1st order laboratory parameters – obligatory laboratory tests.
- Small blood count [leukocytosis (increase in the number of leukocytes (white blood cells)]
- Electrolytes – sodium [hyponatremia/sodium deficiency]
- CSF puncture (collection of cerebrospinal fluid by puncture of the spinal canal) for CSF diagnosis – in the absence of evidence of a bleeding source by imaging techniques.
- After a waiting period of 8-12 hours from the onset of headache.
