Physiology

1. HEADACHE

2. LEARNING OBJECTIVES
 At the end of the lecture, students would be
able to
 Know different types of headache
 Their causes and features
 How to differentiate between these types

4. HEADACHE
Headaches are a type of pain referred to
the surface of the head from deep head
structures.
 Result either from pain stimuli arising
inside the cranium, but others result
from pain arising outside the cranium

5. PAIN-SENSITIVE AREAS IN CRANIAL VAULT.
 The brain tissues themselves are almost totally
insensitive to pain. Therefore, it is likely that much
or most of the pain of headache is not caused by
damage within the brain itself.
 Tugging on the venous sinuses around the brain,
damaging the tentorium, or stretching the dura at the
base of the brain can cause intense pain that is
recognized as headache. Also, almost any type of
traumatizing, crushing, or stretching stimulus to the
blood vessels of the meninges can cause headache.

6.  An especially sensitive structure is the middle
meningeal artery, and neurosurgeons are careful
to anesthetize this artery specifically when
performing brain operations under local
anesthesia.

8. BRAIN MENINGIES

9. BRAIN MENINGIES

10. SUB ARACHNOID SPACE-CSF

11. FALX CEREBRI AND TENTORIUM CEREBRI

12. TENTORIUM CEREBRI

13. FALX CEREBRI AND TENTORIUM CEREBRI

14. TYPES
 Intracranial headache
 Extracranial headache

15. AREAS OF THE HEAD TO WHICH INTRACRANIAL
HEADACHE IS REFERRED
 Stimulation of pain receptors in the cerebral vault
above the tentorium initiates pain impulses in
the cerebral portion of the fifth nerve and causes
referred headache to the front half of the head in
the surface areas supplied by this somatosensory
portion of the fifth cranial nerve

16.  Pain impulses from beneath the tentorium enter
the central nervous system
 Subtentorial pain stimuli cause "occipital
headache" referred to the posterior part of the
head

17. TYPES OF INTRACRANIAL HEADACHE
 Different types are:
1-Headache due to meningitis
2-Headache due to low CSF pressure
3-Migraine headache
4-Alcoholic headache

18. 1- HEADACHE DUE TO MENINGITIS
Inflammation of meninges especially the area of
dura and around the vinous sinus
Such intense damage can cause extreme headache
pain referred over the entire head.

19. AREAS OF HEADACHE RESULTING FROM
DIFFERENT CAUSES.

20. TYPES OF INTRACRANIAL HEADACHE

21. 1-HEADACHE OF MENINGITIS
 One of the most severe headaches of all is that
resulting from meningitis, which causes
inflammation of all the meninges, including the
sensitive areas of the dura and the sensitive areas
around the venous sinuses.
 Such intense damage can cause extreme
headache pain referred over the entire head

22. 2-HEADACHE DUE TO LOW CSF PRESSURE
 Removing as little as 20 milliliters of fluid from the
spinal canal, particularly if the person remains in an
upright position, often causes intense intracranial
headache. Removing this quantity of fluid removes
part of the flotation for the brain that is normally
provided by the cerebrospinal fluid.
 The weight of the brain stretches and distorts the
various dural surfaces and thereby elicits the pain
that causes the Headache.

23. 3-MIGRAINE HEADACHE
 It is a special type of headache that may result from
abnormal vascular phenomena, the exact mechanism
is unknown.
 Migraine headaches often begin with various
prodromal sensations, such as nausea, loss of vision
in part of the field of vision, visual aura, and other
types of sensory hallucinations.
 Ordinarily, the prodromal symptoms begin 30
minutes to 1 hour before the beginning of the
headache

25.  Prolonged emotion or tension causes reflex vasospasm
of some of the arteries of the head, including arteries that
supply the brain. The vasospasm theoretically produces
ischemia of portions of the brain, and this is responsible
for the prodromal symptoms.
 Then, as a result of the intense ischemia. The blood
pressure in the vessels causes them to dilate and pulsate
intensely, and it is postulated that the excessive
stretching of the walls of the arteries—including some
extracranial arteries, such as the temporal artery—causes
the actual pain of migraine headaches.

26.  Other theories of the cause of migraine
headaches include spreading cortical depression,
psychological abnormalities, and vasospasm
caused by excess local potassium in the cerebral
extracellular fluid.
 Genetic background and female gender imp.

28. 4-ALCOHOLIC HEADACHE
Alcohol is toxic to tissues, directly irritates
the meninges and causes the intracranial pain.
Dehydration may also play a role in the
"hangover"

30. 5-HEADACHE CAUSED BY CONSTIPATION
 Results from absorbed toxic products or
from changes in the circulatory system
resulting from loss of fluid into the gut.

31. EXTRACRANIAL TYPES OF HEADACHE
 Different types are:
Due to muscles spasm
Irritation of nasal and accessory nasal
structures
Due to eye disorders

32. 1-DUE TO MUSCLES SPASM
 Emotional tension often causes many of the
muscles of the head, especially muscles
which are attached to the scalp attached to
the occiput, to become spastic, and
 pain of the spastic head muscles is referred
to the overlying areas of head.

34. 2-IRRITATION OF NASAL AND ACCESSORY NASAL
STRUCTURES
 Infection or other irritative processes in
widespread areas of the nasal structures –pain
behind eyes and in the case of frontal sinus
infection cause headache that is referred to frontal
surfaces of the forehead and scalp from the
maxillary sinuses, can be felt in the face.

35. 3-DUE TO EYE DISORDERS
 Difficulty in focusing one's eyes clearly may cause
excessive contraction of the eye ciliary muscles in an
attempt to gain clear vision. these muscles are
extremely small, tonic contraction of them can cause
retro-orbital headache.
 Excessive irradiation by light rays, especially
ultraviolet light. Looking at the sun or the arc of an
arc-welder for even a few seconds may result in
headache that lasts from 24 to 48 hours