Neurology Short Case Flashcards
Investigations for floppy strong
TFTs
Urine metabolic screen
Serum lactate
CT Brain
Karyotype and microarray
Inherited causes of floppy strong
Central cause - UMN lesion
Genetic e.g. PWS, T21
Structural e.g. lissencephaly
Neurodegenerative e.g. Tay-Sachs, MPS, Zellweger
Neurocutaneous e.g. Sturge Weber
Metabolic e.g. amino acidopathies
Acquired causes of floppy strong
Central cause - UMN lesion
Static encephalopathy, prematurity
Infection e.g. TORCH, meningitis, encephalitis
Ischaemia
Trauma
Endocrine e.g. hypothyroidism, hypopituitarism
Causes of floppy weak
Peripheral cause - LMN lesion
Anterior horn: SMA
Peripheral nerve: GBS, hereditary motor/sensory neuropathy
NMJ: myasthenia, infantile botulism
Muscle: congenital or infantile muscular dystrophy, congenital myopathies (e.g. central, core, nemaline rod)
Complications of hypotonia
Ophthalmoplegia
Aspiration
Head lag
Scoliosis
Weak cry, cough, chest infections
Constipation
Hip dislocation
Investigations for floppy weak
CK
EMG and nerve conduction studies
Muscle biopsy
Exome sequence on microarray
Central/UMN clinical signs
Decreased alertness, not age appropriate
Hypertonia +/- clonus
Normal or decreased power
Hyperreflexic + Babinski
Normal or decreased sensation
Decreased coordination
Features of spasticity; some spontaneous/antigravity movements
Peripheral/LMN clinical signs
Normal alertness
Hypotonia
Decreased power
Hyporeflexic
Decreased sensation
Normal or decreased coordination
UMN lesion differentials according to location
Spine: unlikely unilateral, no facial changes, sensory changes at level
Brainstem: arm/leg weakness, facial weakness on opposite side
Subcortical: arm/leg weakness, facial weakness on same side
Cortical: arm/leg weakness, facial weakness on same side, cortical signs (visual fields, aphasia)
LMN lesion/neuromuscular DDx according to location
Anterior horn cell: SMA, polio
Peripheral nerve: GBS, CMT
Neuromuscular junction: myasthenia gravis, botulism
Muscular dystrophy: congenital myopathies (central/core/nemaline), dystrophies (DMD/BMD/FSHD), congenital muscular or myotonic dystrophy
Anterior horn cell signs
Normal extraocular/face strength
**Tongue fasciculations +++
Proximal > distal and LL > UL power
Hyporeflexic or absent reflexes
Types of SMA
SMA 1 - never sit
SMA 2 - sit but not stand, mini myoclonus
SMA 3 - stand and walk
Peripheral nerve signs
Normal extraocular/face strength
**Distal weakness (++)
Hyporeflexic or absent reflexes
Wasting
High stepping gait
Distal sensory loss
Tremor in CMT
Neuromuscular junction signs
**Ptosis and ophthalmoplegia
Decreased extraocular and face strength
Proximal or distal weakness
Hyporeflexic
Fatiguability
Myopathy signs
Normal extraocular strength
Decreased face strength
Proximal weakness
Hyporeflexic
Fish tented mouth
Ophthamoplegia
Facial/bulbar involvement
Normal CK
Myotonia
Muscular dystrophy signs
Normal extraocular strength
Decreased face strength
Proximal weakness
Hyporeflexic
Increased CK
Congenital myotonic dystrophy signs
Normal extraocular strength
Decreased face strength
Proximal or distal weakness
Absent reflexes
Tented upper lip open mouth, high arched palate
Causes of chorea (irregular rapid movements)
Pathology in corpus striatum
Inherited: CP, Wilson’s, neurodegenerative (Lecsh Nyhan, Huntington’s), ataxia telangiectsia
Acquired
Infective: Sydenham’s, EBV
Immune: SLE
Drugs
Causes of athetosis (slow writhing movements of proximal extremities)
Pathology in putamen (same causes as chorea)
Inherited: CP, Wilson’s, neurodegenerative (Lecsh Nyhan, Huntington’s), ataxia telangiectasia
Acquired
Infective: Sydenham’s, EBV
Immune: SLE
Drugs
Causes of dystonia (abnormal posturing)
Inherited: CP, Wilson’s, dopa responsive, Hallevorden-Spatz, Huntington’s
Acquired: drugs
Causes of static tremor (present with rest and gone with action)
Wilson’s
Hallervorden-Spatz
Huntington’s
Causes of postural tremor (throughout range of movement)
Thyrotoxicosis
Phaeochromocytoma
Wilson’s
Familial
Cushing’s syndrome
Hypoglycaemia
Causes of intention tremor (end of movement only)
Cerebellar lesions (multiple sclerosis, stroke,
mass lesion), drugs, chronic alcoholism, Wilson’s
Causes of myoclonus (sudden, disorganised, irregular contraction of muscle/muscle group)
Primary seizure disorder
Structural brain abnormalities e.g. Aicardi
Degenerative e.g. neurocutaneous, Tay Sachs, WIlson’s
Ishcaemic
Infections e.g. HIV encephalopathy, SSPE
Metabolic e.g. amino acidopathies
Key cerebellar signs
Ipsilateral to side of lesion (cross twice in brainstem)
Dysdiadochokinesis
Past pointing/dysmetria; dyssynergia
Ataxic gait - wide-based, veer towards affected side, difficulties heel-toe walking
Nystagmus
Dysarthria (scanning), explosive speech
Hypotonia, pendular reflexes
Head titubation, truncal ataxia
Romberg’s +ve
Causes of ataxia (broad categories)
Cerebellar
Vestibular (acute labyrinthitis)
Dorsal-column loss
Peripheral neuropathy
Investigations for cerebellar pathology
Urine dipstick: glycosuria in AT and FA (Friedreich’s Ataxia)
Imaging: CT/MRI - if no lesion, then genetic/metabolic evaluation
Bloods: FBE, UEC, toxicology screen (blood/urine), metabolic screen (amino acids, lactate, pyruviate, ammonia, pH, ketones)
Other: LP, urine catecholamines for neuroblastoma (VMA/HVA) with chest/abdo imaging
Clinical features of Friedreich’s Ataxia
Ataxia, pes cavus, hammer toes, kyphoscoliosis, sensorineural hearing loss, HOCM
Clinical features of ataxia telangiectasia
Telangiectasia of bulbar, pinnae, nares, flexures
Impaired cognition
Ear/lung infection
Clubbing
Leukaemia/lymphoma
Gonadal atrophy
Causes of cerebellar ataxia
Chemical: EtOH, phenytoin, CBZ, lead
Hypoxic/vascular: CP, cerebellar CVA/bleed/AVM
Infection: abscess, meningitis, encephalitis
Neoplastic: cerebellar, posterior fossa (medulloblastoma, astrocytoma), neuroblastoma
Physical: trauma, structural (Dandy-Walker, Chiari malformation, agenesis of cerebellar vermis), raised ICP
Inflammatory: acute cerebellitis, Miller-Fisher variant of GBS (ataxia, ophthalmoplegia, areflexia)
Genetic: AT, FA, Angelman’s, Bardet-Biedl
Endocrine/metabolic: leukodystrophies, Wilson’s, lysosomal storage, peroxisomal
Nutritional: vitamin E deficiency
Causes of ataxia from posterior column loss
Subacute combined degeneration of the cord - B12 deficiency (also get peripheral neuropathy, absent ankle reflexes, doral column loss, atrophy, dementia)
Diabetes
Hypothyroidism
Tabes dorsalis (untreated syphilis)
Causes of peripheral neuropathy
DAM IT BICH
Drugs: isoniazid, vincristine, phenytoin, nitrofurantoin, cisplatin, heavy metals, amiodarone
Alcohol
Metabolic: diabetes, CRF, neurodegenerative
Infective: GBS
Tumour: lymphoma, leukaemia
B12 deficiency
Idiopathic
Connective tissue disease: SLE, PAN
Hereditary: HSMN
Causes of hemiplegia
SCIT
Systemic: coagulopathies (Factor V Leiden, SLE, ALL), sickle cell, NF-1
Cardiac: hypertension, cyanotic congenital heart (< 2 years - usually cerebral thrombosis, 2 years cerebral abscess), SBE, vessel abnormalities (cerebral AVMs, Sturge Webeter)
Infective: HSV encephalitis, bacterial meningitis, cerebral abscess
Traumatic: MVA, NAI
Signs of spinal cord involvement in hemiplegia e.g. Brown Sequard, hemicord syndrome
Ipsilateral arm involvement if cord level high enough
Sensory changes:
Ipsilateral light touch and proprioception
Contralateral pain and temperature
Signs of brainstem involvement in hemiplegia
Ipsilateral arm involvement
Contralateral face involvement
May have cerebellar signs
Brainstem signs depending on level: midbrain (CN III/IV), pons (V, VI, VII, VIII), medulla (IX, X, XI, XII)
Signs of internal capsule involvement in hemiplegia
Ipsilateral arm involvement
Ipsilateral face involvement
Absence of cortical signs
Signs of cortex involvement in hemiplegia
Ipsilateral arm involvement
Ipsilateral face involvement
Cortical signs: hemianopia, visual field changes, dysphasia
Causes of seizures
Idiopathic
Inherited (PWS, T21, TS, NF-1, Sturge Weber)
Acquired: structural/space occupying, infective (post meningitis/encephalitis), immune (SLE, vasculitis), metabolic, endocrine (low sugar/electrolytes)
Complications of seizures and medications
Seizures: developmental delay, aspiration
Medications: drowsiness, weight gain, gum hypertrophy, rash, cytopaenias, nausea and vomiting
General causes of macrocephaly
Large bones - bony disorders
Large brain - megalencephaly
Large ventricles/fluid - hydrocephalus
Bony disorders causing macrocephaly
Achondroplasia
Rickets
Osteogenesis imperfecta
Chronic haemolytic anaemias
Causes of megalencephaly
Generalised enlargement: Sotos, Neurocutaneous (NF, TS, Klippel-Trenauney-Weber, Sturge-Weber), Metabolic
Localised enlargement: tumours (glioma, ependymoma), abscess, subdural haematoma
Causes of hydrocephalus
Obstructive: aqueductal stenosis and gliosis (secondary to neonatal meningitis, TORCH infections, haemorrhage), Vein of Galen malformation, posterior fossa malformations (Dandy-Walker, Arnold-Chiari, tumours)
Non-obstructive: reduced absorption (subarachnoid haemorrhage, leukaemic infiltrates, infections/meningitis), increased production (very rare)
Closure of sagittal suture
Dolichocephaly/scaphocephaly
Long and boat shaped
Increased AP diameter
Decreased biparietal diameter
Normal intellect and neuro
Closure of coronal suture
Brachycephaly
Widened biparietal diameter and high vault
Decreased AP diameter
Flat and short
Eye signs - proptosis
Closure of unilateral lamboid/coronal suture
Plagiocephaly
Skewed shape
Normal intellect and neuro
Closure of metopic suture
Trigonocephaly
Mid-forehead ridging
Pointed narrow appearance to forehead
Hypotelorism, colobomata, intellectual impairment and midline defects e.g. cleft
> 4 sutures fused
Oxycephaly, turricephaly, acrocephaly
High, narrow, tower-shaped skull
Can cause significant neurological sequelae - raised ICP
Investigations for microcephaly
Imaging: skull X-ray, CT/MRI
Bloods: TORCH serology, karyotype, NST, TSH, metabolic studies
Urine CMV
CSF: TORCH
Signs of Horner’s syndrome
Partial ptosis
Miosis
ANhydrosis
Causes of Horner’s syndrome
Brainstem: vascular, tumour, syringobulbia/myelia (this can be bilateral)
Neck: thyroid mass, trauma
Carotid: aneurysm, dissection
Lung mass
Post cardiac surgery
Approximate visual acuities in normal child
6 months - 6/30
18 months - 6/9
24 months - 6/6
Causes of ptosis
Neurogenic: CN 3 palsy (ptosis and large pupil), Horner’s (ptosis plus small pupil - most commonly post cardiac surgery)
Myogenic: myasthenia (fatiguability), myotonic dystrophy, congenital ptosis
Ages and stages of vision in babies
Neonates: turn head to diffuse light source
6 weeks: face or large coloured object
3 months: eyes converge for finger play
4 months: follows objects through 180 degrees, turning their head
5 months: reach for toy and regard small raisin on table
6 months: move eyes together in all directions
9 months: able to pick up raisin, plays peek a boo
Causes of absent light reflex but intact accommodation
Midbrain lesion - Argyll Robertson pupil
Ciliary ganglion lesion - Adie’s pupil
Parinaud syndrome
Bilateral afferent pupil deficits
Causes of absent convergence but intact light reflex
Cortical lesion (cortical blindness)
Small pupils
Horner’s
Argyll Robertson (neurosyphilis)
Pontine lesion
Narcotics
Dilated pupils
Drugs
Third nerve lesion
Adie’s syndrome
Trauma
Surgical: lens transplant, iridectomy
IFM (iritis)
Congenital
Adie pupil
Efferent parasympathetic pathway affected
Dilated pupil
Decreased light reaction
Slow accommodation
No ptosis
Often young women
Decreased reflexes
Argyll Robertson pupil
Lesion in midbrain - syphilis
Constricted pupil
Decreased light reaction
Normal accommodation
No ptosis
Horner’s pupil
Sympathetic chain lesion
Constricted pupil
Normal light and accommodation reaction
Ptosis present
Ptosis with normal pupils
NMJ: myasthenia, botulism
Muscle: MD, FSHD, thyrotoxic myopathy
Congenitl
Ptosis with small pupils
Nerve: Horner’s, syphilis
Ptosis with large pupils
III nerve palsy
Causes of cataracts
Hereditary: myotonic dystrophy
Acquired: irradiation, trauma, metabolic (e.g. steroids, diabetes)
Causes of papilloedema
Space occupying lesion
Hydrocephalus
Benign intracranial hypertension
Hypertension
Central retinal vein thrombosis
Central venous sinus thrombosis
Papilloedema characteristics
Both eyes
Swollen optic disc
Normal acuity (early)
Normal colour vision
Large blind spot
Peripheral construction
Papillitis (optic neuritis) characteristics
Usually one eye and sudden
Swollen optic disc
Poor acuity
Decreased colour vision (especially red)
Central scotoma
Pain on eye movements
Causes of optic neuropathy
TIIME
Toxic: ethambutol, chloroquine
Immune: MS
Infective
Endocrine: diabetes
Metabolic: decreased B12
Visual field defect for pituitary defect
Bitemporal hemianopia
Visual field defect for optic tract to occipital cortex defect
Homonymous hemianopia
Visual field defect for temporal lobe defect
Superior quadrantanopia
Visual field defect for parietal lobe defect
Inferior quadrantanopia
Visual field defect for optic nerve defect
Complete blindness of ipsilateral eye
Visual field defect for defect in midline chiasmal region
Bitemporal nasal hemianopia
CN III palsy features
Complete ptosis (partial if incomplete lesion)
Eye down and out
Dilated pupil - not reactive to light and accommodation
Exclude IV nerve if III palsy present
Causes of CN III palsy
UMN: vascular, tumour, demyelination
LMN: compression (nasopharyngeal carcinoma, basal meningitis, orbital lesions), infarction (DM)
CN VI palsy features
Failure of lateral movement
Causes of CN VI palsy
UMN: vascular, tumour, demyelination
LMN: trauma, raised ICP
Causes of jerky nystagmus
Horizontal: vestibular, cerebellar (both to side. of lesion), internuclear ophthalmoplegia, toxins
Vertical: brainstem/cerebellar lesion (up - lesion in floor of 4th ventricle, down - lesion in foramen magnum), drugs (EtOH, phenytoin)
Causes of pendular nystagmus
Retinal - decreased macular vision e.g. oculocutaneous albinism
Congenital nystagmus
Features and causes of supranuclear palsy
Both eyes affected
Unequal pupils
No diplopia
Causes: pinealoma, MS, vascular lesions
Causes of exaggerated jaw jerk reflex
UMN lesion
Pseudobulbar palsy
CN V palsy causes
Central: vascular, tumour, demyelination
Peripheral
- posterior fossa: tumour, chronic meningitis
- petrous temporal bone: acoustic neuroma, meningioma, middle fossa fracture
- cavernous sinus: thrombosis, tumour
Cause of loss of sensation in all 3 divisions of CN V
Ganglion or sensory root lesion
Cause of total loss of sensation in 1 division of CN V
Post-ganglion lesion
Loss of pain but intact sensation of CN V
Brainstem or upper cord lesion
Loss of touch but intact pain of CN V
Pons/nucleus lesion
Causes of bilateral facial weakness
NMJ: myasthenia
Muscle
Nerve: GBS, bilateral parotid disease, mononeuritis multiplex
Causes of CN VII palsy
UMN: tumour, vascular
LMN:
Pontine (anterior horn cell) - vascular, tumour, MS
Posterior fossa - acoustic neuroma, meningioma
Petrous temporal bone - Bell’s palsy, Ramsey Hunt, fracture, otitis media
Parotid - tumour, sarcoid
Weber’s test: if sound localises to good ear
Sensorineural hearing loss
Weber’s test: if sound localises to bad ear
Conductive hearing loss
Rinne’s test positive: air conduction > bone conduction
Sensorineural hearing loss or normal
Rinne’s test negative: bone > air
Conductive hearing loss
Causes of sensorineural deafness
Unilateral:
Tumour e.g. acoustic neuroma
Trauma e.g. fracture of petrous temporal bone
Bilateral:
Environmental exposure to noise
Toxicity: gentamicin, frusemide
Infection: congenital rubella
Menière’s disease
Causes of conductive deafness
Wax
OM/effusion
Otosclerosis
Bony disease e.g. Paget’s
Things that point toward lesion
V nerve –> jaw
XII nerve –> tongue
Things that point away from lesion
X nerve –> uvula
Causes of facial weakness
Cortex and brainstem: Moebius, cerebral palsy, tumour, vascular insult, infection
Posterior fossa: acoustic neuroma, meningioma, chronic meningitis
Cranial nerve: GBS, Bell’s, Ramsay Hunt, petrouts temporal bone fracture, parotic gland tumour, osteopetrosis
NMJ: myasthenia gravis, infantile botulism
Muscle: myotonic dystrophy, FSHD
Causes of bilateral facial weakness + ptosis + ophthalmoplegia
Moebius, myotonic dystrophy, myasthenia gravis, infantile botulism
Causes of bilateral facial weakness alone
FSHD, GBS (bilateral LMN CN7), CP (bilateral UMN CN7)
Causes of unilateral CN7 palsy
UMN (spares the forehead): cortical vascular lesion or tumours
LMN:
Pontine lesions: tumours, vascular, demyelination
Posterior fossa: acoustic neuroma, meningioma, chronic meningitis
Petrous temporal bone: Bell’s, fracture, Ramsay Hunt, otitis media
Parotid gland: tumour
Features of pseudobulbar palsy (UMN lesion of IX, X, XII)
Increased gag reflex
Spastic movements of tongue
Spastic dysarthria
Labile emotions
Bilateral limb UMN signs
Features of bulbar palsy (LMN lesion of IX, X, XII)
Decreased gag reflex
Wasted, fasciculations of tongue
Nasal speech
Normal emotions
Signs of underlying cause
