Neurology 3

Question 1

What is ataxia?

Answer 1

an abnormaility in gait that is wide-based, staggering, unsteady, intention tremor and dysmetria- incoordination of movement, speech and posture due to either cerebellar (more common in children) or posterior pathway problems

Question 2

What are the causes of cerebellar ataxia?

Answer 2

o	Medication & drugs
o	Varicella infection
o	Vascular disorder
o	Inborn errors of metabolism
o	Poisoning
o	Brainstem encephalitis
o	Post-infectious or autoimmune  acute cerebellar ataxia
o	Trauma
o	Congenital malformation
o	Posterior fossa lesions or tumours
o	Genetic & degenerative disorders  eg. ataxic CP
o	Friedreich ataxia
o	Ataxia telangiectasia

Question 3

What is Friedreich’s ataxia?

Answer 3

Autosomal recessive
worsening ataxia, distal wasting in the legs, absent lower limb reflexes but extensor plantar responses because of pyramidal involvement, pes cavus (high arch) and dysarthria
impairment of joint position and vibration sense, extensor plantars and there is often optic atrophy
Evolving kyphoscoliosis and cardiomyopathy can cause cardiorespiratory compromise and death at 40-50 years

Question 4

What is ataxia telangiectasia?

Answer 4

Autosomal recessive- disorder of DNA repair
mild delay in motor development in infancy and oculomotor problems with incoordination and delay in ocular pursuit of objects, with difficulty with balance and coordination becoming evident at school age
deterioration with a mixture of dystonia and cerebellar signs
Many children require a wheelchair

Question 5

Where does telangiectasia develop?

Answer 5

conjunctiva, neck and shoulders from about 4 years
susceptible to infection (IgA defect), develop malignant disorders, have raised alpha-fetoprotein and have increased white cell sensitivity to radiation

Question 6

What are the clinical features of ataxia telangiectasia?

Answer 6

o Speech- increased separation of syllables and varied volumes – scanning speech
o Neurology- sensory disturbance in proprioception, positive Romberg, nystagmus with eye movements
o Systemic- immunodeficiency, hypertrophic cardiomyopathy and DM in Fanconi’s anaemia

Question 7

What are the investigations needed for ataxia telangiectasia?

Answer 7

o Cerebral imaging- assess for tumours or damage
o Lumbar puncture- for plasma & CSF analysis, particular reference to varicella, strep and other infections
o Inborn errors of metabolism assessment eg. urea cycle disorders

Question 8

What are the types of brain tumours?

Answer 8

o	Astrocytoma (40%)- varies from benign to highly malignant (glioblastoma multiforme)
o	Medulloblastoma (20%)- arises in the midline of the posterior fossa, may seed through the CNS via CSF, up to 20% have spinal metastases at diagnosis
o	Ependymoma (8%)- mostily in posterior fossa where it behaves like a medulloblastoma
o	Brainstem glioma (6%)
o	Craniopharyngioma (4%)- a developmental tumour arising from the squamous remnant of Rathke pouch, it is not truly malignant, but is locally invasive and grows slowly in the suprasella region

Question 9

What are the clinical features of brain tumours?

Answer 9

o	Headache- worse in the morning
o	Vomiting- especially on waking
o	Behaviour/personality change
o	Visual disturbance
o	Papilloedema
o	Separation of sutures/tense fontanelle
o	Increased head circumference
o	Head tilt/posturing
o	Developmental delay/regression

Question 10

How can spinal tumours, primary or metastatic present with?

Answer 10

o Back pain
o Peripheral weakness of arms or legs
o Bladder or bowel dysfunction

Question 11

What is Battens disease?

Answer 11

Autosomal recessive, fatal neurodegenerative disorder
symptoms 4-10yrs
Onset of visual problems and seizures
Change in behaviour, speech and a regression in learning
may be a slow in growth & breath holding attacks, eventually function with deteriorate to dementia and death

Question 12

What is Rett’s syndrome?

Answer 12

Disorder almost exclusively affecting girls and presenting after 1 y/o with developmental regression and loss or purposeful hand movements
may develop seizures, scoliosis, erratic breathing with episodes of breath-holding & hyperventiliation and stereotypic hand-wringing

Question 13

What are leukodystrophies?

Answer 13

dysfunction of the white matter of the brain- incorrect growth of myelin sheath
gradual decline in an infant/child who was previously doing well, progressive loss of movement, speech, vision, hearing and behaviour

Question 14

What is Wilson’s disease?

Answer 14

Autosomal recessive
reduced synthesis of copper binding protein, as well as defective excretion of copper in the bile, which leads to accumulation in the liver, brain, kidney & cornea
rarely present in children <3y/o and can present with almost any form of liver disease including hepatitis, cirrhosis & portal hypertension
• neuropsychiatric features are more common after the 2nd decade and include deterioration in school performance, mood, behaviour and coordination

Question 15

What is subacute sclerosis panencephalitis (SSPE)?

Answer 15

rare, chronic, progressive encephalitis caused by a persistent infection of immune resistant measles virus
history is a primary infection between 2yrs ad then 6-15 asymptomatic years before gradual psychoneurological deterioration

Question 16

What are the causes of non-communicating hydrocephalus?

Answer 16

o Congenital malformation
 Aqueduct stenosis
 Atresia of the outflow foramina in the 4th ventricle- Dandy-Walker malformation
 Chiari malformation
o Posterior fossa neoplasm or vascular malformation
o Intraventricular haemorrhage in pre-term infant

Question 17

What are the causes of communication hydrocephalus?

Answer 17

o Subarachnoid haemorrhage

o Meningitis- eg. pneumococcal, tuberculous

Question 18

What are the clinical features of hydrocephalus?

Answer 18

o Disproportionately large head circumference
o Excessive rate of head growth- due to failure of suture formation
o Skull sutures separate- anterior fontanelle bulges and scalp veins become distended
o Fixed downwards gaze or sun setting of eyes- advanced sign
o Signs of increased ICP- covered above

Question 19

What are the causes of macrocephaly?

Answer 19

head circumference above 98th gentile
o	Tall stature
o	Familial macrocephaly
o	Raised ICP
o	Hydrocephalus- progressive or arrested
o	Chronic subdural haematoma
o	Cerebral tumour
o	Neurofibromatosis
o	Cerebral gigantism- Sotos syndrome
o	CNS storage disorder eg. mucopolysaccharidosis – Hurler syndrome

Inv using US if anterior fontanelle is still open or CT/MRI

Question 20

What are the causes of microcephaly?

Answer 20

Head circumference below the 2nd centile
o Familial- when it is present from birth and development is often normal
o Autosomal recessive condition- when it is associated with developmental delay
o Caused by a congenital infection
o Acquired after an insult to the developing brain eg. perinatal hypoxia, hypoglycaemia or meningitits, when it is often accompanied by CP & seizures