Neurology Flashcards
Causes of a 6th nerve (abducens) palsy?
Causes of mononeuritis multiplex
Vascular lesion
Malignancy
Demyelination
Infection (Lyme disease, syphilis)
Raised IC pressure (false localising sign)
Wernicke’s encephalopathy (if bilateral)
Causes of mononeuritis multiplex? WARDS PLC
Wegener’s granulomatosis
Amyloidosis
Rheumatoid arthritis
Diabetes mellitus
Sarcoidosis
Polyarteritis nodosa
Leprosy
Cancer
Define and give causes of an internuclear ophthalmoplegia?
INO is a disorder of conjugate gaze, where the eye ipsilateral to the lesion will fail to adduct, and the contralateral eye will exhibit nystagmus. It is caused by a lesion of the median longitudinal fasciculus (MLF).
Causes of an INO include:
Vascular lesion and MS.
Clinical findings of a 3rd (oculomotor) nerve palsy?
Ptosis
Eye ‘down and out’
Pupil may be unreactive + dilated depending on cause
Clinical findings of a 4th (trochlear) nerve palsy?
Weakness of downward movement of the eye, causing vertical diplopia
Clinical findings of a 6th (abducens) nerve palsy?
Cannot abduct affected eye
Causes of a complex ophthalmoplegia?
Nerve lesions: mononeuritis, demyelination
Myasthenia gravis
Graves’ disease
Mitochondrial diseases
Surgical causes of a 3rd nerve palsy?
SURGICAL causes affect the pupil (dilated and unreactive).
Posterior communicating artery aneurysm.
SOL.
ICH.
Medical causes of a 3rd nerve palsy?
MEDICAL causes do not affect the pupil.
Causes of mononeuritis multiplex.
Demyelination (MS).
Infarction.
Investigations in an ocular palsy?
MRI of brainstem and posterior fossa
Investigations for causes of mononeuritis multiplex
Investigations for myasthenia gravis and thyroid disease
Bamford classification of a TACS (total anterior circulation stroke)
Hemiplegia (contralateral to lesion)
Homonymous hemianopia (contralateral to lesion)
Higher cortical dysfunction (dysphasia, dyspraxia, neglect)
Bamford classification of a PACS (partial anterior circulation stroke)
2/3 of TACS criteria
Bamford classification of a LACS (lacunar stroke)
Pure hemi-motor or sensory loss
What is the NIHSS?
The NIHSS is a stroke severity scale, a systematic assessment to measure the neurological deficits seen with acute stroke.
Designed to standardise and document an easy to perform, reliable and valid neurological assessment.
Can be used to determine eligibility for thrombectomy, and to assess treatment success. Can be used before and after thrombolysis or thrombectomy.
How would you assess speech in a patient you suspect has had a stroke?
Give simple, then 2-step commands.
Ask to repeat phrases ‘42 West Register Street’.
Test naming objects: hold up and ask them to name what you’re holding.
What is used to consider eligibility for thrombectomy?
Patient’s overall clinical status
NIHSS (score >5)
Modified Rankin Scale (score >3)
Territories of infarction on brain imaging
How is a POCS (posterior circulation stroke) defined? cerebellum + brainstem
Need ONE of:
Cranial nerve palsy + contralateral motor or sensory deficit.
Bilateral motor / sensory deficit.
Gaze palsy.
Cerebellar dysfunction.
Isolated homonymous hemianopia.
Investigations and management of suspected acute stroke?
Bedside: A-E assessment, observations, GCS, blood glucose (stroke mimics), ECG (AF), urine dip (infection). Obtain collateral history to determine sx onset for thrombolysis eligibility.
Bloods: FBC, CRP/ESR (young stroke - arteritis), UE, TFTs, cholesterol / lipid profile.
Imaging: CT head to rule out haemorrhage. MR brain.
Acute management is either thrombolytic or endovascular:
- Thrombolysis with alteplase (tPA) if <4.5 of sx onset and no ICH.
- If outside thrombolysis window, consider whether eligible for thrombectomy (6-12h sx onset)
- If not eligible, give aspirin 300mg OD for 2 weeks then 75mg clopidogrel lifelong
Longer-term management:
- Consider: echo, carotid doppler, CT venogram (to rule out CVST in young pt), clotting screen (thrombophilia), vasculitis screen (young stroke).
- Referral to HASU
- MDT input: SLT, PT, OT, dietetics (consider NG feeding)
- Secondary prevention: statin, HTN management, smoking cessation, consider anticoagulation if AF
- DVT prophylaxis with IPCs
Differential diagnosis for hemiparesis?
Anterior circulation vascular event affecting R or L cortex or lacunar infarct.
SOL (tumour, SDH, abscess).
Hemiplegic cerebral palsy.
Less common: Todd’s paresis following seizure, hemiplegic migraine, stroke mimic (sepsis, hypoglycaemia, demyelination).
Clinical features of a patient with myotonic dystrophy?
Face:
- long, thin, expressionless face
- wasting of facial muscles
- bilateral ptosis + cataracts
- frontal balding
- dysarthria (myotonia of tongue)
Hands:
- grip myotonia (grip my hand and let go)
- percussion myotonia (percuss thenar eminence + watch for thumb flexion)
Chest:
- cardiomyopathy / pacemaker due to brady and tachyarrhythmias
Limbs:
- wasting and weakness of distal muscles
- areflexia
Other features:
- diabetes - look for libre monitor
- testicular atrophy
- dysphagia
Investigations to perform in myotonic dystrophy?
EMG: ‘dive bomber’ action potentials.
Genetic testing.
Muscle biopsy: fibre atrophy type 1.
Management of complications of myotonic dystrophy?
Affected individuals die prematurely due to respiratory complications.
Weakness is a problem without treatment options.
Phenytoin may help myotonia.
Advise against general anaesthetic.
What are the genetics of myotonic dystrophy?
Type 1: expansion of the trinucleotide repeat sequence on chromosome 19.
Type 2: expansion of the tetranucleotide repeat sequence on chromosome 3.
Shows genetic anticipation (worsening severity + earlier age of presentation with successive generations).
Autosomal dominant condition.
Usually presents in 20-40s.
List the different types of muscular dystrophy.
Duchenne’s muscular dystrophy.
Becker’s muscular dystrophy.
Fascioscapulohumeral muscular dystrophy (affects arms + shoulders).
Limb-girdle muscular dystrophy.
Myotonic dystrophy.
Oculopharyngeal muscular dystrophy.
What are the features of limb-girdle muscular dystrophy?
Inherited muscular dystrophy, characterised by progressive weakness of the shoulders and pelvic girdle muscles. It has a variable phenotypic presentation depending on the specific type of dystrophy.
Unilateral and bilateral causes of ptosis?
Unilateral: 3rd nerve palsy, Horner’s syndrome.
Bilateral: myotonic dystrophy, myasthenia gravis, congenital.
Side effects of Parkinson’s disease treatment?
Impulsivity + disinhibition can be associated with dopaminergic therapies.
Levodopa is associated with on/off phenomena and dose-related dyskinesia.
Management of Parkinson’s disease?
L-dopa (Madopar) with peripheral inhibitor
Dopamine agonists (Apomorphine)
MAO-B inhibitor (Selegeline)
Anticholinergics
COMT inhibitors (Entacapone)
Amantadine
Surgery: deep brain stimulation
MDT approach: PT/OT/SLT
What is the pathophysiology of Parkinson’s disease?
Degeneration of the dopaminergic neurones between the substantia nigra and basal ganglia.
List some causes of tremor.
Rest tremor: Parkinson’s disease
Postural tremor: anxiety, essential tremor, hyperthyroidism, hepatic encephalopathy, co2 retention, alcohol
Intention tremor: cerebellar disease
List some causes of Parkinsonism.
Idiopathic Parkinson’s disease
Parkinson’s plus syndromes: multisystem atrophy, progressive supranuclear palsy, corticobasal degeneration
Drug-induced Parkinsonism (phenothiazines)
Hypoxic brain injury
Post-encephalitis
MPTP toxicity
Clinical findings expected in a patient with Parkinson’s disease?
Expressionless face
Coarse, pill-rolling, 4-6 Hz tremor, classically asymmetrical
Bradykinesia (‘snap test’ on each thumb)
Cogwheel rigidity at wrists (exaggerated by synkinesis)
Gait: slow, shuffling and festinant. Absence of arm swing, often asymmetrical
Speech: slow, faint, monotonous
Additional things to request at the end of a Parkinsonism exam (thinking about Parkinson’s plus syndromes)
BP looking for evidence of MSA (Parkinsonism with postural hypotension, cerebellar and pyramidal signs)
Test vertical eye movements (for evidence of PSP)
Test cognition (LBD)
Take a medication history (phenothiazines)
Assess patient’s handwriting (micrographia) and ask to draw an Archimedes’ spiral
What is the classical triad of features of idiopathic Parkinson’s disease?
‘BRR’
Bradykinesia
Rigidity
Rest tremor
Non-motor symptoms of Parkinson’s disease?
Anosmia
Cognitive effects
Mood disorders
Pain
REM sleep disorder
Why do a carotid doppler following stroke?
To look for evidence of stenosis, to see if it could be the cause of stroke. If suitable for carotid endarterectomy, could arrange that.
What other investigations could you consider if a patient has a normal ECG and carotid doppler following a stroke?
Look more closely for paroxysmal AF using a 24h or 5-day Holter monitor.
Consider a TTE looking for structural cause (PFO - paradoxical embolism).
How does the nature of a visual field defect help you localise the lesion?
In an MCA stroke - would expect sensory changes.
Homonymous hemianopia can result from lesions of the optic tract, lateral geniculate body or optic radiation.
A left HH would signify a right-sided lesion.
In a posterior cerebral artery stroke, would expect macular sparing of the visual field defect (due to supply from the MCA)
Signs of a dominant parietal lobe cortical infarct?
Dysphasia
Gerstmann’s syndrome: dyslexia, dyscalculia, finger agnosia, left and right disorientation
‘Dominant side - D’s’
Signs of a non-dominant parietal lobe infarct?
Dressing and constructional apraxia
Spatial neglect
List the corresponding lesions for the following visual field defects:
unilateral field loss, bitemporal hemianopia, homonymous hemianopia, superior homonymous quadrantanopia, inferior homonymous quadrantanopia
Unilateral field loss: lesion at ipsilateral optic nerve.
Bitemporal hemianopia: lesion at optic chiasm.
Homonymous hemianopia: lesion at contralateral optic tract.
Superior homonymous quadrantanopia: lesion at contralateral temporal lobe of optic radiation.
Inferior homonymous quadrantanopia: lesion at contralateral parietal lobe of optic radiation.
Management of MS?
MDT approach: nursing, PT, OT, social worker, doctor.
Disease-modifying treatments: interferon beta and glatiramer. MAB therapy (natalizumab).
Symptomatic treatments:
IV methylprednisolone for acute attacks.
Antispasmodics (baclofen).
Carbamazepine (neuropathic pain).
Laxatives / intermittent catheterisation for bladder and bowel symptoms.
What are the different types of MS?
Relapsing-remitting
Primary progressive
Secondary progressive
Clinically isolated syndrome
Define multiple sclerosis?
CNS demyelination causing neurological impairment that is disseminated in time and space.
Investigations to perform in suspected MS?
CSF: oligoclonal IgG bands
MRI brain/spinal cord: periventricular white matter plaques
Visual evoked potentials (VEPs): delayed velocity but normal amplitude (evidence of previous optic neuritis)
Differential diagnosis for MS?
If acute onset, consider vascular cause.
Disc prolapse.
Demyelination (MS) is more likely if there are other features such as RAPD, pale optic disc (optic neuritis), and INO.
Clinical signs present in MS?
Mobility aids
Cranial nerves: bilateral INO, optic atrophy, reduced visual acuity, cranial nerve palsies
UL/LL exam: UMN spasticity, weakness, brisk reflexes, altered sensation
Cerebellar: dysdiadochokinesia, ataxia, nystagmus, intention tremor, hypotonia
Other clinical features include: depression, autonomic (urinary retention + bowel problems), Uthoff’s phenomenon (worsening of sx after hot bath or exercise), L’hermitte’s sign: lightening pain down spine on flexion of neck
Signs of cerebellar syndrome to elicit on examination and the corresponding conditions that can cause cerebellar syndrome?
INO/RAPD/UMN weakness/sensory disturbance - demyelination
Cachexia/clubbing/tar staining - paraneoplastic cause
Weakness/visual field defects - stroke / SOL
CN 5, 7, 8 lesion pathology - cerebellopontine angle lesion
Parkinsonism - MSA
Gum hypertrophy - phenytoin use
Stigmata of CLD - alcohol
Ophthalmoplegia - Miller-Fisher syndrome
Pes cavus - Freidreich’s ataxia
Horner’s syndrome - lateral medullary syndrome
List some causes of a bilateral cerebellar syndrome
Demyelination (MS)
Paraneoplastic conditions
Bilateral posterior strokes / SOL
List some causes of a unilateral cerebellar syndrome
Demyelination
Posterior ischaemic stroke / haemorrhage
SOL in the posterior fossa
Differentials for a spastic paraparesis and cerebellar signs?
Demyelination
Freidreich’s ataxia
Spinocerebellar ataxia
Arnold-Chiari malformation
Syringomyelia
How do you differentiate between a cerebellar and a sensory ataxia?
Cerebellar: nystagmus and dysarthria.
Sensory: impaired sensation (joint position / vibration), pseudoathetosis, finger-nose testing ok with eyes open but struggles with eyes closed.
If sensory ataxia, need to decide if CENTRAL or PERIPHERAL. Spinal cord pathology, neuropathy, or both (B12 deficiency)
What investigations are appropriate to request in cerebellar syndrome?
Bloods: TFTs, copper studies, paraneoplastic screen, coeliac screen, infective screen, autoimmune screen, FBC, LFTs, B12, drug levels (lithium / phenytoin / carbamazepine).
Imaging: MRI brain + spinal cord (superior to CT for imaging the posterior fossa).
Special: LP (oligoclonal bands - MS), EMG + nerve conduction studies, genetic testing.
What is a Charcot joint?
A neuropathic joint where impaired joint position and pain sense leads to chronic damage to ankle and midfoot, resulting in deformity.
Which medications cause neuropathy?
Sensory: isoniazid
Sensorimotor: vincristine, amiodarone
Motor: dapsone
How would you distinguish between a neuropathy and a myopathy on examination?
A myopathy has a proximal pattern of weakness, absence of fasciculations, preserved reflexes and contractures.
A neuropathy has sensory signs.
NB if thinking myopathy, impt to consider cardiac involvement.
Differential diagnosis for a sensory polyneuropathy?
Most common = diabetes.
Metabolic: uraemia, hyperthyroidism, B12 deficiency.
Toxic: chemotherapy, nitrofurantoin, isoniazid.
Inflammatory: CIDP, sarcoid, vasculitis.
Paraneoplastic: lung cancer / paraproteinaemia
What is the purpose of doing nerve conduction studies in a peripheral neuropathy?
To determine whether the neuropathy is demyelinating or axonal in nature.
Demyelinating neuropathy is more likely to be due to an underlying inflammatory condition such as CIDP.
Can also figure out whether it is length-dependent. If length-dependent, it is more likely to be inflammatory.
Investigations to request in a case of peripheral neuropathy?
Bedside: CBG, urinalysis (glucose), fundoscopy (diabetic retinopathy).
Bloods: FBC (macrocytic anaemia), UEs (urea), LFTs (alcohol use), TFTs, B12, AI screen with ESR. HbA1c, immunoglobulins and serum electrophoresis.
Special: nerve conduction studies and EMG.
Why do we do Romberg’s test on examination?
To determine whether unsteadiness is due to a sensory ataxia. Often, it is positive in peripheral neuropathy.
Differential diagnosis for a peripheral motor and sensory neuropathy?
Diabetic neuropathy
Hereditary neuropathy with pressure palsy (HNPP)
Metabolic: B12, porphyria
Drugs / toxins: platinum chemo, lead, alcohol, isoniazid, dapsone
Inflammatory: AIDP, CIDP, GBS, sarcoid, vasculitis causing mononeuritis multiplex
Infections: HIV, Lyme, leprosy
Paraneoplastic phenomenon
Inheritance and pathophysiology of Charcot Marie Tooth disease?
Caused by genetic mutations that affect the myelin sheath, but occasonally the axons of neurones.
Inherited in autosomal dominant, autosomal recessive, and x-linked patterns.
How would you go about investigating a mononeuropathy?
Need to arrange neurophysiological studies.
Nerve conduction studies - to localise the lesion.
EMG would help provide prognosis in terms of recovery.
MRI neck to rule out cervical radiculopathy.
How would you treat neuropathic pain associated with neuropathy?
Amitriptyline is 1st line.
Gabapentin / pregabalin - 2nd line
Duloxetine - 3rd line
Topical therapies if tablets not tolerated (capsacium)
How can you differentiate between an ulnar neuropathy and a C8/T1 nerve root lesion?
The power in abductor pollicis brevis would be strong in ulnar neuropathy.
Sensation in T1 dermatome would be normal in an ulnar neuropathy.
How would you rule out a lesion of the other major upper limb peripheral nerves in a suspected ulnar nerve palsy?
Wrist extension - motor aspect of radial nerve.
Finger extension - motor function of posterior interroseus nerve.
Thumb abduction - motor function of median nerve (abductor pollicis brevis).
Sensation would only be affected in the distribution of the ulnar nerve in an ulnar neuropathy.
Clinical signs of an isolated ulnar neuropathy?
Resting flexion of interphalangeal joints of 4th and 5th digits ‘ulnar claw’.
Wasting of the first dorsal interrosei and hypothenar eminence.
Scars may give clue as to MOI.
Weakness of finger abduction.
Altered sensation in the region of the ulnar nerve.
NB ulnar lesions are often caused by trauma or a surgical procedure.
How would you differentiate a mononeuropathy from a more generalised neurological disorder such as mononeuritis multiplex?
Reflexes would be normal in mononeuropathy.
In a generalised inflammatory neurological condition, you would expect some degree of areflexia.
Differential diagnosis of chorea?
Immune-mediated inflammatory causes (Sydenham’s chorea or SLE-associated chorea).
Hyperglycaemia.
Vascular causes.
Genetic: Huntington’s disease.
Management of Huntington’s disease?
No disease-modifying therapy.
MDT approach focused on symptom management: neurology, neuropsych, dietician.
OT/PT for work/home adaptations.
Support groups: Huntington’s Disease Association
What is the inheritance of Huntington’s disease?
Trinucleotide repeat disorder.
Inherited from affected parent who carries a mutation in the Hungtintin gene. 10% de novo mutations.
Autosomal dominant condition - 50% chance of passing on.
Shows ‘genetic anticipation’ - where subsequent generations are often affected earlier or have more severe phenotype.
Clinical signs of tuberous sclerosis?
Skin: perinasal butterfly rash, angiofibromata. Periungual fibromas. Shagreen patch (roughened skin over lumbar region), ash-leaf macules (depigmented macules on trunk).
Respiratory: cystic lung disease.
Abdo: renal enlargement, transplanted kidney, dialysis fistulae.
Eyes: retinal phakomas (dense white patches).
CNS: mental retardation, seizures, signs of antiepileptic treatment.
Pathophysiology of tuberous sclerosis?
Autosomal dominant inheritance with variable penetrance.
Caused by a mutation in either of two genes: TSC1 or TSC2 (tumour suppressor genes)
80% have epilepsy (most present in childhood).
Cognitive defects in 50%.
Renal manifestations of tuberous sclerosis?
Renal angiomyolipomas, renal cysts, RCC
The genes for TS and ADPKD are contiguous on chromosome 16, hence some mutations lead to both conditions
Renal failure may result from cystic disease or parenchymal destruction
Investigations for a patient with suspected tuberous sclerosis?
Skull films: ‘railroad track’ calcification
CT/MR head: tuberous masses in cerebral cortex
Echo and abdominal USS: hamartomas and renal cysts
Causes of a spastic paraparesis?
Demyelination (MS)
Cord compression / cervical myelopathy
Trauma
Motor neuron disease
Causes of a spastic paraparesis + sensory level
Cord compression
Cord infarction
Transverse myelitis (infection / autoimmune / paraneoplastic / sarcoid / NMO)
Causes of a spastic paraparesis + dorsal column loss (joint position / vibration sense)
Demyelination
Freidreich’s ataxia
SACD of the spinal cord
Syphilis
Cervical myelopathy
Causes of a spastic paraparesis + spinothalamic loss
Syringomyelia
Anterior spinal artery infarction
Causes of a spastic paraparesis + cerebellar signs
Demyelination
Freidreich’s ataxia
Spinocerebellar ataxia
Arnold-Chiari malformation
Syringomyelia
Spastic paraparesis + small muscle of the hand wasting
Cervical myelopathy
MND
Syringomyelia
Other causes of spastic paraparesis
Hereditary spastic paraparesis
Tropical spastic paraparesis due to HTLV-1
Cerebral palsy
Investigations to do in a suspected spastic paraparesis?
Bloods: FBC, UE, bone, CRP, HIV, syphilis, HTLV-1, autoimmune panel, AQP4 antibodies (NMO), paraneoplastic screen, serum electrophoresis, B12 (SACD of the cord)
Other: NCS + EMG, LP (MS), visual evoked potentials (MS), MR brain and spine (cord compression / tumour / MS)
Causes of flaccid paraparesis?
ACL MNM
Anterior horn cell disease: MND, polio
Cauda equina syndrome: disc herniation, mets, abscess
Lumbosacral plexopathy: tumour, trauma, abscess
Motor neuropathies: inflammatory, toxins, drugs, metabolic, infectious, congenital (CMT, HMSN)
NMJ disorders: MG, LEMS, botulism
Myopathies: inflamm (SLE), CTD (RA), cancer (paraneoplastic), infection (HIV / CMV / EBV), toxins (alcohol), endocrine (Cushings’, Addison’s, thyroid)
Features of Guillain-Barre syndrome?
An acute, inflammatory, demyelinating polyneuropathy.
Onset over days to weeks, usually secondary to infection (mycoplasma / campylobacter).
Ascending flaccid limb weakness, areflexia, fatigue, distal parasthesia, patchy sensory loss, spinal pain.
CNS: ptosis, ophthalmoplegia, facial nerve, bulbar weakness.
Autonomic: tachycardia / labile BP, bladder and bowel dysfunction.
Resp: SOB + fatigue.
Investigations to do in suspected Guillain-Barre syndrome?
LP: albuminocytological dissociation of CSF.
Reduced velocity + conduction block on NCS.
Antibodies to gangliosides.
FVC
ECG
Management of Guillain-Barre syndrome?
ICU if FVC <1.3L or bulbar dysfunction.
IVIG +/- methylprednisolone.
Consider plasma exchange.
Causes of foot drop?
Myopathy of anterior tibialis muscle.
Common peroneal nerve palsy: trauma / surgery / compression / mononeuritis multiplex.
Sciatic nerve palsy.
Lumbosacral plexopathy: trauma / tumour.
L5 root lesion: prolapsed disc.
How to differentiate between a CPN palsy, sciatic nerve lesion and an L5 lesion?
CPN palsy: lose plantarflexion and foot eversion. inversion and ankle reflex intact.
Sciatic nerve lesion: lose plantarflexion and eversion. Lose dorsiflexion and inversion too. Weak knee flexion and lose ankle reflex.
L5 lesion: ankle jerk preserved. Lose inversion, eversion, dorsiflexion. Also lose sensation on sole + dorsum of foot, and anterolateral shin.
Investigations to request in a foot drop of unknown cause?
Urine dip (blood / protein)
Bloods: screen for causes of neuropathy / mononeuritis multiplex (autoimmune, infectious, inflammatory, endocrine causes)
Imaging: XR fibula, EMG + NCS, MR spine and sacrum.
Management of a foot drop?
Conservative: splint / calliper, avoid leg crossing, PT/OT, DVLA considerations
Medical: analgesia, treat cause
Surgical: repair fracture / severed nerve
Clinical features of a patient presenting with a foot drop?
Wasting of the lower leg, fasciculations and reduced tone.
Weak ankle dorsiflexion and eversion.
Ankle reflex may or may not be intact. Inversion and plantarflexion may be intact.
Distribution of sensory loss: lateral lower leg, foot dorsum, webspace between 1-2nd toes, sole of foot.
High-stepping gait, walking aid, splint, insoles.
Scars in fibula area / back.
Clinical signs of syringomyelia?
Weakness + wasting of small muscles of the hands
Loss of reflexes in ULs
Dissociated sensory loss in ULs and chest: loss of pain / temperature sensation but preserved joint position / vibration sense (spares dorsal columns).
Scars from painless burns.
Charcot joints: shoulder and elbow.
Which sensory modalities are affected in syringomyelia?
Spinothalamic - pain + temperature loss at level of syrinx.
Anterior horn cells - LMN weakness at level of syrinx.
Corticospinal tract - UMN weakness - below level of syrinx.
Usually spares dorsal columns - proprioception.
Define syringomyelia.
Syringomyelia is caused by a progressively expanding fluid-filled cavity within the cervical cord, typically spanning several levels.
It is associated with spina bifida and Arnold-Chiari malformation. Investigation of choice is an MRI spine.