Chiari Malformations

Overview

Definition

Chiari malformations (CMs) are a group of disorders defined by structural deficits in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification and spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy leading to limited space in the posterior fossa, which forces cerebellar structures to protrude through the foramen magnum.

Classification

• Type I: tonsillar herniation Herniation Omphalocele > 5 mm inferior to plane of foramen magnum
  • Abnormally shaped cerebellar tonsils Tonsils Tonsillitis
  • No associated brainstem herniation Herniation Omphalocele or supratentorial anomalies
  • Associated hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage and hydrosyringomyelia common
• Type II: herniation Herniation Omphalocele of cerebellar vermis, brainstem, and 4th ventricle into foramen magnum
  • Associated with myelomeningocele and multiple brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification anomalies
  • Associated hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage and syringomyelia Syringomyelia Longitudinal cavities in the spinal cord, most often in the cervical region, which may extend for multiple spinal levels. The cavities are lined by dense, gliogenous tissue and may be associated with spinal cord neoplasms; spinal cord traumatic injuries; and vascular malformations. Syringomyelia is marked clinically by pain and paresthesia, muscular atrophy of the hands, and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved (sensory dissociation). Lower extremity spasticity and incontinence may also develop. Central Cord Syndrome are very common.
• Type III: herniation Herniation Omphalocele of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy and brainstem compressing spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy
  • High cervical or occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy encephalocele Encephalocele Brain tissue herniation through a congenital or acquired defect in the skull. The majority of congenital encephaloceles occur in the occipital or frontal regions. Clinical features include a protuberant mass that may be pulsatile. The quantity and location of protruding neural tissue determines the type and degree of neurologic deficit. Visual defects, psychomotor developmental delay, and persistent motor deficits frequently occur. Neural Tube Defects containing herniated cerebellar and brainstem tissue
  • Rare and typically incompatible with life
• Type IV: incomplete or underdeveloped cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy with exposed skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy and spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy
  • Hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS) or aplasia Aplasia Cranial Nerve Palsies of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy and tentorium
  • Rare and always incompatible with life

Epidemiology

Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency:

• Type I:
  • Most common form
  • 1 in 1,000–5,000 live births 
  • Slight female predominance
• Type II:
  • Approximately 1 in 2,000 live births 
  • Decreased incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency with prenatal folate Folate Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects. Folate and Vitamin B12 supplementation
  • No gender Gender Gender Dysphoria predominance
  • Always associated with myelomeningocele 
• Type III:
  • Rarest form
  • Makes up 1%–4.5% of all CMs

Associated conditions:

• Pierre Robin sequence Robin sequence Pierre Robin sequence, also known as Pierre Robin syndrome or simply Robin sequence, is a condition in infants that is characterized by a smaller-than-normal mandible, a tongue that retracts back into the throat, and difficulty breathing. Pierre Robin Sequence
• Noonan syndrome Noonan syndrome A genetically heterogeneous, multifaceted disorder characterized by short stature, webbed neck, ptosis, skeletal malformations, hypertelorism, hormonal imbalance, cryptorchidism, multiple cardiac abnormalities (most commonly including pulmonary valve stenosis), and some degree of intellectual disability. The phenotype bears similarities to that of turner syndrome that occurs only in females and has its basis in a 45, X karyotype abnormality. Noonan syndrome occurs in both males and females with a normal karyotype (46, XX and 46, xy). Mutations in a several genes (ptpn11, kras, sos1, nf1 and raf1) have been associated the ns phenotype. Mutations in ptpn11 are the most common. Leopard syndrome, a disorder that has clinical features overlapping those of noonan syndrome, is also due to mutations in ptpn11. In addition, there is overlap with the syndrome called neurofibromatosis-noonan syndrome due to mutations in nf1. Hypogonadism
• Neurofibromatosis type 1 Type 1 Spinal Muscular Atrophy

Etiology and Pathophysiology

Etiology

• Mechanism for herniation Herniation Omphalocele
  • Formation of small posterior fossa ➝ limited growth of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy and nearby structures 
  • Growing structures herniate through foramen magnum or vermis.
• Multiple proposed causes:
  • Genetics Genetics Genetics is the study of genes and their functions and behaviors. Basic Terms of Genetics:
    • Abnormal segmentation Segmentation Gastrointestinal Motility of hindbrain 
    • Causes abnormal embryonic development of bony and nervous tissues
  • Restricted growth of posterior fossa causes compression Compression Blunt Chest Trauma of neural tissues.
  • Progressive hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage pushes structures downward.

Pathophysiology

Neurologic symptoms are caused by:

• Compression Compression Blunt Chest Trauma of central nervous system Central nervous system The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges. Nervous System: Anatomy, Structure, and Classification (CNS; cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy, brainstem) against foramen magnum and spinal canal Spinal Canal The cavity within the spinal column through which the spinal cord passes. Spinal Cord Injuries
• Formation of cavitations in spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy (syrinx or syringomyelia Syringomyelia Longitudinal cavities in the spinal cord, most often in the cervical region, which may extend for multiple spinal levels. The cavities are lined by dense, gliogenous tissue and may be associated with spinal cord neoplasms; spinal cord traumatic injuries; and vascular malformations. Syringomyelia is marked clinically by pain and paresthesia, muscular atrophy of the hands, and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved (sensory dissociation). Lower extremity spasticity and incontinence may also develop. Central Cord Syndrome) due to backup of CSF outflow

Clinical Presentation

Type I

Symptoms:

• Asymptomatic in some cases
• Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess:
  • Most common symptom (60%–70%) 
  • Usually occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy and upper cervical
  • Occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess worse on Valsalva maneuver Valsalva maneuver Forced expiratory effort against a closed glottis. Rectal Prolapse
• Ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia and nystagmus Nystagmus Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. Albinism (due to compression Compression Blunt Chest Trauma of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy) 
• Compression Compression Blunt Chest Trauma of cranial nerves Cranial nerves There are 12 pairs of cranial nerves (CNs), which run from the brain to various parts of the head, neck, and trunk. The CNs can be sensory or motor or both. The CNs are named and numbered in Roman numerals according to their location, from the front to the back of the brain. The 12 Cranial Nerves: Overview and Functions can lead to:
  • Hoarseness Hoarseness An unnaturally deep or rough quality of voice. Parapharyngeal Abscess
  • Vocal cord paralysis
  • Tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy asymmetry Asymmetry Examination of the Upper Limbs
• Central sleep apnea Sleep apnea Repeated cessation of breathing for > 10 seconds during sleep and results in sleep interruption, fatigue, and daytime sleepiness. Obstructive Sleep Apnea

Physical signs:

• Syringomyelia Syringomyelia Longitudinal cavities in the spinal cord, most often in the cervical region, which may extend for multiple spinal levels. The cavities are lined by dense, gliogenous tissue and may be associated with spinal cord neoplasms; spinal cord traumatic injuries; and vascular malformations. Syringomyelia is marked clinically by pain and paresthesia, muscular atrophy of the hands, and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved (sensory dissociation). Lower extremity spasticity and incontinence may also develop. Central Cord Syndrome and central cord syndrome Central Cord Syndrome Central cord syndrome (CCS) is a neurological syndrome caused by an injury to the center of the spinal cord, affecting the spinothalamic tracts ((STTs) sensory) and medial aspect of the corticospinal tracts ((CSTs) motor), most often due to trauma in patients with cervical spondylosis. Central Cord Syndrome:
  • Develops at level of C8–T1
  • “Cape-shaped” area of pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and temperature sensation loss due to spinothalamic tract involvement
  • Flaccid paralysis and muscle atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation due to lower motor neuron Lower Motor Neuron Motor Neuron Lesions involvement
• Scoliosis Scoliosis Scoliosis is a structural alteration of the vertebral column characterized by a lateral spinal curvature of greater than 10 degrees in the coronal plane. Scoliosis can be classified as idiopathic (in most cases) or secondary to underlying conditions. Scoliosis: due to asymmetric development of vertebral columns

Type II

Symptoms:

• Signs of brainstem dysfunction (e.g., ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia, urinary incontinence Urinary incontinence Urinary incontinence (UI) is involuntary loss of bladder control or unintentional voiding, which represents a hygienic or social problem to the patient. Urinary incontinence is a symptom, a sign, and a disorder. The 5 types of UI include stress, urge, mixed, overflow, and functional. Urinary Incontinence)
• Swallowing Swallowing The act of taking solids and liquids into the gastrointestinal tract through the mouth and throat. Gastrointestinal Motility and feeding difficulties
• Stridor Stridor Laryngomalacia and Tracheomalacia/difficulty in breathing/apnea
• Weak cry
• Nystagmus Nystagmus Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. Albinism
• Occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy headaches

Physical signs:

• Myelomeningocele: protrusion of CNS and meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges: Anatomy
  • Commonly lumbosacral or thoracic
  • Usually prenatally diagnosed
• Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage (< 10%):
  • Tense/bulging fontanelles Fontanelles Physical Examination of the Newborn 
  • Increased head circumference Head Circumference Physical Examination of the Newborn > 98th percentile
  • Nuchal rigidity Nuchal Rigidity Meningitis and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess tenderness
  • Cognitive deterioration
  • Imbalance and gait Gait Manner or style of walking. Neurological Examination disturbances
  • Urinary incontinence Urinary incontinence Urinary incontinence (UI) is involuntary loss of bladder control or unintentional voiding, which represents a hygienic or social problem to the patient. Urinary incontinence is a symptom, a sign, and a disorder. The 5 types of UI include stress, urge, mixed, overflow, and functional. Urinary Incontinence

Type III

There is high infant mortality Mortality All deaths reported in a given population. Measures of Health Status with this type.

Symptoms:

• Severe neurological, developmental, and cranial nerve defects
• Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
• Respiratory insufficiency
• Upper and lower motor neuron Lower Motor Neuron Motor Neuron Lesions paralysis

Physical signs:

• Encephalocele Encephalocele Brain tissue herniation through a congenital or acquired defect in the skull. The majority of congenital encephaloceles occur in the occipital or frontal regions. Clinical features include a protuberant mass that may be pulsatile. The quantity and location of protruding neural tissue determines the type and degree of neurologic deficit. Visual defects, psychomotor developmental delay, and persistent motor deficits frequently occur. Neural Tube Defects: protruding defect that contains part of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy and higher structures
• Spastic or flaccid paralysis

Type IV

• CNS is undeveloped.
• Infants die shortly after birth.

Diagnosis

Work-up

• Rule out other causes of tonsillar herniation Herniation Omphalocele (e.g., intracranial mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast lesion, hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage).
• Antenatal:
  • Obstetric ultrasounds looking for congenital abnormalities Congenital Abnormalities Malformations of organs or body parts during development in utero. Omphalocele in 18th week of gestation (absent vermis)
  • Amniocentesis Amniocentesis Percutaneous transabdominal puncture of the uterus during pregnancy to obtain amniotic fluid. It is commonly used for fetal karyotype determination in order to diagnose abnormal fetal conditions. Polyhydramnios and karyotyping Karyotyping Mapping of the karyotype of a cell. Chromosome Testing
• Postnatal:
  • Ultrasound of head preferred in neonates
  • MRI scan preferred in older children and adults

Diagnosis

• Clinical findings with diagnostic imaging to confirm
• Can be done prenatally

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Favorable prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas with normal life expected after intervention
• Chiari III malformation has the poorest prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas.

Management and Complications

Surgical therapy

• Decompression of cervicomedullary junction → restoring normal CSF dynamics 
• Options:
  • Posterior fossa craniectomy alone or with dural scoring
  • Electrocautery Electrocautery Surgical Instruments and Sutures of cerebellum Cerebellum The cerebellum, Latin for “little brain,” is located in the posterior cranial fossa, dorsal to the pons and midbrain, and its principal role is in the coordination of movements. The cerebellum consists of 3 lobes on either side of its 2 hemispheres and is connected in the middle by the vermis. Cerebellum: Anatomy via high-frequency electric currents
  • Spinal laminectomy Laminectomy A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the spinal cord and/or spinal nerve roots. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots. Neurosurgery to remove pathological bony roof of spinal canal Spinal Canal The cavity within the spinal column through which the spinal cord passes. Spinal Cord Injuries

Conservative management

• Analgesics and muscle relaxants for headaches and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess pains
• Occasional use of soft neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess collar
• Special education needed in event of delayed developmental milestones Developmental milestones Developmental milestones are the skills or abilities that most children are able to perform when they reach a certain age. Understanding the appropriate milestones and at what age they are reached helps clinicians identify symptoms of delayed development. Developmental milestones are divided into 5 important domains: gross motor, fine motor, language, social, and cognitive. Developmental Milestones and Normal Growth

Complications

• Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage: accumulation of CSF within cranial cavity; CM is obstructive, or non-communicating, cause of hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage
• Pseudomeningocele formation and CSF leakage
• Meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis and wound infection post-surgery
• Neurovascular injury during surgery
• Cerebellar ptosis Ptosis Cranial Nerve Palsies in large occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy craniectomy

Differential Diagnosis

• Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage: potentially life-threatening condition caused by excess accumulation of CSF within the ventricular system Ventricular System The ventricular system is an extension of the subarachnoid space into the brain consisting of a series of interconnecting spaces and channels. Four chambers are filled with cerebrospinal fluid (CSF): the paired lateral ventricles, the unpaired 3rd ventricle, and the unpaired 4th ventricle. Ventricular System: Anatomy. Clinical presentation is nonspecific and includes headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess, behavioral changes, developmental delays, or nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia. Diagnosis is confirmed with neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant (ultrasound, head CT, or MRI) showing ventriculomegaly Ventriculomegaly Hydrocephalus in Children. Treatment is placement of CSF shunt.
• Meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of leptomeninges Leptomeninges Meninges: Anatomy, usually due to infectious agent. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will present with headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and a stiff neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess. Diagnosis is suspected by clinical presentation and confirmed by lumbar puncture Lumbar Puncture Febrile Infant. Treatment is aimed at the causative infection. 
• Neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation disorders: disorders caused by failure of the neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation to close properly during embryological development. Symptoms range from asymptomatic to very severe malformations of spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy and brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. Etiologies are multifactorial, ranging from maternal nutrition to genetic determinants. Prenatal diagnosis is by ultrasound and maternal α-fetoprotein level. Management is mainly surgical.