Category Archives: Neurology

Hypokalaemia

Clinical, General paediatrics, Neurology, Renal

Could be reduced intake but usually excessive losses –

RenalNon-renal
Renal tubular acidosis (type 1 or 2)Vomiting eg pyloric stenosis
Bartters or Gitelmans syndromeDiarrhoea
DiureticsLaxative overuse
Hyperaldosteronism (CAH, tumour)Thyrotoxicosis
Salbutamol
Familial periodic paralysis
Pseudo-Bartter’s
Trauma
Diabetic ketoacidosis

Symptoms depend on severity and how rapidly decrease has happened. Chronic low levels are better tolerated. Since potassium important for membrane potentials, effects are mostly neuromuscular.

  • Cramps, weakness, paralysis
  • Ileus
  • Metabolic acidosis (although underlying cause often produces alkalosis)
  • Arrhythmia, heart failure
  • Rhabdomyolysis

ECG classically shows U waves, T wave flattening, and ST-segment changes. Can be tall wide P waves, can look like long QT if T and U waves merge.

Do urine and blood electrolytes to look at fractional excretion.

[Endocrine connections 2018][Current Treatment Options in Peds 2022]

Benign neonatal sleep myoclonus

Clinical, Common, General paediatrics, Neurology, OPD

Not a great name, as it can persist for up to 6 months!

Large muscle groups, usually limbs but can be face. Can wax and wane with child remaining sleep. Usually bursts lasting seconds, up to a few minutes.

During sleep only, and stops when wakes.

Other normal baby movements include neonatal release phenomena, including tremors (equal amplitude around fixed axis), jitters (recurrent tremor).

Reassuring if baby unbothered by it; baby in first 7 days of life; if it can be suppressed by passive flexion.

Differential would be hypoglycaemia, hypokalaemia; drug withdrawal; HIE or intracranial lesion; myoclonic epilepsy, startle (including hyperekplexia), hyperthyroidism.

[https://doi.org/10.1093/pch/13.8.680]

Rett Syndrome

General paediatrics, Genetics, Neurology

Exclusively females (lethal in males? Or rate of germ cell mutations higher in male germ cells?).  Virtually always sporadic – so not exactly X linked dominant.

MECP2 gene on X chromosome.

Developmental arrest at 6-18 months, then regression, loss of speech, stereotypies esp hands.

Often epilepsy, then complications of severe neurodisability eg chronic lung issues.

Not degenerative however – can live into middle life.

Focal epilepsy

General paediatrics, Neurology

As opposed to generalized epilepsy. Potentially associated with a brain lesion (congenital or acquired), but not always. EEG will usually confirm.

Associated with prolonged or focal febrile convulsion – chicken or egg?

See:

Temporal lobe epilepsy

The most common focal epilepsy.  Sense of déjà vu, phantom smells, panic attacks as possible aura symptoms! Talking gibberish, lip smacking, staring, posturing are more obvious.

Treatment

Levetiracetam or Lamotrigine first line, the former (Keppra) can be loaded more quickly though.

Honey in medicine

Allergy, General paediatrics, Infectious disease, Neurology, Nutrition

Contains a range of different sugars, aromatic oils, also pollens and bee proteins. Royal jelly and beeswax related, of course.

High fructose content can cause GI intolerance in some.

Allergic reactions can happen, often unrecognised, mostly due to specific pollens (depending on what flowers the bees feed on), in minority to bee proteins. Commercial honey tends to contain v low amounts of pollen, due to production techniques. IgE test for honey is available, but you may need to skin prick test with the specific honey if negative.

Honey eaten all year round is rumoured to prevent hay fever symptoms because of the pollens it contains, but this has not been proven, although it’s a nice idea related to immunotherapy. Depends on getting the right pollens of course – bees don’t like grass and birch flowers, probably. In some it may just trigger allergy symptoms.

Cross reaction between honey and bee venom is reported, not surprisingly, but not automatic.

Plant toxins can be present in sufficient quantities in honey to cause poisoning eg rhododendrons (some species).

Botulism reported in infants – failure to thrive, hypotonia, cranial nerve palsies. Clostridium and other bacteria cannot grow in honey due to the high sugar content, but spores can be present. So advice is not to give honey to infants.

Dravet syndrome

General paediatrics, Genetics, Neurology

Previously Severe myoclonic epilepsy of infancy. Charlotte Dravet described in 70s. Characterised by:

  • Refractory epilepsy
  • Onset in infancy
  • Associated neurodevelopmental problems

Due to defect in SCN1A gene on chromosome 2q24 (a sodium channel), usually de novo. Many mutations, don’t predict severity, unfortunately.

Accounts for about 7% of epilepsy presenting in first 3 years of life.

Onset around 5-8 months, often with febrile illness so can look like typical febrile convulsion. But often prolonged. Neurodevelopmental problems come later…

Later though, multiple seizure types. Hypotonia, ataxia, spasticity all seen. Dysautomnia can be a feature. ADHD and autistic traits common later.

EEG can be normal, or vary over time, with multifocal or generalised changes, photosensitivity too.

Prolactin

Endocrinology, General paediatrics, Neurology

Secreted from the anterior pituitary (along with growth hormone, ADH, ACTH, TSH, FSH/LH), but also a stress hormone (can be used to distinguish pseudo seizures from epileptic seizures). So can go up to 1000 in healthy people. Always worth repeating a high result at least 24hrs hours later, after a 20 minute rest.

Important because of prolactinomas, which can cause:

  • gynaecomastia
  • galactorrhoea
  • delayed puberty
  • space occupying lesion effects – headaches, visual field defects

Any lesion in the vicinity of the pituitary may also cause raised prolactin so not specific.

High levels can also be due to presence of “macroprolactin“, antibody complex polymers without biological action – usually less than 30% of the total – lab can check and give true monomeric value.

Arnold Chiari malformation

Neurology

Thought to be congenital but often only picked up in adulthood when symptoms develop.

Type 1 most common, where cerebellar tonsils protrude into spinal canal, potentially putting pressure on brainstem, spinal cord and cause obstruction to flow of cerebrospinal fluid.

Can be found incidentally. Symptoms however include:

  • headache (especially occipital)
  • neck pain
  • numbness or paraesthesiae of fingers, arms, lower limbs
  • Coordination problems, dizziness

Can be complicated by upper spinal syringomyelia.

Rarely familial.

Fabry’s disease

Cardiology, General paediatrics, Neurology, Renal

Alpha-galactosidase defect, one of the lysosomal storage disorders, with accumulation in various tissues.

X-linked but females get disease, so not correct to call them carriers.

Classically, “pain attacks”, affecting the extremities. In the abdomen, can mimic appendicitis. Due to accumulation in nerves. Since nothing to really see on examination, easily misdiagnosed as functional.

Other features:

  • Renal impairment and failure.
  • Angiokeratomas – a more specific feature, but not always present, and seen in other lysosomal disorders.
  • Corneal changes
  • Cerebrovascular and cardiac problems

[Omim]