Category Archives: Neurology

Polymicrogyria

General paediatrics, Neurology

One of the most common malformations of cortical development.  

Bilateral perisylvian polymicrogyria (BPP) is the most common subtype , causes the congenital bilateral perisylvian syndrome:

  • oromotor dysfunction,
  • cognitive impairment,
  • epilepsy.

Many possible causes eg vascular or hypoxaemic insults (eg twin-to-twin transfusion syndrome) and congenital cytomegalovirus infection. Genetic causes also important – some syndromes eg 1p36.3 and 22q11.2 deletion syndromes. PIK3R2  gene defects are the most common genetic cause of BPP in patients with normal head size, and the second (to  PIK3CA ) most common cause of polymicrogyria associated with large head size. RTTN gene  also associated with isolated BPP.

[Lancet Neurology, The, 2015-12-01, Volume 14, Issue 12, Pages 1182-1195]

Urate

Community, General paediatrics, Genetics, Metabolic, Neurology

Product of amino acid metabolism.

In developmental delay, an abnormally high or low result is significant viz:

  • Glycogen Storage disorder
  • Purine disorders eg Lesch Nyhan
  • Molybdenum Cofactor deficiency – other features are microcephaly, hyperekplexia

High urate levels can also be risk factor for urolithiasis (stones in urinary tract)

Cerebral Arteriovenous malformation (AVM)

Cardiology, General paediatrics, Neurology

Present with hydrocephalus or else cardiac failure in neonatal period. Clue is that heart is structurally normal!

Life time risk of haemorrhage is high, presenting with headache or seizure.  Annual rate about 6%.  Focal neuro signs rare prior to haemorrhage!  Risk slightly higher in deep locations eg basal ganglia.

Once haemorrhage has occurred, risk of further haemorrhage increases significantly.  Microsurgery, radiosurgery or embolization techniques used alone or in combination.

 

Niemann Pick disease

General paediatrics, Metabolic, Neurology, Respiratory

Sphingomyelinase (lysosome) disorder.  Type B has only visceral involvement, can survive into adulthood.  More common in Ashkenazi Jews.

Typically develop symptoms at around 6 months.  Can be prolonged jaundice as baby, else abdominal distension (hepatosplenomegaly), growth failure, hypotonia, failure to meet milestones.

Death usually around 3yrs, recurrent lung infections, interstitial lung disease.  Spasticity develops later.

Cherry red spot seen on fundoscopy in macula, possibly not in early stages.

Seizures

Clinical, Emergency medicine, General paediatrics, Neurology, OPD

Seizures, fits, funny turns, convulsions, attacks…  None of these really has a medical meaning.  Convulsion suggests rhythmic motor activity, but that’s about it.  The implication of most of these is that there is excessive abnormal, involuntary muscle contraction, usually bilateral.  But more broadly, some involuntary, usually sudden and self terminating episode of abnormal (or at least non-purposeful) activity and/or impaired awareness. Can be sustained or interrupted.

Nottingham RCPCH approved guideline distinguishes:

  • Febrile?
  • Already on anti-epileptic medication?  Consider checking levels, or at least storing sample.
  • Predisposing conditions? eg neurodevelopmental problem, brain injury/surgery.
  • Neonate or young infant? Some additional possibilities eg hypoxic ischaemic encephalopathy (HIE), Fifth day fits, drug withdrawal (neonatal abstinence syndrome), pyridoxine dependent epilepsy.

Most commonly Febrile convulsions ie age related, benign.  Beware complex (multiple seizures in same illness, focal features, prolonged >15 mins) and any abnormal findings eg neck stiffness, bulging fontanelle, prolonged illness, abnormal cognition before/after.

Important differentials are:

  • meningitis
  • encephalitis
  • shaken baby (non-accidental injury)
  • brain tumour/haemorrhage, hydrocephalus
  • ingestion (deliberate or accidental)
  • metabolic (low glucose, calcium/magnesium, low/high sodium)

May represent first evidence of epilepsy.

Horner’s syndrome

Clinical, General paediatrics, Neurology

Horner’s syndrome = small pupil, ipsilateral ptosis +/- reduced sweating.  Compare Holmes Adie pupil.

Anhidrosis localizes lesion to preganglionic branch.

Turn down the lights to make it more obvious!  Look for associated Klumpke’s.

In babies usually congenital or related to birth trauma, rarely it can be due to:

Other cranial nerve involvement clearly points to brainstem problem.

[British Journal of Ophthalmology 1998;82:51-54. ]

Angelman syndrome

General paediatrics, Genetics, Neurology

Caused (mostly) by absence of maternal contribution to a region of the 15q chromosome.  Paternal uniparental disomy is one way this can happen, although mostly there is de novo maternal deletion.  The same region is also responsible for Beckwith-Wiedemann syndrome, but this syndrome is the result of a paternal deletion.

Characteristically “happy puppet” –

  • severe speech and language delay
  • learning disability and epilepsy
  • Movement disorder esp ataxia, also tremor, hyperreflexia
  • open mouthed expression, large mandible
  • Excitability, paroxysmal laughter

[https://www.omim.org/clinicalSynopsis/105830]

SUDEP

General paediatrics, Neurology

Definition is sudden unexpected death with or without seizures, after exclusion of status epilepticus, where PM does not identify another cause.  Cases almost exclusively in symptomatic epilepsy.

SPEN response to determination of Sheriff Duff (that SUDEP should be discussed with all patients with epilepsy) –

  • Most data on SUDEP from adults.
  • Risk is unlikely to be predictable at time fo diagnosis so debatable that this is the appropriate time to discuss it.
  • No evidence that increased supervision of sleep is of benefit.  So arguable that discussion will cause unnecessary anxiety.

Berg AT, Shinnar S, Testa FM, Levy SR, Smith SN, Beckerman B. Mortality in childhood-onset epilepsy. Arch Pediatr Adolesc Med. 2004 Dec;158(12):1147-52.

Camfield CS, Camfield PR, Veuglers PJ: Death in children with epilepsy: a population-based study. Lancet 2002;359:1891-1895

Weber P, Bubl R, Blauenstein U, Tillmann BU, Lütschg J. Sudden unexplained death in children with epilepsy: a cohort study with an eighteen-year follow-up.  Acta Paediatr. 2005 May;94(5):564-7.