Tetany

Tetania is a syndrome of increased irritability CNS and PNS caused by changes in ion concentrations in  ECT.


 * Tetany can be manifest or latent, hypocalcemia or normocalcemic.
 * Main changes of ions leading to tetany:
 * decrease: Ca 2+ (hypocalcemia), H + (alkalosis),  Mg 2 + (hypomagnesemia);
 * rise: K + (hyperkalemia),  Na + (hypernatremia) ( and indirectly P - this reduces Ca…).
 * Neuromuscular excitability = (Ca 2+ × H + × Mg 2+) / (K + × PO 4 2- × OH -).

Hypocalcemic tetany

 * Early and late neonatal tetany;
 * deficiency vitamin D;
 * congenital parathyroid defects (isolated or DiGeorg's syndrome);
 * losses calcium;
 * alkalosis (hyperventilation, hysterical seizures…);
 * renal insufficiency.

Normocalcemic tetany

 * Hypomagnesaemia;
 * neurogenic (organic CNS disorders - inflammation, tumor, injuries, CNS functional disorders - neurosis,  psychosis);
 * spasmophilia syndrome.

Manifest tetany

 * Classically, it manifests itself in three forms:
 * recurring generalized tonic cramps in patient s full consciousness - starting at the fingertips and spreading cranially;
 * carpopedal spasm (tonic wrist flexion, finger extension, thumb adduction into the palm), spasms are very painful, paraesthesia persists between seizures - increased irritability of peripheral nerves of the limbs;
 * laryngospasm - laryngeal muscle spasm, loud strenuous inspiration, dyspnoea, cyanosis.

Latent tetany

 * It manifests itself as a so-called spasmophilia - a tendency to convulsions;
 * manifests as convulsions after ischemia or after electrical or mechanical irritation.
 * It shows various symptoms:
 * Chvostek sign - tap in front of the ear on n. & Nbsp; VII → the corner twitches;
 * Lust's symptom - phenomenon of nerve peronei - tapping over the proximal head of the fibula → lifting of the lateral edge of the foot;
 * Trousseau's symptom - inflate the cuff of the tonometer on the arm, it ischemic to the nerves of the arm - spasm.

Differential diagnostics

 * Eg. aminoaciduria and other inherited metabolic disorders, epilepsy, CNS inflammation.