Neurology Flashcards
Cerebellar signs
Dysdiadochokinesia
Ataxia
Nystagmus
Intention tremor
Slurred speech
Hypotonia
Differentials for ataxia
Acute - post-infection cerebellitis, tumour, drugs (phenytoin), stroke, head injury
Intermittent - migraine
Chronic - Friedrich’s ataxia, ataxia telangiectasia, Wilson’s disease, ataxic cerebral palsy, multiple sclerosis
Viral causes of cerebellitis
VICE
Varicella
Influenza
Coxsackie
Enterovirus
Definition of hydrocephalus
Increased volume of CSF, usually with increased pressure and with some degree of dilatation of the ventricles
3 causes of hydrocephalus
Obstructive
Decreased absorption of CSF
Overproduction of CSF (only really due to papilloma of the choroid plexus - incredibly rare)
What is communicating hydrocephalus
CSF can flow from 4th ventricular foramina to subarachnoid space but is not absorbed by arachnoid granulations
What is non-communicating hydrocephalus
There is no communication between the ventricles and sub-arachnoid space
Causes of non-obstructive hydrocephalus
Infection: encephalitis, meningitis, intrauterine toxoplasmosis
IVH or intracranial bleed
Sagittal sinus thrombosis
(Arachnoid villi hypoplasia)
Causes of obstructive hydrocephalus
Tumour
Dandy-walker cyst
Arnold chiari malformation
Aqueduct stenosis
Vein of Galen malformation
Achondroplasia
What is a Dandy walker cyst
absence or deficiency of cerebella vermis and fourth ventricular foramina outlets leads to cystic dilatation of 4th ventricle
What is the Arnold-Chiari malformation
Small posterior fossa, downward displacement of cerebellar tonsils and medulla into foramen magnum - often associated with spina bifida
Aqueduct stenosis
Genetics?
Clinical features?
X-linked or sporadic.
X-linked - short 1st metacarpal + thumb flexed in opposition
(child will have hydrocephalus/macrocephaly and overlapping fingers)
How does achondroplasia cause hydrocephalus
bony abnormalities causes obstruction of CSF flow
Normal ratio of white cells to red cells in peripheral blood
1:500
CSF glucose
Usually less than 2/3 blood glucose
Most common organisms implicated in meningitis neonatal period
GBS
Listeria
E. coli
Neurological sequelae in meningitis.
Pneumococcal?
Haemophilus?
Neurological sequelae most common in pnuemococcal
Effect of dexamethasone greatest in Haemophilus
Hypsarrythmia on EEG may be seen in:
prenatal: Tuberous sclerosis, infantile spasms
perinatal: Birth asphyxia
post-natal: Head injury, PKU,
How is diagnosis of SSPE confirmed
High anti-measles Ab titire in CSF
Herpes simplex encephalitis on EEG
Periodic complexes in leads over the temporal lobes
Classification of IVH
Grade I: Bleed in germinal matrix
Grade II: Bleed extending into the lateral ventricle, no ventricular dilatation
Grade III: Bleed extending into ventricles (>50%) with ventricular dilatation
Grade IV: Parenchymal involvement
Brudzinski’s sign
+ve = hip and knee flexion when neck is flexed (due to neck stiffness)
Kernig’s sign
Patient lying flat with knee flexed at 90 degrees, pain on extension of knee is positive Kernig sign
Neurological causes of the floppy infant
Congenital myotonic dystrophy
Congenital myasthaenia
SMA
Congenital myopathy
learn differences between these
Poor prognostic indicators in spina bifida
Hydrocephalus
Incontinent of faeces or urine
Paralysis of legs
Lumbar kyphosis
Side effects of phenytoin
Megaloblastic anaemia
Rickets (secondary to vitamin D metabolism)
Gum hypertrophy
Neurological complications of B12 deficiency
Subacute combined degeneration of the cord
peripheral neuropathy
Optic neuritis
Dementia
Drugs that cause peripheral neuropathy
metronidazole
isoniazid
Nitrofurantoin
Vincristine/vinblastine (chemo)
amiodarone
Cisplatin (chemo)
Phenytoin (seizures)
AZT (HIV)
Facial features in congenital myotonic dystrophy
Thin face
Inverted V shape upper lip
high arched palate
Thinning hair in temporal regions
ptosis
Features of myotonic dystrophy
Eyes: cataracts
Learning impairment
testicular atrophy
IDDM
cardiomyopathy (most die from arrhythmias)
Myotonic handshake (slow to release hand grasp)
Juvenile myasthenia gravis
Fatigueability
Ophthalmoplegia
Bulbar symptoms
Rx of myasthenia gravis
Pyridostigmine (acetylcholinesterase)
steroids
plasmaphoresis
thymectomy (thymomas are feature)
Pattern of weakness:
Myopathy
Neuropathy
Myopathy = proximal weakness
Neuropathy = distal weakness
Features of Duchenne muscular dystrophy on examination
prominent calves (pseudohypertrophy)
Gower sign
Trendelenburg (waddling) gait
kyphosis, scoliosis or lumbar lordosis
tip-toe walking
Bilateral pes cavus (high arch in foot)
Genetics of BMD + DMD
X-linked
Miller-Fisher syndrome
Areflexia, ataxia, ophthalmoplegia
Key features of Landau-Kleffner
normal language development until acute regression in comprehension and verbal auditory agnosia.
Able to interact in socially normal manner
Up to 80% go on to have seizures
(EEG may show continuous spike wave during slow wave sleep)
Friedrich’s ataxia
Inheritance
Onset
Typical features (neuro signs)
Deformity
Other systems
Autosomal recessive
5-15 years
Spasticity + upgoing plantars (corticospinal tracts)
Broad based gait (ataxia)
Absent ankle reflexes
Pes cavus, scoliosis
Cardiomyopathy, optic atrophy
3 subtypes of cerebral palsy
Hemiplegia
Quadriplegia
Diplegia
Diagnosis of NF-1
≥6 cafe au lait patches (>5mm pre-puberty, >15mm post-puberty)
Axillary freckling
≥2 neurofibromas OR 1 plexiform neurofibroma (more diffuse, on face and neck)
Optic glioma
≥2 Lisch nodules
Fibrous dysplasia of bone
≥1 relative with neurofibromatosis
2 or more of above
Incidence of NF-1
1 in 2,500
On examinaiton in NF
Short stature
Kyphoscoliosis
Macrocephaly
Follow up in NF-1
- Annual full physical examination -
- BP monitoring (because of renal artery stenosis, phaeochromocytoma)
- Annual vision exam
- Tumour surveillance
(risk of Wilms, medulloblastoma, neuroblastoma, astrocytoma, ependymoma, meningioma, phaeochromocytoma, medullary Ca thyroid)
NF-1 cf. NF-2
1st clinical manifestation: cataracts (not cafe au lait patch)
no learning impairment (NF-1 has learning impairment)
schwannoma most common neoplasm
Features hearing loss, tinnitus
NF-2 diagnosis
- Bilateral acoustic neuromas
- Unilateral acoustic neuroma + 1st degree relative with NF-2
- Unilateral acoustic neuroma OR 1st degree relative with NF-2 + 1 of:
meningioma, ependymoma, non-vestibular schwannoma, cataract
DDx for cafe au lait
NF-1 and NF-2
Tuberous sclerosis
Turner syndrome
McCune-Albright syndrome
Russell-Silver syndrome
Gottron’s patches
Juvenile dermatomyositis
Heliotrope rash
Juvenile dermatomyositis
Subungal fibroma
Tuberous sclerosis
Adenoma sebaceum
Tuberous sclerosis
Ash leaf patch
Tuberous sclerosis
Examination findings in Sturge-Weber
Port wine stain (naevus flammeus) in the distribution of the sensory divisions of the trigeminal nerve
Incidence of Sturge-Weber
1 in 20,000 to 1 in 50,000
Features of Sturge Weber
Vascular neurocutaneous syndrome which leads to headaches, seizures, hemiparesis, glaucoma (due to malformations in vessels of the eye), intellectual disability
Seizures onset from 1 month to 1 year. Often focal clonic, contralateral to PWS
Features of UMN facial nerve palsy
Causes of UMN facial nerve palsy
Contralateral weakness below eyebrows, brow sparing
Cerebral palsy, bleed, tumour
Features of LMN facial nerve palsy
Causes of LMN facial nerve palsy
Ipsilateral weakness with no sparing of the brow (no ptosis)
Causes: Idiopathic, infection (Ramsay-Hunt = Herpes Zoster) mastoiditis or mastoid surgery, GBS
Incidence of Charcot-Marie-Tooth disease
(Peroneal muscular atrophy, HMSN Type IIa)
Genetics
3.8 in 100,000
Autosomal dominant (and AR but rarer)
CMT onset
late childhoo/early adolescence but gait abnormality may be present from 1-2 years
Features of CMT on examination
Anterior compartment of LLs become wasted
Progressive weakness of ankle dorsiflexion and eventually foot drop
Drop foot gait - look for orthotics!!
Pes cavus deformity
Defects in vibration, proprioception, pain + tempearature + motor and autonomic
Tests in CMT
Diagnosis
Test = EMG
Sural nerve biopsy diagnostic
Tell me about Bell’s palsy
Common in all age groups
Usually occurs around 2 wks after viral infection
Activation or reactivation of HSV, varicella-zoster
(Rarer) DDx for unilateral (or bilateral) facial nerve palsy
Infection: Lyme disease, EBV, CMV
Malignant: leukaemic infiltration, schwannoma, neurofibromas
Other: hypertension, T1DM, trauma
Prognosis of Bell’s palsy
90% make good recovery over weeks
<10% have residual weakness
