The term dolichoectasia means elongation and distension. It is used to characterize arteries throughout the human body which have shown significant deterioration of their tunica intima (and occasionally the tunica media), weakening the vessel walls and causing the artery to elongate and distend.

VBD

- Hemifacial spasm

- Paresis

- Trigeminal neuralgia

ICD

- Progressive visual field defect

The most common symptom of IIH is headache, which occurs in almost all (92–94%) cases. It is characteristically worse in the morning, generalized in character and throbbing in nature. It may be associated with nausea and vomiting. The headache can be made worse by any activity that further increases the intracranial pressure, such as coughing and sneezing. The pain may also be experienced in the neck and shoulders. Many have pulsatile tinnitus, a whooshing sensation in one or both ears (64–87%); this sound is synchronous with the pulse. Various other symptoms, such as numbness of the extremities, generalized weakness, loss of smell, and loss of coordination, are reported more rarely; none are specific for IIH. In children, numerous nonspecific signs and symptoms may be present.

The increased pressure leads to compression and traction of the cranial nerves, a group of nerves that arise from the brain stem and supply the face and neck. Most commonly, the abducens nerve (sixth nerve) is involved. This nerve supplies the muscle that pulls the eye outward. Those with sixth nerve palsy therefore experience horizontal double vision which is worse when looking towards the affected side. More rarely, the oculomotor nerve and trochlear nerve (third and fourth nerve palsy, respectively) are affected; both play a role in eye movements. The facial nerve (seventh cranial nerve) is affected occasionally –- the result is total or partial weakness of the muscles of facial expression on one or both sides of the face.

The increased pressure leads to papilledema, which is swelling of the optic disc, the spot where the optic nerve enters the eyeball. This occurs in practically all cases of IIH, but not everyone experiences symptoms from this. Those who do experience symptoms typically report "transient visual obscurations", episodes of difficulty seeing that occur in both eyes but not necessarily at the same time. Long-term untreated papilledema leads to visual loss, initially in the periphery but progressively towards the center of vision.

Physical examination of the nervous system is typically normal apart from the presence of papilledema, which is seen on examination of the eye with a small device called an ophthalmoscope or in more detail with a fundus camera. If there are cranial nerve abnormalities, these may be noticed on eye examination in the form of a squint (third, fourth, or sixth nerve palsy) or as facial nerve palsy. If the papilledema has been longstanding, visual fields may be constricted and visual acuity may be decreased. Visual field testing by automated (Humphrey) perimetry is recommended as other methods of testing may be less accurate. Longstanding papilledema leads to optic atrophy, in which the disc looks pale and visual loss tends to be advanced.

Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure (pressure around the brain) without a detectable cause. The main symptoms are headache, vision problems, ringing in the ears with the heartbeat, and shoulder pain. Complications may include vision loss.

Risk factors include being overweight or a recent increase in weight. Tetracycline may also trigger the condition. The diagnosis is based on symptoms and a high intracranial pressure founding during a lumbar puncture with no specific cause found on a brain scan.

Treatment includes a healthy diet, salt restriction, and exercise. Bariatric surgery may also be used to help with weight loss. The medication acetazolamide may also be used along with the above measures. A small percentage of people may require surgery to relieve the pressure.

About 2 per 100,000 people are newly affected per year. The condition most commonly affects women aged 20–50. Women are affected about 20 times more often than men. The condition was first described in 1897.

Patients with arachnoid cysts may never show symptoms, even in some cases where the cyst is large. Therefore, while the presence of symptoms may provoke further clinical investigation, symptoms independent of further data cannot—and should not—be interpreted as evidence of a cyst's existence, size, location, or potential functional impact on the patient.

Symptoms vary by the size and location of the cyst(s), though small cysts usually have no symptoms and are discovered only incidentally. On the other hand, a number of symptoms may result from large cysts:

- Cranial deformation or macrocephaly (enlargement of the head), particularly in children

- Cysts in the suprasellar region in children have presented as bobbing and nodding of the head called bobble-head doll syndrome.

- Cysts in the left middle cranial fossa have been associated with ADHD in a study on affected children.

- Headaches. A patient experiencing a headache does not necessarily have an arachnoid cyst.

- In a 2002 study involving 78 patients with a migraine or tension-type headache, CT scans showed abnormalities in over a third of the patients, though arachnoid cysts only accounted for 2.6% of patients in this study.

- A study found 18% of patients with intracranial arachnoid cysts had non-specific headaches. The cyst was in the temporal location in 75% of these cases.

- Seizures

- Hydrocephalus (excessive accumulation of cerebrospinal fluid)

- Increased intracranial pressure

- Developmental delay

- Behavioral changes

- Nausea

- Hemiparesis (weakness or paralysis on one side of the body)

- Ataxia (lack of muscle control)

- Musical hallucination

- Pre-senile dementia, a condition often associated with Alzheimer's disease

- In elderly patients (>80 years old) symptoms were similar to chronic subdural hematoma or normal pressure hydrocephalus:

- Dementia

- Urinary incontinence

- Hemiparesis

- Headache

- Seizures

Note: *faciobrachial deficits greater than that of the lower limb

Most people who develop SCSFLS feel the sudden onset of a severe and acute headache. It is a headache usually made worse by standing, typically becoming prominent throughout the day, with the pain becoming less severe when lying down. Orthostatic headaches can become chronic and disabling to the point of incapacitation. Some patients with SCSFLS will develop headaches that begin in the afternoon. This is known as "second-half-of-the-day headache". This may be an initial presentation of a spontaneous CSF leak or appear after treatment such as an epidural patch, and likely indicates a slow CSF leak.

Apart from headache, about 50% of patients experience neck pain or stiffness, nausea, and vomiting. Other symptoms include dizziness and vertigo, facial numbness or weakness, unusually blurry or double vision, neuralgia, fatigue, or a metallic taste in the mouth. Leaking CSF can sometimes be felt or observed as a discharge from the nose or ear.

Lack of CSF pressure and volume can allow the brain to sag and descend through the foramen magnum (large opening) of the occipital bone, at the base of the skull. The lower portion of the brain is believed to stretch or impact one or more cranial nerve complexes, thereby causing a variety of sensory symptoms. Nerves that can be affected and their related symptoms are detailed in the table at right.

Arachnoid cysts can be found on the brain or on the spine. Intracranial arachnoid cysts usually occur adjacent to the arachnoidal cistern. Spinal arachnoid cysts may be extradural, intradural, or perineural and tend to present with signs and symptoms indicative of a radiculopathy.

Arachnoid cysts may also be classified as primary (congenital) or secondary (acquired) and have been reported in humans, cats, and dogs.

Arachnoid cysts can be relatively or present with symptoms; for this reason, diagnosis is often delayed.

Typically not diagnosed until late childhood or later, Bonnet–Dechaume–Blanc syndrome usually presents itself with a combination of central nervous system features (midbrain), ophthalmic features (retina), and facial features. The degree of expression of the syndrome's components varies both clinically and structurally. Common symptoms that lead to diagnosis are headaches, retro-orbital pain and hemianopia.

The ophthalmic features of the Bonnet–Dechaume–Blanc syndrome occur as retinal arteriovenous malformation (AVMs). There are three categories of AVMs that are categorized depending on the severity of the malformation. The first category consists of the patient having small lesions that usually are asymptomatic. The second category, more severe than the first, is when the patient’s malformation is missing a connecting capillary. The missing capillary is meant to serve as a link between an artery and a vein; without it, edemas, hemorrhages, and visual impairments can result. Category three, the most severe, occurs when the patient’s malformations are so severe that the dilated vessels cause no distinction between artery and vein. When the symptoms are this severe, the patient has a significantly increased risk of developing vision loss. Since the retinal lesions categorized vary from large vascular malformations that affect a majority of the retina to malformations that are barely visible, the lesions cause a wide range of symptoms including decrease in visual sharpness, proptosis, pupillary defects, optic degeneration and visual field defects. The most common type of visual field impairment due to AVMs is homonymous hemianopia. Homonymous hemianopia typically presents unilaterally, but bilateral cases have been reported as well.

The extent of the central nervous system (CNS) features/symptoms of Bonnet–Dechaume–Blanc syndrome is highly dependent of the location of the cerebral AVMs and the extent of the malformation. The most common symptom affecting the CNS is an intracranial hemangioma in the midbrain. Along with hemangiomas, the malformations result in severe headaches, cerebral hemorrhages, vomiting, meningism, seizures, acute strokes or progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.

The distinguishable facial features that result from Bonnet–Dechaume–Blanc syndrome vary from case to case. A person showing signs of the syndrome may display faint skin discoloration, nevi and angiomas of the skin. Some patients with this disorder also present with high flow arteriovenous malformations of the maxillofacial or mandibular (jaw) regions. Another facial indicator of this disease is malformations affecting the frontal and/or maxillary sinuses.

Middle cerebral artery syndrome is a condition whereby the blood supply from the middle cerebral artery (MCA) is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel: the lateral aspects of frontal, temporal and parietal lobes, the corona radiata, globus pallidus, caudate and putamen. The MCA is the most common site for the occurrence of ischemic stroke.

Depending upon the location and severity of the occlusion, signs and symptoms may vary within the population affected with MCA syndrome. More distal blockages tend to produce milder deficits due to more extensive branching of the artery and less ischemic response. In contrast, the most proximal occlusions result in widespread effects that can lead to significant cerebral edema, increased intracranial pressure, loss of consciousness and could even be fatal. In such occasions, mannitol (osmotic diuretic) or hypertonic saline are given to draw fluid out of the edematous cerebrum to minimise secondary injury. Hypertonic saline is better than mannitol, as mannitol being a diuretic will decrease the mean arterial pressure and since cerebral perfusion is mean arterial pressure minus intracranial pressure, mannitol will also cause a decrease in cerebral perfusion.

Contralateral hemiparesis and hemisensory loss of the face, upper and lower extremities is the most common presentation of MCA syndrome. Lower extremity function is more spared than that of the faciobrachial region. The majority of the primary motor and somatosensory cortices are supplied by the MCA and the cortical homunculus can, therefore, be used to localize the defects more precisely. Middle cerebral artery lesions mostly affect the dominant hemisphere i.e. the left cerebral hemisphere.

Sinus pericranii typically present as soft palpable masses along midline skull, which may fluctuate in size depending on body positioning. Classically, these lesions are not associated with color change of the overlying skin, such as with other vascular lesions such as hemangioma.

If there are symptoms, people with empty sella syndrome can have headaches, as symptoms, which subsides when lying down. Additional symptoms are as follows:

- Abnormality (middle ear ossicles)

- Cryptorchidism

- Dolichocephaly

- Arnold-Chiari type I malformation

- Meningocele

- Patent ductus arteriosus

- Muscular hypotonia

- Platybasia

Review of past cases, patients often do not exhibit many symptoms or obtain a diagnosis until they are around 20 to 40 years old. If the patient does show symptoms, it is most likely due to pressure from growth of the tumor. Depending on which part the epidermoid is pressing against can result in varying symptoms.

- Headaches – often worse in the morning or by changing positions; can be constant and become more severe or more frequent; not your typical headache

- Vision problems like blurred vision, double vision, or loss of peripheral vision

- Loss of sensation or movement in the arms, legs, or face

- Dizziness or difficulty with balance and walking, unsteadiness, vertigo

- Speech difficulties

- Confusion in everyday matters or disorientation

- Seizures, especially in someone who hasn’t had seizures before

- Hearing loss or buzzing or ringing in the ear

- Swallowing or speech difficulty

- Fatigue or sleepiness especially in children

A headache is called "thunderclap headache" if it is severe in character and reaches maximum severity within seconds to minutes of onset. In many cases, there are no other abnormalities, but the various causes of thunderclap headaches may lead to a number of neurological symptoms. The most important causes are subarachnoid hemorrhage, cerebral venous sinus thrombosis, and cervical artery dissection.

In subarachnoid hemorrhage, there may be syncope (transient loss of consciousness), seizures, 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 sinus 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.

Carotid artery dissection and vertebral artery dissection (together cervical artery dissection), in which a tear forms inside the wall of the blood vessels that supply the brain, often causes pain on the affected side of the head or neck. The pain usually precedes other problems that are 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.

The two main theories as to the underlying cause of SCSFLS are as a result of a connective tissue disorder or spinal drainage problems.

Nasal glial heterotopia refers to congenital malformations of displaced normal, mature glial tissue, which are no longer in continuity with an intracranial component. This is distinctly different from an encephalocele, which is a herniation of brain tissue and/or leptomeninges, that develops through a defect in the skull, where there is a continuity with the cranial cavity.

Sinus pericranii (SP) is a rare disorder characterized by a congenital (or occasionally, acquired) epicranial venous malformation of the scalp. Sinus pericranii is an abnormal communication between the intracranial and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for aesthetic reasons and prevention of hemorrhage.

Bonnet–Dechaume–Blanc syndrome, also known as Wyburn-Mason syndrome, is a rare congential arteriovenous malformation of the brain, retina or facial nevi. The syndrome has a number of possible symptoms and can affect the skin, bones, kidneys, muscles, and gastrointestinal tract. When the syndrome affects the brain, people can experience severe headaches, seizures, acute stroke, meningism and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.

As for the retina, the syndrome causes retinocephalic vascular malformations that tend to be present with intracranial hemorrhage and lead to decreased visual acuity, proptosis, pupillary defects, optic atrophy, congestion of bulbar conjunctiva, and visual field defects. Retinal lesions can be unilateral and tortuous, and symptoms begin to appear in the second and third decades of life.

The syndrome can present cutaneous lesions, or skin with different texture, thickness, and color, usually on the face. The facial features caused by the syndrome vary from slight discoloration to extensive nevi and angiomas of the skin. In some cases, the frontal and maxillary sinus can present problems in the subject due to the syndrome.

There have only been 52 reported cases of patients with Bonnet–Dechaume–Blanc syndrome as of 2012. Symptoms are rarely noticed in children and the syndrome is often diagnosed in late childhood or early adulthood when visual impairment is noticed. Fluorescein angiography is commonly used to diagnose the syndrome.

There have been several methods in treating patients who display Bonnet–Dechaume–Blanc syndrome. However, which method seems to work the most is within argument. Patients with intracranial lesions have been treated with surgical intervention and in some cases, this procedure has been successful. Other treatments include embolization, radiation therapy, and continued observation.

With limited research on Bonnet–Dechaume–Blanc syndrome, researchers have focused on the clinical and radiological findings rather than how to manage this rare and non-heritable syndrome.

There are two types of ESS: "primary" and "secondary".

- Primary ESS happens when a small anatomical defect above the pituitary gland increases pressure in the sella turcica and causes the gland to flatten out along the interior walls of the sella turcica cavity. Primary ESS is associated with obesity and increase in intracranial pressure in women.

- Secondary ESS is the result of the pituitary gland regressing within the cavity after an injury, surgery, or radiation therapy. Individuals with secondary ESS due to destruction of the pituitary gland have symptoms that reflect the loss of pituitary functions, such as intolerance to stress and infection.

Because Non-parenchymal NBD targets vascular structures, the symptoms arise in the same area. The main clinical characteristic is the cerebral venous thrombosis (CVT). If one experiences CVT, a clot in one of the blood vessels in the brain blocks the blood flow and may result in stroke. This happens in the dural venous sinuses. Stroke-like symptoms such as confusion, weakness, and dizziness may be monitored. Headache tends to worsen over the period of several days.

Some of the less common symptoms include intracranial hypertension and intracranial aneurysms.

The main symptom is meningoencephalitis which happens in ~75% of NBD patients. Other general symptoms of Behçet's disease are also present among parenchymal NBD patients such as fever, headache, genital ulcers, genital scars, and skin lesions. When the brainstem is affected, ophthalmoparesis, cranial neuropathy, and cerebellar or pyramidal dysfunction may be observed. Cerebral hemispheric involvement may result in encephalopathy, hemiparesis, hemisensory loss, seizures, dysphasia, and mental changes including cognitive dysfunction and

psychosis. As for the spinal cord involvement, pyramidal signs in the limbs, sensory level dysfunction, and, commonly, sphincter dysfunction may be observed.

Some of the symptoms are less common such as stroke (1.5%), epilepsy (2.2–5%), brain tumor, movement disorder, acute meningeal syndrome, and optic neuropathy.

Patients come to clinical attention early in life (usually at birth or within the first few months), with a firm subcutaneous nodule at bridge of nose, or as a polypoid mass within the nasal cavity, or somewhere along the upper border of the nasal bow. If the patient presents with an intranasal mass, there may be obstruction, chronic rhinosinusitis, or nasal drainage. If there is a concurrent cerebrospinal fluid (CSF) leak, then an encephalocele is much more likely.

This lesion is separated into two types based on the anatomic site of presentation:

1. Extranasal (60%): Subcutaneous bridge of nose

2. Intranasal (30%): Superior nasal cavity

3. Mixed (10%): Subcutaneous tissues and nasal cavity (larger lesions)

Cerebral atherosclerosis is a type of atherosclerosis where build-up of plaque in the blood vessels of the brain occurs. Some of the main components of the plaques are connective tissue, extracellular matrix, including collagen, proteoglycans, fibronectin, and elastic fibers; crystalline cholesterol, cholesteryl esters, and phospholipids; cells such as monocyte derived macrophages, T-lymphocytes, and smooth muscle cells. The plaque that builds up can lead to further complications such as stroke, as the plaque disrupts blood flow within the intracranial arterioles. This causes the downstream sections of the brain that would normally be supplied by the blocked artery to suffer from ischemia. Diagnosis of the disease is normally done through imaging technology such as angiograms or magnetic resonance imaging. The risk of cerebral atherosclerosis and its associated diseases appears to increase with increasing age; however there are numerous factors that can be controlled in attempt to lessen risk.

Thunderclap headaches can be caused by a number of primary conditions including:

- Subarachnoid hemorrhage (10–25% of all cases of thunderclap headache)

- Cerebral venous sinus thrombosis

- Cervical artery dissection

- Hypertensive emergency (severely raised blood pressure)

- Spontaneous intracranial hypotension (unexplained low cerebrospinal fluid pressure)

- Stroke (headache occurs in about 25% of strokes but usually not thunderclap character)

- Retroclival hematoma (hematoma behind the clivus in the skull, usually due to physical trauma but sometimes spontaneous)

- Pituitary apoplexy (infarction or hemorrhage of the pituitary gland)

- Colloid cyst of the third ventricle

- Meningitis (rarely features thunderclap headache)

- Reversible cerebral vasoconstriction syndrome (previously Call-Fleming syndrome, several subtypes)

- Primary cough headache, primary exertional headache, and primary sexual headache

- Primary thunderclap headache

Raised intracranial pressure as a result of one or more of the following: