Less Common Neurological Problems Flashcards
What is the classic triad of Horner’s syndrome?
- Partial ptosis
- Miosis
- Anhidrosis
Which type nerves are affected in Horner’s syndrome?
Sympathetic nerves supplying the eye.
Describe the course of the sympathetic fibres of the head and neck that are relevant in Horner’s syndrome.
- Originate in hypothalamus, and descend the cors to C8-T2
- Synapse onto preganglionic fibres, which leave the cord and ascend the sympathetic chain over the apex of the lung.
- Synapse to thrid order fibres at C3/4 level/level of carotid artery bifurcation, then travel aling internal carotid, sending branches off to structures in H&N.
Which structures in the H+N have sympathetic innervation?
Blood vessels
Sweat glands
Eye (iris dilator)
Occular muscles
Paralysis of which muscle is responsible for the partial ptosis seen in Horner’s syndrome?
Superior tarsal muscle
Paralysis of which muscle is responsible for the miosis seen in Horner’s syndrome?
Dilator pupillae
What are:
a) anhydrosis
b) miosis
c) partial ptosis?
a) decreased sweating
b) constriction of the pupil
c) dropping of the upper eyelid
Other than the classic triad, what symptoms might a pt with Horner’s syndrome present with?
- Facial flushing
- Orbital pain/headache
- Neck pain
- Facial pain
Depends on the cause as to how they present.
How can miosis be detected on examination?
Pupil on affected side is more constricted - look at them in a darkened room, then check for pupil response to light source being removed - it will cause less pupil dilation in affected eye.
What sign can indicate anhydrosis on examination?
Ipsilateral dry skin on the face - more friction on running fingers over the skin.
According to anatomy, how can we divide the causes of Horner’s syndrome?
Into central lesion, preganglionic, and postganglionic nerve lesions.
What are the central causes of Horner’s syndrome?
- CVA
- Multiple sclerosis
- Pituitary/basal skull tumours
- Neck trauma
- Syringomyelia
- Spinal cord tumours
What are the preganglionic causes of Horner’s syndrome?
- Apical lung tumours
- Lymphadenopathy
- Lower brachial plexus trauma
- Aortic/subclavian/carotid aneurysms
- Neck or chest surgery/trauma
- Neuroblastoma
- Mandibular dental abscess
What are the postganglionic causes of Horner’s syndrome?
- Cluster headache/migraine
- Herpes zoster infection
- Internal carotid dissection
- Carotid-cavernous fistula
- Temporal arteritis
What differentials should you have for a presentation of Horner’s syndrome with pain?
Arm/shoulder/hand pain -> Pancoast tumour
Face/neck -> carotid dissection
How should Horner’s syndrome be investigated?
According to suspected cause:
- CXR if suspecting apical lung cancer
- CT/MRI for CVA
- CT angiography/carotid USS for carotid dissection
Is Horner’s syndrome a symptom, sign, or diagnosis?
It is a physical sign
What is a cerebellopontine angle lesion?
Something present within the posterior fossa of the brain. Most of them are benign.
What are the 4 most common cerebellopontine angle lesions?
- Vestibular schwannomas (80%)
- Lipomas
- Vascular malformations
- Haemangiomas
What are the common presenting symptoms of cerebellopontine angle lesions?
- Hearing loss (95%)
- Tinnitus (80%)
- Vertigo
- Headache
- Facial hypesthesia
- Diplopia
Exact symptoms vary according to size and location of lesion.
What is a vestibular schwannoma also called?
Acoustic neuroma
What is an acoustic neuroma?
A tumour of the vestibulocochlear nerve arising from the Schwann cells of the nerve sheath.
What are the 2 risk factors for developing an acoustic neuroma?
- Neurofibromatosis
- High-dose ionising radiation
What is the classic presentation of an acoustic neuroma?
- Unilateral hearing loss
- Vestibular dysfunction
- Tinnitus
How do symptoms develop/get worse over time with an acoustic neuroma? Why?
- Develop facial pain due to trigeminal nerve involvement
- Facial weakness (uncommon even with facial nerve compression)
- Earache
- Ataxia due to cerebellar compression
What are the differentials for an acoustic neuroma?
Other cerebellopontine angle lesions
What Ix should be done for a cerebellopontine angle lesion?
- Audiology to qualify that hearing loss is sensorineural
- MRI/CT depending on the suspected cause
Are most cerebellopontine angle lesions benign or malignant?
Benign
Where is the cerebellopontine angle?
Within the posterior fossa of the cranium, between the cerebellum and the pons.
Can cerobellopontine lesions be removed surgically?
Yes some of them can - it depends where they are and what structures they are involved with. Partial resection can also be an option, especially as a form of debulking.
How can a cerebellopontine lesion be imaged?
CT is usually sufficient - may be hypo or hyper dense structures depending on specific diagnosis.
What medical therapy can be done for patients with cerebellopontine angle lesions?
Serial imaging for observation
Diuretic therapy can be used if there is a symptomatic arachnoid cyst.
Radiotherapy and surgery can also be considered.
Why imaging modality is the best for diagnosing an acoustic neuroma?
MRI
What % of acoustic neuromas do not get bigger over time?
Around 75%
What are the 3 treatment options for acoustic neuromas?
- Observation
- Stereotactic radiosurgery
- Microsurgery
Who is most appropriate for observation with an acoustic neuroma?
Pts with small neuromas and good hearing preservation.
Is microsurgery or stereotactic radiosurgery more commonly done for an acoustic neuroma?
Microsurgery
What are the risks of surgery on an acoustic neuroma?
- 1% mortality risk
- CSF leak
- Cerebellar injury
- Stroke
- Epilepsy
- Facial paralysis
- Hearing loss
- Balance impairment
- Persistent headache
Sounds like a bundle of laughs!
What is stereotactic radiosurgery?
Targets a tumour with single large dose of radiation, which aims to control or slow the growth of the tumour.
What is subacute combined degeneration of the spinal cord?
Degeneration of posterior and lateral columns of the spinal cord, most commonly due to vitamin B12 deficiency.
What causes subacute combined degeneration of the spinal cord?
Vit B12 deficiency (most common)
Vit E deficiency
Copper deficiency
Which senses are lost in subacute combined degeneration of the spinal cord?
Joint position sensation and vibration sense first.
Later on distal parasthesia develops.
What signs do pt with subacute combined degeneration of the spinal cord develop?
Upper motor neurone signs in the legs
How does subacute combined degeneration of the spinal cord present?
Weakness of arms, legs, and trunk, and progressively worsening tingling and numbness.
PMHx of pernicious anaemia or alcohol abuse may be present.
How can B12 causing subacute combined degeneration of the spinal cord be diagnosed?
Serum B12 and FBC showing macrocytic anaemia to confirm B12 deficiency.
How can subacute combined degeneration of the spinal cord be managed?
If caused by B12 deficiency, replace B12 - the efficacy of this depends on the duration and extent of the neurodegeneration.
Where are the cavernous sinuses situated?
On the body of the sphenoid bone.
Which structures does the cavernous sinus run between?
The superior orbital fissure and the petrous temporal bone.
What sits medial to the cavernous sinuses?
The pituitary fossa and sphenoid sinus
What sits lateral to the cavernous sinuses?
The temporal lobe of the brain
Which cranial nerves pass through the cavernous sinuses?
Oculomotor nerve
Trochlear
Ophthalmic
Maxillary
Abducens nerves passes through the sinus, the others sit in the lateral wall.
Where do the cranial nerves pass through the cavernous sinus?
Lateral wall of each cavernous sinus.
What do the cavernous sinuses contain (medial to lateral)?
Internal carotid artery (and sympathetic plexus)
Abducens nerve
Which veins supply the cavernous sinuses?
Ophthalmic vein, superficial cortical veins, and basilar plexus. These then drain into internal jugular vie the superior and inferior petrosal sinuses.
What is the classic triad of Wernicke’s encephalopathy?
Mental confusion
Ataxia
Ophthalmoplegia
What develops if Wernicke’s encephalopathy is indequately treated?
Wernicke-Korsakoff syndrome
What is Wernicke-Korsakoff syndrome?
A specturm of disease resulting from thiamine deficiency, usually related to alcohol abuse.
How does chronic alcohol consumption cause a thiamine deficiency?
- Reduced oral intake of dietary thiamine
- Decreased absorption from GI tract
- Impaired utilisation of thiamine by cells
A patient with a hx of alcohol misuse presents with confusion, weakness, and vomiting. What should come high up on the lost of differentials?
Wernicke’s encephalopathy
What are the symptoms of Wernicke’s encephalopathy?
- Visual changes (diplopia, movement disorders, ptosis)
- Loos of muscle co-ordination
- Memory loss
- Inability to form new memories
- Hallucinations
- N+V
What are the signs of Wernicke’s encephalopathy?
- Neurological signs in line with symptoms experienced
- Abnormal reflexes
- Hypotension
- Hypothermia
- Tachycardia
- Cachexia
What is the diagnostic criteria for Wernicke’s encephalopathy?
2 of the following 4 should be present:
- Dietary deficiency
- Oculomotor abnormalities
- Cerebella dysfunction
- Altered mental state or memory impairment
How should suspected Wernicke’s encephalopathy be investiagted?
Bloods - FBC looking at MCV, U&Es to exclude electrolyte imbalance, LFTs, glucose, and blood gas. Serum thiamine (B1) and cholesterol should also be performed.
How should Wernicke’s encephalopathy be managed?
- MDT approach to include alcohol services where needed.
- Address issues with alcohol and diet.
- Oral thiamine and vit B complex long term
- Lactulose (increases bowel clearance for reduced nitrogen absorption to prevent hyperuricaemia).
A patient comes to his GP with recurrent very severe headaches behind one eye, with episodes lasting for half an hour or so. What diagnosis is top of your differential list?
Cluster Headaches
How long does a period of cluster headaches typically last?
Between 2 to 12 weeks
Are cluster headaches more common in women or men?
Men, by about 4.3 times.
What lifestyle factors are associated with a poorer prognosis for cluster headaches?
Smoking and alcohol use
Can cluster headaches run in a family?
Yes, there is a genetic link but no clear inheritence pattern.
When is the most common time for a cluster headache to occur?
At night a few hours after falling asleep, hence the nickname “alarm clock headache”
Describe the onset of a cluster headache.
Onset of very severe unilateral headache over about ten minutes without aura, lasting up to about 3 hours.
What symptoms are common to get alingside a cluster headache?
Autonomic symtpoms on the ipsilateral side i.e. lacrimation, nasal congestion and rhinorrhoea, facial swelling/flushing, partial ptosis, miosis.
Does sititng still help a cluster headache?
No - pts with cluster headaches are often described as restless.
What are some of the common known triggers of cluster headaches?
- Alcohol (during a cluster period)
- Histamine
- Nitroglycerine
- Heat
- Exercise
- Solvents
- Disturbed sleep patterns
Do cluster headaches need investiagting?
No - the diagnosis can be made clinically as long as there are no red flags
What are the red flags that would cause you to investiagte a patient with ?cluster headaches?
- Change in pattern of headaches
- New headaches over age 50
- Seizures
- Concurrent systemic illness
- Perosnality change
- Sx of RICP
- Thunderclap presentation
How can cluster headaches be managed?
These treatments may not work for all patients:
- Reassurance, smoking cessation, alcohol avoidance, and sleep hygiene.
- High flow oxygen and SC sumatriptan for acute attacks.
- Verapamil for prophylaxis
If a pt presents with ?cluster headaches to their GP, what should the GP do?
Give lifestyle advice and urgently refer to neurologist.
What is the pathophysiology of prion disease?
Accumulation of small infectious protein-containing pathogens causing neurodegenertive illnesses
What is the most commonly known prion disease?
Creutzfeldt-Jakob disease i.e. mad cow diease or bovine spongiform encephalopathy
What is important to remember about Creutzfeldt-Jacob disease?
It is a notifiable disease - the CDC should be informed if someone is even being investigated for it.
How does CJD present?
Neurological disturbance alongside rapidly progressive cognitive and functional impairment
What neurological disturbances can be seen in CJD?
Myoclonus Visual disturbance Cerebellar signs Pyramidal signs Extra-pyramidal signs
How is CJD investiagted?
CSF biochemical markers
EEG has specific waveform in some variants
Brain biopsy is only considered if there is a good chance of another diagnosis
How is CJD managed?
Supportively
What is the name of the peripheral neuropathy that sometimes follows an infection, typically a respiratory or GI infection?
Guillain-Barré syndrome
What is the pathophysiology of Guillain-Barré syndrome?
Peripheral nerve tissue demyelination and axonal degenration caused possibly by antibodies to infectious organisms, causing acute and progressive ascending neuropathy
What risk factors are there for developing Guillain-Barré syndrome?
- GI/resp tract infection in preceeding 1-3 weeks.
- Zika virus
- Some vaccinations
- Malignancy
- Post-partum period
Is Guillain-Barré syndrome weakness symmetrical or not?
Yes it is symmetrical
Where does peripheral weakness usually start in Guillain-Barré syndrome?
Lower extremities, then works it’s way up.
Where do patients with Guillain-Barré syndrome typically experience pain? What kind?
Neuropathic pain usually in legs, but also the back.
What pattern of abnormal reflexes is seen with Guillain-Barré syndrome?
Hyporeflexia or absent reflexes.
Other than weakness, pain, and abnormal reflexes, what symptoms can be caused by Guillain-Barré syndrome?
Parasthesiae
Sensory loss
These both start peripherally and work upwards like the weakness.
What are the differentials for Guillain-Barré syndrome?
- Stroke
- Encephalitis
- Brainstem compression
- SCC
- Vasculitis
- Lead poisoning
- Porphyria
- Myasthenia gravis
- Hypokalaemia
How is Guillain-Barré syndrome investigated?
Diagnosis usually made on clinical grounds.
U&Es may be derranged due to SIADH
Antibodies to peripheral and central nerves may be seen
Nerve conduction studies abnormal in 85% of cases.
How is Guillain-Barré syndrome managed?
IV Ig to induce remission
DVT prophylaxis and supportive care
Pain relief
Admission to ITU if ventilation required.
