Subarachnoid Hemorrhage (SAH) 

Subarachnoid hemorrhage is a bleeding in an area near the brain known as the Subarachnoid Space. This may be lead to syncope (temporary loss of consciousness), seizures/ convulsions, meningism (neck pain and stiffness), visual symptoms, and vomiting. 50–70% of people with subarachnoid hemorrhage have an isolated headache without decreased level of consciousness. The headache typically persists for several days.

Cerebral Venous Thrombosis

Thrombosis of the veins of the brain, usually causes a headache that reflects raised intracranial pressure, and is therefore made worse by anything that makes the pressure rise further, such as coughing.

In 2–10% of cases, the headache is of thunderclap character. In most cases there are other neurological abnormalities, such as seizures and weakness of part of the body, but in 15–30% the headache is the only abnormality.

Cervical Artery Dissection

Carotid artery dissection, and vertebral artery dissection occur when a tear forms inside the wall of the blood vessels that supply the brain. This often causes pain on the affected side of the head or neck. The pain usually precedes other problems caused by impaired blood flow through the artery into the brain; these may include visual symptoms, weakness of part of the body, and other abnormalities depending on the vessel affected.

Reversible Cerebral Vasoconstriction Syndrome (RCVS)

RCVS is a group of disorders characterized by severe headaches, and a narrowing of the blood vessels in the brain. RCVS is reversible and recover is possible within three months. RCVS occurs when persistent contraction of the blood vessels (vasoconstriction) causes arteries to narrow. This reduces blood flow and oxygen delivery to the affected area. When vasoconstriction occurs in the blood vessels of the brain, it is called cerebral vasoconstriction.

Spontaneous intracranial hypotension (unexplained low cerebrospinal fluid pressure) is a sudden decrease in the flow of blood to the brain, or a sudden drop in Intracranial pressure (ICP). ICP is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue.

Pituitary apoplexy is bleeding into or impaired blood supply of the pituitary gland. This usually occurs in the presence of a tumor of the pituitary, although in 80% of cases this has not been diagnosed previously. The most common initial symptom is a sudden headache, often associated with a rapidly worsening visual field defect or double vision caused by compression of nerves surrounding the gland.

Colloid cyst of the 3rd ventricle is a benign tumor in the brain. It is a gelatinous substance contained within a membrane. It is associated with symptoms that include headache, vertigo, memory deficits, diplopia, and behavioral disturbances. If it occurs in the part of the brain called the 3rd ventricle it may trigger headaches.

Acute Hypertensive Crisis is related to s sudden and severe increase in blood pressure. Severely elevated blood pressure (equal to or greater than a systolic 180 or diastolic of 110) is referred to as a hypertensive crisis, as blood pressure at this level confers a high risk of complications. it is also known as malignant or accelerated hypertension.

https://www.cedars-sinai.org/health-library/diseases-and-conditions/r/reversible-cerebral-vasoconstriction-syndrome-rcvs.html

https://my.clevelandclinic.org/health/diseases/17876-thunderclap-headaches

https://en.wikipedia.org/wiki/Thunderclap_headache

https://en.wikipedia.org/wiki/Subarachnoid_hemorrhage

https://en.wikipedia.org/wiki/Pituitary_apoplexy

https://en.wikipedia.org/wiki/Colloid_cyst

https://en.wikipedia.org/wiki/Intracranial_pressure#Low_ICP

https://en.wikipedia.org/wiki/Hypertensive_crisis

 Prodromal (premonitory) phase: the prodrome, may start to occur hours or days before the headache. Symptoms may include varied phenomena, including: moodiness, irritability, depression (or euphoria), fatigue, food craving, stiff muscles, constipation (or diarrhea), and sensitivity to smells, light, heat etc.

Aura phase: Aura is a transient focal neurological phenomenon that occurs before or during the headache. Aura appears gradually over a number of minutes and generally lasts less than 60 minutes. Symptoms can be visual, sensory or motoric in nature.

Visual disturbances often vary and may appear as disturbances in the field of vision, blurring, flicking etc. 

Sensory aura are the second most common type; they include: feelings of pins-and-needles, and tingling sensations, that may spread from hands towards the neck and mouth; followed by numbness, and a loss of position sense, or disorientation.

Other symptoms of the aura phase can include speech or language disturbances, world spinning, mumbling, and in rare cases motor symptoms. Motor symptoms indicate that this is a hemiplegic migraine, and weakness often lasts longer than one hour unlike other auras. Auditory hallucinations, or delusions have also been reported in some patients.

Headache phase: classically the headache is unilateral, throbbing, and moderate to severe in intensity. It usually comes on gradually and is aggravated by physical activity. In more than 40% of cases, however, the pain may be bilateral and neck pain is commonly associated with it. Bilateral pain is particularly common in those who have migraine without aura. The frequency of attacks is variable, from a few in a lifetime to several a week, with the average being about one a month. The pain is frequently accompanied by nausea, vomiting, sensitivity to light, sensitivity to sound, sensitivity to smells, fatigue and irritability. Other symptoms may include blurred vision, nasal stuffiness, diarrhea, frequent urination, pallor, or sweating. Swelling or tenderness of the scalp may occur as can neck stiffness. Associated symptoms are less common in the elderly.

Postdromal phase: The migraine postdrome are symptoms occurring once the acute headache has settled. Symptoms include: soreness in the area affected by the migraine, impaired thinking/ disorientation for a few days, tiredness or “feeling hung over”, cognitive difficulties, gastrointestinal symptoms, mood changes, and weakness. Conversely in rare cases, feelings of refreshment, or euphoric have been reported.

Interictal phase: the interictal state is defined as “the period between episodes. In the timeline of a migraine attack there are four distinct phases. Many symptoms appear during prodrome, the period before an attack begins, or during postdrome the post-headache phase also known as the migraine hangover. The interictal phase, includes symptoms that occur in the period between migraine attacks. Symptoms can be neuropsychiatric, like experiencing changes in emotional state or thinking patterns, or feeling tired. There are also sensory symptoms like heightened sensitivity to light and sound, or gastrointestinal symptoms like nausea or food cravings. Anxiety is also a commonly-reported psychological symptom of the interictal state

Molecular Mediators such as CGRP: calcitonin gene-related peptide (CGRP), and it is a protein that is released around the brain. When CGRP is released, it causes intense inflammation in the coverings of the brain (the meninges), and for most migraine patients, causes the pain of a migraine attack. In fact, if you give CGRP by an intravenous method to a person with migraine, within four hours, most of them will get a migraine. That’s the basis of all the new CGRP treatments that include large molecules (monoclonal antibodies) that may be administered via injections. 

Women experience migraine attacks three times more frequently than men do; and, menstrual migraine affects 60% of these women. They occur before, during, or immediately after the period, or during ovulation.

While it is not the only hormonal culprit, serotonin is the primary hormonal trigger in headache. Some researchers believe that migraine is an inherited disorder that somehow affects the way serotonin is metabolized in the body. But, for women, it is also the way the serotonin interacts with uniquely female hormones.

Menstrual migraine is primarily caused by estrogen, the female sex hormone that specifically regulates the menstrual cycle fluctuations throughout the cycle. When the levels of estrogen and progesterone change, women will be more vulnerable to headache. Because oral contraceptives influence estrogen levels, women on birth control pills may experience more frequent menstrual migraine attacks.

Symptoms
Menstrual migraine symptoms are similar to migraine without aura. It begins as a one-sided, throbbing headache accompanied by nausea, vomiting, or sensitivity to bright lights and sounds. An aura may precede the menstrual migraine.

Menstrual Syndrome (PMS) Headaches
The PMS headache occurs before your period and is associated with a variety of symptoms that distinguish it from the typical menstrual headache. The symptoms include headache pain accompanied by fatigue, acne, joint pain, decreased urination, constipation, and lack of coordination. You may also experience an increase in appetite and a craving for chocolate, salt, or alcohol.

https://americanmigrainefoundation.org/resource-library/migraine-symptoms-between-attacks/

https://www.msdmanuals.com/en-in/professional/neurologic-disorders/headache/migraine#:~:text=The%20pain%20is%20often%20unilateral,is%20more%20than%20a%20headache.

https://en.wikipedia.org/wiki/Migraine

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3134175/

https://americanmigrainefoundation.org/resource-library/anti-cgrp-treatment-options/

https://headaches.org/2019/10/25/menstrual-migraine/

• Limited use in Migraine
• Likely to cause more harm than benefit
• Should not be prescribed as a first line
• Should not be prescribed for a longer period of time

1. Ergotamine (DHE nasal spray/ DHE parenteral formulation)
2. Triptans (seven different types)
3. Ditans (Lasmitidan)
4. Gpants (Ubrogepant, Rimagepant)

• External trigeminal nerve stimulation
• Single-pulse transcranial magnetic stimulation
• Noninvasive vagus nerve stimulation
• Remote electrical neuromodulation

• Most likely rooted in hypothalamic dysfunction and related effects through hypothalamic connections.
• The interplay of trigeminovascular, trigeminocervical, and trigeminoautonomic reflex alterations with hypothalamic, pituitary, and nociceptive system malfunction could explain much of TAC phenomenology.

• S stands for side-locked
• E stands for excruciating
• A stands for agitating
• R refers to regularly recurring attacks with circadian and circannual periodicity and predictability,

• Substantially reduced resting cerebral blood flow
• Has CSF volume lowering effects
• May act as a nitric oxide synthase inhibitor
• Interleukin 1 inhibitor (IL-1 activates HPA axis, involved in rage behavior, modulates sleep cycle)