosphenytoin
- Stage 3 (refractory S.E.) - induction of coma (IV propofol/thiopental/phenobarbital)
Seizure disorders:
Consequences of status epilepticus if not promptly managed?
- Cerebral oedema
- Hyperthermia
- Rhabdomyolysis
- Cardiovascular failure
Seizure disorders:
What is West syndrome (aka infantile spasms)?
- A condition of epileptic spasms with an onset within the first year of life
- Typically accompanied by a global developmental delay.
Seizure disorders:
Features and diagnosis of West syndrome?
- Sudden, synchronous spasms, in clusters of 5-10
- Diagnosed with EEG, showing ๐ต๐๐ฝ๐๐ฎ๐ฟ๐ฟ๐ต๐๐๐ต๐บ๐ถ๐ฎ
Seizure disorders:
Management of West syndrome?
- 1st line = vigabatrin
- 2nd line = ACTH
- Poor prognosis (33% mortality by 1 year old)
Seizure disorders:
What is Lennox-Gastaut syndrome?
A rare, complex childhood epilepsy syndrome characterised by a variety of different seizure types, with a significant cognitive dysfunction
Seizure disorders:
Diagnosis of Lennox-Gastaut syndrome?
- History: multiple seizure types, 50% have history of West syndrome
- EEG: ๐๐น๐ผ๐ ๐๐ฝ๐ถ๐ธ๐ฒ-๐๐ฎ๐๐ฒ ๐ฝ๐ฎ๐๐๐ฒ๐ฟ๐ป
Seizure disorders:
Management of Lennox-Gastaut syndrome?
- Antiepileptics
- Ketogenic diet may help
- Poor prognosis (high mortality, only 10% have controlled symptoms)
Seizure disorders:
Symptoms of a simple febrile seizure?
- Symmetrical, generalised tonic-clonic seizure
- Lasts < 15 mins
- Short post-ictal phase (full recovery by 1 hour)
Seizure disorders:
Symptoms of a complex febrile seizure?
Any of:
- Focal onset
- Lasts > 15 mins
- Asymmetrical generalised seizure
- Multiple seizures within 24hrs
Seizure disorders:
Management of a febrile seizure?
- All complex seizures should be referred to a specialist
- May be diagnosed clinically if obvious, refer to first fit clinic wherever there is any doubt
Seizure disorders:
Prognosis of febrile seizures?
- 33% will have another febrile seizure
- Risk of epilepsy increases if: family history, complex febrile convulsion, history of neurodevelopmental delay
- Advise parents to call ambulance if seizure lasts >5 minutes
Seizure disorders:
Side effects of phenytoin?
๐ฃ-450 inducer (phenyto-in-ducer) ๐irsutism ๐nlarged gums (gingival hyperplasia) ๐กystagmus ๐ฌellow-brown skin (melasma) ๐งeratogenic ๐ขsteomalacia ๐nteracts with folate ๐กeuropathy
Seizure disorders:
Side effects of valproate?
๐ฉomiting & nausea ๐norexia ๐iver toxicity ๐ฃancreatitis ๐ฅetaining weight ๐ขedema ๐lopecia ๐งeratogenic ๐nzyme inhibitor
Brain tumours:
Commonest brain tumours in children?
Most are primary tumours:
- Pilocytic astrocytoma (commonest benign)
- Medulloblastoma (commonest malignant)
- Ependymoma
- Craniopharyngioma
Brain tumours:
Commonest brain tumours in adults?
Most are metastatic
Brain primaries account for around 2% of adult cancers:
- Glioblastoma multiforme (commonest malignant)
- Meningioma (commonest benign)
- Schwannoma
- Oligodendroglioma
- Pituitary adenoma
Brain tumours:
Commonest sources of brain metastases?
- Lung cancer (commonest)
- Breast cancer
- Renal cell carcinoma
- Colorectal cancer
- Malignant melanoma
- Prostate cancer
- Testicular cancer
Brain tumours:
Presentation of brain tumours?
- Often asymptomatic, especially when small
- Focal neurological deficits when they grow larger, dependant on the type and location of the tumour
- May also show signs and symptoms of raised ICP
Brain tumours:
Features of raised intracranial pressure?
Symptoms:
- Progressive headache, worst when lying down and worsened by Valsalva manoeuvre
- Nausea and vomiting
Signs:
- Papilloedema
- Cushingโs triad (bradycardia, wide pulse pressure, irregular breathing)
- Reduced consciousness
Brain tumours:
What is a glioblastoma multiforme (GBM)?
How is it diagnosed, and what is the prognosis?
- Fast-growing, malignant brain tumour
- Arises from astrocytes
- Ring enhancing lesion with perifocal oedema on CT
- Incurable
- Rapid death after onset of symptoms (often within wks)
Brain tumours:
What are acoustic neuromas (aka vestibular schwannomas)?
What does the presence of bilateral acoustic neuromas indicate?
- Tumours arising from Schwann cells, predominantly those in the vestibular portion of CN VIII
- Bilateral acoustic neuromas is highly suggestive of neurofibromatosis type 2 (NF2)
Brain tumours:
Features of acoustic neuromas?
- Unilateral sensorineural hearing loss (commonest symptom)
- Tinnitus
- Vertigo
In later stages they can compress CN V and CN VII at the cerebellopontine angle, causing facial numbness and facial paralysis
Brain tumours:
Diagnosis of acoustic neuromas?
Cranial nerve testing:
- Rinneโs test (air > bone conduction)
- Weberโs test (lateralises to normal ear)
- Audiometry
Imaging
- MRI of the cerebellopontine angle (gold standard for dx)
Brain tumours:
Treatment and prognosis of acoustic neuromas?
- If small and asymptomatic or in an especially elderly patient, can be managed expectantly with regular MRI screening
- If significantly large or symptomatic, surgery or radiation therapy are most appropriate
Good prognosis: neuromas are WHO grade 1 and have <5% rate of recurrence
Brain tumours:
What are the main types of pituitary adenoma (i.e. what do they secrete)?
- Prolactinoma (prolactin, 40% of pituitary adenomas)
- Somatroph (growth hormone โ acromegaly, 10-15%)
- Corticotroph (ACTH โ Cushingโs disease, 5%)
- Thyrotroph (TSH, 1%)
- Gonadotroph (FSH & LH, rare)
- โผ35% are non-secretory โincidentalomasโ
Brain tumours:
Symptoms of a prolactinoma?
Women:
- Glactorrhoea
- Amenorrhoea
- Reduced bone density due to suppression of oestrogen
Men:
- Gynaecomastia
- Reduced libido
- Infertility
All macroadenomas can cause a bitemporal hemianopia
Brain tumours:
Management of pituitary adenomas?
- Prolactinoma = bromocriptine 1st line, surgery 2nd line
- All other macroadenomas = trans-sphenoidal surgery
- Octreotide = 2nd line for GH secreting adenomas
Brain tumours:
An important complication of pituitary adenomas?
Pituitary apoplexy: infarction of the pituitary resulting from ischaemia/haemorrhage
Meningitis:
Commonest organisms in children aged <1 month?
- ๐๐ฟ๐ผ๐๐ฝ ๐ ๐๐๐ฟ๐ฒ๐ฝ๐๐ผ๐ฐ๐ผ๐ฐ๐ฐ๐ถ (commonest cause in neonates aged โค72h)
- Listeria monocytogenes
- Gram-negative bacilli (e.g. E. coli)
Meningitis:
Commonest organisms in children aged between 1 month and 2 years?
- ๐ฆ๐๐ฟ๐ฒ๐ฝ๐๐ผ๐ฐ๐ผ๐ฐ๐ฐ๐๐ ๐ฝ๐ป๐ฒ๐๐บ๐ผ๐ป๐ถ๐ฎ๐ฒ
- Neisseria meningitidis
- Group B strep (e.g. S. agalactiae)
- Haemophilus influenzae B (if not vaccinated)
Meningitis:
Commonest organism in teenagers aged 11 - 17?
- ๐ก๐ฒ๐ถ๐๐๐ฒ๐ฟ๐ถ๐ฎ ๐บ๐ฒ๐ป๐ถ๐ป๐ด๐ถ๐๐ถ๐ฑ๐ถ๐ (gram-negative diplococci)
Meningitis:
Commonest organisms in adults?
- ๐ฆ๐๐ฟ๐ฒ๐ฝ๐๐ผ๐ฐ๐ผ๐ฐ๐ฐ๐๐ ๐ฝ๐ป๐ฒ๐๐บ๐ผ๐ป๐ถ๐ฎ๐ฒ
- E. coli
(+ ๐๐ถ๐๐๐ฒ๐ฟ๐ถ๐ฎ ๐บ๐ผ๐ป๐ผ๐ฐ๐๐๐ผ๐ด๐ฒ๐ป๐ฒ๐ in >50s)
Meningitis:
Commonest organisms in immunocompromised patients?
- ๐๐ถ๐๐๐ฒ๐ฟ๐ถ๐ฎ ๐บ๐ผ๐ป๐ผ๐ฐ๐๐๐ผ๐ด๐ฒ๐ป๐ฒ๐
- ๐ฆ๐๐ฟ๐ฒ๐ฝ๐๐ผ๐ฐ๐ผ๐ฐ๐ฐ๐๐ ๐ฝ๐ป๐ฒ๐๐บ๐ผ๐ป๐ถ๐ฎ๐ฒ
- ๐๐ฎ๐ฒ๐บ๐ผ๐ฝ๐ต๐ถ๐น๐๐ ๐ถ๐ป๐ณ๐น๐๐ฒ๐ป๐๐ฎ๐ฒ ๐
- E. coli
- Salmonella
Meningitis:
Commonest viral causes?
(Typically cause meningoencephalitis)
- Enteroviruses e.g. coxsackievirus
- Herpesviruses (mostly HSV2)
- HIV
- West Nile virus
- JC virus (progressive multifocal leukencephalopathy_
Meningitis:
Incubation period of bacterial meningitis?
3 - 7 days
Meningitis:
Features of neonatal meningitis?
Typically vague, without the classic triad:
- Lethargy
- Hypotonia
- Vomiting
- Hypo-/hyperthermia
- Bulging anterior fontanelle (late sign)
Meningitis:
Features of meningitis in children and adults?
Classic triad:
- Fever
- Headache
- Nuchal rigidity
Also:
- Altered mental status
- Photophobia
- N&V
- Seizures
Meningitis:
Two classical signs of meningitis?
Kernigโs sign: with a flexed hip, extension of the knee yields pain and resistance
Brudzinskiโs sign: flexion of the neck causes involuntary flexion of the hips and knees
Meningitis:
Additional sign for haematogenous infection (meningococcal septicaemia)?
- Petechial rash
N.B. a maculopapular rash is not uncommon in viral meningitis
Meningitis:
Investigations in suspected meningitis?
โManagement should be initiated immediately with empirical drug therapy, and should not be delayed for investigationsโ
- Blood cultures
- Diagnosis confirmed with LP and CSF analysis
- CT or MRI with contrast in high-risk patients (e.g. immunocompromised)
Meningitis:
Contraindications to lumbar puncture?
Signs of raised ICP (may cause coning)
- Papilloedema
- Bulging anterior fontanelle
- Focal neurological deficit
- etc.
Petechial rash (septicaemia) - risks worsening/introducing infection in CSF
Meningitis:
What is cerebral coning?
- Coning is when removal of CSF from the spinal cord (e.g. by LP) causes cerebral herniation
- In inflammatory or neoplastic causes of raised ICP, diagnostic LP creates an acute pressure gradient resulting in the downward displacement of the cerebrum and brainstem. Although rare, this is usually terminal.
- Hence, LP is contraindicated whenever there is a raised ICP*
*The exception to this rule is where the raised ICP is due to increased CSF production, such as in idiopathic intracranial hypertension, where LPs are therapeutic
Meningitis:
Findings of CSF analysis in bacterial meningitis?
(Normal values in brackets)
Appearance: cloudy, purulent fluid White cell count: >1000/mmยณ (< 5) Opening pressure: โโ (5-18cmHโO) Protein: โ (15-45mg/dL) Glucose: โ (40-75mg/dL)
Meningitis:
Findings of CSF analysis in viral meningitis?
(Normal values in brackets)
Appearance: clear fluid White cell count: โ lymphocytes Opening pressure: -/โ (5-18cmHโO) Protein: -/โ (15-45mg/dL) Glucose: normal (15-45mg/dL)
Meningitis:
Empirical antibiotic therapy in patients aged < 3 months?
- IV cefotaxime + amoxicillin (or ampicillin)
Meningitis:
Empirical antibiotic therapy in patients aged between 2 months and 50 years?
- IV cefotaxime (or ceftriaxone)
Meningitis:
Empirical antibiotic therapy in patients aged > 50 years?
- IV cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
Meningitis:
Antibiotic therapy in meningococcal meningitis?
- IV benzylpenicillin OR cefotaxime OR ceftriaxone
Meningitis:
Antibiotic therapy in meningitis caused by listeria?
- IV amoxicillin OR ampicillin OR gentamicin
Meningitis:
What can be given to reduce the risk of neurological complications?
- IV dexamethasone
withhold in septicaemia, sepsis or if immunocompromised
Meningitis:
Prophylaxis for close contacts of patients with bacterial meningitis?
- Offer if close contact within 7 days before onset
- Oral ciprofloxacin or rifampicin
Meningitis:
Management of tuberculous meningitis?
- Same as for pulmonary tuberculosis
- R.I.P.E.
Meningitis:
Complications of meningitis?
- Sensorineural hearing loss (most common)
- Seizures
- Cognitive impairment
- Focal neurological deficit
- Brain abscess
Meningitis:
Complication of meningococcal septicaemia?
What is it and who does it affect?
- Waterhouse-Friederichson syndrome
- Intra-adrenal haemorrhage โ hypovolaemic shock
- Seen almost exclusively in children/asplenic patients
Brain abscess:
Clinical features?
- Dull, persistent headache
- Focal neurological deficit (usually CN III / CN VI palsies due to raised ICP)
- Fever
- Seizures
Brain abscess:
Commonest organisms?
Aetiology important:
- Strep viridans (often secondary to sinusitis)
- S. aureus
- If immunocompromised โ ๐๐ผ๐ ๐ผ๐ฝ๐น๐ฎ๐๐บ๐ผ๐๐ถ๐
Brain abscess:
Diagnosis?
Blood tests:
- โCRP
- โWCC
Imaging (CT/MRI):
- Best initial test
- Shows necrotic core & peripheral ring enhancement
Biopsy:
- Confirms diagnosis
- Can be used for M, C & S
Brain abscess:
Management?
Surgery:
- Craniotomy โ incision and drainage
Antibiotic therapy (< 2.5cm, no raised ICP): - IV ceftriaxone and metronidazole
Management of ICP if raised:
- IV dexamethasone
Herpes simplex encephalitis:
Clinical features?
Prodromal phase (N&V, headache, fever)
Acute encephalitis:
- Reduced consciousness
- Seizures
- Focal neurological deficits (e.g. ataxia, memory loss, changes in smell and loss of vision)
N.B. may present similarly to meningitis, although the triad above is more common in HSV encephalitis
Herpes simplex encephalitis:
Diagnosis?
โProgressses very rapidly and diagnosis should not delay management if suspectedโ
- CSF PCR for HSV-1 and HSV-2 = gold standard initial test
- MRI head = most specific and sensitive test (shows hyperintense temporal lobe lesions)
Herpes simplex encephalitis:
Management?
Immediate IV aciclovir
- Monitor for nephrotoxicity, keep the patient hydrated
Toxoplasmosis:
Clinical manifestations?
Immunocompetent patient
- Typically asymptomatic
Immunocompromised patient
- Cerebral toxoplasmosis (most common neurological AIDS-defining illness)
Cerebral toxoplasmosis:
Clinical features?
- Fever
- Headache
- Change in level of consciousness
Cerebral toxoplasmosis:
Diagnosis?
CT or MRI with contrast:
- MULTIPLE, ring-enhancing lesions
Cerebral toxoplasmosis:
Management?
Toxo๐ฃ๐a๐ฆmosis
- ๐ฃyrimethamine
- ๐eucovorin
- ๐ฆulfadiazine
Tetanus:
Whatโs the causative organism?
How does infection occur?
- Clostridium tetani
Wounds with compromised blood supply create anaerobic conditions for growth, such as:
- Deep penetrating wounds
- Open fractures
- Burns
- Surgical wounds
Tetanus:
Pathophysiology?
- C. tetani produces tetanospasmin, a toxin
- This travels retrograde up axons, preventing GABA transmission in the spinal cord
- This lack of inhibition causes constant firing of motor neurones
Tetanus:
Clinical features?
Generalised tetanus; painful muscle spasms and rigidity
- Trismus (lockjaw)
- Abnormal facial expressions (called risus sardonicus)
- Arched back
Life-threatening complications:
- Laryngospasm
- Autonomic dysfunction
Tetanus:
Diagnosis?
Clinical - presence of classical muscle spasms associated with a possible entry point for bacteria
Tetanus:
Prevention and management?
- Childhood vaccination
- Wound cleaning and debridement
Consider need for tetanus vaccine or immunoglobulin:
- If patient has had a full course of vaccination with last dose within 10 years:
โข no vaccine or Ig is needed, regardless of wound severity
- Patient has had full course of vaccines, last dose >10 years ago:
โข high-risk wound โ vaccine & immunoglobulin
โข medium-risk โ vaccine - Patient not had vaccines/vaccination status unknown:
โข vaccine regardless of wound severity
โข for medium and high-risk wounds give Ig too
Rabies:
How is it transmitted and how does it spread through the CNS?
- Expressed by salivary glands in affected animals
- Transmitted through bites, most commonly from dogs and bats
- Binds to ACh receptor of peripheral nerves in the bite wound โ migrates retrogradely up axons โ infects the brain
Rabies:
Incubation period?
4 - 12 weeks average
Rabies:
What are the two types?
- Encephalitic (furious) rabies
- Paralytic rabies
Rabies:
Features of encephalitic rabies?
- ๐๐๐ฑ๐ฟ๐ผ๐ฝ๐ต๐ผ๐ฏ๐ถ๐ฎ (involuntary, painful pharyngeal contractions when the patient attempts to drink water)
- CNS symptoms (e.g. anxiety, confusion, photophobia)
- Hypersalivation
- Coma and death occur within days to weeks of neurological symptom onset
Rabies:
Features of paralytic rabies?
- Flaccid paralysis
- Paraplegia
- Respiratory failure and death
Rabies:
Diagnosis?
- Clinical features after an animal bite
- Usually diagnosed in post-mortem
Rabies:
Management?
- Assess risk (find and test animal if possible)
- Clean and debride wound
- Initiate PEP (rabies immunoglobulin AND vaccine)
Shingles:
What is it?
Reactivation of herpes zoster that was dormant in a dorsal root ganglion
Shingles:
Clinical features?
Dermatomal distrubution of:
- Burning/stabbing pain & hyperesthesia
- Erythematous maculopapular rash โ vesicular rash
Shingles:
Treatment?
- Oral acyclovir (IV if immunocompromised)
- Neuropathic painkillers if needed
Shingles:
Complications?
- Post-herpetic neuralgia
- Herpes zoster encephalitis
Neurosyphilis:
What is it?
Invasion of the CNS by syphilis, causing inflammation of the meninges and cortex
Neurosyphilis:
Signs and symptoms?
General symptoms:
- Personality changes and memory loss
- Neuro symptoms e.g. tremor, dysarthria and hypotonia
Signs:
- Argyll-Robertson pupil - absent light reflex, but constrict with accommodation (looking at a near object)
Tabes dorsalis:
- Late-stage manifestation
- Demyelination of the dorsal columns
- Causes wide, ataxic gait, loss of proprioception and vibration sense, and absent reflexes
Vertigo:
What is benign paroxysmal positional vertigo (BPPV)?
- Idiopathic condition
- Dysfunction of the semicircular canals due to the presence of canaliths (crystals)
- Changes in head position โ abnormal vestibulocochlear nerve stimulation โ severe vertigo lasting seconds
Vertigo:
BPPV features?
- Episodic, severe vertigo
- Stimulated by changing head position
- Lasts several seconds (โค 1 minute)
- Transient horizontal nystagmus
DOES NOT cause hearing loss or tinnitus
Vertigo:
BPPV diagnosis?
- Can be diagnosed clinically
- Diagnosis made if symptoms provoked by Dix-Hallpike manoeuvre
Vertigo:
BPPV management?
- Teach the patient repositioning measures (Epley manoeuvre) - successful in 80%
- Vestibular suppressants are of limited use, and if used long-term inhibit central compensation, worsening sx
Vertigo:
Meniereโs disease pathophysiology?
Impaired endolymph absorption from endolymphatic sac โ โendolymph hydropsโ โ compresses semicircular canals
Vertigo:
Meniereโs disease features?
Classic triad:
- Vertigo
- Tinnitus
- Asymmetrical, fluctuating sensorineural hearing loss
Other symptoms:
- Feeling of fullness in the ear
- N&V
- Spontaneous horizontal nystagmus
Vertigo:
Meniereโs disease diagnosis?
Diagnosed clinically, should be confirmed by ENT specialist
Vertigo:
Meniereโs disease treatment?
- Symptom prevention: betahistine and vestibular rehabilitation exercises
- Acute flares: buccal or IM prochlorperazine
Vertigo:
Vestibular neuronitis features?
Symptoms arising after URTI:
- Severe, sudden-onset vertigo
- N&V
- Gait instability
- Nystagmus
Typically lasts 1 - 2 days, can be milder but last for months
NO tinnitus/hearing loss
Vertigo:
Vestibular neuronitis management?
- Vestibular rehabilitation exercises if chronic symptoms
Acute symptoms:
- Buccal/intramuscular prochlorperazine if severe
- Oral prochlorperazine/antihistamines if mild
Vertigo:
Labyrinthitis features?
- Inflammation of the vestibular nerve and labyrinth occurring secondary to a URTI
Acute onset of:
- Vertigo, worsened by, but not triggered by movement
- Hearing loss
- Tinnitus
- N&V
- Horizontal nystagmus
Vertigo:
Labyrinthitis management?
- Episodes are usually self-limiting
- Symptom control with prochlorperazine or antihistamines
Alzheimerโs disease:
Pathological changes?
Macroscopic:
- Widespread cerebral atrophy, especially of the cortex and hippocampus
Microscopic:
- ฮฒ-amyloid plaques
- Neurofibrillary tangles (hyperphosphorylated tau protein โ unstable microtubules)
Biochemical:
- โACh secondary to forebrain atrophy
Alzheimerโs disease:
Clinical features?
Cognitive:
- Short-term memory impairment
- Insidious onset, slow progression
- Language impairment
- Visuospatial disorientation
Non-cognitive:
- Behavioural changes (apathy, agitation)
- Depression
- Urinary incontinence
Alzheimerโs disease:
Diagnosis?
- Neuropsychological testing e.g. MMSE
- CT/MRI will show generalised cerebral atrophy (narrow gyri, widened sulci, enlarged ventricles)
- Rule out reversible causes of dementia e.g. normal pressure hydrocephalus
Alzheimerโs disease:
Non-pharmacological management?
- Offer a range of activities to promote wellbeing
- Offer group cognitive stimulation therapy
- Consider options like group reminiscence therapy, cognitive rehabilitation
Alzheimerโs disease:
Pharmacological management?
Mild-moderate:
- Acetylcholinesterase inhibitors
- Donepezil, rivastigmine, galantamine recommended
Moderate-severe:
- Memantine
- NMDA receptor antagonist
- Can be monotherapy or used with ACh-ase inhibitors
Alzheimerโs disease:
Management of non-cognitive symptoms?
Depression:
- NICE does not recommend antidepressants for mild to moderate depression (SSRIs if severe - avoid TCAs)
Psychosis:
- Only use antipsychotics (e.g. risperidone) if patient is at risk of harm or severely distressed
Alzheimerโs disease:
Complications and prognosis?
- Infections
- Malnourishment/dehydration
- Intracerebral haemorrhage (โrisk due to amyloid deposits)
- Mean survival time is 3-10 years after diagnosis
Vascular dementia:
Risk factors for vascular dementia?
(Same as stroke risk factors)
๐ฉascular disease hx e.g. stroke/TIA ๐trial fibrillation ๐ฆmoking ๐oronary heart disease ๐จnderlying genetic predisposition (e.g. thrombophilia) ๐ipids (hyperlipidaemia) ๐ge ๐ฅaised BP/glucose (hypertension & diabetes)
Vascular dementia:
What is it?
- Gradual cognitive decline caused by small or large vessel disease.
- Large vessel disease โ thrombosis โ localised infarction
- Small vessel disease โ more diffuse lesions
Vascular dementia:
Clinical features?
- ๐ฆ๐๐ฒ๐ฝ๐๐ถ๐๐ฒ deterioration
- Often present after months/years
Symptoms vary, but may include:
- Memory disturbance
- Gait disturbance
- Memory disturbance
- Focal neurological abnormalities e.g. visual change, sensory and/or motor symptoms
Vascular dementia:
Diagnosis?
- Can be diagnosed clinically, with use of MMSE and history & examination
- Diagnosis confirmed with MRI, showing multiple cortical/subcortical infarcts and white matter lesions
Vascular dementia:
Treatment?
- Detect and address vascular risk factors to slow/halt progression
Non-pharmacological:
- Offer cognitive stimulation e.g. music & art therapy
Pharmacological:
- No specific treatment approved
- ACh-ase inhibitors or memantine can be used in mixed (AD & vascular) dementia
Frontotemporal lobar degeneration:
What is it?
A varied group of syndromes involving degeneration of frontal, insular, and/or temporal cortices
Frontotemporal lobar degeneration:
Epidemiology & onset?
- Typically affects younger people than Alzheimerโs disease
- Insidious, slow onset
Frontotemporal lobar degeneration:
Commonest variety?
Pickโs disease (frontotemporal dementia)
Frontotemporal dementia:
Pathophysiology?
Intracellular inclusion bodies (Pick bodies) caused by mutations in tau proteins
Frontotemporal dementia:
Clinical features?
Early changes in personality and behaviour:
- ๐๐ฝ๐ฎ๐๐ต๐
- ๐๐ถ๐๐ถ๐ป๐ต๐ถ๐ฏ๐ถ๐๐ถ๐ผ๐ป and hypersexuality
Changes in cognition:
- ๐๐ฝ๐ต๐ฎ๐๐ถ๐ฎ
- Intelligence, memory and orientation initially preserved
Motor deficits:
- ๐ฃ๐ฎ๐ฟ๐ธ๐ถ๐ป๐๐ผ๐ป๐ถ๐๐บ (later stages)
Frontotemporal dementia:
Diagnosis?
Clinical diagnosis based on classic features.
CT/MRI:
- Rule out other pathology
- Atrophy of frontal and/or temporal lobes
- โKnife-bladeโ appearance of frontal gyri
Frontotemporal dementia:
Management?
Non-pharmacological management:
- Supportive care
- Group therapy
Pharmacological management:
- Dementia: AChE inhibitors and memantine NOT effective
- Agitation: benzos, atypical antipsychotics as last resort
- Depression: SSRIs
Frontotemporal lobar degeneration:
What are the two other types?
- Progressive non-fluent aphasia
- Semantic dementia
Normal pressure hydrocephalus:
What is it?
A ๐ฟ๐ฒ๐๐ฒ๐ฟ๐๐ถ๐ฏ๐น๐ฒ cause of ๐ฑ๐ฒ๐บ๐ฒ๐ป๐๐ถ๐ฎ, due to a chronic ๐ฐ๐ผ๐บ๐บ๐๐ป๐ถ๐ฐ๐ฎ๐๐ถ๐ป๐ด ๐ต๐๐ฑ๐ฟ๐ผ๐ฐ๐ฒ๐ฝ๐ต๐ฎ๐น๐๐ with normal (or episodic increase in) ICP
Normal pressure hydrocephalus:
Clinical features?
Clinical triad:
- Wet (urinary incontinence)
- Wacky (dementia)
- Wobbly (ataxic, โmagneticโ gait)
Normal pressure hydrocephalus:
Diagnosis?
MRI:
- Ventriculomegaly without widened sulci
LP confirms dx:
- Normal opening pressure
- Symptoms improve after CSF removal
Normal pressure hydrocephalus:
Management?
Insertion of a ventriculoperitoneal (VP) shunt
Creutzfelt-Jakob disease:
What is it?
- A neurodegenerative condition caused by misfolded protein particles, called ๐ฝ๐ฟ๐ถ๐ผ๐ป๐.
- Some prions exist in ๐ฎ๐น๐ฝ๐ต๐ฎ-๐ต๐ฒ๐น๐ถ๐ฐ๐ฎ๐น structures to protect the brain from oxidative radicals
- When these ๐บ๐ถ๐๐ณ๐ผ๐น๐ฑ ๐ถ๐ป๐๐ผ ๐ฏ๐ฒ๐๐ฎ-๐ฝ๐น๐ฒ๐ฎ๐๐ฒ๐ฑ ๐๐ต๐ฒ๐ฒ๐๐, they become insoluble and ๐ฝ๐ฟ๐ผ๐๐ฒ๐ฎ๐๐ฒ-๐ฟ๐ฒ๐๐ถ๐๐๐ฎ๐ป๐. They induce other prions to misfold, progressing to ๐๐ฝ๐ผ๐ป๐ด๐ถ๐ณ๐ผ๐ฟ๐บ ๐ฒ๐ป๐ฐ๐ฒ๐ฝ๐ต๐ฎ๐น๐ผ๐ฝ๐ฎ๐๐ต๐.
Creutzfelt-Jakob disease:
What is variant CJD?
- Cows can develop a prion disease called bovine spongiform encephalopathy (aka โmad cow diseaseโ)
- People get infected by eating beef containing prions
Creutzfelt-Jakob disease:
Clinical features?
- ๐ฅ๐ฎ๐ฝ๐ถ๐ฑ๐น๐ ๐ฝ๐ฟ๐ผ๐ด๐ฟ๐ฒ๐๐๐ถ๐ป๐ด ๐ฑ๐ฒ๐บ๐ฒ๐ป๐๐ถ๐ฎ (weeks-months)
- ๐ ๐๐ผ๐ฐ๐น๐ผ๐ป๐๐
- Cerebellar disturbances (e.g. ataxia)
- Autonomic dysfunction
Creutzfelt-Jakob disease:
Diagnosis?
CSF analysis:
- โ 14-3-3 protein
Imaging:
- MRI shows hyperintensity in the basal ganglia
EEG:
- Sharp wave complexes
Diagnosis can only be confirmed by biopsy/autopsy
Creutzfelt-Jakob disease:
Management?
- Typically leads to death within a year of symptom onset
- Symptom management and palliation
Stroke:
Define stroke
Acute neurological injury and cerebral infarction caused by ischaemia or haemorrhage
Stroke:
Define transient ischaemic attack
Temporary, focal ๐ถ๐๐ฐ๐ต๐ฎ๐ฒ๐บ๐ถ๐ฎ, ๐๐ถ๐๐ต๐ผ๐๐ ๐ถ๐ป๐ณ๐ฎ๐ฟ๐ฐ๐๐ถ๐ผ๐ป or permanent loss of function
Stroke:
Types?
Ischaemic (85%)
- Thrombotic
- Embolic
Haemorrhagic (15%)
- Intacerebral haemorrhage
- Subarachnoid haemorrhage
Stroke:
Risk factors?
๐ฉascular disease hx e.g. stroke/TIA ๐trial fibrillation ๐ฆmoking ๐oronary heart disease ๐จnderlying genetic predisposition ๐ipids (hyperlipidaemia) ๐ge ๐ฅaised BP/glucose (hypertension & diabetes)
Ischaemic stroke:
What kind of infarct occurs with systemic hypoperfusion?
- Watershed infarct
- Common during cardiac surgery
Ischaemic stroke:
What areas are most vulnerable to hypoxia?
(Sorry for the stupid mnemonic)
Remember that ๐๐ถ๐ฝ๐ฝ๐ผs ๐ก๐ฒed ๐ฃ๐๐ฟe ๐ช๐ฎ๐๐ฒ๐ฟ:
- ๐๐ถ๐ฝ๐ฝ๐ผcampus
- ๐ก๐ฒocortex
- ๐ฃ๐๐ฟkinje fibres (cerebellum)
- ๐ช๐ฎ๐๐ฒ๐ฟshed areas
Ischaemic stroke:
Initial assessment and stablisiation?
- Primary survey
- Neurological examination
Investigations:
- Check glucose
- Arrange emergency non-contrast CT head to rule out intracranial haemorrhage
- Treatment should not be delayed for any other investigations
- Other investigations include ECG and carotid artery doppler ultrasound
Ischaemic stroke:
Findings on non-contrast CT head?
May be normal or show evolving change over time:
- Hyperacute โ hyperdense occluded vessels
- Later on all that remains is hypodense parenchyma
Ischaemic stroke:
Most sensitive imaging?
- MRI with diffusion-weighted imaging (DWI)
Ischaemic stroke:
Management?
- Maintain vital signs within normal levels (avoid rapid lowering of BP โ ischaemia)
- Aspirin 300mg orally ASAP once haemorrhagic stroke excluded
- Reperfusion therapy if indicated
Ischaemic stroke:
Indications for thrombolysis?
IV altiplase if:
- Administered within ๐ฐ.๐ฑ ๐ต๐ผ๐๐ฟ๐ of ๐๐๐บ๐ฝ๐๐ผ๐บ ๐ผ๐ป๐๐ฒ๐
- Haemorrhage has been excluded with imaging
Ischaemic stroke:
Absolute contraindications for thrombolysis?
Any of the following means ๐ก๐ข alte-/tenecte๐ฃ๐๐๐ฆ๐:
- ๐กeoplasm (intracranial)
- ๐ขesophageal varices
- ๐ฃregnancy
- ๐umbar puncture in last 7 days
- ๐ctive bleeding
- ๐ฆtroke/TBI in last 3 months
- ๐pileptiform seizure at stroke onset (โSAH)
Ischaemic stroke:
Indications for thrombectomy?
Offer ASAP:
- Within ๐ฒ ๐ต๐ผ๐๐ฟ๐ of ๐๐๐บ๐ฝ๐๐ผ๐บ ๐ผ๐ป๐๐ฒ๐
- Confirmed occlusion of ๐ฝ๐ฟ๐ผ๐ ๐ถ๐บ๐ฎ๐น ๐ฎ๐ป๐๐ฒ๐ฟ๐ถ๐ผ๐ฟ ๐ฐ๐ถ๐ฟ๐ฐ๐๐น๐ฎ๐๐ถ๐ผ๐ป on angiography
OR
- Within ๐ฎ๐ฐ ๐ต๐ผ๐๐ฟ๐ of ๐๐๐บ๐ฝ๐๐ผ๐บ ๐ผ๐ป๐๐ฒ๐
- With ๐ฝ๐ฟ๐ผ๐ ๐ถ๐บ๐ฎ๐น ๐ฎ๐ป๐๐ฒ๐ฟ๐ถ๐ผ๐ฟ ๐ฐ๐ถ๐ฟ๐ฐ๐๐น๐ฎ๐๐ถ๐ผ๐ป occlusion
- With a salvagable ๐ฑ๐ฆ๐ฏ๐ถ๐ฎ๐ฃ๐ณ๐ข around the infarct core
Ischaemic stroke:
Secondary prevention?
- Antiplatelet (clopidogrel 1st line, aspirin + dipyridamole 2nd)
- Carotid endarterectomy only if severe carotid stenosis
Ischaemic stroke:
What stroke syndromes are classified in the Bamford Classification system (aka Oxford Stroke Classification)?
- Total anterior circulation infarcts (TACI, 15%)
- Partial anterior circulation infarcts (PACI, 25%)
- Lacunar infarcts (LACI, 25%)
- Posterior circulation infarcts (POCI, 25%)
Ischaemic stroke:
What are the symptoms of an anterior circulation infarct, and how do you differentiate a TACI from a PACI?
- Unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- Homonymous hemianopia
- Higher cognitive dysfunction (e.g. dysphasia)
TACI = all 3 PACI = 2/3
Ischaemic stroke:
What vessels are involved in TACI and PACI?
TACI = MCA & ACA PACI = small divisions of MCA & ACA
Ischaemic stroke:
Features of lacunar infarcts?
What vessels are affected?
Presents with one of:
- Pure motor stroke (commonest)
- Pure sensory stroke (rare)
- Sensorimotor stroke
- Ataxic hemiparesis
Affects perforating branches of MCA
Ischaemic stroke:
Features of POCI?
What vessels are affected?
One of:
- Cerebellar syndromes
- LOC
- Isolated homonymous hemianopia (with macular sparing)
Involves vertebrobasilar arteries
Epidural haematoma:
What is it?
Bleeding in the epidural space, typically due to damage of the middle meningeal artery which underlies the pterion (weakes part of the skull)
Epidural haematoma:
Clinical features?
- Head trauma โ LOC
- Temporary recovery (๐น๐๐ฐ๐ถ๐ฑ ๐ถ๐ป๐๐ฒ๐ฟ๐๐ฎ๐น)
- Rapid decline in neurological status due to โICP
Epidural haematoma:
Diagnosis?
Non-contrast CT head:
- ๐๐ถ๐ฐ๐ผ๐ป๐๐ฒ๐ ๐ต๐๐ฝ๐ฒ๐ฟ๐ฑ๐ฒ๐ป๐๐ฒ lesion
- Limited by suture lines
- Possible skull fracture
Epidural haematoma:
Management?
- ๐จ๐ฟ๐ด๐ฒ๐ป๐ ๐ฐ๐ฟ๐ฎ๐ป๐ถ๐ผ๐๐ผ๐บ๐ โ haematoma/clot evacuation โ vessel ligation
Subdural haematoma:
What is it?
Bleeding into the subdural space (between dura and arachnoid mater), caused by damage to bridging veins
Subdural haematoma:
Whoโs at risk, and why?
- Elderly/alcoholic patients โ cerebral atrophy โ bridging veins are fragile
- Babies โ weak neck muscles and underdeveloped brains โ fragile bridging veins & stronger impact โ โshaken baby syndromeโ
Subdural haematoma:
Clinical features?
- Headache
- Confusion
- Pupil signs (e.g. CN III palsy)
- Focal neurological deficits
Can be chronic, with recurrent headaches and declining mental function, eventually progressing to coma
Subdural haematoma:
Diagnosis?
(Acute vs. chronic)
Non-contrast CT head
- ๐ฐ๐ผ๐ป๐ฐ๐ฎ๐๐ฒ, ๐ฐ๐ฟ๐ฒ๐๐ฐ๐ฒ๐ป๐-๐๐ต๐ฎ๐ฝ๐ฒ๐ฑ lesion
- crosses suture lines, but not midline
Acute = ๐ต๐๐ฝ๐ฒ๐ฟ๐ฑ๐ฒ๐ป๐๐ฒ Chronic = ๐ต๐๐ฝ๐ผ๐ฑ๐ฒ๐ป๐๐ฒ
N.B. this is the other way round on T2-weighted MRI imaging
Subdural haematoma:
Management?
- Small subdurals can be observed
Acute:
- If โICP then craniectomy
Chronic:
- If symptomatic then burr hole decompression
Subarachnoid haemorrhage:
What is it?
Bleeding into the subarachnoid space, typically due to trauma or a ruptured berry aneurysm
Subarachnoid haemorrhage:
Features?
- Occipital, โthunderclapโ headache (very severe and sudden)
- Meningism (Kernigโs & Brudzinskiโs)
- Reduced consciousness
- Seizures
Subarachnoid haemorrhage:
Complications?
- Cerebral vasospasm (can cause ischaemic stroke)
- Hydrocephalus
- SIADH
- Lengthens QT โ TdP
Subarachnoid haemorrhage:
Diagnosis?
Non-contrast CT head:
- Hyperdense blood in star shaped pattern
- Normal in 7%
Lumbar puncture:
- 12 hours after symptom onset
- Xanthochromia from blood breakdown
- โ/- opening pressure
Subarachnoid haemorrhage:
Management?
- Immediate neurosurgical referral
- Identify cause
- Typically treated by coiling
- Some may require craniotomy and clipping
- Nimodipine to prevent vasospasm
Stroke syndromes:
Where do the cranial nerves arise from? (The rule of 4โs)
- 1-4 from the midbrain*
- 5-8 from the pons
- 9-12 from the medulla
Good video on YouTube about the rule of 4โs by Dirty Medicine
Stroke syndromes:
Features of lateral medullary syndrome?
What vessels are affected?
(Aka Wallenberg syndrome)
๐ateral ๐ edullary = ๐end ๐ e a ๐๐๐ก๐
- ๐ornerโs syndrome
- ๐taxia
- ๐กystagmus
- ๐๐๐๐ฝ๐ต๐ฎ๐ด๐ถ๐ฎ (key feature)
Caused by occlusion of the vertebral and posterior inferior cerebellar arteries (PICA)
N.B. Can be remembered as Pikachu - PICA occlusion โ canโt chew (dysphagia)
Stroke syndromes:
What is locked-in syndrome?
What vessels are affected?
- Bilateral, ventral (anterior) pontine stroke
- Also caused by demyelination
- Causes quadriplegia with preserved use of ocular muscles
Occlusion of the ๐ฏ๐ฎ๐ilar artery
Think โlocked-in the ๐ฏ๐ฎ๐ementโ
Stroke syndromes:
What are the features of medial medullary syndrome?
What vessels are affected?
- Contralateral arm and leg weakness
- Contralateral vibration & proprioception loss
- Tongue deviation towards lesion
Caused by anterior spinal artery occlusion
Stroke syndromes:
What are the features of Weberโs syndrome?
What vessels are affected?
(Midbrain lesion)
- Contralateral hemiplegia
- Ipsilateral CN III palsy
Caused by posterior cerebral artery occlusion
Stroke syndromes:
Features of Hornerโs syndrome?
What is it caused by?
- Partial ptosis
- Miosis
- Hemifacial anhidrosis (loss of sweating)
Caused by compression/damage to the cervical sympathetic chain
Spinal cord syndromes:
What is Brown-Sรฉquard syndrome? How does it present?
- Hemisection of the spinal cord
At the level of the lesion:
- Loss of all modalities of sensation
- LMN signs (e.g. flaccid paralysis)
Below lesion, ipsilateral:
- Loss of proprioception, vibration, and fine-touch sensation
- UMN signs (e.g. spastic paralysis)
Below lesion, contralateral:
- Loss of pain, temperature and crude touch sensation
Spinal cord syndromes:
What is syringomyelia?
Compression of the central spinal cord due to the presence of a fluid-filled syrinx
Spinal cord syndromes:
Clinical features of syringomyelia?
- โ๐๐ฎ๐ฝ๐ฒ-๐น๐ถ๐ธ๐ฒโ loss of ๐ฝ๐ฎ๐ถ๐ป ๐ฎ๐ป๐ฑ ๐๐ฒ๐บ๐ฝ๐ฒ๐ฟ๐ฎ๐๐๐ฟ๐ฒ sensation
- Can be LMN signs too e.g. wasting
Spinal cord syndromes:
Diagnosis of syringomyelia?
Can be diagnosed clinically, confirmed with MRI
Spinal cord syndromes:
Features of spinal stenosis?
Depends on level of narrowing:
- Lumbar spinal stenosis โ lower back pain and claudication pains
- Cervical spinal stenosis โ neck pain
Spinal cord syndromes:
Diagnosis of spinal stenosis?
MRI spine โ narrowing of spinal canal ยฑ compression
Spinal cord syndromes:
Management of spinal stenosis?
- Conservative management with NSAIDs and physio
- Surgical decompression if poor response
Spinal cord syndromes:
What is autonomic dysreflexia? What condition is it usually seen in?
- Typically seen in complete trans-section of the spinal cord, usually at or above the level of T6
- Excessive sympathetic and parasympathetic nervous system activation following a stimulus below the level of injury e.g. catheterisation
Spinal cord syndromes:
At what level does the cauda equina arise?
L1-L2
Spinal cord syndromes:
What is cauda equina syndrome?
Damage to or compression of the cauda equina with nerve fibres of L3-S5
Spinal cord syndromes:
Features of cauda equina syndrome?
- Saddle anaesthesia
- Asymmetrical flaccid paralysis of the legs
- Loss of anal sphincter tone โ faecal incontinence
- Urinary retention
Spinal cord syndromes:
Diagnosis of cauda equina syndrome?
Urgent MRI
Spinal cord syndromes:
Management of cauda equina syndrome?
Urgent neurosurgical referral for decompression
Spinal cord syndromes:
What is conus medullaris syndrome? How does it differ from cauda equina syndrome?
Compression of the conus medullaris at the spinal level of the L1 vertebra
The presentation tends to be more acute onset, with bilateral symptoms, and UMN signs. It is still a medical emergency!
Spinal cord syndromes:
Diagnosis and management of conus medullaris syndrome?
Same as cauda equina syndrome:
- Urgent MRI for diagnosis
- Urgent surgical decompression to prevent permanent damage
Spinal cord syndromes:
Features of degenerative cervical myelopathy (DCM)?
- LMN signs in the upper limbs
- Bilateral, progressive carpal-tunnel-like symptoms
- Loss of balance and proprioception in the lower limbs
Spinal cord syndromes:
Diagnosis and management of DCM?
- MRI spine (x-rays not sufficient)
- Neurosurgical referral for decompression
Parkinsonโs disease:
Pathophysiology?
- Progressive depletion of dopaminergic neurones in the substantia nigra โ hypoactivity of the direct pathway
- Depletion of dopamine in the striatum โ โD2 receptor activation โ hyperactivity of the indirect pathway
Overall effect is more inhibition of the motor cortex with less stimulation โ motor syptoms of Parkinsonโs
Parkinsonโs disease:
Features?
Classic triad:
- Bradykinesia - short, shuffling steps with โ arm swing
- Tremor - asymmetrical, 3-5Hz, โpill-rollingโ, worse at rest
- Rigidity - lead-pipe, with cogwheeling
Other features:
- Micrographia
- Depression develops in 40%
- Poor REM sleep and fatigue
- Postural hypotension (later feature)
Parkinsonโs disease:
Diagnosis?
- Should be diagnosed by a specialist
- Diagnosis is usually made clinically
- Imaging is NOT routinely used
Parkinsonโs disease:
What are Lewy Bodies? What are they seen in?
- ฮฑ-synuclein deposits seen in brainstem, substantia nigra, and cortex
- Seen in Parkinsonโs disease and dementia with Lewy Bodies
Parkinsonโs disease:
Management of motor symptoms?
- Should be initiated and coordinated by a Parkinsonโs specialist
First line:
- Motor symptoms impacting patientโs QOL โ levodopa
- Motor symptoms not impacting patientโs QOL โ levodopa, MAO-B inhibitor (e.g. selegiline), COMT inhibitor (e.g. entacapone) or dopamine agonist (e.g. ropinirole/apomorphine)
Parkinsonโs disease:
Management of sickness?
- Common exam question
- Donโt use a D2 receptor antagonist that crosses the BBB (e.g. metoclopramide, prochlorperazine)
- Domperidone can be used as it doesnโt cross the BBB
- Other options include ondansetron, promethazine, or cyclizine
Parkinsonโs disease:
Management option for severe Parkinsonโs disease?
Deep Brain Stimulation (DBS)
Parkinsonโs-plus syndromes:
Give some examples
- Multi-system atrophy (MSA)
- Progressive-supranuclear palsy (PSP)
- Corticobasal degeneration
Parkinsonโs-plus syndromes:
Key features of MSA? (other than parkinsonism)
- Autonomic dysfunction (orthostatic hypotension, erectile dysfunction, urinary incontinence/retention)
- Cerebellar symptoms (DANISH)
Parkinsonโs-plus syndromes:
Key features of PSP? (other than parkinsonism?)
- Vertical gaze palsy (especially downward gaze)
2. Frontal lobe abnormalities (disinhibition, apathy)
Parkinsonโs-plus syndromes:
Key features of corticobasal degeneration? (other than parkinsonism)
- Asymmetrical motor abnormalities โ โ๐ฎ๐น๐ถ๐ฒ๐ป ๐น๐ถ๐บ๐ฏ ๐ฝ๐ต๐ฒ๐ป๐ผ๐บ๐ฒ๐ป๐ผ๐ปโ - the perception that the affected limb does not belong to them
Huntingtonโs disease:
Gene mutation? How is it inherited?
- CAG trinucleotide repeat on chromosome 4
- Autosomal dominant, with anticipation (each subsequent generation is affected more severely)
Huntingtonโs disease:
Pathophysiology?
- Neuronal loss in the striatum (esp. caudate nucleus)
- Reduced indirect pathway activity and increased direct pathway activity
- Impaired motor inhibition and increased motor excitation
Huntingtonโs disease:
Clinical features?
Early:
- Chorea
- Athetosis (involuntary writhing movements)
Later:
- Parkinsonism
- Akinetic mutism (canโt move or talk)
- Dementia
- Depression
Huntingtonโs disease:
Management?
- MDT, co-ordinated by specialist neurologist
Cerebral palsy:
What is it?
Non-progressive, perinatal hypoxic brain injury
Cerebral palsy:
Clinical features?
All types:
- Neurodevelopmental delay
- Intellectual disability
- Joint contractures
Spastic CP: (70%)
- โ muscle tone in one or more limbs
- โ deep tendon reflexes
- scissor gait
Non-spastic CP (dyskinetic or ataxic)
- Dysarthria and dysphagia
- Ataxia
N.B. Hand preference BEFORE the age of 1 indicates one-sided muscle weakness and should be investigated
Cerebral palsy:
Management?
- MDT approach
- Treatments for spasticity (e.g. baclofen, Botulinum Toxin-A)
- Orthopaedic surgery
Friedrichโs ataxia:
Clinical features?
- Progressive ataxia
- Spastic paralysis
- Scoliosis
- Hypertrophic cardiomyopathy (main cause of death)
Multiple sclerosis:
Pathophysiology?
- Autoimmune inflammation, demyelination and axonal degeneration
- Only affects oligodendrocytes (CNS), not Schwann cells (PNS)
Multiple sclerosis:
Presentation?
Can present with a diverse range of symptoms, typically coming in bouts lasting a few weeks at a time.
Optic neuritis:
- Most common manifestation
- Painful (esp. on movement)
- Relative afferent pupillary defect (RAPD) (light reflex absent, but concentric constriction intact)
Internuclear ophthalmoplegia:
- Demyelination of the medial longitudinal fasciculus (MLF)
- Good video by HippocraTV on YouTube
- Disconjugate, lateral gaze nystagmus in contralateral eye
Other symptoms include:
- Demyelination of the pyramidal tracts โ Lhermitte sign, UMN signs, loss of fine touch & vibration sensation, ataxia
- Cerebellar involvement
- Cranial nerve palsies
- Symptoms worse in the head (Uhthoff phenomenon)
Multiple sclerosis:
How can MS be categorised based on its clinical course?
- Relapsing-remitting (RR-MS)
- Primary progressive (PP-MS)
- Secondary progressive (SP-MS)
Multiple sclerosis:
Diagnosis?
MRI ๐๐ถ๐๐ต ๐ฐ๐ผ๐ป๐๐ฟ๐ฎ๐๐:
- Multiple white-matter lesions disseminated in time and space
Lumbar puncture:
- Oligoclonal bands
Multiple sclerosis:
Management of an acute relapse?
- High dose steroids (oral or IV methylprednisolone)
- Shortens the course of relapse but doesnโt improve long-term recovery
- 2nd line = plasmapheresis
Multiple sclerosis:
Maintaining relapse?
- Beta-interferon - reduces relapse rate by 30%
- Glatiramer acetate
- Natalizumab
Guillain-Barrรฉ syndrome:
Pathophysiology?
- โ have URTI or diarrhoeal illness 1 - 4 weeks prior
- Most commonly associated with Campylobacter jejuni
- Immune system activation โ makes cross-reactive antibodies that work against Schwann cells (molecular mimicry) โ axonal degeneration of motor and sensory fibres in peripheral nervous system
Guillain-Barrรฉ syndrome:
Features?
- ๐ฃ๐ฟ๐ผ๐ด๐ฟ๐ฒ๐๐๐ถ๐๐ฒ, ๐๐๐บ๐บ๐ฒ๐๐ฟ๐ถ๐ฐ๐ฎ๐น ๐๐ฒ๐ฎ๐ธ๐ป๐ฒ๐๐ ๐ผ๐ณ ๐ฎ๐น๐น ๐๐ต๐ฒ ๐น๐ถ๐บ๐ฏ๐ ๐๐ถ๐๐ต ๐ต๐๐ฝ๐ผ๐ฟ๐ฒ๐ณ๐น๐ฒ๐ ๐ถ๐ฎ
- Weakness is ascending i.e. legs are affected first
- Sensory symptoms tend to be mild e.g. distal paraesthesia
Guillain-Barrรฉ syndrome:
Diagnosis?
Lumbar puncture:
- Raised protein with normal white cell count
- called โalbuminocytologic dissociationโ
Nerve conduction studies can be performed showing decreased conduction velocity
Guillain-Barrรฉ syndrome:
Treatment?
- Supportive care (in some cases intubation and ITU may be needed)
- Intravenous Immunoglobulin
- Plasmapheresis
Motor neurone disease:
What are the types?
- Amyotrophic lateral sclerosis (ALS)
- Progressive bulbar palsy (PBP)
- Pseudobulbar palsy
- Progressive muscular atrophy (PMA)
- Primary lateral sclerosis (PLS)
There are others, but they are exceedingly rare.
Motor neurone disease:
Clinical features of ALS?
- ๐ ๐ถ๐ ๐ฒ๐ฑ ๐๐ฝ๐ฝ๐ฒ๐ฟ ๐ฎ๐ป๐ฑ โ๐บ๐ผ๐๐ผ๐ฟ ๐ป๐ฒ๐๐ฟ๐ผ๐ป๐ฒ ๐๐ถ๐ด๐ป๐
- ๐๐ฎ๐๐ฐ๐ถ๐ฐ๐๐น๐ฎ๐๐ถ๐ผ๐ป๐
- Progresses from typically starting in one limb to affect all skeletal muscle in the body
Late symptoms:
- Cognitive impairment
- Dysphagia
- Respiratory failure โ death
Motor neurone disease:
Diagnosis?
- History and examination findings
- Electromyography โ denervation
- Nerve conduction studies โ usually normal
- Bedside swallowing test to screen for dysphagia
Motor neurone disease:
Treatment?
- Riluzole: prevents glutamate release, prolongs life by โผ3 months
- NIV: use of BiPAP at home prolongs life by โผ 7 months
Prognosis is poor, roughly 50% mortality at 3 years
Poliomyelitis:
What is polio? How is it treated?
Anterior horn cell disease caused by poliovirus, causing progressive LMN signs and eventually respiratory failure
Treatment is supportive, with analgesia and mechanical ventilation
Myasthenia gravis:
Pathophysiology?
Autoimmune antibodies against post-synaptic acetylcholine receptors โ ACh receptor decay โ fatiguability
Myasthenia gravis:
Clinical features?
- Eye muscle weakness โ diplopia, ptosis, blurred vision
- Bulbar muscle weakness โ slurred speech
- Proximal muscle weakness โ difficulty standing from chair
- Respiratory muscle weakness โ dyspnoea
Weakness gets worse throughout the day
Myasthenia gravis:
Investigations and diagnosis?
- Diagnosis usually confirmed by EMG and AChR antibody screening
- Chest CT to rule out thymoma (commonly associated)
- Edrophonium test (tensilon test) โ administration of short acting acetylcholinesterase inhibitor rapidly improves symptoms
Myasthenia gravis:
Long-term management:
- 1st line = pyridostigmine
- Immunosuppression can be added: prednisolone first, then azathioprine/ciclosporin if not sufficient
- Thymectomy
Myasthenia gravis:
Management of myasthenic crisis?
- Intravenous immunoglobulins
- Plasmapheresis
Facial nerve palsy:
Clinical features of Bellโs palsy?
- Lower motor neurone facial palsy (forehead not spared)
- Dry eyes
- Altered taste
- Hyperacusis
Facial nerve palsy:
Diagnosis of Bellโs palsy?
Itโs a diagnosis of exclusion; other causes of facial nerve palsy should be ruled out first
Facial nerve palsy:
Management of Bellโs palsy?
- Prescribe prednisolone (ideally within 72 hours of symptom onset)
- Prescribe artificial tears and eye lubricants
- Antivirals (e.g. aciclovir) may be used, with a small improvement. in symptoms, though this is not yet NICE guidance
- If no improvement by 3 weeks then refer urgently to ENT
Facial nerve palsy:
Clinical features of Ramsay-Hunt syndrome?
- Auricular pain (often first feature)
- Facial nerve palsy
- Vesicular rash around the ear
- Other symptoms include tinnitus and vertigo
Facial nerve palsy:
Management of Ramsay-Hunt syndrome?
- Oral prednisolone and aciclovir
Wernicke-Korsakoff syndrome:
Pathophysiology of Wernickeโs encephalopathy?
- Chronic alcoholism downregulates intestinal B1 (thiamine) absorption channels โ B1 deficiency
- Thiamine pyrophosphate (TPP) is the active form of B1
- TPP is involved in glycolysis, acting as a coenzyme for pyruvate dehydrogenase
- Therefore low B1 โ impaired/absent aerobic respiration โ neuronal injury
Wernike-Korsakoff syndrome:
Pathophysiology of Korsakoff syndrome?
- Long term B1 deficiency โ permanent damage to the limbic system (e.g. mamillary bodies)
- Destruction of these components โ memory loss, apathy and emotional dysregulation
Wernicke-Korsakoff syndrome:
Clinical features?
Classic triad:
- Confusion
- Oculomotor dysfunction (most commonly nystagmus/conjugate gaze palsy)
- Gait ataxia
Wernicke-Korsakoff syndrome:
Clinical features?
- Confabulation
- Anterograde and retrograde amnesia
- Personality change
Wernicke-Korsakoff syndrome:
What are the differences between Wernickeโs encephalopathy and Korsakoff syndrome?
(In terms of onset and prognosis)
Wernicke's = acute, reversible Korsakoff = chronic, irreversible
Wernicke-Korsakoff syndrome:
Diagnosis?
- Usually a clinical diagnosis (features are quite distinctive)
- Laboratory tests โ low serum B1
- Brain MRI โ periventricular haemorrhage/๐ฎ๐๐ฟ๐ผ๐ฝ๐ต๐ ๐ผ๐ณ ๐๐ต๐ฒ ๐บ๐ฎ๐บ๐ถ๐น๐น๐ฎ๐ฟ๐ ๐ฏ๐ผ๐ฑ๐ถ๐ฒ๐ and dorsomedial nuclei of the thalamus
Wernicke-Korsakoff syndrome:
Management?
Wernickeโs encephalopathy:
- Urgent thiamine replacement
- Glucose replacement if needed (MUST be after thiamine replacement or glucose accumulates โ cerebral oedema)
- Abstinence from alcohol
Korsakoff syndrome:
- Treatment aimed at halting the progression
- Long-term thiamine supplementation
- Abstinence from alcohol
Neurocutaneous disorders:
Neurofibromatosis 1 mutation?
- NF1 gene
- Chromosome 17
- Encodes neurofibromin (tumour suppressor factor)
- 100% penetrance
Neurocutaneous disorders:
Neurofibromatosis 1 features?
The main cutaneous feature is the presence of โcafรฉ au lait spotsโ. To remember the features think of the mnemonic ๐๐๐๐ ๐ฆ๐ฃ๐ข๐ง๐ฆ:
๐afรฉ au lait spots (โฅ6, 15mm in diameter)
๐xillary/groin freckles
๐ibromas (neurofibromas)
๐ye nodules (iris hamartomas - โLisch nodulesโ)
๐ฆkeletal abnormalities (e.g. scoliosis, sphenoid dysplasia)
๐ฃhaeochromocytoma โ high blood pressure
๐ขptic ๐งumour (optic nerve glioma)
๐ฆhort stature
Neurocutaneous disorders:
Neurofibromatosis 2 mutation?
- NF2 gene
- Chromosome 22
- Encodes neurofibromin 2 (more commonly called Merlin; also a tumour suppressor protein)
Neurocutaneous disorders:
Neurofibromatosis 2 features?
- Bilateral acoustic neuromas
- Bilateral cataracts
- Multiple cerebral and spinal tumours
- Epilepsy
- Skin lesions
Neurocutaneous disorders:
Tuberous sclerosis mutation?
Either:
- TSC1 gene encoding tuberin
- TSC2 gene encoding hamartin
- Both are tumour suppressor genes, so mutations cause unchecked growth
Neurocutaneous disorders:
Tuberous sclerosis features?
Skin manifestations: (KEY)
- ๐๐๐ต ๐น๐ฒ๐ฎ๐ณ ๐บ๐ฎ๐ฐ๐๐น๐ฒ๐ (hypopigmented)
- ๐ฆ๐ต๐ฎ๐ด๐ฟ๐ฒ๐ฒ๐ป ๐ฝ๐ฎ๐๐ฐ๐ต (thickened, scaly patch over lower back)
- ๐๐ฑ๐ฒ๐ป๐ผ๐บ๐ฎ ๐๐ฒ๐ฏ๐ฎ๐ฐ๐ฒ๐๐บ (angiofibromas on face, often misdiagnosed as acne)
- Subungual fibroma (under the nail)
- Cafรฉ au lait spots (hyperpigmented) may be seen
Neurological manifestations:
- Developmental delay
- Treatment-resistant epilepsy
Other:
- Polycystic kidneys
- Rhabdomyomas of the heart
- ๐ฅ๐ฒ๐๐ถ๐ป๐ฎ๐น hamartomas (these affect the iris in NF1)