Neurology Flashcards
Floppy strong causes
- Genetic: PWS, T21
- Structural: lissencephaly
- Metabolic: amino acidopathy, Zellweger, Tay-Sachs
- Neurocutaneous: SWS
- Static encephalopathy (CP)
- Infection: TORCH, Meningitis, encephalitis
- Ischaemia
- Trauma
- Endocrine (hypothyroidism, hypopituitarism)
Floppy weak causes
- Anterior horn: SMA
- Peripheral nerve: CMT, GBS
- NMJ: infantile botulism, MG
- Muscle: congenital muscular dystrophy, myotonic dystrophy, congenital myopathies
Investigations if floppy strong
History always!
Examine parents
Newborn screening results
TFTs
Serum lactate
Karyotype and microarray
Urine metabolic screen (OA, AA)
CT/MRI brain
Investigations if floppy weak
History
Newborn screening
CK
EMG and nerve conduction studies
Microarray?
Grading reflexes
0 = Absent
1= reduced (hyporeflexic)
2= normal
3= brisk
4= very brisk, elicits clonus (abnormal)
Which side are cerebellar signs on?
Cerebellar signs are IPSILATERAL to the side of the lesion
Horizontal nystagmus maximal towards side of lesion
Stagger towards side of lesion
Key cerebellar signs
- Dysdiadochokinesis
- Past pointing (dysmetria)
- Ataxic gait
- Nystagmus
Features of Freidreichs Ataxia
- Neuro dysfunction - cerebellar and posterior column mainly
- Cardiomyopathy
- Diabetes mellitus in 8-32%
Atrophy of spinal cord and medulla on MRI
Triplet repeat expansion of FXN gene
Cranial nerve pathologies that point TOWARDS side of lesion?
CN 5: jaw deviation
CN 12: tongue
Cranial nerve pathologies that point AWAY from side of lesion:
CN 10: uvula
Causes of horners syndrome (ipsilateral ptosis, miosis, anhydrous)?
Anything that disrupts the sympathetic nerve supply to the eye
Brainstem (lateral medullary syndrome)
- tumour, vascular insult, syringobulbia
Neck
- thyroid mass, trauma
- carotid anerysm or dissection
Lung mass
Post cardiac surgery
How to localise diplopia?
Abnormal is present at 30degrees
Cover each eye to find out which image disappears - loss of the lateral images indicates that the covered eye is responsible
Causes of abnormally small pupils
- Horners syndrome (sympathetic chain)
- Pontine lesions
- Argyll robertson pupil + loss of light reflex (syphilis)
Causes of abnormally dilated pupils
- CN3 lesion
- Trauma
- Surgical - lens transplant, iridectomy
- Drugs (eg dilating)
- Congenital
- Adies pupil (idiopathic)
CN3 palsy features
- Complete ptosis (partial if incomplete lesion)
- Eye down and out
- Dilated pupil, unreactive to light and accomodation
+/- CN 4 lesion
Ddx for CN 3 or 6 lesion
UMN: Brainstem
- vascular, tumour, demyelination
LMN: peripheral nerve
- compression
- trauma
Raised ICP often -> CN6 palsy
Causes of horizontal nystagmus?
- Vestibular lesion (to side of lesion)
- Cerebellar lesion (to side of lesion)
- Toxins
Causes of vertical nystagmus
Brainstem/ cerebellar
-Upbeat: lesion in floor of 4th ventricle
- Downbeat: lesion in foramen magnum
Causes of CN7 palsy?
UMNL (forehead sparing)
- pons tumour or vascular lesion
LMNL
- vascular, tumour, demyelination
Posterior fossa: acoustic neuroma, meningioma
Petrous temporal bone: Ramsay Hunt, #, otitis media
- Bell’s palsy
- Parotid tumour or sarcoid
Causes of SNHL
- Weber localises to good ear and AC>BC
Unilateral
- tumour eg acoustic neuroma
- trauma eg # of temporal bone
Bilateral
- toxicity eg gent, frusemide
- congenital rubella
- Meniere’s
Causes of conductive hearing loss
- Wax
- OM/effusion
- Otosclerosis
- Bony disease eg Pagets
What is a pseudo bulbar palsy?
- Bilateral UMNL of corticobulbar tract, affecting CN 9, 10, 12
- dysasthria
- dysphagia
- facial and tongue weakness
- increased gag reflex
- emotional lability
What is a bulbar palsy?
Bilateral impairment of the LMN of CN 9, 10, 12
- reduced gag reflex
- wasted tongue with fasciculations
- nasal speech
- normal emotions
Caused by brainstem strokes and tumours, GBS and some genetic conditions
Features of myotonic dystrophy
Facial: V shaped upper lip, narrow head, thin cheeks, high arched palate
Weakness and wasting distal >proximal
Weak speech and swallow
Myotonia from >5yrs
External ophthalmoplegia and cataracts
Endocrine anomalies incl dm, hypothyroidism, adrenal insufficiency
Low IgG
Features of Dandy Walker syndrome?
Congenital condition where the cerebellum doesn’t develop properly
- Cerebellar signs
- Hydrocephalus (incr HC, sunsetting)
- Hypotonia
- Hearing/vision problems
Features of limb girdle muscular dystrophy
- Weakness of shoulder/pelvic girdle
(minimal facial/EOM weakness) - Nasal speech, dysarthria
- Elbow contractures
- Cardiac conduction defectsF
Features of facioscapulohumeral muscular dystrophy
- Facial weakness
- Weakness of shoulder, hips, wrist drop
- Scapular winging
- Atrophy of biceps, triceps
- Epilepsy and SNHL with infant form
Infant and classic form (2nd-3rd decade onset)
Features of myotonic dystrophy
Weakness of facial muscles, V shaped lip
Weakness of SCM, forearm, hand, ankle -> foot drop
Mytonia (slowed relaxation): percussion over thenar eminence, grip hypotonia
Cardiac conduction defects
Cataracts
Hypogammaglobulinemia, insulin resistance
Features of CIDP
Symmetric sensorimotor polyneuropathy
Weakness > sensory loss
Distal = proximal weakness
(Sensory involvement often worse distally and more posterior column than spinothalamic)
Reduced/absent reflexes
Symptoms present for >8 weeks
NCS: conduction velocity slowing
CSF protein elevated, with normal WCC (albuminocytologic dissociation)
Would do MRI spine with GAD
Clinical features of transverse myelitis
- back pain
- paraparesis
- initial flaccidity then spasticity, preferentially affecting flexors of legs and extensors of arms
- reduced reflexes initially -> Hyperreflexia lateral
- sensory level with pain and paraesthesias below that
- autonomic symptoms incl urgency, retention, constipation
Investigations for transverse myelitis
- MRI brain and spine with GAD - evidence of inflammation (hyperintense T2 signal), exclude compression
- CSF: mild elevation in protein, normal or mildly incr WCC, oligoclonal bands (can be seen with MS)
- Serology for MOD and AQ-4 (NMOSD)
- Serology for campylobacter
Causes of cerebellar ataxia?
Genetic
- Freidrichs, A-T, Joubert, Dandy Walker syndrome, congenital cerebellar hypoplasia
Vascular
- AVM/stroke
Infective
- meningitis, encephalitis, cerebellitis
Structural
- Chiari II
Tumour
- Medulloblastoma, astrocytoma
Metabolic
- LSDs, leukodystrophies, Wilsons disease
