Cluster headaches are extremely painful headaches that occur in cyclical patterns. They are characterized by severe, burning pain around the eye and can be more intense than migraines. Attacks typically last 15-180 minutes and occur multiple times per day during "cluster periods" that can last for weeks or months, followed by remission periods without headaches. The cause of cluster headaches is thought to involve hypothalamic dysfunction that triggers the trigeminal nerve and causes blood vessel dilation, producing the severe pain. Prevention focuses on treatments to suppress attacks and shorten cluster periods since there is no cure.

1. Cluster
headaches
Understanding the Brain:
Neurobiology of our Everyday Life
Final Project.

2. What are Cluster Headaches?
• Cluster headaches are excruciating attacks of pain in one side of the
head, often felt around the eye.
• They usually occur in cyclic bursts, hence giving it the name "Cluster
Headaches"

3. Characteristics of
Cluster Headaches
• Cluster Headaches can be more
severe than migraines, but usually
don't last as long.
• It is known as the most painful of all
headaches, lasting for a shorter
duration as compared to
migraines, but reoccurring every few
months.
• It has been described as "burning"
and a "hot poker in your face".

4. History of Cluster
Headaches
• The first complete description of cluster
headache was given by the London
neurologist Wilfred Harris in 1926, who
named the disease migrainous neuralgia.
• The condition was originally named
Horton's cephalalgia after B.T. Horton, a
US neurologist who postulated the first
theory as to their pathogenesis.
• His original paper describes the severity of
the headaches as being able to take
normal men and force them to attempt or
complete suicide.

5. Bouts of Headaches
• Bouts of frequent attacks (cluster periods), may last from weeks to
months, usually followed by remission periods when the headache
attacks stop completely.
• The starting date and the duration of each cluster period may be
consistent from period to period. For example, cluster periods may
occur seasonally, such as every spring or every fall.
• Chronic cluster periods may continue for more than a year, or pain-free
periods may last less than one month.

6. Periodicity of Bouts
• Headaches usually occur every day during a cluster periods, sometimes
up to 8 times a day.
• A single attack may last from 15 minutes to 3 hours. The attacks often
happen at the same time within each 24- hour day.
• The majority of attacks occur at night, usually one to two hours after you
go to bed. The pain usually ends as suddenly as it begins, with rapidly
decreasing intensity.

7. Causes of Cluster Headaches
• Hypothalamic Dysfunction
• PET and MRA findings
• Hypothalamic Cover Activity
• Activation of Trigeminal Nerve
• Vasodilation of Arteries

8. Hypothalamic Dysfunction
• Cluster attacks usually occur with clocklike regularity during a 24-hour
day, and the cycle of cluster periods often follows the seasons of the
year.
• These patterns suggest that the body's biological clock is involved. In
humans, the biological clock is in the hypothalamus. Hypothalamic
dysfunction may explain the timing and cyclical nature of cluster
headache.

9. • Positron emission tomography (PET) and voxel-based morphometry
have identified the posterior hypothalamic gray matter as the key area
for the basic defect in Cluster attacks.
• Research suggests that the hypothalamus becomes overactive during
each attack.
• However, it is not known what causes this overactivity.

10. PET and MRA findings
• Average activation across nine cluster headache patients during an
acute right-sided attack compared to the headache-free resting state.
• PET demonstration of hypothalamic activation in cluster headache

11. Hypothalamic Cover Activity
• During an attack, the hypothalamus is thought to release
neurotransmitters (such as histamine).
• These activate a nerve pathway in the base of the brain (the trigeminal-
autonomic reflex pathway) causing the pain and other symptoms.
• The trigeminal nerve is the main nerve of the face responsible for
sensations (such as heat or pain).

12. Activation of Trigeminal Nerve
• When activated, the trigeminal nerve causes the eye pain associated
with cluster headaches.
• The trigeminal nerve also stimulates another group of nerves that
causes the eye tearing and redness, nasal congestion, and discharge
associated with cluster attacks.

13. Vasodilation of the arteries
• The nerve overactivity may also cause vasodilation of the arteries (such
as internal carotid and superior cerebellar arteries) in the affected side
of the brain.
• These blood vessels then press on nearby brain tissues and nerves,
which can cause pain.

14. Factors related to:
• Cluster headaches affect around 60 up to 280 per 100,000. E.g.: up to
~170'000 people in Italy or up to ~880'000 in USA Males are two to four
times more likely to develop cluster headache than females.
• The first cluster typically develops between the ages of 20 to 40 years,
but it can start at any age!

15. Risk Factors:
• Many people (~80%) who get cluster headache attacks are smokers.
• Alcohol can trigger an attack if you're at risk of cluster headache.
• If a parent or sibling has ever had a cluster headache, you may have an
increased risk of cluster headaches. Anyone can be affected!

16. Prevention of Cluster Headaches
• There is no known cure, hence prevention is the only way to avoid
cluster headaches.
• The goal of treatment is to decrease the severity of pain, shorten the
headache period and prevent the attacks.
• Preventive therapy starts at the onset of the cluster episode with the
goal of suppressing attacks. Calcium channel blockers, Corticosteroids,
Lithium carbonate, Nerve block, Ergots (vasoconstricting agent),
Melatonin, others.

17. The last option: Surgery
• Rarely doctors recommend surgery for people who don't find relief with
aggressive treatment or who can't tolerate the medications. Surgical
procedures (such as radiofrequency thermocoagulation or gamma knife
radiosurgery) for CH attempt to damage the nerve pathways thought to
be responsible for pain.
• The long-term benefits of surgery are disputed. Also, because of the
possible complications, including muscle weakness in the jaw or
sensory loss in certain areas of the face and head.

18. How this course has helped me:
• Not only has this course allowed to me understand and grasp the
concepts of the events occurring around me, but also given me the
opportunity to empathize with those close to me, giving me a new
perspective on how I can help and support them.
• Understanding the fundamental aspects of the brain grants one a
chance to learn more about other illnesses and issues, which I am very
thankful for as it is a wonderful opportunity to learn more.

19. Sources:
• Cluster Headaches and it's characteristics.
• Duration and reoccurence.
• History of Cluster Headaches
• Periodicity of Bouts.
• An overview of the hypothalamus.
• Surgery : The Last Option
• Vasodilation, PET and MRA findings.
• Risk Factors.