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86-664: The trochlear nerve is unique among the cranial nerves in several respects: The superior oblique muscle which the trochlear nerve innervates ends in a tendon that passes through a fibrous loop, the trochlea , located anteriorly on the medial aspect of the orbit. Trochlea means “pulley” in Latin; the fourth nerve is thus also named after this structure. The words trochlea and trochlear ( / ˈ t r ɒ k l i ə / , / ˈ t r ɒ k l i ər / ) come from Ancient Greek τροχιλέα trokhiléa , “pulley; block-and-tackle equipment”. The trochlear nerve provides motor innervation to

172-543: A pitch accent . In Modern Greek, all vowels and consonants are short. Many vowels and diphthongs once pronounced distinctly are pronounced as /i/ ( iotacism ). Some of the stops and glides in diphthongs have become fricatives , and the pitch accent has changed to a stress accent . Many of the changes took place in the Koine Greek period. The writing system of Modern Greek, however, does not reflect all pronunciation changes. The examples below represent Attic Greek in

258-491: A CT and MRI scan, and were astonished to see "massive enlargement" of the lateral ventricles in the skull. Dr. Lionel Feuillet of Hôpital de la Timone in Marseille said, "The images were most unusual... the brain was virtually absent." Intelligence tests showed the person had an IQ of 75, considered " Borderline intellectual functioning ", just above what would be officially classified as intellectually disabled. The person

344-528: A change in personality, weakness in the arms or legs, strabismus , and double vision to appear when the person is vertical. If the person lies down, the symptoms usually vanish quickly. A CT scan may or may not show any change in ventricle size, particularly if the person has a history of slit-like ventricles. Difficulty in diagnosing over-drainage can make treatment of this complication particularly frustrating for people and their families. Resistance to traditional analgesic pharmacological therapy may also be

430-492: A constant feature of kleeblattschadel and frequently seen in syndomic cases (mostly in Crouzon syndrome ). Hydrocephalus has also been seen in cases of congenital syphilis . In newborns and toddlers with hydrocephalus, the head circumference is enlarged rapidly and soon surpasses the 97th percentile. Since the skull bones have not yet firmly joined, bulging, firm anterior and posterior fontanelles may be present even when

516-495: A decrease in Perilymphatic pressure and cause secondary endolymphatic hydrops. In addition to the increased hearing loss, there have also been findings of resolved hearing loss after ventriculoperitoneal shunt placement, where there is a release of CSF pressure on the auditory pathways. The diagnosis of CSF buildup is complex and requires specialist expertise. Diagnosis of the particular complication usually depends on when

602-525: A fifth major dialect group, or it is Mycenaean Greek overlaid by Doric, with a non-Greek native influence. Regarding the speech of the ancient Macedonians diverse theories have been put forward, but the epigraphic activity and the archaeological discoveries in the Greek region of Macedonia during the last decades has brought to light documents, among which the first texts written in Macedonian , such as

688-414: A good medical history can help to differentiate external hydrocephalus from subdural hemorrhages or symptomatic chronic extra-axial fluid collections which are accompanied by vomiting, headaches, and seizures. Examples of possible complications include shunt malfunction, shunt failure, and shunt infection, along with infection of the shunt tract following surgery (the most common reason for shunt failure

774-399: A newborn baby is often full of liquid, either because the matron has compressed it excessively or for other, unknown reasons. The volume of the skull then increases daily, so that the bones of the skull fail to close. In this case, we must open the middle of the skull in three places, make the liquid flow out, then close the wound and tighten the skull with a bandage. In 1881, a few years after

860-550: A prefix /e-/, called the augment . This was probably originally a separate word, meaning something like "then", added because tenses in PIE had primarily aspectual meaning. The augment is added to the indicative of the aorist, imperfect, and pluperfect, but not to any of the other forms of the aorist (no other forms of the imperfect and pluperfect exist). The two kinds of augment in Greek are syllabic and quantitative. The syllabic augment

946-402: A sign of shunt overdrainage or failure. Following placement of a ventriculoperitoneal shunt there have been cases of a decrease in post-surgery hearing. It is presumed that the cochlea aqueduct is responsible for the decrease in hearing thresholds. The cochlea aqueduct has been considered as a probable channel where CSF pressure can be transmitted. Therefore, the reduced CSF pressure could cause

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1032-542: A strong Northwest Greek influence, and can in some respects be considered a transitional dialect, as exemplified in the poems of the Boeotian poet Pindar who wrote in Doric with a small Aeolic admixture. Thessalian likewise had come under Northwest Greek influence, though to a lesser degree. Pamphylian Greek , spoken in a small area on the southwestern coast of Anatolia and little preserved in inscriptions, may be either

1118-510: A vowel or /n s r/ ; final stops were lost, as in γάλα "milk", compared with γάλακτος "of milk" (genitive). Ancient Greek of the classical period also differed in both the inventory and distribution of original PIE phonemes due to numerous sound changes, notably the following: The pronunciation of Ancient Greek was very different from that of Modern Greek . Ancient Greek had long and short vowels ; many diphthongs ; double and single consonants; voiced, voiceless, and aspirated stops ; and

1204-405: Is a relatively typical manifestation of the distinct entity normal-pressure hydrocephalus. Focal neurological deficits may also occur, such as abducens nerve palsy and vertical gaze palsy ( Parinaud syndrome due to compression of the quadrigeminal plate , where the neural centers coordinating the conjugated vertical eye movement are located). The symptoms depend on the cause of the blockage,

1290-418: Is added to stems beginning with consonants, and simply prefixes e (stems beginning with r , however, add er ). The quantitative augment is added to stems beginning with vowels, and involves lengthening the vowel: Some verbs augment irregularly; the most common variation is e → ei . The irregularity can be explained diachronically by the loss of s between vowels, or that of the letter w , which affected

1376-599: Is caused by impaired CSF reabsorption in the absence of any obstruction of CSF flow between the ventricles and subarachnoid space. This may be due to functional impairment of the arachnoidal granulations (also called arachnoid granulations or Pacchioni's granulations ), which are located along the superior sagittal sinus , and is the site of CSF reabsorption back into the venous system. Various neurologic conditions may result in communicating hydrocephalus, including subarachnoid/intraventricular hemorrhage, meningitis, and congenital absence of arachnoid villi. Scarring and fibrosis of

1462-552: Is complete recovery within weeks to months. Isolated injury to the fourth nerve can be caused by any process that stretches or compresses the nerve. A generalized increase in intracranial pressure— hydrocephalus , pseudotumor cerebri , hemorrhage , edema —will affect the fourth nerve, but the abducens nerve (VI) is usually affected first (producing horizontal diplopia , not vertical diplopia ). Infections ( meningitis , herpes zoster ), demyelination ( multiple sclerosis ), diabetic neuropathy and cavernous sinus disease can affect

1548-448: Is considered by some linguists to have been closely related to Greek . Among Indo-European branches with living descendants, Greek is often argued to have the closest genetic ties with Armenian (see also Graeco-Armenian ) and Indo-Iranian languages (see Graeco-Aryan ). Ancient Greek differs from Proto-Indo-European (PIE) and other Indo-European languages in certain ways. In phonotactics , ancient Greek words could end only in

1634-446: Is damage to the trochlear nucleus. It affects the contralateral eye. The nuclei of other cranial nerves generally affect ipsilateral structures (for example, the optic nerves - cranial nerves II - innervate both eyes). The trochlear nucleus and its axons within the brainstem can be damaged by infarctions, hemorrhage , arteriovenous malformations , tumors and demyelination . Collateral damage to other structures will usually dominate

1720-402: Is head trauma. Even relatively minor trauma can transiently stretch the fourth nerve (by transiently displacing the brainstem relative to the posterior clinoid process). Patients with minor damage to the fourth nerve will complain of “blurry” vision. Patients with more extensive damage will notice frank diplopia and rotational (torsional) disturbances of the visual fields. The usual clinical course

1806-471: Is infection of the shunt tract). Although a shunt generally works well, it may stop working if it disconnects, becomes blocked (clogged) or infected, or it is outgrown. If this happens, the CSF begins to accumulate again and a number of physical symptoms develop (headaches, nausea, vomiting, photophobia /light sensitivity), some extremely serious, such as seizures . The shunt failure rate is also relatively high (of

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1892-611: Is present in the infant prior to birth, meaning the fetus developed hydrocephalus in utero during fetal development . The most common cause of congenital hydrocephalus is aqueductal stenosis, which occurs when the narrow passage between the third and fourth ventricles in the brain is blocked or too narrow to allow sufficient cerebral spinal fluid to drain. Fluid accumulates in the upper ventricles, causing hydrocephalus. Other causes of congenital hydrocephalus include neural-tube defects, arachnoid cysts , Dandy–Walker syndrome , and Arnold–Chiari malformation . The cranial bones fuse by

1978-550: Is sometimes combined with choroid plexus cauterization, which reduces the amount of cerebrospinal fluid produced by the brain. The technique, known as ETV/CPC, was pioneered in Uganda by neurosurgeon Benjamin Warf and is now in use in several U.S. hospitals. Hydrocephalus can be successfully treated by placing a drainage tube (shunt) between the brain ventricles and abdominal cavity. Some risk exists of infection being introduced into

2064-418: Is thought to reflect the distribution of nerve damage to the brain. Hydrocephalus that is present from birth can cause long-term complications with speech and language. Children can have issues such as nonverbal learning disorder, difficulty understanding complex and abstract concepts, difficulty retrieving stored information, and spatial/perceptual disorders. Children with hydrocephalus are often known in having

2150-574: Is typically made by physical examination and medical imaging . Hydrocephalus is typically treated by the surgical placement of a shunt system . A procedure called a third ventriculostomy is an option in some people. Complications from shunts may include overdrainage, underdrainage, mechanical failure, infection , or obstruction. This may require replacement. Outcomes are variable, but many people with shunts live normal lives. Without treatment, permanent disability or death may occur. About one to two per 1,000 newborns have hydrocephalus. Rates in

2236-406: Is usually painful. The cause of hydrocephalus is not known with certainty and is probably multifactorial. It may be caused by impaired CSF flow, reabsorption, or excessive CSF production. Hydrocephalus can be classified into communicating and noncommunicating (obstructive). Both forms can be either congenital or acquired. Communicating hydrocephalus, also known as nonobstructive hydrocephalus,

2322-679: The Archaic or Epic period ( c.  800–500 BC ), and the Classical period ( c.  500–300 BC ). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers . It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance . This article primarily contains information about

2408-606: The Epic and Classical periods of the language, which are the best-attested periods and considered most typical of Ancient Greek. From the Hellenistic period ( c.  300 BC ), Ancient Greek was followed by Koine Greek , which is regarded as a separate historical stage, though its earliest form closely resembles Attic Greek , and its latest form approaches Medieval Greek . There were several regional dialects of Ancient Greek; Attic Greek developed into Koine. Ancient Greek

2494-516: The One Small Voice Foundation , promote awareness and fundraising activities. One case of hydrocephalus was a man whose brain shrank to a thin sheet of tissue, due to a buildup of cerebrospinal fluid in his skull. As a child, the man had a shunt, but it was removed when he was 14. In July 2007, at age 44, he went to a hospital due to mild weakness in his left leg. When doctors learned of the man's medical history, they performed

2580-501: The Pella curse tablet , as Hatzopoulos and other scholars note. Based on the conclusions drawn by several studies and findings such as Pella curse tablet , Emilio Crespo and other scholars suggest that ancient Macedonian was a Northwest Doric dialect , which shares isoglosses with its neighboring Thessalian dialects spoken in northeastern Thessaly . Some have also suggested an Aeolic Greek classification. The Lesbian dialect

2666-450: The developing world may be higher. Normal pressure hydrocephalus is estimated to affect about 5 per 100,000 people, with rates increasing with age. Description of hydrocephalus by Hippocrates dates back more than 2,000 years. The word hydrocephalus is from the Greek ὕδωρ , hydōr , meaning 'water' and κεφαλή , kephalē , meaning 'head'. The clinical presentation of hydrocephalus varies with chronicity . Acute dilatation of

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2752-581: The developing world while North America has the fewest number of cases. A systematic review in 2019 estimated that there are 180,000 childhood hydrocephalus cases from the African continent per year, followed by 90,000 cases from Southeast Asia and the Western Pacific. Latin America also has a high prevalence of hydrocephalus. However, data on hydrocephalus disease burden in adults are lacking. In

2838-417: The dura just under free margin of the tentorium cerebelli , close to the crossing of the attached margin of the tentorium and within millimeters of the posterior clinoid process . It runs on the outer wall of the cavernous sinus . Finally, it enters the orbit through the superior orbital fissure and to innervate the superior oblique muscle . The human trochlear nerve is derived from the basal plate of

2924-403: The embryonic midbrain . Injury to the trochlear nerve cause weakness of downward eye movement with consequent vertical diplopia (double vision). The affected eye drifts upward relative to the normal eye, due to the unopposed actions of the remaining extraocular muscles. The patient sees two visual fields (one from each eye), separated vertically. To compensate for this, patients learn to tilt

3010-603: The epic poems , the Iliad and the Odyssey , and in later poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic and other Classical-era dialects. The origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between

3096-501: The present , future , and imperfect are imperfective in aspect; the aorist , present perfect , pluperfect and future perfect are perfective in aspect. Most tenses display all four moods and three voices, although there is no future subjunctive or imperative. Also, there is no imperfect subjunctive, optative or imperative. The infinitives and participles correspond to the finite combinations of tense, aspect, and voice. The indicative of past tenses adds (conceptually, at least)

3182-417: The superior oblique muscle of the eye, a skeletal muscle; the trochlear nerve thus carries axons of general somatic efferent type . Each trochlear nerve originates from a trochlear nucleus in the medial midbrain . From their respective nuclei, the two trochlear nerves then travel dorsal-ward through the substance of the midbrain surrounded by the periaqueductal gray , crossing over (decussating) within

3268-515: The ventricular system is more likely to manifest with the nonspecific signs and symptoms of increased intracranial pressure (ICP). By contrast, chronic dilatation (especially in the elderly population) may have a more insidious onset presenting, for instance, with Hakim's triad (Adams' triad). Symptoms of increased ICP may include headaches , vomiting , nausea , papilledema , sleepiness , or coma . With increased levels of CSF, there have been cases of hearing loss due to CSF creating pressure on

3354-501: The 40,000 surgeries performed annually to treat hydrocephalus, only 30% are a person's first surgery) and people not uncommonly have multiple shunt revisions within their lifetimes. Another complication can occur when CSF drains more rapidly than it is produced by the choroid plexus , causing symptoms of listlessness, severe headaches, irritability, light sensitivity, auditory hyperesthesia (sound sensitivity), hearing loss, nausea, vomiting, dizziness , vertigo , migraines , seizures,

3440-1031: The 5th century BC. Ancient pronunciation cannot be reconstructed with certainty, but Greek from the period is well documented, and there is little disagreement among linguists as to the general nature of the sounds that the letters represent. /oː/ raised to [uː] , probably by the 4th century BC. Greek, like all of the older Indo-European languages , is highly inflected. It is highly archaic in its preservation of Proto-Indo-European forms. In ancient Greek, nouns (including proper nouns) have five cases ( nominative , genitive , dative , accusative , and vocative ), three genders ( masculine , feminine , and neuter ), and three numbers (singular, dual , and plural ). Verbs have four moods ( indicative , imperative , subjunctive , and optative ) and three voices (active, middle, and passive ), as well as three persons (first, second, and third) and various other forms. Verbs are conjugated through seven combinations of tenses and aspect (generally simply called "tenses"):

3526-495: The Archaic period of ancient Greek (see Homeric Greek for more details): Μῆνιν ἄειδε, θεά, Πηληϊάδεω Ἀχιλῆος οὐλομένην, ἣ μυρί' Ἀχαιοῖς ἄλγε' ἔθηκε, πολλὰς δ' ἰφθίμους ψυχὰς Ἄϊδι προΐαψεν ἡρώων, αὐτοὺς δὲ ἑλώρια τεῦχε κύνεσσιν οἰωνοῖσί τε πᾶσι· Διὸς δ' ἐτελείετο βουλή· ἐξ οὗ δὴ τὰ πρῶτα διαστήτην ἐρίσαντε Ἀτρεΐδης τε ἄναξ ἀνδρῶν καὶ δῖος Ἀχιλλεύς. The beginning of Apology by Plato exemplifies Attic Greek from

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3612-607: The Classical period of ancient Greek. (The second line is the IPA , the third is transliterated into the Latin alphabet using a modern version of the Erasmian scheme .) Ὅτι [hóti Hóti μὲν men mèn ὑμεῖς, hyːmêːs hūmeîs,   Hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain . This typically causes increased pressure inside

3698-545: The Dorians. The Greeks of this period believed there were three major divisions of all Greek people – Dorians, Aeolians, and Ionians (including Athenians), each with their own defining and distinctive dialects. Allowing for their oversight of Arcadian, an obscure mountain dialect, and Cypriot, far from the center of Greek scholarship, this division of people and language is quite similar to the results of modern archaeological-linguistic investigation. One standard formulation for

3784-465: The Perilymphatic space of the inner ear with the subarachnoid space of the posterior cranial fossa. A loss of CSF pressure can induce Perilymphatic loss or endolymphatic hydrops resembling the clinical presentation of Ménière's disease associated hearing loss in the low frequencies. CSF can accumulate within the ventricles, this condition is called internal hydrocephalus and may result in increased CSF pressure. The production of CSF continues, even when

3870-550: The aorist. Following Homer 's practice, the augment is sometimes not made in poetry , especially epic poetry. The augment sometimes substitutes for reduplication; see below. Almost all forms of the perfect, pluperfect, and future perfect reduplicate the initial syllable of the verb stem. (A few irregular forms of perfect do not reduplicate, whereas a handful of irregular aorists reduplicate.) The three types of reduplication are: Irregular duplication can be understood diachronically. For example, lambanō (root lab ) has

3956-496: The arms may become tremulous . Papilledema is absent, but vision may be reduced. The head becomes so enlarged that they eventually may be bedridden. About 80–90% of fetuses or newborn infants with spina bifida —often associated with meningocele or myelomeningocele —develop hydrocephalus. This condition is acquired as a consequence of CNS infections , meningitis , brain tumors , head trauma , toxoplasmosis , or intracranial hemorrhage (subarachnoid or intraparenchymal), and

4042-524: The auditory pathways or disrupting the communication of inner ear fluid. Elevated ICP of different etiologies have been linked to sensorineural hearing loss (SNHL). Transient SNHL has been reported after the loss of CSF with shunt surgeries. Hearing loss is a rare but well-known sequela of procedures resulting in CSF loss. Elevated ICP may result in uncal or tonsillar herniation , with resulting life-threatening brain stem compression. Hakim's triad of gait instability, urinary incontinence , and dementia

4128-419: The augment when it was word-initial. In verbs with a preposition as a prefix, the augment is placed not at the start of the word, but between the preposition and the original verb. For example, προσ(-)βάλλω (I attack) goes to προσ έ βαλoν in the aorist. However compound verbs consisting of a prefix that is not a preposition retain the augment at the start of the word: αὐτο(-)μολῶ goes to ηὐ τομόλησα in

4214-405: The brain through these shunts, as they must be replaced as the person grows. External hydrocephalus is a condition generally seen in infants which involves enlarged fluid spaces or subarachnoid spaces around the outside of the brain. This condition is generally benign , and resolves spontaneously by two years of age and therefore usually does not require insertion of a shunt. Imaging studies and

4300-549: The brain", a historical name, and "water baby syndrome". September was designated National Hydrocephalus Awareness Month in July 2009 by the U.S. Congress in H.Res. 373 . The resolution campaign is due in part to the advocacy work of the Pediatric Hydrocephalus Foundation. Prior to July 2009, no awareness month for this condition had been designated. Many hydrocephalus organizations, such as

4386-574: The brain, its ventricles and the spinal cord and is continuously drained away into the circulatory system. Alternatively, the condition may result from an overproduction of the CSF, from a congenital malformation blocking normal drainage of the fluid, or from complications of head injuries or infections. Compression of the brain by the accumulating fluid eventually may cause neurological symptoms such as convulsions , intellectual disability , and epileptic seizures . These signs occur sooner in adults, whose skulls are no longer able to expand to accommodate

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4472-421: The clinical picture. The fourth nerve is one of the final common pathways for cortical systems that control eye movement in general. Cortical control of eye movement ( saccades , smooth pursuit, accommodation ) involves conjugate gaze , not unilateral eye movement. The trochlear nerve is tested by examining the action of its muscle, the superior oblique. When acting on its own this muscle depresses and abducts

4558-485: The diagnosis, but other causes must be ruled out. For example, torticollis can produce a similar appearance. The clinical syndromes can originate from both peripheral and central lesions. A peripheral lesion is damage to the bundle of nerves, in contrast to a central lesion, which is damage to the trochlear nucleus. Acute symptoms are probably a result of trauma or disease, while chronic symptoms probably are congenital. The most common cause of acute fourth nerve palsy

4644-615: The dialect of Sparta ), and Northern Peloponnesus Doric (including Corinthian ). All the groups were represented by colonies beyond Greece proper as well, and these colonies generally developed local characteristics, often under the influence of settlers or neighbors speaking different Greek dialects. After the conquests of Alexander the Great in the late 4th century BC, a new international dialect known as Koine or Common Greek developed, largely based on Attic Greek , but with influence from other dialects. This dialect slowly replaced most of

4730-530: The dialects is: West vs. non-West Greek is the strongest-marked and earliest division, with non-West in subsets of Ionic-Attic (or Attic-Ionic) and Aeolic vs. Arcadocypriot, or Aeolic and Arcado-Cypriot vs. Ionic-Attic. Often non-West is called 'East Greek'. Arcadocypriot apparently descended more closely from the Mycenaean Greek of the Bronze Age. Boeotian Greek had come under

4816-497: The difficulty in understanding the concepts within conversation and tend to use words they know or have heard. However, the severity of hydrocephalus can differ considerably between individuals, and some are of average or above-average intelligence. Someone with hydrocephalus may have coordination and visual problems, or clumsiness. They may reach puberty earlier than the average child (this is called precocious puberty ). About one in four develops epilepsy . Congenital hydrocephalus

4902-510: The divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period. They have the same general outline but differ in some of the detail. The only attested dialect from this period is Mycenaean Greek , but its relationship to the historical dialects and the historical circumstances of the times imply that the overall groups already existed in some form. Scholars assume that major Ancient Greek period dialect groups developed not later than 1120 BC, at

4988-461: The end of the third year of life. For head enlargement to occur, hydrocephalus must occur before then. The causes are usually genetic, but can also be acquired and usually occur within the first few months of life, which include intraventricular matrix hemorrhages in premature infants , infections, type II Arnold-Chiari malformation, aqueduct atresia and stenosis, and Dandy-Walker malformation. Hydrocephalus can also occur with craniosynostosis , being

5074-421: The eyeball. However, movements of the eye by the extraocular muscles are synergistic (working together). Therefore, the trochlear nerve is tested by asking the patient to look 'down and in' as the contribution of the superior oblique is greatest in this motion. Common activities requiring this type of convergent gaze are reading the newspaper and walking down stairs. Diplopia associated with these activities may be

5160-604: The fourth nerve, as can orbital tumors and Tolosa–Hunt syndrome . In general, these diseases affect other cranial nerves as well. Isolated damage to the fourth nerve is uncommon in these settings. The most common cause of chronic fourth nerve palsy is a congenital defect, in which the development of the fourth nerve (or its nucleus) is abnormal or incomplete. Congenital defects may be noticed in childhood, but minor defects may not become evident until adult life, when compensatory mechanisms begin to fail. Congenital fourth nerve palsies are amenable to surgical treatment. Central damage

5246-446: The head forward (tuck the chin in) in order to bring the fields back together—to fuse the two images into a single visual field. This accounts for the “dejected” appearance of patients with “pathetic nerve” palsies. Trochlear nerve palsy also affects torsion (rotation of the eyeball in the plane of the face). Torsion is a normal response to tilting the head sideways. The eyes automatically rotate in an equal and opposite direction, so that

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5332-402: The increasing fluid volume within. Fetuses, infants, and young children with hydrocephalus typically have an abnormally large head, excluding the face, because the pressure of the fluid causes the individual skull bones—which have yet to fuse—to bulge outward at their juncture points . Another medical sign , in infants, is a characteristic fixed downward gaze with whites of the eyes showing above

5418-400: The initial symptom of a fourth nerve palsy. Alfred Bielschowsky 's head tilt test is a test for palsy of the superior oblique muscle caused by damage to cranial nerve IV (trochlear nerve). Homologous trochlear nerves are found in all jawed vertebrates . The unique features of the trochlear nerve, including its dorsal exit from the brainstem and its contralateral innervation, are seen in

5504-452: The iris, as though the infant were trying to examine its own lower eyelids. The elevated ICP may cause compression of the brain, leading to brain damage and other complications. A complication often overlooked is the possibility of hearing loss due to ICP. The mechanism of ICP on hearing loss is presumed that the transmission of CSF pressure to and from the Perilymphatic space through a patent cochlear aqueduct. The cochlear aqueduct connects

5590-480: The landmark study of Retzius and Key, Carl Wernicke pioneered sterile ventricular puncture and external drainage of CSF for the treatment of hydrocephalus. It remained an intractable condition until the 20th century, when cerebral shunt and other neurosurgical treatment modalities were developed. The word hydrocephalus is from the Greek ὕδωρ , hydōr meaning 'water' and κεφαλή , kephalē meaning 'head'. Other names for hydrocephalus include "water on

5676-511: The lumbar space of the spine and have the CSF redirected to the peritoneal cavity ( lumbar-peritoneal shunt ). An alternative treatment for obstructive hydrocephalus in selected people is the endoscopic third ventriculostomy (ETV), whereby a surgically created opening in the floor of the third ventricle allows the CSF to flow directly to the basal cisterns , thereby shortcutting any obstruction, as in aqueductal stenosis. This may or may not be appropriate based on individual anatomy. For infants, ETV

5762-412: The midbrain before emerging from the dorsal midbrain just inferior to the inferior colliculus . Each trochlear nerve thus comes to course on the contralateral side, first passing laterally (to the side) and then anteriorly around the pons , then running forward toward the eye in the subarachnoid space . It passes between the posterior cerebral artery and the superior cerebellar artery . It then pierces

5848-508: The older dialects, although the Doric dialect has survived in the Tsakonian language , which is spoken in the region of modern Sparta. Doric has also passed down its aorist terminations into most verbs of Demotic Greek . By about the 6th century AD, the Koine had slowly metamorphosed into Medieval Greek . Phrygian is an extinct Indo-European language of West and Central Anatolia , which

5934-524: The orientation of the environment remains unchanged—vertical things remain vertical. Weakness of intorsion results in torsional diplopia, in which two different visual fields, tilted with respect to each other, are seen at the same time. To compensate for this, patients with trochlear nerve palsies tilt their heads to the opposite side, in order to fuse the two images into a single visual field. The characteristic appearance of patients with fourth nerve palsies (head tilted to one side, chin tucked in) suggests

6020-448: The passages that normally allow it to exit the brain are blocked. Consequently, fluid builds inside the brain, causing pressure that dilates the ventricles and compresses the nervous tissue . Compression of the nervous tissue usually results in irreversible brain damage . If the skull bones are not completely ossified when the hydrocephalus occurs, the pressure may also severely enlarge the head. The cerebral aqueduct may be blocked at

6106-487: The perfect stem eilēpha (not * lelēpha ) because it was originally slambanō , with perfect seslēpha , becoming eilēpha through compensatory lengthening. Reduplication is also visible in the present tense stems of certain verbs. These stems add a syllable consisting of the root's initial consonant followed by i . A nasal stop appears after the reduplication in some verbs. The earliest extant examples of ancient Greek writing ( c.  1450 BC ) are in

6192-440: The person is in an upright position. The infant exhibits fretfulness, poor feeding, and frequent vomiting. As the hydrocephalus progresses, torpor sets in, and infants show lack of interest in their surroundings. Later on, their upper eyelids become retracted and their eyes are turned downwards ("sunset eyes") (due to hydrocephalic pressure on the mesencephalic tegmentum and paralysis of upward gaze). Movements become weak and

6278-609: The person's age, and how much brain tissue has been damaged by the swelling. In infants with hydrocephalus, CSF builds up in the central nervous system (CNS), causing the fontanelle (soft spot) to bulge and the head to be larger than expected. Early symptoms may also include: Symptoms that may occur in older children can include: Because hydrocephalus can injure the brain, thought and behavior may be adversely affected. Learning disabilities , including short-term memory loss , are common among those with hydrocephalus, who tend to score better on verbal IQ than on performance IQ, which

6364-523: The placement of a ventricular catheter (a tube made of silastic ) into the cerebral ventricles to bypass the flow obstruction/malfunctioning arachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed. Most shunts drain the fluid into the peritoneal cavity ( ventriculoperitoneal shunt ), but alternative sites include the right atrium ( ventriculoatrial shunt ), pleural cavity ( ventriculopleural shunt ), and gallbladder . A shunt system can also be placed in

6450-421: The pre-historic area, there were various paintings or artifacts depicting children or adults with macrocephaly (large head) or clinical findings of hydrocephalus. The earliest scientific description of hydrocephalus was written by the ancient Greek physician Hippocrates , who coined the word 'hydrocephalus' from the Greek ὕδωρ, hydōr meaning 'water' and κεφαλή, kephalē meaning 'head'. A more accurate description

6536-405: The primitive brains of sharks. Ancient Greek Ancient Greek ( Ἑλληνῐκή , Hellēnikḗ ; [hellɛːnikɛ́ː] ) includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek ( c.  1400–1200 BC ), Dark Ages ( c.  1200–800 BC ),

6622-745: The skull . Older people may have headaches , double vision , poor balance, urinary incontinence , personality changes, or mental impairment . In babies, it may be seen as a rapid increase in head size. Other symptoms may include vomiting , sleepiness, seizures , and downward pointing of the eyes . Hydrocephalus can occur due to birth defects or be acquired later in life. Associated birth defects include neural tube defects and those that result in aqueductal stenosis . Other causes include meningitis , brain tumors , traumatic brain injury , intraventricular hemorrhage , and subarachnoid hemorrhage . The four types of hydrocephalus are communicating, noncommunicating, ex vacuo , and normal pressure . Diagnosis

6708-464: The subarachnoid space following infectious, inflammatory, or hemorrhagic events can also prevent reabsorption of CSF, causing diffuse ventricular dilatation. Noncommunicating hydrocephalus, or obstructive hydrocephalus, is caused by an obstruction to the flow of CSF. Hydrocephalus is usually due to blockage of CSF outflow in the ventricles or in the subarachnoid space over the brain. In a person without hydrocephalus, CSF continuously circulates through

6794-517: The syllabic script Linear B . Beginning in the 8th century BC, however, the Greek alphabet became standard, albeit with some variation among dialects. Early texts are written in boustrophedon style, but left-to-right became standard during the classic period. Modern editions of ancient Greek texts are usually written with accents and breathing marks , interword spacing , modern punctuation , and sometimes mixed case , but these were all introduced later. The beginning of Homer 's Iliad exemplifies

6880-415: The symptoms appear, that is, whether symptoms occur when the person is upright or in a prone position, with the head at roughly the same level as the feet. Standardized protocols for inserting cerebral shunts have been shown to reduce shunt infections. There is tentative evidence that preventative antibiotics may decrease the risk of shunt infections. The hydrocephalus disease burden are concentrated in

6966-422: The time of birth or may become blocked later in life because of a tumor growing in the brainstem . Hydrocephalus treatment is surgical, creating a way for the excess fluid to drain away. In the short term, an external ventricular drain (EVD), also known as an extraventricular drain or ventriculostomy, provides relief. In the long term, some people will need any of various types of cerebral shunt . It involves

7052-467: The time of the Dorian invasions —and that their first appearances as precise alphabetic writing began in the 8th century BC. The invasion would not be "Dorian" unless the invaders had some cultural relationship to the historical Dorians . The invasion is known to have displaced population to the later Attic-Ionic regions, who regarded themselves as descendants of the population displaced by or contending with

7138-480: Was Aeolic. For example, fragments of the works of the poet Sappho from the island of Lesbos are in Aeolian. Most of the dialect sub-groups listed above had further subdivisions, generally equivalent to a city-state and its surrounding territory, or to an island. Doric notably had several intermediate divisions as well, into Island Doric (including Cretan Doric ), Southern Peloponnesus Doric (including Laconian ,

7224-452: Was a pluricentric language , divided into many dialects. The main dialect groups are Attic and Ionic , Aeolic , Arcadocypriot , and Doric , many of them with several subdivisions. Some dialects are found in standardized literary forms in literature , while others are attested only in inscriptions. There are also several historical forms. Homeric Greek is a literary form of Archaic Greek (derived primarily from Ionic and Aeolic) used in

7310-605: Was a married father of two children, and worked as a civil servant, leading an at least superficially normal life, despite having enlarged ventricles with a decreased volume of brain tissue. "What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life", commented Dr. Max Muenke, a pediatric brain-defect specialist at the National Human Genome Research Institute . "If something happens very slowly over quite some time, maybe over decades,

7396-637: Was later given by the Roman physician Galen in the second century AD. The first clinical description of an operative procedure for hydrocephalus appears in the Al-Tasrif (1,000 AD) by the Arab surgeon Abulcasis , who described the evacuation of superficial intracranial fluid in hydrocephalic children. He described it in his chapter on neurosurgical disease, describing infantile hydrocephalus as being caused by mechanical compression. He wrote: The skull of

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