Classification Headaches Primary Secondary International Classification of Headache Disorders ( ICHD )
Primary Headache A headache that is not caused by another underlying disease,trauma or medical condition. Accounts for about ninety percent of all headaches. secondary headache Caused by exogenous disorders
BENIGN PAROXYSMAL HEADACHES Ice pick Ice cream Exertional Cough Chronic paroxysmal hemicrania SUNCT(Short-lasting unilateral neuralgiform head ache with conjunctival injection and tearing)
secondary causes of headache Intracerebral bleeding Raised intracranial pressure Infection Inflammatory disease Post-herpetic neuralgia Referred pain from other structures
PATHO PHYSIOLOGY Stimulation of primary nociceptors Lesions in pain-producing pathways of PNS&CNS
Pain-producing structures Scalp Middle meningeal artery, Dural sinuses, Falx cerebri & Proximal segments of the large pial arteries
The ventricular ependyma , choroid plexus, pial veins, and much of the brain parenchyma are not pain-producing.
Large intracranial vessels and dura mater Peripheral terminals of the trigeminal nerve that innervate these structures Caudal portion of the trigeminal nucleus, which extends into the dorsal horns of the upper cervical spinal cord and receives input from the first and second cervical nerve roots (the trigeminocervical complex) Pain modulatory systems in the brain that receive input from trigeminal nociceptors Key structures involved
Nerves involved Trigeminal nerve First 3 cervical nerves Fascial nerve Glossopharyngeal and vagus nerve
Mechanisms Distension,traction or dilatation of i/c or e/c arteries. Traction or displacement of large intracranial veins or their envelope. Meningial irritation & raised ICT.
Compression ,traction or inflammation of cranial or spinal nerves. Spasm ,inflammation & trauma to cranial & cervical muscles. Disturbance of intracerebral serotonic projection/ activtn of brain stem structures.