Neurology Flashcards
Causes of stroke in pts <50 yrs
Carotid artery dissection
Vasculitis
Thrombophilias
Illict drug use (e.g cocaine or amphetamines)
Anterior cerebral artery infarct
CONTRALATERAL hemiparesis & hemisensory loss (Lower limb > upper limb)
Limb apraxia
Dysarthria
Middle Cerebral artery infarct
CONTRALATERAL Hemiparesis + Hemisensory loss (UL > LL)
CONTRALATERAL homonymous hemianopia
Aphasia
Posterior cerebral artery infarct
CONTRALATERAL homonymous hemianopia with Macular sparing
CONTRALATERAL sensory loss
Visual agnosia
IPSILATERAL CN III palsy + CONTRALATERAL hemiparesis
- where is the stroke?
Posterior cerebral artery - the branches to the midbrain (Weber’s syndrome)
Lateral medullary syndrome
A.K.A wallenburgs syndrome
Infarct of the Posterior inferior cerebral artery
Features;
* IPSILATERAL horner’s syndrome (Miosis, ptosis + Anhidrosis)
* Nystagmus & Ataxia
* IPSILATERAL facial pain + temperature loss
* Vertigo + Vomitting
* CONTRALATERAL limb/torso pain & temperature loss
Lateral pontine syndrome
Anterior inferior cerebellar artery infarct
Features;
* IPSILATERAL facial paralysis & Deafness
* Sudden onset vertigo + vomitting
Locked in syndrome
Basillar artery stroke
Features;
* Complete paralysis or ‘herald hemiparesis’
* Sudden drop in GCS
* Headache + vision changes prior to onset
Often presents with an insidious gradual GCS drop and paralysis followed by a sudden advacned drop in GCS.
Lacunar strokes
Usually presents with one of;
* Isolated hemiparesis
* Isolated hemisensory loss
* Hemiparesis + Limb ataxia
Commonly in the BG, thalamus or internal capsule
Painful CN III palsy is indicative of what
Posterior communicating artery stroke
Management of suspected stroke
Immediate CT head to determine if haemorrhagic or Ischemic
If ischemic;
* Aspirin 300mg stat - continue for 2 weeks then change to Clopidogrel
* Start a statin (after 48 hrs due to risk of haemorrhagic transformation)
Thrombolysis with Atleplase if <4.5hrs
+/- Thrombectomy if < 6 hours
What clinical examination can be done for suspected posterior strokes
HINTS examintion
Head impulse test
Nystagmus
Test of skew
Central venous sinus thrombosis
Venous thrombosis of any veins or venous sinuses in the brain.
Risk is increased with COCP use
50% are in the saggital sinus
50% are in the lateral + Cavernous sinus
Investigations = CT/MRI may look normal. CT venography is better.
Medical management = Immediate LMWH + long term warfarin/NOAC.
Cavernous sinus syndrome vs Lateral sinus
Cavernous = CN III palsy & CN V palsy (extraocular muscles + facial senses)
Lateral = CN III palsy + CN VII palsy (facialmovements)
*May be signs of raised ICP and signs of stroke
Features of Sagittal sinus venous thrombosis
Seizures + Hemiplegia
Venography shows **empty delta sign **
Tension headache
Tight band around the head.
Pain comes and goes gradually
Associated with stress, depression, alcohol & dehydration
Management = reassurance + basic analgesia. Warm compresses helpful.
Sinusitis
Facial pain located behind the nose, forehead or eyes.
Associated with tenderness on palpation of the sinuses.
Management = usually viral and should resolve within 2-3 weeks. Saline irrigation may be useful.
If persistent or recurring then Nasal steroid spray may be useful
Analgesic headache
Similar to tension headache, caused by long term analgesic use.
Mx = stop the analgesic
Hormonal headache
Typically comes on 2 days prior to menstruation & is associated with low levels of oestrogen.
May occur in first few weeks of pregnancy.
Trigeminal neuralgia
Intense, spontaneous facial pain lasting seconds - hours.
An **electric-shooting pain **
Triggers = Brushing teeth, cold weather, spicy food, caffeine, citrus
Management = Carbamazepine 1st line
Note - can be associated with MS so if any Red flags then refer e.g Optic neuritis symptoms.
Cluster headaches
Features;
Severe unilateral headaches around the eye which occur in clusters of attacks lasting 15mins-3hours.
Red swollen watering eye
Miosis
Nasal discharge
Invx = MRI with gadnolinium contrast to look for brain lesions.
Management = **SC Triptan’s **& High flow oxygen.
Prophylaxis with **Verapamil. **
Migraines
Unilateral throbbing headache behind the eye.
pain relieved by going into a dark room
May be preceeded by a prodrome + Aura (photophobia, scotoma, N&V etc)
Headache can last anywhere from 4hrs - 72hrs.
Management = Sumatriptan (5-H5 agonists) in acute attack.
Prophylaxis with Propanolol. (if contraindicated then use topiramate or amitriptyline)
*May have triggers such as chocolate or caffeine. Particularly in hemiplegic migraines.
Raised ICP headache
Raised ICP activates the pain receptors in the dura.
Can be idiopathic or secondary to tumour, hydrocephalus or haematoma.
Features;
* Constant headache which is poorly localised.
* Dull pain
* Worsened by lying down, walking, coughing, straining, bending over etc
Other Red flags = N&V, Papillodema, Reduced visual fields + focal neurological signs.
Low pressure headache
Caused by a low volume of CSF (often following a lumbar puncture or spinal)
Features;
* Diffuse pain across head: dull/throbbing pain which is made worse on standing
* N&V
* May be better when lying down (unlike raised ICP which would be worse)
Management = Caffeine + Fluids. If this fails then consider a blood patch (injfection of autologous blood into spinal epidural to seal a leak).
Viral Encephalitis
Inflammation of the brain + Glia.
Cause;
* Typically a viral cause = HSV1 most commonly (HSV2 in neonates)
* In immunocomprimised people CMV, CJD, HIV more common
* Can also be an autoimmune cause e.g SLE or sarcoidosis
Features;
* Similar to encephalopathy or meningitis (if you cannnot distinguish between them you should treat for both until you know)
* Headache & Fever & Psychiatric Sx & Focal neurological deficit.
Main differentiators = Encephalitis typically occurs over days (whereas meningitis is more acute over hours) and is more associated with personality changes + drowsiness. Also if they have a past medical history of AI condition then consider this.
Invx = LP & CSF analysis (shows viral meningitis)
CT head
EEG may show lateralised periodic dishcarges at 2Hz
Management: Acyclovir if viral
(IV steroids + IgG if autoimmune )
Glioblastoma multiforme
A.K.A astrocytoma
Most common adult brain tumour.
Imaging shows = Solid tumour with central necoris and a contrast-enhanced rim + Associated vasogenic oedema
Histology = Pleomorphic tumour cells bordering necrosed areas.
Management = surgery & adjunct chemo/radio
Dexamethasone if vasogenic oedema.
Meningioma
2nd most common type of brain tumour
Typically benign
Extrinsic to the CNS (in the meninges) so cause compressive issues rather than invasive issues.
Most commonly found at the falx cerebri or skull base
Histology = **Spindle cells in concentric whirls + calcified psammoma bodies **
Most common type of brain tumour in children
Pliocytic astrocytoma = Rosenthal fibres (corkscrew appearance) - usually infratentorial
Medulloblastoma
Aggresive brain tumour in children. Usually arises in the cerebellum and spreads through the CSF.
Histology = small blue cells with rosette pattern.
Craniopharyngioma
Most common supratentorial brain tumour in children. Derived from the remnants of Rathke’s pouch.
Presentation = hormonal disturbance + hydrocephalus + Bitemporal hemianopia
Decorticate posturing
UL flexion - due to a loss of the red nucleus (which controls the upper limbs through the rubrospinal tract - which subsequnetly becomes tonically activated)
Decerebrate
UL Extension + wrist flexion/pronation.
Due to a lesion below the red nucleus.
What medication can be used to decreased raised ICP acutely?
IV mannitol
How does artifical ventilation help raised ICP
By controlling ventilation we can induce hyperventilation to reduce pC02 (blow off more CO2) therefore vasoconstricting the cerebral arteries and thus reducing ICP.
Management of vasogenic oedema
Dexamethasone - use this when there is evidence of brain swelling e.g in brain tumours.
Brain abscess
Cause = sepsis due to Middle ear infections / Trauma / Scalp surgery / Penetrating head injuries / Embolus from infective endocarditis etc
Presetnation;
* dull & persistent headache
* fever
* focal neurology e.g CN III or CN IV palsy
* Seziures, nausea, papillodema
Management = IV ceftriazone + Metronidazole. Give dexamethasone if evidence of vasogenic oedema.
Sunset eyes are indicative of what
Upward gaze paralysis - may be normal in children but in adults it indicates compression of the midbrain (gaze center) typically due to brain herniation.
Coning
When the cerebellar tonsils pass through the foramen magnum + compress the lower brainstem.
- causes cardiorespiratory dysfunction
Normal pressure hydrocephalus
Normal ICP but large ventricles
Triad of Sx;
1. Dementia
2. Incontinence
3. Disturbed gait
Hydrocephalus
= excessive volume of CSF in the ventricular system. Caused by an imbalance of production + absorption.
Causes
1. Obstructive - due to a structural pathology blocking the flow of CSF Tumours / haemorrhage / abnormalities
2. Non-obstructive - due to an imbalance of CSF production + reabsorption e.g Meningitis or post-haemorrhagic
Clinical Features;
1. Headache - worse in morning + when lying down
2. N&V
3. Papillodema
4. Coma
Invx = CT head is 1st line. LP is both diagnostic + therapeutic (however must not be used in obstructive hydrocephalus due to risk of herniation)
Management = external ventricular drain (acute management). Ventriculoperitoneal shunt (long term management)
Kernohan’s phenomenon
Ipsilateral weakness (same side as the bleed) due to compression of the contralateral cerebral peduncle in extradural haematomas.
Extradural haematoma
Blood above the dura.
CT shows hyperdense biconvex shape
Presentation;
* Typically caused by trauma / skull fracture. Pts lose conciousness, then regain conciousness then lose it again (lucid interval)
* May have fixed, dilated pupils / CN III palsy
* Anisocaria
Mx = CT head. Craniotomy + exacuation of the haematoma is definitive management.
Careful observation for mass effect.
Subdural haematoma
Blood beneath the dura (but above the arachnoid)
Acute : Occured in past 1-3 days. Cause = Trauma / acceleration injury / AV malformation
CT shows hyperdense cresent shape bleed (may cause midline shift)
Mx = Small ones can be left / severe need decompressive craniotomy
Chronic: Blood present for > 3weeks. Common in older patients & alcoholics. Progressive confusion, reduced GCS and weakness
**CT shows hypodense crescent. **
Management = burr hole drainage.
Subarachnoid haemorrhage
Bleed into the subarachnoid space.
Cause = Trauma / Berry aneurysm (More common in those with PCKD, Ehlers danlos, Coarctation of aorta).
Presentation;
* V severe & acute Thunderclap headache
* May be a few weeks history of headache prior to presentation (particularly if berry aneurysm)
* Meningism
* Seizures
* ECG changes e.g ST elevation (can be due to autonomic stimultion).
CT shows hyperdense material in the basal cisterns + sulci
Management = Non-contrast CT head 1st line. If done within 6 hours and is normal then consider alternative diagnosis. If done >6hours and is normal, do an LP to confirm (this will show xanthochromia - RBC breakdown products in CSF)
CT angiogram can be done to look for berry aneurysm.
Management = Give nimodipine to prevent vasospasm. Coil, craniotomy or clipping may be needed.
Associated with SIADH (hyponatremia) + seziures
Parkinsons pathophysiology
Loss of dopaminergic neurons in the substantia nigra resulting in;
* Less stimulation of the excitatory (d1) pathway* - meaning initiation of movement is more difficult*
* Less suppression of the inhibitory (d2) pathway* - meaning there is more involuntary movement. *
Features of Parkinsons
TRAP
Tremor (resting)
Rigidity (cog wheel + lead pipe)
Akinesia
Postural instability.
others = Hypotonia / Hypomimia / Micrographia / Psychological changes e.g REM sleep disorder / Urinary urgency / Orthostatic hypotension / Restless leg syndrome / Dementia / Psychosis
Special clinical examination tests in parkinsons
- Repetitive pinch = ask pt to put finger and thumb together repeadetly.
- Glabellar tap test = Repetitively tap the patients nose, they won’t stop blinking
- Ask the patient to write - it will get smaller
What does a DAT scan show in parkinsons
Full stop sign in striatum (looses the comma shape)
Multi-system atrophy
Parkinsons + syndrome characterised by a non-response to levodopa and presence of cerebellar signs
Also Erectile dysfunction + postural hypotension + atonic bladder.
MRI shows **hot cross bun sign **
Progressive supranuclear palsy
Features;
* Postural instability - forward falls* (PD patients typically fall backwards)*
* Vertical gaze palsy - makes it difficult for pt to read or walk downstairs
* Pseudobulbar palsy - dysphagia, slurred speech, brisk jaw reflex
**MRI shows humminbird sign **
Alien limb phenomenon
Involuntary movement of the hand + feeling estranged from the hand.
A feature of corticobasal degeneration (parkinsons + syndrome)
Immediate management of pituitary apoplexy
IV steroids - to replace ACTH
Treatment for restless leg syndrome
Ropinirole
Ataxia indicates a lesion where
Cerebellar vermis
Benign essential tremor
No basis of neurological disease. Important to consider this when assesing someone with parkinson’s.
Features;
* Tremor is ABSENT at rest
* Postural tremor: worse when arms are outstretched or holidng something
* Fast rate + **symmetrical **
* Improved by rest / alcohol and can be exacerbated by activity, caffeine and stress
Management;
1. Beta blockers - propanolol is best (non-selective)
2. 2nd line = Baributurates e.g primidone may be useful
3rd line = Gabapentin
Huntington’s disease
Autosomal dominant neurodegenerative disorder with genetic anticipation (onset gets younger down generations). It is a CAG trinucleotide repeat in the HTT gene (Cr 4).
Leads to excess of dopamine due to a degeneration of GABA and cholinergic neurones in the basal ganglia.
Features;
* Chorea
* Athetosis / Dystonia
* Poor coorination + saccadic eye movements
* Subtle cognitive changes: irritability, apathy or depression
* Psychosis
There will be a strong FHx.
Invx = Genetic blood testing + Counselling.
* **MRI shows severe atrophy of the head of the caudate nucleus **
Management;
There is no cure for huntingtons. Symptomatic management is priority.
* Tetrabenazine = For the hyperkinesis. Works by increasing the breakdown of dopamine (SE is depression)
* Antidepressants
* Olanzapine/Benzos if psychosis
Hemiballismus
Uncontrollable violent swinging movement of one limb. Like a wild Chorea.
Usually caused by infarct/haemorrhage in the subthalamic nucleus.
Tourette’s
Condition characterised by Tics.
onset in childhood
more common in males
Associated with ADHD and OCD.
Most common cause of ataxia in children
Acute cerebritis - typically occurs 3 weeks after a febrile illness (varicella zoster mainly). There will be no signs of meningism or muscle weakness
Friedrich’s ataxia
Autosomal recessive genetic disease caused by GAA trinucleotide repeat in the FRA1 gene.
Leads to mitochondrial dysfunction due a build up of iron in cells.
Features;
* Presents between age 2 - 16yrs.
* Progressive limb ataxia causing staggering gait & falls
* Loss of ankle/knee reflex.
* +ve babinski’s
* Muscle weakness
* Pes cavus
* Loss of proprioception + Vibration sense
**Other features = Optic atrophy + Kyphoscoliosis + HOCM. 25% will have Diabetes. **
Invx = Genetic testing / EMG / nerve conduction studies / MRI Brain & spinal cord.
Ataxia telangiectasia
Autosomal recessive loss of the ATM protein (normally repairs damaged DNA - hence predisposition to cancer).
Features;
* Presents <5yrs with increasing cerebellar ataxia (unsteady gait + trouble with fine motor skills)
* Telangiectasia on bulbar conjunctiva & ears & neck
* IgA deficiency ( recurrent infections)
NOTE - these patients have a predisposition to blood cancer due to their ATM protein loss.
MS - pathophys + features
Demyelinating disease of the CNS (brain, spinal cord, CI and CNII)
Pathophys = BBB is distrubted by a trigger which allows entrance of T cells against myelin-containing oligodendrocytes, triggering a T4 hypersensitivity reaction causing demyelination)
Typically affects the white matter areas
Epidemiology = presents aged 20-40yrs. More common in females. 2nd most common cause of disability in young people. (inc risk if autoimmune condition or family history)
RF = smoking / Fhx / Vit D defieincy /** EBV virus **
Features;
* Relapsing & remitting course (potentially recoverable between attacks)
* Visual = Optic neuritis (most common presenting features) + CN VI palsy (internuclear opthalmoplegia + gaze disorder)
* Uhtoff’s pnenomenon
* Sensory = pins & needles, trigeminal neuralgia, lhermitte’s syndrome.
* Motor = spastic weakness mainly in the legs
* Cerebellar signs (ataxia + tremor)
* Bell’s palsy
* Horner’s syndrome
* Urinary incontinence
* sexual dysfunction
* Intellectual decline
Diagnosis = MRI + contrast (lesions disseminated in time and space). Can show cottonwool areas + dawson fingers.
Lumbar puncture = oligoclonal bands of igG in the CSF.
Uhtoff’s phenomenon
Worsening of vision in MS following a rise in body temp (e.g exercise or baths)
Lhermitte’s syndrome
Parasthesia in the limbs upon neck flexion
Management of MS
Acute flare = High dose steroids for 5 days.
Long-term management;
1. DMARDs for relapsing/remitting disease or secondary progressive disease. Usually natalizumab / Ocrelizumab 1st line.
Symptomatic control;
* Amantidine for fatigue
* Baclofen/Gabapentin for spasticity
* Anticholinergics e.g oxybutyning for bladder dysfunction (may worsen symptoms)
* Gabapentin for oscillopsia
Optic neuritis
Features;
* unilateral reduced vision developing over hours-days
* Painful eye movements
* Central scotoma
* Impaired color vision - particularly with red
* afferent pupillary defect.
Causes = MS, SLE, Sarcoidosis, syphillis, Measles, Mumps, lyme disease.
Manageent = urgent referall + high dose steroids. 50% develop MS in next 15 years.
Acute disseminated encephalomyelitis
T cell mediated autoimmune demyelonation of multiple areas of the brain + spinal cord.
Causes = Infection (MMR, HHV, Strep, influenza) or vaccination.
Features;
* Acute severe encepahlitis (i.e drowsiness, delirium, confusion) & Demyelination (visual problems, seizures or weakness).
* Systemic features e.g N&V, Headache, Fever etc.
MRI shows widespread lesions
Devics disease
= Neuomyelitis optica.
This is an antibody mediated relapsing + remitting demyelinating disorder. It is characterised by More severe + debilitating attacks than MS.
Features;
* Transverse myelitis
* Recurrent bilateral optic neuritis (unlike MS which is unilateral)
Invx = Serum IgG
Management = immunosupression.
Motor neurone disease - Features
Epidemiology = Typically presents age 50-75yrs (rare to present <40yrs). Typically sporadic but may be inherited.
Features;
It is characterised by a presence of both UMN and LMN signs.
* 90% present with single limb weakness
* Fasiculations (lmn)
* 10% Present with a bulbar palsy (lip trembling, drooling, weak jaw etc - CN 9-12 signs)
Essentially it means finding LMN signs at a level higher than the UMN signs (e.g wasting of the arm, but hypertonia of the leg).
Also consider other manifestations e.g T2RF, Breathlessness, Palpitations, foot drop, muscle stiffness etc.
**MND spares the extra-occular muscles + does not affect the cerebellum. **
Types of MND
- ALS - 50% have this kind. It is typically LMN signs in the arms + UMN in the legs. Strong familial link.
- PLS = UMN signs only. may progress into ALS
- Progressive muscular atrophy = LMN signs only. Usually affects distal muscles first. Best prognosis
- Progressive bulbar palsy
How is MND diagnosed
EMG = reduced action potentials + Increased amplitude.
Management of MND
No cure - is a neuodegenerative disease
1. Riluzole - Na+ channel blocker
Supportive management = Gastrostomy & NIV.
Which type of dementia is MND associated with?
Fronto-temporal
Myasthenia gravis - Features
Autoimmune condition against ACh receptors. More common in women.
Features;
* Muscle fatiguability - weakness increases with use
* Diplopia & Ptosis - often worse in the evening or after reading etc.
* Proximal muscle weakness
* Dysphagia
* **Myasthenic sneer ** = expressionless face due to facial muscle weakness
Investigations;
1. EMG
2. CT: to rule out thymommas (strongly associated with myasthenia - as myoid cells have ACh receptors)
3. CK = normal
4. AChR antibodies
Tensilon test & Ice pack test can be useful in aiding diagnosis.
Describe the tensilon test and Ice pack test for Myasthenia gravis
Tensilon test = IV edrophonium temporarily reduces the muscle weakness.
Ice pack test = Ptosis is improved after an ice pack is held on eyelid.
Management of myasthenia gravis
- Pyridostigmine = Long acting ACh inhibitor.
- Prednisolone
- Thymectomy if thymomma
Myashtenic crisis
This is an acute worsening of muscle weakness in myasthenia gravis leading to the need for respiratory support.
Often triggered by medication = Antibiotics, beta-blockers, CCBs, NMJ blockers e.g atracurium, Phenytoin, lithium, magnesium.
Also illness, surgery, stress etc.
Consider NIV if;
* significant bulbar symptoms
* low FVC (<30)
* Resp symptoms
Management = Plasmaphoresis + IV immunoglobulins.
*Note - you should avoid pyridostigmine in crisis due to risk of aspiration.
Lambert eaton syndrome
Typically associated with SCLC or autoimmune.
Can also be seen in breast/ovarian cancer.
Features;
* Muscle weakness - gets stronger with repeated contraction (opposite of MG)
* Typically affects lower limbs first.
* Hyporeflexia
* Autonomic symptoms = dry mouth, impotence, difficulty urinating.
* Eye symptoms are less common than MG
Diagnosis = EMG. This shows an incremental response to repetitive electrical stimulation.
Management;
* Treat underlying malignancies
* Immunosupression: **Prednisolone / Azathioprine *
Complete cord injury
Typically results from trauma. Can be caused by transverse myelitis.
Features;
* Complete bilateral loss of motor + sensory function below the level
* LMN at the level of injury
* UMN below the injury
Remember: C3,C4,C5 keeps the diaphragm alive.
C5-T1 = upper limb.
Autonomic dysreflexia
Clinical syndrome in patients with a complete injury at T6 or above.
Often occurs in response to autonomic stimulation (e.g urinary retention or faecal impaction).
Results in;
* Extreme HTN
* Flushing + sweating
* Agitation
It can lead to haemorrhagic stroke or death. Mx is removal of the stimulus i.e catherise or remove faceal matter.
Brown sequard syndrome
Cord hemisection.
Features;
* Ipsilateral UMN lesion + dorsal loss (soft touch, vibration + proprioception) BELOW the lesion
* **Ipsilateral **LMN + Spinothalamic loss (pain, crude touch + temp) AT the lesion
* Contralateral loss of spinothalamic 1-2 levels ABOVE the lesion.
Syringomyelia
Synrix (collection of CSF) in the central spinal cord.
Affects the spinothalamic tract due to anterior location in the SC.
Dorsal columns are usually always spared
Causes = Chiari malformation. Trauma. Tumours. Idiopathic.
Features;
–> The classic presentation is a cape-like loss of pain + temperature sensation but a preservation of light touch, proprioception & vibration.
* Most common in C3-C7
* Usually bilateral
* LMNL at the level of the lesion, UMNL below the lesion.
* Parasthesia & Neuropathic pain
* Bladder & bowel dysfunction
* Horner’s syndrome
Investigations;
1. Full spine MRI - to exclude cauda equina
2. Brain MRI - to exclude chiari malformation.
Management = treat the cause of the syrinx. Can place a shunt if persistent.
Strumpell-Lorrain disease
Autosomal dominant heriditary spastic paraplegia
Features;
* Bilateral spasticity in lower limbs + UMN signs
* Complex strumpell-lorrain may also have ataxia + dementia.
Transverse Myelitis
Acute inflammation of the spinal cord with swelling + loss of function.
Typically only affects 1-2 spinal segments.
Causes;
* Inflammatory response after viral infection/immunization (e.g syphillis, lyme disease, viral)
* SLE / Sjogrens / Sarcoidosis / Behcets
* MS
* Neuromyelitis optica
Features;
* A myelopathy will develop gradually over a few days with no evidence of truama
* LMNL at level of lesion + UMNL below the lesion
* Radiculopathy
Invx = MRI & Gadolinium enhancement shows cord swelling + oedema.
Management = high dose steroids. Treat the cause.
Sub acute combined degeneration of the spinal cord.
Results from vitamin B12 deficiency (or replacement of folate before B12).
Sx caused by DC, lateral corticospinal and spinocerebellar tract involvement,.
Other causes = pernicious anemia / Tropical sprue / NO inhalation.
Features;
* Distal sensory loss - particularly in fingers + toes
* Typically loss of propriocetpion/vibration sense first as dorsal columns affected first.
* typically UMN signs affecting legs first but LMN can also occur.
* Brisk knee reflexes
* Absent ankle jerk
* +ve babinski’s
* Bilateral limb ataxia
Management = B12 replacement.
Neurofibromatosis Type 1
= Recklinghausen’s syndrome - mutation on chromosome 17.
Features;
–> must have 2 features for diagnosis;
* FHx
* Cafe-au-lait spots (15mm in diameter, >6)
* 2 + Neurofibromas = nodular growth of nerve under skin.
* Axillary/groin freckles
* Iris haematomas / Lisch nodules (kerri’s eye)
* Optic glioma
Associations = Increased risk of epilepsy, LD, scoliosis, leukemia & phaeochromocytomas.
Neurofibromatosis Type 2
More rare. Caused by a gene mutation on chromosome 22.
Features;
* Bilateral acoustic neuromas
* Multiple intracranil schwaanomas, meningiomas + ependydmomas.
Tuberous sclerosis
Autosomal dominant
Features;
* Depigmented **‘ash-leaf’ **spots which fluoresce under UV light.
* Shagreen patches - roughened patches of skin over the lumbar spine
* Angiofibroma = butterfly distrbution of weird vesicles over nose. (adenoma sebaceum)
* Subungal fibromata = under the nails
* Developmental delay
* Epilepsy / infantile spasms
Also associated with polycystic kidneys, rhabdomyomas of the heart + lung cysts.
Sturge weber syndrome
Congenital neurocutaneous syndrome which arises spontaneously.
Features;
* Port-wine stain
* Tortuous/fragile vessels in the brain (ipsilateral to the stain) leading to brain atrophy and calcification.
* Seizures / Intellectual disability / Hemiparesis
CN VII Palsy
= Facial nerve.
Causes = Sarcoidosis, GBS, Lyme disease & Bell’s palsy (hepes simplex virus)
Think: *Face, Ear, Taste + Tear *
Features;
* Flaccid paralysis of face (inc forehead)
* Loss of corneal reflex
* Loss of taste
* Hyperacusis
Management of bells palsy
Prednisolone
Also advise eyecare to prevent exposure keratopathy. This includes taping the eye shut at night.
If no improvement in 3 weeks - refer to ENT
CN III palsy
Features;
* Ptosis
* Mydriasis
* Down & out eye.
CN IV palsy
Vertical diplpia due to a defective downward gaze (CN IV = Superior oblique which is responsible for pulling eye down)
CN VI palsy
Horizontal diplopia
Down & in eye.
Cavernous sinus syndrome
Cavernous sinus = blood filled spaces either side of the pituitary. They contain CN III, IV & VI and part of the trigeminal nerve as well as the internal carotid.
Causes;
* Cavernous sinus thrombosis
* Pituitary apoplexy = acute haemorrhage into the pituitary - may be due to tumour or sheehan’s syndrome
* Caroid cavernous fistuala
* Carotid artery aneurysm
Features;
* Painful CN III, IV or VI palsy
* Loss of forehead sensation
* Proptosis
* Peri-orbital oedema
Which medications can induce IIH
“COMAAR”
Ciclosporin
OCP
Mineralocorticoids
Amiodarone
Antibiotics
Retinioic acid
Miller fisher syndrome
A sub-type of Guillain barre syndrome characterised by:
* Areflexia
* Opthalmoplegia
* Ataxia
* Descending weakness (unlike other forms of GBS which is usually ascending)
